From Martin.Lange sci-worx.com Thu May 4 09:57:22 2006 From: Martin.Lange sci-worx.com (Martin.Lange@sci-worx.com) Date: Thu May 4 14:08:06 2006 Subject: [Mp4-tech] [H.264] output timing, bumping process, missing HRD parameters Message-ID: <7E6219E8CD869D4186B919B0DCF127C0012EEEEA@hajse201.eu.infineon.com> Hello everyone, I have a question on H.264 regarding the relationship between output timing and the bumping process in the HRD when no HRD parameters are sent by the encoder: To be able to display a picture in each time slot, I obviously need an initial delay between decoding and displaying the first picture. Now how do I know about this delay when there are no HRD parameters present? Is the delay inferred to be equal to max_dec_frame_buffering, which is inferred to be equal to MaxDpbSize when it is not present? When this is the case, I don't see where this is pointed out in the standard. I will give an example about the problem which can arise when the encoder behaves in some manner and doesn't tell the decoder about it and there is no inferred default value of that delay: Let's assume max_dec_frame_buffering = 6. The encoder could however commit itself for some reason to let the output delay be 2, i.e. a frame will be able to be displayed at most 2 decoded frames later. The picture sequence with the following POCs would satisfy this constraint: 0, 3, 2, 1, 5, 4, 6, ... (continues somehow in a manner which is ok for the mentioned constraint) After the frame with POC 2 has been decoded (which is also the 3rd frame in decoding order in this example) a decoder knowing about the delay being 2 could display frame 0 and then display a frame after each decoded frame like this: decoding: 0, 3, 2, 1, 5, 4, 6, ... output: -, -, 0, 1, 2, 3, 4, 5, 6, ... Let's now assume the frame with POC 4 is a non-reference frame. After frame 6 has been decoded, frame 4 will be displayed. So it has been output and is no reference frame, so gets discarded from the DBP and a place is free for the frame with POC 6. A decoder without this information must assume a delay of 6 since the encoder could as well base it's calculations on this "worst case" delay. So it will not be able to output frame 0 until frame 6 has been decoded. But now the bumping process says of course that frame 4 must be evicted from the DPB to able to store frame 6. Thus, the decoder would have to output frames 1 .. 3 in no time. What is the solution to this problem? Is it that the encoder, when it doesn't send the appropiate information, must take the worst case delay as the base for it's calculations of the DPB state, which would make the above sequence non conformant with the HRD? If yes, where do I find this agreement in the standard? Best regards, Martin Lange From Julien.Bes thomson.net Thu May 4 15:42:57 2006 From: Julien.Bes thomson.net (Bes Julien) Date: Thu May 4 14:08:11 2006 Subject: [Mp4-tech] [Audio] LOAS streams Message-ID: <9C1918067C3BC14C9C351C206D8A84370227EE5C@rennsmail03.eu.thmulti.com> Dear all, Could you confirm that audio raw data blocks encapsulated in LOAS/LATM header are not byte-aligned? Best regards, Julien -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060504/bfd7d935/attachment.html From garysull windows.microsoft.com Thu May 4 14:53:07 2006 From: garysull windows.microsoft.com (Gary Sullivan) Date: Fri May 5 13:03:08 2006 Subject: [Mp4-tech] [H.264] output timing, bumping process, missing HRD parameters In-Reply-To: <7E6219E8CD869D4186B919B0DCF127C0012EEEEA@hajse201.eu.infineon.com> Message-ID: <03CB47D9C3F8074498E4653F814D6E8F8E4D0B@WIN-MSG-20.wingroup.windeploy.ntdev.microsoft.com> Martin, You seem to have a good grasp of the basic issue. Timing information must be provided by encoders or systems, or fully-proper decoded output display may be difficult. Further response in-line. Best Regards, Gary Sullivan +> -----Original Message----- +> From: mp4-tech-bounces@lists.mpegif.org +> [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of +> Martin.Lange@sci-worx.com +> Sent: Thursday, May 04, 2024 12:57 AM +> To: mp4-tech@lists.mpegif.org +> Subject: [Mp4-tech] [H.264] output timing, bumping +> process,missing HRD parameters +> +> Hello everyone, +> +> I have a question on H.264 regarding the relationship between output +> timing and the bumping process in the HRD when no HRD parameters are +> sent by the encoder: +> +> To be able to display a picture in each time slot, I It is not necessarily the case that there should be a new picture to display in every "time slot", unless fixed_frame_rate_flag is equal to 1. +> obviously need an +> initial delay between decoding and displaying the first +> picture. Now how +> do I know about this delay when there are no HRD parameters present? Timing information equivalent to the HRD picture timing data is supposed to be conveyed to the decoder in some fashion. Otherwise, a decoder would, at best, be able to do something like the bumping process and would have difficulty providing perfect timed-output behavior unless it has some extra memory capacity. I believe it is generally agreed that if such timing information is not provided, decoders may not display some of the output pictures for the reasons you describe. +> Is the delay inferred to be equal to +> max_dec_frame_buffering, which is +> inferred to be equal to MaxDpbSize when it is not present? +> When this is +> the case, I don't see where this is pointed out in the +> standard. Perhaps you're looking for this sentence from E.2.1: "When the max_dec_frame_buffering syntax element is not present, the value of max_dec_frame_buffering shall be inferred to be equal to MaxDpbSize." +> I will +> give an example about the problem which can arise when the encoder +> behaves in some manner and doesn't tell the decoder about it +> and there +> is no inferred default value of that delay: +> +> Let's assume max_dec_frame_buffering = 6. The encoder could however +> commit itself for some reason to let the output delay be 2, +> i.e. a frame +> will be able to be displayed at most 2 decoded frames later. +> The picture +> sequence with the following POCs would satisfy this constraint: +> 0, 3, 2, 1, 5, 4, 6, ... (continues somehow in a manner +> which is ok for +> the mentioned constraint) After the frame with POC 2 has been decoded +> (which is also the 3rd frame in decoding order in this example) a +> decoder knowing about the delay being 2 could display frame +> 0 and then +> display a frame after each decoded frame like this: +> decoding: 0, 3, 2, 1, 5, 4, 6, ... +> output: -, -, 0, 1, 2, 3, 4, 5, 6, ... +> +> Let's now assume the frame with POC 4 is a non-reference frame. After +> frame 6 has been decoded, frame 4 will be displayed. So it has been +> output and is no reference frame, so gets discarded from the +> DBP and a +> place is free for the frame with POC 6. +> +> A decoder without this information must assume a delay of 6 since the +> encoder could as well base it's calculations on this "worst +> case" delay. +> So it will not be able to output frame 0 until frame 6 has +> been decoded. +> But now the bumping process says of course that frame 4 must +> be evicted +> from the DPB to able to store frame 6. Thus, the decoder +> would have to +> output frames 1 .. 3 in no time. Time is not really part of the concept of the bumping process decoder operation. Neither is display. For example, "output" does not necessarily imply display. Note, for example, that a decoder that only claims output order conformance is not required to be able to keep up with the full input rate of the incoming video bitstream. The feeding of bits into such a decoder follows a "pull" model, not a "push" model. Note where the standard says the following: "For output order decoder conformance, the HSS delivers the bitstream to the DUT "by demand" from the DUT, meaning that the HSS delivers bits (in decoding order) only when the DUT requires more bits to proceed with its processing. NOTE - This means that for this test, the coded picture buffer of the DUT could be as small as the size of the largest access unit." +> +> What is the solution to this problem? Is it that the encoder, when it +> doesn't send the appropiate information, must take the worst +> case delay +> as the base for it's calculations of the DPB state, which +> would make the +> above sequence non conformant with the HRD? If yes, where do +> I find this +> agreement in the standard? The best solution is that the encoder must send something equivalent to the DPB decoding and output timing information. Without that, as you have figured out, a decoder may not be able to provide proper output behavior with proper output timing unless the decoder includes sufficient extra memory to hold some extra pictures that are queued for display. Note that the standard says: "In order to check conformance of a bitstream using the HRD, all sequence parameter sets and picture parameters sets referred to in the VCL NAL units, and corresponding buffering period and picture timing SEI messages shall be conveyed to the HRD, in a timely manner, either in the bitstream (by non-VCL NAL units), or by other means not specified in this Recommendation | International Standard." Without proper timing information, fully-proper decoder output behavior may not be possible unless the decoder has some extra memory. In my opinion it would acceptable for a real-time decoder that has received your example bitstream and has not received any timing information to, for example, not display any of the output frames that precede frame 4 -- or perhaps to display frame 0 and then frames 5, 6, etc. Adding some more memory to the decoder could decrease the number of frames that are not displayed -- however there may be a limit to how much effort and cost are necessary to address this scenario that shouldn't happen with a good system and encoder design anyway. +> +> Best regards, +> Martin Lange +> +> _______________________________________________ +> NOTE: Please use clear subject lines for your posts. Include +> [audio, [video], [systems], [general] or another +> apppropriate identifier to indicate the type of question you have. +> +> Note: Conduct on the mailing list is subject to the +> Antitrust guidelines found at +> http://www.mpegif.org/public/documents/vault/mp-out-30042-Ant +> itrust.php +> From dmitriy graphics.cs.msu.ru Fri May 5 02:39:16 2006 From: dmitriy graphics.cs.msu.ru (Dmitriy Vatolin) Date: Fri May 5 13:03:12 2006 Subject: [Mp4-tech] Video Quality measurement tool release Message-ID: <621501879.20060505023916@graphics.cs.msu.ru> Dear All! MSU Graphics & Media Lab release "Video Quality Measurement Tool" This tool support formats: *.AVI, *.AVS, *.YUV, *.BMP Implemented metrics: PSNR, Delta, MSAD, MSE, SSIM, VQM, Blurring, Blocking (last 2 metrics are experimental research). In last release final metric analysis dialog was reworked (for faster and more convenient analysis of comparative measurements results). Program available from: http://compression.ru/video/quality_measure/video_measurement_tool_en.html In next release we planning to include metrics plug-in's. So any other researchers will be able to extend metric's set. There will be possible to wrote: * New special blurring (blocking, interlacing, etc) measures * Faster metrics (using MMX-SSE2, HW acceleration, DirectShow Shaders etc) * New perfect formal metrics (again better than PSNR) Any ideas about future metric development are welcome! -- Best regards, Dmitriy mailto:dmitriy@graphics.cs.msu.ru From jingli888ca 163.com Fri May 5 09:29:17 2006 From: jingli888ca 163.com (jingli888ca) Date: Fri May 5 13:03:15 2006 Subject: [Mp4-tech] Latest JM code? Message-ID: <445AAA6D.00002F.11126@bj163app66.163.com> Hello, Experts: I wonder if anyone can point me to the latest JM code? Many Thanks. Jing -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060505/559b4ef6/attachment.html From Ye-Kui.Wang nokia.com Fri May 5 13:08:51 2006 From: Ye-Kui.Wang nokia.com (Ye-Kui.Wang@nokia.com) Date: Fri May 5 13:03:19 2006 Subject: [Mp4-tech] [H.264] output timing, bumping process, missing HRD parameters In-Reply-To: <7E6219E8CD869D4186B919B0DCF127C0012EEEEA@hajse201.eu.infineon.com> Message-ID: <1C1F3D15859526459B4DD0A7A9B2268B020B69AA@trebe101.NOE.Nokia.com> Hi Martin, First of all, the bumping process is used only for output order decoder conformance, which requires only the output order of the decoded pictures produced by the decoder under test is the same as by the HRD. For output order decoder conformance, it does not matter if you don't output any picture at some time slots, or you output more than one picture at some other time slots. So I would say both the decoder output behaviors you mentioned below are conforming to the output order conformance requirement. In case no other information is present to decide the initial DPB output delay, num_reorder_frames (should be equal to 2 in your example) can be used. If not present, num_reorder_frames is inferred to be equal to max_dec_frame_buffering, which is actually also not present when num_reorder_frames is not present, so finally inferred to be equal to MaxDpbSize. Final remark: in practical systems, timing information is always present to guide picture output/display, e.g. using the RTP timestamp in RTP based transport. BR, YK >-----Original Message----- >From: mp4-tech-bounces@lists.mpegif.org >[mailto:mp4-tech-bounces@lists.mpegif.org] >Sent: 04 May, 2006 10:57 >To: mp4-tech@lists.mpegif.org >Subject: [Mp4-tech] [H.264] output timing, bumping >process,missing HRD parameters > >Hello everyone, > >I have a question on H.264 regarding the relationship between >output timing and the bumping process in the HRD when no HRD >parameters are sent by the encoder: > >To be able to display a picture in each time slot, I obviously >need an initial delay between decoding and displaying the >first picture. Now how do I know about this delay when there >are no HRD parameters present? >Is the delay inferred to be equal to max_dec_frame_buffering, >which is inferred to be equal to MaxDpbSize when it is not >present? When this is the case, I don't see where this is >pointed out in the standard. I will give an example about the >problem which can arise when the encoder behaves in some >manner and doesn't tell the decoder about it and there is no >inferred default value of that delay: > >Let's assume max_dec_frame_buffering = 6. The encoder could >however commit itself for some reason to let the output delay >be 2, i.e. a frame will be able to be displayed at most 2 >decoded frames later. The picture sequence with the following >POCs would satisfy this constraint: >0, 3, 2, 1, 5, 4, 6, ... (continues somehow in a manner which >is ok for the mentioned constraint) After the frame with POC 2 >has been decoded (which is also the 3rd frame in decoding >order in this example) a decoder knowing about the delay being >2 could display frame 0 and then display a frame after each >decoded frame like this: >decoding: 0, 3, 2, 1, 5, 4, 6, ... >output: -, -, 0, 1, 2, 3, 4, 5, 6, ... > >Let's now assume the frame with POC 4 is a non-reference >frame. After frame 6 has been decoded, frame 4 will be >displayed. So it has been output and is no reference frame, so >gets discarded from the DBP and a place is free for the frame >with POC 6. > >A decoder without this information must assume a delay of 6 >since the encoder could as well base it's calculations on this >"worst case" delay. >So it will not be able to output frame 0 until frame 6 has >been decoded. >But now the bumping process says of course that frame 4 must >be evicted from the DPB to able to store frame 6. Thus, the >decoder would have to output frames 1 .. 3 in no time. > >What is the solution to this problem? Is it that the encoder, >when it doesn't send the appropiate information, must take the >worst case delay as the base for it's calculations of the DPB >state, which would make the above sequence non conformant with >the HRD? If yes, where do I find this agreement in the standard? > >Best regards, >Martin Lange > >_______________________________________________ >NOTE: Please use clear subject lines for your posts. Include >[audio, [video], [systems], [general] or another apppropriate >identifier to indicate the type of question you have. > >Note: Conduct on the mailing list is subject to the Antitrust >guidelines found at >http://www.mpegif.org/public/documents/vault/mp-out-30042-Antitrust.php > From getsunil_6 yahoo.co.in Fri May 5 04:50:40 2006 From: getsunil_6 yahoo.co.in (venkata sunil) Date: Fri May 5 13:03:25 2006 Subject: [Mp4-tech] Information regarding "Downloadable Sounds Level 1" In-Reply-To: <200603281708.k2SH7eXj004383@lists1.magma.ca> Message-ID: <20060505115040.51236.qmail@web8503.mail.in.yahoo.com> Hi All, Currently i am working on "Downloadable Sounds Level 1" (DLS1). I would like to know information about DLS wavetable format, and how to parse this wavetable data to different structures. Please help me in this regard, Thanks in advance, Sunil. --------------------------------- New Yahoo! Messenger with Voice. Call regular phones from your PC and save big. -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060505/f4fc34ea/attachment.html From jianpengdong yahoo.com Fri May 5 16:43:24 2006 From: jianpengdong yahoo.com (James (Jianpeng) Dong) Date: Sat May 6 17:52:08 2006 Subject: [Mp4-tech] Why I or B frame can have one fixed QP? Message-ID: <20060505234324.91682.qmail@web30007.mail.mud.yahoo.com> Dear experts, Just wondering why I or B frame can only have one fixed QP in H.264 JM reference software? Is a fixed QP required by H.264/AVC standard? Thanks, James --------------------------------- Yahoo! Messenger with Voice. Make PC-to-Phone Calls to the US (and 30+ countries) for 2?/min or less. -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060505/ea2c8111/attachment.html From masedaghat yahoo.com Fri May 5 22:25:29 2006 From: masedaghat yahoo.com (Mohammad Ali Sedaghat) Date: Sat May 6 17:52:11 2006 Subject: [Mp4-tech] Scalable H.264 input stream format Message-ID: <20060506052529.12714.qmail@web31012.mail.mud.yahoo.com> Dear Friends, does anybody know that what is the file format for JSVM software. I did debug it with YUV stream and it failed in extraction of input stream. Regards, M. A. Sedaghat --------------------------------- New Yahoo! Messenger with Voice. Call regular phones from your PC and save big. -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060505/82e7855e/attachment.html From garysull windows.microsoft.com Sat May 6 20:30:46 2006 From: garysull windows.microsoft.com (Gary Sullivan) Date: Sun May 7 14:14:09 2006 Subject: [Mp4-tech] Why I or B frame can have one fixed QP? In-Reply-To: <20060505234324.91682.qmail@web30007.mail.mud.yahoo.com> Message-ID: <03CB47D9C3F8074498E4653F814D6E8F8E552D@WIN-MSG-20.wingroup.windeploy.ntdev.microsoft.com> I don't think it's true that an I or B frame can only have one fixed QP value in the JM reference software. No, there is no requirement of fixed QP in the standard. QP can change (from any value to any other value) on a macroblock (16x16) basis in the standard. Best Regards, Gary Sullivan ________________________________ From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of James (Jianpeng) Dong Sent: Friday, May 05, 2024 4:43 PM To: mp4-tech-bounces@lists.mpegif.org; mp4-tech@lists.mpegif.org Cc: jianpengdong@yahoo.com Subject: [Mp4-tech] Why I or B frame can have one fixed QP? Dear experts, Just wondering why I or B frame can only have one fixed QP in H.264 JM reference software? Is a fixed QP required by H.264/AVC standard? Thanks, James ________________________________ Yahoo! Messenger with Voice. Make PC-to-Phone Calls to the US (and 30+ countries) for 2?/min or less. -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060506/de12789c/attachment.html From Alexis.Tourapis dolby.net Sun May 7 11:17:22 2006 From: Alexis.Tourapis dolby.net (Tourapis, Alexis) Date: Mon May 8 13:14:05 2006 Subject: [Mp4-tech] Why I or B frame can have one fixed QP? Message-ID: <7272EE229DA1AA48B47EBDC47EB0C68B01F9BE9D@sapphire.dolby.net> Dear James, There is no quantization limitation in H.264/AVC. I am guessing your observation relates to the current Rate Control algorithm supported by the JM software. This should only be seen as an example design. Best regards, Alexis _____ From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of Gary Sullivan Sent: Saturday, May 06, 2024 8:31 PM To: James (Jianpeng) Dong; mp4-tech-bounces@lists.mpegif.org; mp4-tech@lists.mpegif.org Subject: RE: [Mp4-tech] Why I or B frame can have one fixed QP? I don't think it's true that an I or B frame can only have one fixed QP value in the JM reference software. No, there is no requirement of fixed QP in the standard. QP can change (from any value to any other value) on a macroblock (16x16) basis in the standard. Best Regards, Gary Sullivan _____ From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of James (Jianpeng) Dong Sent: Friday, May 05, 2024 4:43 PM To: mp4-tech-bounces@lists.mpegif.org; mp4-tech@lists.mpegif.org Cc: jianpengdong@yahoo.com Subject: [Mp4-tech] Why I or B frame can have one fixed QP? Dear experts, Just wondering why I or B frame can only have one fixed QP in H.264 JM reference software? Is a fixed QP required by H.264/AVC standard? Thanks, James _____ Yahoo! Messenger with Voice. Make PC-to-Phone Calls to the US (and 30+ countries) for 2?/min or less. ----------------------------------------- This message (including any attachments) may contain confidential information intended for a specific individual and purpose. If you are not the intended recipient, delete this message. If you are not the intended recipient, disclosing, copying, distributing, or taking any action based on this message is strictly prohibited. -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060507/f17dc931/attachment-0001.html From Alexis.Tourapis dolby.net Sun May 7 11:22:45 2006 From: Alexis.Tourapis dolby.net (Tourapis, Alexis) Date: Mon May 8 13:14:13 2006 Subject: [Mp4-tech] Latest JM code? Message-ID: <7272EE229DA1AA48B47EBDC47EB0C68B01F9BE9E@sapphire.dolby.net> Dear Jing, The latest official JM version can be found at http://iphome.hhi.de/suehring/tml/, currently at version 10.2. Various bug fixes have been added in the software since then but have not yet been officially released. Best regards Alexis _____ From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of jingli888ca Sent: Thursday, May 04, 2024 6:29 PM To: mp4-tech@lists.mpegif.org Subject: [Mp4-tech] Latest JM code? Hello, Experts: I wonder if anyone can point me to the latest JM code? Many Thanks. Jing 你 不 想 试 试 今 夏 最 “酷” 的 邮 箱 吗 ？ 蕴 涵 中 华 传 统 文 化 于 世 界 一 流 科 技 之 中，创 新 Ajax 技 术，126 “D 计 划”火 热 体 验 中 ！ ----------------------------------------- This message (including any attachments) may contain confidential information intended for a specific individual and purpose. If you are not the intended recipient, delete this message. If you are not the intended recipient, disclosing, copying, distributing, or taking any action based on this message is strictly prohibited. -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060507/cdf2ccb4/attachment-0001.html From garysull windows.microsoft.com Sun May 7 12:11:37 2006 From: garysull windows.microsoft.com (Gary Sullivan) Date: Mon May 8 13:14:17 2006 Subject: [Mp4-tech] Why I or B frame can have one fixed QP? In-Reply-To: <7272EE229DA1AA48B47EBDC47EB0C68B01F9BE9D@sapphire.dolby.net> Message-ID: <03CB47D9C3F8074498E4653F814D6E8F8E554A@WIN-MSG-20.wingroup.windeploy.ntdev.microsoft.com> But I'm under the strong impression that the current JM rate control algorithm, although it does have some shortcomings, does have the ability to change QP within an I or B picture -doesn't it? (One of these days we need to improve that rate control.) Best Regards, -Gary Sullivan ________________________________ From: Tourapis, Alexis [mailto:Alexis.Tourapis@dolby.net] Sent: Sunday, May 07, 2024 11:17 AM To: Gary Sullivan; James (Jianpeng) Dong; mp4-tech-bounces@lists.mpegif.org; mp4-tech@lists.mpegif.org Subject: RE: [Mp4-tech] Why I or B frame can have one fixed QP? Dear James, There is no quantization limitation in H.264/AVC. I am guessing your observation relates to the current Rate Control algorithm supported by the JM software. This should only be seen as an example design. Best regards, Alexis ________________________________ From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of Gary Sullivan Sent: Saturday, May 06, 2024 8:31 PM To: James (Jianpeng) Dong; mp4-tech-bounces@lists.mpegif.org; mp4-tech@lists.mpegif.org Subject: RE: [Mp4-tech] Why I or B frame can have one fixed QP? I don't think it's true that an I or B frame can only have one fixed QP value in the JM reference software. No, there is no requirement of fixed QP in the standard. QP can change (from any value to any other value) on a macroblock (16x16) basis in the standard. Best Regards, Gary Sullivan ________________________________ From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of James (Jianpeng) Dong Sent: Friday, May 05, 2024 4:43 PM To: mp4-tech-bounces@lists.mpegif.org; mp4-tech@lists.mpegif.org Cc: jianpengdong@yahoo.com Subject: [Mp4-tech] Why I or B frame can have one fixed QP? Dear experts, Just wondering why I or B frame can only have one fixed QP in H.264 JM reference software? Is a fixed QP required by H.264/AVC standard? Thanks, James ________________________________ Yahoo! Messenger with Voice. Make PC-to-Phone Calls to the US (and 30+ countries) for 2?/min or less. ________________________________ This message (including any attachments) may contain confidential information intended for a specific individual and purpose. If you are not the intended recipient, delete this message. If you are not the intended recipient, disclosing, copying, distributing, or taking any action based on this message is strictly prohibited. -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060507/eb71e252/attachment-0001.html From jianpengdong yahoo.com Mon May 8 00:13:34 2006 From: jianpengdong yahoo.com (James (Jianpeng) Dong) Date: Mon May 8 13:14:21 2006 Subject: [Mp4-tech] Why I or B frame can have one fixed QP? In-Reply-To: <03CB47D9C3F8074498E4653F814D6E8F8E554A@WIN-MSG-20.wingroup.windeploy.ntdev.microsoft.com> Message-ID: <20060508071334.9562.qmail@web30005.mail.mud.yahoo.com> Dear Gary and Alexis, Thanks a lot. My observation is the same as Alexis'. The JM reference software (the rate control part) does restrict the QP to be fixed (or, simply use the same QP value) for all the MBs within an I-frame/B-frame in a GOP, although the QP value for I-frame or B-frame may change on a frame basis. This may be due to the fact (as pointed out by Alexis) that the rate control in the JM reference software is only for the demo purpose. I am glad that there is no such restriction in the H.264 standard. Regards, James Gary Sullivan wrote: But I'm under the strong impression that the current JM rate control algorithm, although it does have some shortcomings, does have the ability to change QP within an I or B picture -doesn't it? (One of these days we need to improve that rate control.) Best Regards, -Gary Sullivan --------------------------------- From: Tourapis, Alexis [mailto:Alexis.Tourapis@dolby.net] Sent: Sunday, May 07, 2024 11:17 AM To: Gary Sullivan; James (Jianpeng) Dong; mp4-tech-bounces@lists.mpegif.org; mp4-tech@lists.mpegif.org Subject: RE: [Mp4-tech] Why I or B frame can have one fixed QP? Dear James, There is no quantization limitation in H.264/AVC. I am guessing your observation relates to the current Rate Control algorithm supported by the JM software. This should only be seen as an example design. Best regards, Alexis --------------------------------- From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of Gary Sullivan Sent: Saturday, May 06, 2024 8:31 PM To: James (Jianpeng) Dong; mp4-tech-bounces@lists.mpegif.org; mp4-tech@lists.mpegif.org Subject: RE: [Mp4-tech] Why I or B frame can have one fixed QP? I don't think it's true that an I or B frame can only have one fixed QP value in the JM reference software. No, there is no requirement of fixed QP in the standard. QP can change (from any value to any other value) on a macroblock (16x16) basis in the standard. Best Regards, Gary Sullivan --------------------------------- From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of James (Jianpeng) Dong Sent: Friday, May 05, 2024 4:43 PM To: mp4-tech-bounces@lists.mpegif.org; mp4-tech@lists.mpegif.org Cc: jianpengdong@yahoo.com Subject: [Mp4-tech] Why I or B frame can have one fixed QP? Dear experts, Just wondering why I or B frame can only have one fixed QP in H.264 JM reference software? Is a fixed QP required by H.264/AVC standard? Thanks, James --------------------------------- Yahoo! Messenger with Voice. Make PC-to-Phone Calls to the US (and 30+ countries) for 2???/min or less. --------------------------------- This message (including any attachments) may contain confidential information intended for a specific individual and purpose. If you are not the intended recipient, delete this message. If you are not the intended recipient, disclosing, copying, distributing, or taking any action based on this message is strictly prohibited. --------------------------------- Get amazing travel prices for air and hotel in one click on Yahoo! FareChase -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060508/5ac75127/attachment-0001.html From dv2 naver.com Tue May 9 00:30:06 2006 From: dv2 naver.com (=?utf-8?B?IuydtOyEseyaqSI=?=) Date: Tue May 9 14:20:09 2006 Subject: [Mp4-tech] Latest JM code? Message-ID: <445F63FE.000001.17545@i5a007> yes. -----Original Message----- From: "Tourapis, Alexis" To: "jingli888ca" , Cc: Sent: 2024-05-08 23:48 Subject: RE: [Mp4-tech] Latest JM code? Dear Jing, The latest official JM version can be found at http://iphome.hhi.de/suehring/tml/, currently at version 10.2. Various bug fixes have been added in the software since then but have not yet been officially released. Best regards Alexis From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of jingli888ca Sent: Thursday, May 04, 2024 6:29 PM To: mp4-tech@lists.mpegif.org Subject: [Mp4-tech] Latest JM code? Hello, Experts: I wonder if anyone can point me to the latest JM code? Many Thanks. Jing ? ? ? ? ? ? ? ? ??? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ??? ? Ajax ? ??126 ?D ? ??? ? ? ? ? ? This message (including any attachments) may contain confidential information intended for a specific individual and purpose. If you are not the intended recipient, delete this message. If you are not the intended recipient, disclosing, copying, distributing, or taking any action based on this message is strictly prohibited. -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060509/a85c369c/attachment.html From kaustubh.patankar vsnl.net Tue May 9 13:10:03 2006 From: kaustubh.patankar vsnl.net (kaustubh.patankar@vsnl.net) Date: Tue May 9 14:20:16 2006 Subject: [Mp4-tech] Why I or B frame can have one fixed QP? In-Reply-To: <03CB47D9C3F8074498E4653F814D6E8F8E554A@WIN-MSG-20.wingroup.windeploy.ntdev.microsoft.com> References: <7272EE229DA1AA48B47EBDC47EB0C68B01F9BE9D@sapphire.dolby.net> <03CB47D9C3F8074498E4653F814D6E8F8E554A@WIN-MSG-20.wingroup.windeploy.ntdev.microsoft.com> Message-ID: Hi I think there are options to have Frame level and MB level rate control in JM code and it also works for I and B frames. regards Kaustubh -------------- next part -------------- Skipped content of type multipart/alternative-------------- next part -------------- _______________________________________________ NOTE: Please use clear subject lines for your posts. Include [audio, [video], [systems], [general] or another apppropriate identifier to indicate the type of question you have. Note: Conduct on the mailing list is subject to the Antitrust guidelines found at http://www.mpegif.org/public/documents/vault/mp-out-30042-Antitrust.php From srimks yahoo.co.in Tue May 9 01:56:25 2006 From: srimks yahoo.co.in (Mukesh K. Srivastava) Date: Tue May 9 14:20:20 2006 Subject: [Mp4-tech] Video HandHeld Message-ID: <20060509085625.96711.qmail@web8412.mail.in.yahoo.com> I am new to this group and new to Video domain too. I am looking for some fundamentals related to Video to be cleared (e.g.: Profile, frame rate, Previwing, Cropping, etc.) for HandHeld Devices. Is there any resource/website which provides all these information. Also, looking for some discussion forum related to OpenMax IL - Video components with Linux as platform. Regards, Mukesh K Srivastava --------------------------------- How low will we go? Check out Yahoo! Messenger?s low PC-to-Phone call rates. -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060509/2459aed1/attachment.html From Alexis.Tourapis dolby.net Tue May 9 11:59:31 2006 From: Alexis.Tourapis dolby.net (Tourapis, Alexis) Date: Wed May 10 14:38:07 2006 Subject: [Mp4-tech] Why I or B frame can have one fixed QP? Message-ID: <7272EE229DA1AA48B47EBDC47EB0C68B01F9C0FB@sapphire.dolby.net> Dear Kaustubh, I would suggest checking the function updateQuantizationParameter() and carefully read the code for the case that: if(img->BasicUnit!=img->Frame_Total_Number_MB) Correct me if I am wrong (I never use this RC myself while the truth is that have been slow in using/updating the JM lately) but you will observe that for I slices the QP remains unchanged (i.e. m_Qc=MyInitialQp), while for B slices the QP depends on the QPs of the last two "reference" pictures (I have not tested this but my guess is that would be the last QP used in those pictures). Note that this rate control obviously does not support hierarchical coding structures, picture level RDO decisions (these are based on multiple encodes and the software does not handle this correctly for RC), and interlace type of encodings. I would strongly caution anyone myself in using this particular rate control especially for evaluation purposes. It does not adapt its statistics very well (and does that quite slowly), can create severe artifacts (do not be misled by RD curves who tend to average results and hide quality variations), but also (if I recall correctly) has issues with high motion sequences. In any case, this is just my personal opinion. I would mainly see the RC in the software as an educational module than a practical one. Best regards, Alexis _____ From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of kaustubh.patankar@vsnl.net Sent: Tuesday, May 09, 2024 1:10 AM To: Gary Sullivan Cc: James (Jianpeng) Dong; mp4-tech@lists.mpegif.org; mp4-tech-bounces@lists.mpegif.org; Tourapis, Alexis Subject: Re: RE: [Mp4-tech] Why I or B frame can have one fixed QP? But I'm under the strong impression that the current JM rate control algorithm, although it does have some shortcomings, does have the ability to change QP within an I or B picture -doesn't it? (One of these days we need to improve that rate control.) Best Regards, -Gary Sullivan _____ From: Tourapis, Alexis [mailto:Alexis.Tourapis@dolby.net] Sent: Sunday, May 07, 2024 11:17 AM To: Gary Sullivan; James (Jianpeng) Dong; mp4-tech-bounces@lists.mpegif.org; mp4-tech@lists.mpegif.org Subject: RE: [Mp4-tech] Why I or B frame can have one fixed QP? Dear James, There is no quantization limitation in H.264/AVC. I am guessing your observation relates to the current Rate Control algorithm supported by the JM software. This should only be seen as an example design. Best regards, Alexis _____ From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of Gary Sullivan Sent: Saturday, May 06, 2024 8:31 PM To: James (Jianpeng) Dong; mp4-tech-bounces@lists.mpegif.org; mp4-tech@lists.mpegif.org Subject: RE: [Mp4-tech] Why I or B frame can have one fixed QP? I don't think it's true that an I or B frame can only have one fixed QP value in the JM reference software. No, there is no requirement of fixed QP in the standard. QP can change (from any value to any other value) on a macroblock (16x16) basis in the standard. Best Regards, Gary Sullivan _____ From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of James (Jianpeng) Dong Sent: Friday, May 05, 2024 4:43 PM To: mp4-tech-bounces@lists.mpegif.org; mp4-tech@lists.mpegif.org Cc: jianpengdong@yahoo.com Subject: [Mp4-tech] Why I or B frame can have one fixed QP? Dear experts, Just wondering why I or B frame can only have one fixed QP in H.264 JM reference software? Is a fixed QP required by H.264/AVC standard? Thanks, James _____ Yahoo! Messenger with Voice. Make PC-to-Phone Calls to the US (and 30+ countries) for 2?/min or less. _____ This message (including any attachments) may contain confidential information intended for a specific individual and purpose. If you are not the intended recipient, delete this message. If you are not the intended recipient, disclosing, copying, distributing, or taking any action based on this message is strictly prohibited. -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060509/24f6b91e/attachment-0001.html From dv2 naver.com Wed May 10 11:43:05 2006 From: dv2 naver.com (=?euc-kr?B?IsDMvLq/6yI=?=) Date: Wed May 10 14:38:11 2006 Subject: [Mp4-tech] Why I or B frame can have one fixed QP? Message-ID: <44615339.000001.16841@i4j049> HI ~ I think so. you can have control that configuration file. <-----Original Message-----> > From: > To: "Gary Sullivan" > Cc: "James \(Jianpeng\) Dong" , , , "Tourapis, Alexis" > Sent: 2024-05-09 23:56 > Subject: Re: RE: [Mp4-tech] Why I or B frame can have one fixed QP? Hi I think there are options to have Frame level and MB level rate control in JM code and it also works for I and B frames. regards Kaustubh ------------------------------------------------------------------------ ??? ?? ??? ??, ??? http://happybean.naver.com From dv2 naver.com Wed May 10 13:59:22 2006 From: dv2 naver.com (=?euc-kr?B?IsDMvLq/6yI=?=) Date: Wed May 10 14:38:14 2006 Subject: [Mp4-tech] HI~ can i something asking for JM code? Message-ID: <4461732A.000001.00618@i4j049> Hi...i'm working in JM code of decoder. But i dont understand. not exactly Would please let me know that read_significant_coefficients() function of JM code 10.2 ? regards Carter <-----Original Message-----> > From: > To: "Gary Sullivan" > Cc: "James \(Jianpeng\) Dong" , , , "Tourapis, Alexis" > Sent: 2024-05-09 23:56 > Subject: Re: RE: [Mp4-tech] Why I or B frame can have one fixed QP? Hi I think there are options to have Frame level and MB level rate control in JM code and it also works for I and B frames. regards Kaustubh ------------------------------------------------------------------------ ??? ?? ??? ??, ??? http://happybean.naver.com From kaustubh.patankar vsnl.net Wed May 10 13:22:07 2006 From: kaustubh.patankar vsnl.net (kaustubh.patankar@vsnl.net) Date: Wed May 10 14:38:18 2006 Subject: [Mp4-tech] Why I or B frame can have one fixed QP? In-Reply-To: <7272EE229DA1AA48B47EBDC47EB0C68B01F9C0FB@sapphire.dolby.net> References: <7272EE229DA1AA48B47EBDC47EB0C68B01F9C0FB@sapphire.dolby.net> Message-ID: Dear Alexis, It is a very precise explanation of the RC algorithm in JM. We have seen these limitations and this will become very adverse where the system can not afford the time required to carry RD On mode. If the system needs to take a decision based on heuristics and may be based on cost matrics such as SAD, MAD ...., then the decision of Qp based on RD curve will result in wrong selection of Qp value using the present RC algorithm. It seems that the RC works okay for Baseline profile. In my view for Frame level rate control it may result in to moderate results but in case of MB level (where the Qp changes per MB) will result in more artifacts. I agree with your statement that this RC is better to be treated as educational module. Also for the Constant Bit rate case. For Variable bit rate (i am not saying Constant Qp) still seems to be far off. In my opinion, the TM5 core model with necessary modifications is better way to have practical RC. The only variant is to have own cost function to decide the Distortation. Please suggest your view. Regards Kaustubh ----- Original Message ----- From: "Tourapis, Alexis" Date: Wednesday, May 10, 2024 0:29 am Subject: RE: RE: [Mp4-tech] Why I or B frame can have one fixed QP? > Dear Kaustubh, > > I would suggest checking the function > updateQuantizationParameter() and carefully read the code for the > case that: > > if(img->BasicUnit!=img->Frame_Total_Number_MB) > > Correct me if I am wrong (I never use this RC myself while the > truth is that have been slow in using/updating the JM lately) but > you will observe that for I slices the QP remains unchanged (i.e. > m_Qc=MyInitialQp), while for B slices the QP depends on the QPs of > the last two "reference" pictures (I have not tested this but my > guess is that would be the last QP used in those pictures). Note > that this rate control obviously does not support hierarchical > coding structures, picture level RDO decisions (these are based on > multiple encodes and the software does not handle this correctly > for RC), and interlace type of encodings. I would strongly caution > anyone myself in using this particular rate control especially for > evaluation purposes. It does not adapt its statistics very well > (and does that quite slowly), can create severe artifacts (do not > be misled by RD curves who tend to average results and hide > quality variations), but also (if I recall correctly) has issues > with high motion sequences. In any case, this is just my personal > opinion. I would mainly see the RC in the software as an > educational module than a practical one. > > Best regards, > > Alexis > > _____ > > From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech- > bounces@lists.mpegif.org] On Behalf Of kaustubh.patankar@vsnl.net > Sent: Tuesday, May 09, 2024 1:10 AM > To: Gary Sullivan > Cc: James (Jianpeng) Dong; mp4-tech@lists.mpegif.org; mp4-tech- > bounces@lists.mpegif.org; Tourapis, Alexis > Subject: Re: RE: [Mp4-tech] Why I or B frame can have one fixed QP? > > > But I'm under the strong impression that the current JM rate > control algorithm, although it does have some shortcomings, does > have the ability to change QP within an I or B picture -doesn't > it? (One of these days we need to improve that rate control.) > > Best Regards, > > -Gary Sullivan > > > _____ > > From: Tourapis, Alexis [mailto:Alexis.Tourapis@dolby.net] > Sent: Sunday, May 07, 2024 11:17 AM > To: Gary Sullivan; James (Jianpeng) Dong; mp4-tech- > bounces@lists.mpegif.org; mp4-tech@lists.mpegif.org > Subject: RE: [Mp4-tech] Why I or B frame can have one fixed QP? > > > Dear James, > > There is no quantization limitation in H.264/AVC. I am guessing > your observation relates to the current Rate Control algorithm > supported by the JM software. This should only be seen as an > example design. > > Best regards, > > Alexis > > _____ > > From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech- > bounces@lists.mpegif.org] On Behalf Of Gary Sullivan > Sent: Saturday, May 06, 2024 8:31 PM > To: James (Jianpeng) Dong; mp4-tech-bounces@lists.mpegif.org; mp4- > tech@lists.mpegif.org Subject: RE: [Mp4-tech] Why I or B frame can > have one fixed QP? > > > I don't think it's true that an I or B frame can only have one > fixed QP value in the JM reference software. No, there is no > requirement of fixed QP in the standard. QP can change (from any > value to any other value) on a macroblock (16x16) basis in the > standard. > Best Regards, > > Gary Sullivan > > > _____ > > From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech- > bounces@lists.mpegif.org] On Behalf Of James (Jianpeng) Dong > Sent: Friday, May 05, 2024 4:43 PM > To: mp4-tech-bounces@lists.mpegif.org; mp4- > tech@lists.mpegif.org Cc: jianpengdong@yahoo.com > Subject: [Mp4-tech] Why I or B frame can have one fixed QP? > > > Dear experts, > > Just wondering why I or B frame can only have one fixed > QP in H.264 JM reference software? Is a fixed QP required by > H.264/AVC standard? > > Thanks, > > James > > > _____ > > Yahoo! Messenger with Voice. Make PC-to-Phone Calls > to the US (and 30+ countries) for 2?/min or less. > > > _____ > > > > > > > This message (including any attachments) may contain confidential > information intended for a specific individual and purpose. If you > are not the intended recipient, delete this message. If you are > not the intended recipient, disclosing, copying, distributing, or > taking any action based on this message is strictly prohibited. > > > From Marco.Miehe sci-worx.com Wed May 10 10:45:03 2006 From: Marco.Miehe sci-worx.com (Marco.Miehe@sci-worx.com) Date: Wed May 10 14:38:21 2006 Subject: [Mp4-tech] [H.264]Question about num_ref_idx_lx_active_minus1 Message-ID: <7E6219E8CD869D4186B919B0DCF127C001368540@hajse201.eu.infineon.com> Dear Members I post this mail again. Please can someone clarify this. -----Original Message----- From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of Miehe Marco (SCI) Sent: Friday, April 28, 2024 4:01 PM To: Mp4-tech@lists.mpegif.org Subject: RE: [Mp4-tech] [H.264]Question about num_ref_idx_lx_active_minus1 I agree with you, but that's not the point. Let's consider the case that MbaffFrameFlag = 1, i.e., as you say, mb_adaptive_frame_field_flag = 1 and field_pic_flag = 0. This means, we have an Mbaff Frame. Now, for a field macroblock, the semantics of num_ref_idx_lx_active_minus1 in the slice header say that the maximum index value is 2*num_ref_idx_lx_active_minus1 + 1, and that the range of num_ref_idx_lx_active_minus1 is from 0 to 15. This results in a maximum possible index value of 2*15 + 1 = 31, which is logical since there can be up to 32 reference fields in the reference list for a field MB. But in the semantics of the same syntax element in the Picture Parameter Set, it again says that for field MBs in Mbaff frames the maximum index value is 2*num_ref_idx_lx_active_minus1 + 1, but the range of num_ref_idx_lx_active_minus1 here is only limited from 0..31. This now looks as if the maximum possible reference index is 2*31 + 1 = 63, which does not makes sense regarding the maximum number of 32 reference fields. I believe that the semantics should be the same as for num_ref_idx_lx_active_minus1 in the slice header and everything would be clear. I think this is just an inaccurate description here which should be corrected. BR, Marco Miehe -----Original Message----- From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of Ye-Kui.Wang@nokia.com Sent: Wednesday, April 26, 2024 1:18 PM To: Mp4-tech@lists.mpegif.org Subject: RE: [Mp4-tech] [H.264]Question about num_ref_idx_lx_active_minus1 Note that MbaffFrameFlag = ( mb_adaptive_frame_field_flag && !field_pic_flag ), i.e. when field_pic_flag == 1, MbaffFrameFlag = 0. BR, YK -----Original Message----- From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] Sent: 25 April, 2006 15:23 To: Mp4-tech@lists.mpegif.org Subject: [Mp4-tech] [H.264]Question about num_ref_idx_lx_active_minus1 Dear Members I have a question regarding the max size of the reference picture list. In the standard ITU-T Rec. H.264 chapter 7.4.3 (Slice header semantics) the variable "num_ref_idx_lx_active_minus1" says if the field_pic_flag is equal to 0 the max. size of the ref. pic. list is 16. And otherwise (field_pic_flag is equal to 1) the max. size of the ref. pic. list is 32 (num_ref_idx_lx_active_minus1 shall be in range of 0..31). The variable "num_ref_idx_lx_active_minus1" is also in the PictureParameterSet. I think this definition could be misunderstood. Picture parameter set semantics (chapter 7.4.2.2): ... When MbaffFrameFlag is equal to 1, num_ref_idx_l0_active_minus1 is the maximum index value for the decoding of frame macroblocks and 2 * num_ref_idx_l0_active_minus1 + 1 is the maximum index value for the decoding of field macroblocks. The value of num_ref_idx_l0_active_minus1 shall be in the range of 0 to 31, inclusive. When I read this definition I might think (altough I think it dosen't make sense) the max. size of the ref. pic list is 64. Up to now I thought the Max. Size of the DPB is 16 and the max. size of the reference picture list is also 16 or 32 (in case of fields). I'd appreciate if some one clarifies this. Best regards, Marco Miehe _______________________________________________ >NOTE: Please use clear subject lines for your posts. Include [audio, >[video], [systems], [general] or another apppropriate identifier to >indicate the type of question you have. > >Note: Conduct on the mailing list is subject to the Antitrust >guidelines found at >http://www.mpegif.org/public/documents/vault/mp-out-30042-Antitrust.php > _______________________________________________ NOTE: Please use clear subject lines for your posts. Include [audio, [video], [systems], [general] or another apppropriate identifier to indicate the type of question you have. Note: Conduct on the mailing list is subject to the Antitrust guidelines found at http://www.mpegif.org/public/documents/vault/mp-out-30042-Antitrust.php _______________________________________________ NOTE: Please use clear subject lines for your posts. Include [audio, [video], [systems], [general] or another apppropriate identifier to indicate the type of question you have. Note: Conduct on the mailing list is subject to the Antitrust guidelines found at http://www.mpegif.org/public/documents/vault/mp-out-30042-Antitrust.php From maria.farrugia vodafone.com Wed May 10 09:52:18 2006 From: maria.farrugia vodafone.com (Farrugia, Maria, VF-Group) Date: Wed May 10 14:38:25 2006 Subject: [Mp4-tech] H.264 and MPEG-4 Video codecs compatibility Message-ID: Dear all, Could someone please let me know if H.264 can decode video content encoded with MPEG-4 Visual simple Profile? And also if an MPEG-4 decoder can decode content encoded with H.264? Thanks in advance, Dr Maria Farrugia Terminal Technologies Team Vodafone Group Research & Development .UK Tel: +44 (0)1635 665886 Fax: +44 (0)1635 676147 Mobile: +44 (0)7919 994677 E-mail: maria.farrugia@vodafone.com Vodafone Group Services Limited Registered Office: Vodafone House, The Connection, Newbury, Berkshire RG14 2FN Registered in England No 3802001 -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060510/c77e1d6e/attachment.html From jianpengdong yahoo.com Wed May 10 09:13:04 2006 From: jianpengdong yahoo.com (James (Jianpeng) Dong) Date: Wed May 10 20:02:05 2006 Subject: [Mp4-tech] Why I or B frame can have one fixed QP? In-Reply-To: <44615339.000001.16841@i4j049> Message-ID: <20060510161304.32754.qmail@web30013.mail.mud.yahoo.com> Dear experts, Here is some code snippet for basic unit rate contrl from ratectl.c from JM 10.2 (note that the comment for bottom field of I frame and the related code do not match, I believe this might be a bug?): /*top filed of I frame*/ if(img->type==I_SLICE) { m_Qc=MyInitialQp; return m_Qc; } /*bottom field of I frame*/ else if((img->type==P_SLICE)&&(img->IFLAG==1)&&(img->FieldControl==1)) { m_Qc=MyInitialQp; return m_Qc; } Note also MyInitialQp won't change util a new GOP arrives. From the above, it is apparent that the rate control in JM 10.2 uses a fixed QP for I SLICEs. The parameters in the configuration file won't affect the I-frames: ######################################################################################## #Rate control ######################################################################################## RateControlEnable = 1 # 0 Disable, 1 Enable Bitrate = 48000 # Bitrate(bps) InitialQP = 26 # Initial Quantization Parameter for the first I frame # InitialQp depends on two values: Bits Per Picture, # and the GOP length BasicUnit = 1 # Number of MBs in the basic unit # should be a fractor of the total number # of MBs in a frame ChannelType = 0 # type of channel( 1=time varying channel; 0=Constant channel) Regards, James "??????????????" wrote: HI ~ I think so. you can have control that configuration file. <-----Original Message-----> > From: > To: "Gary Sullivan" > Cc: "James \(Jianpeng\) Dong" , , , "Tourapis, Alexis" > Sent: 2024-05-09 23:56 > Subject: Re: RE: [Mp4-tech] Why I or B frame can have one fixed QP? Hi I think there are options to have Frame level and MB level rate control in JM code and it also works for I and B frames. regards Kaustubh ------------------------------------------------------------------------ ??????????? ????????? ?????????????? ????????????, ?????????????? http://happybean.naver.com --------------------------------- Get amazing travel prices for air and hotel in one click on Yahoo! FareChase -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060510/561980e7/attachment-0001.html From Alexis.Tourapis dolby.net Wed May 10 10:06:46 2006 From: Alexis.Tourapis dolby.net (Tourapis, Alexis) Date: Wed May 10 20:02:10 2006 Subject: [Mp4-tech] Why I or B frame can have one fixed QP? Message-ID: <7272EE229DA1AA48B47EBDC47EB0C68B01F9C20C@sapphire.dolby.net> Dear James, This has nothing to do with Rate Control but, by default, if field coding is selected to encode an entire frame, and if that frame was originally scheduled to use I slices, only the top field would be coded as I and the bottom will be coded as P. This enabled the encoder to exploit correlation that may exist between top and bottom field to improve performance. This consideration could be disabled with a flag that we added a considerable time ago named "IntraBottom". Furthermore, the software also allows you to test the use of B slices for encoding this bottom field as well. Although to some it might sound odd in fact, for some content this can provide further benefits due to biprediction considerations. Kind regards, Alexis _____ From: James (Jianpeng) Dong [mailto:jianpengdong@yahoo.com] Sent: Wednesday, May 10, 2024 9:13 AM To: ??????????????; kaustubh.patankar@vsnl.net Cc: mp4-tech@lists.mpegif.org; mp4-tech-bounces@lists.mpegif.org; Tourapis, Alexis; Gary Sullivan Subject: RE: Re: RE: [Mp4-tech] Why I or B frame can have one fixed QP? Dear experts, Here is some code snippet for basic unit rate contrl from ratectl.c from JM 10.2 (note that the comment for bottom field of I frame and the related code do not match, I believe this might be a bug?): /*top filed of I frame*/ if(img->type==I_SLICE) { m_Qc=MyInitialQp; return m_Qc; } /*bottom field of I frame*/ else if((img->type==P_SLICE)&&(img->IFLAG==1)&&(img->FieldControl==1)) { m_Qc=MyInitialQp; return m_Qc; } Note also MyInitialQp won't change util a new GOP arrives. From the above, it is apparent that the rate control in JM 10.2 uses a fixed QP for I SLICEs. The parameters in the configuration file won't affect the I-frames: ######################################################################################## #Rate control ######################################################################################## RateControlEnable = 1 # 0 Disable, 1 Enable Bitrate = 48000 # Bitrate(bps) InitialQP = 26 # Initial Quantization Parameter for the first I frame # InitialQp depends on two values: Bits Per Picture, # and the GOP length BasicUnit = 1 # Number of MBs in the basic unit # should be a fractor of the total number # of MBs in a frame ChannelType = 0 # type of channel( 1=time varying channel; 0=Constant channel) Regards, James "??????????????" wrote: HI ~ I think so. you can have control that configuration file. <-----Original Message-----> > From: > To: "Gary Sullivan" > Cc: "James \(Jianpeng\) Dong" , , , "Tourapis, Alexis" > Sent: 2024-05-09 23:56 > Subject: Re: RE: [Mp4-tech] Why I or B frame can have one fixed QP? Hi I think there are options to have Frame level and MB level rate control in JM code and it also works for I and B frames. regards Kaustubh ------------------------------------------------------------------------ ??????????? ????????? ?????????????? ????????????, ?????????????? http://happybean.naver.com _____ Get amazing travel prices for air and hotel in one click on Yahoo! FareChase ----------------------------------------- This message (including any attachments) may contain confidential information intended for a specific individual and purpose. If you are not the intended recipient, delete this message. If you are not the intended recipient, disclosing, copying, distributing, or taking any action based on this message is strictly prohibited. -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060510/7342989c/attachment-0001.html From garysull windows.microsoft.com Wed May 10 11:34:14 2006 From: garysull windows.microsoft.com (Gary Sullivan) Date: Wed May 10 20:02:14 2006 Subject: [Mp4-tech] H.264 and MPEG-4 Video codecs compatibility In-Reply-To: Message-ID: <03CB47D9C3F8074498E4653F814D6E8F998CBD@WIN-MSG-20.wingroup.windeploy.ntdev.microsoft.com> The answer to your first question is somewhat a product decision question as much as it is anything else. Many products that can decode "H.264" (a.k.a. MPEG-4 AVC a.k.a. 14496-10) can also decode MPEG-4 Visual Simple Profile bitstreams. However, that is at the discretion of the product designer or the system designer. There are no requirements for such functionality in those video coding standards themselves. In your second sentence, when you refer to "an MPEG-4 decoder", are you referring to an MPEG-4 AVC decoder or an MPEG-4 Visual decoder? Best Regards, Gary Sullivan ________________________________ From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of Farrugia, Maria, VF-Group Sent: Wednesday, May 10, 2024 1:52 AM To: mp4-tech@lists.mpegif.org Subject: [Mp4-tech] H.264 and MPEG-4 Video codecs compatibility Dear all, Could someone please let me know if H.264 can decode video content encoded with MPEG-4 Visual simple Profile? And also if an MPEG-4 decoder can decode content encoded with H.264? Thanks in advance, Dr Maria Farrugia Terminal Technologies Team Vodafone Group Research & Development .UK Tel: +44 (0)1635 665886 Fax: +44 (0)1635 676147 Mobile: +44 (0)7919 994677 E-mail: maria.farrugia@vodafone.com Vodafone Group Services Limited Registered Office: Vodafone House, The Connection, Newbury, Berkshire RG14 2FN Registered in England No 3802001 -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060510/41c7c0c6/attachment-0001.html From garysull windows.microsoft.com Wed May 10 15:07:42 2006 From: garysull windows.microsoft.com (Gary Sullivan) Date: Thu May 11 00:02:07 2006 Subject: [Mp4-tech] [H.264]Question about num_ref_idx_lx_active_minus1 In-Reply-To: <7E6219E8CD869D4186B919B0DCF127C001368540@hajse201.eu.infineon.com> Message-ID: <03CB47D9C3F8074498E4653F814D6E8FA2DD3A@WIN-MSG-20.wingroup.windeploy.ntdev.microsoft.com> Marco et al, I don't think there is any big problem in the language of the standard, if you read it properly and completely. However, perhaps it could be improved. One thing to notice is that the value of MbaffFrameFlag is unknown when parsing the PPS (because MbaffFrameFlag is determined from field_pic_flag, which is not in the PPS). However, the value of MbaffFrameFlag is known when parsing the slice header. But the slice header also provides the ability to override the value of the num_ref_idx_lx_active_minus1 syntax elements. Another thing to notice is that although there are syntax elements with the same name in the PPS and slice header, the semantics do not need to be exactly the same in both situations. The semantics description that appears in the PPS section is for the syntax element in the PPS and the semantics description that appears in the slice header section is for the syntax element in the slice header. Note that although the PPS semantics allows values greater than 15 for num_ref_idx_lx_active_minus1, we have the following statement in the slice header semantics: "When the current slice is a P, SP, or B slice and field_pic_flag is equal to 0 and the value of num_ref_idx_l0_active_minus1 in the picture parameter set exceeds 15, num_ref_idx_active_override_flag shall be equal to 1." So num_ref_idx_lx_active_minus1 can be greater than 15 in the PPS, but when that is the case and the picture uses inter prediction and is not a field picture, the value in the PPS must be overridden in the slice header. The key issue is to determine what value is "in effect" for num_ref_idx_lx_active_minus1. It says in the slice header semantics that "num_ref_idx_active_override_flag equal to 0 specifies that the values of the syntax elements num_ref_idx_l0_active_minus1 and num_ref_idx_l1_active_minus1 specified in the referred picture parameter set are in effect. num_ref_idx_active_override_flag equal to 1 specifies that the num_ref_idx_l0_active_minus1 and num_ref_idx_l1_active_minus1 specified in the referred picture parameter set are overridden for the current slice (and only for the current slice) by the following values in the slice header." For example, an encoder can set num_ref_idx_lx_active_minus1 = 31 in the PPS and then code some pictures with field_pic_flag = 1 and num_ref_idx_active_override_flag = 0 and code some other pictures with field_pic_flag = 0 and num_ref_idx_active_override_flag = 1 and num_ref_idx_lx_active_minus1 = 15. That would be perfectly OK. So where the standard says "When MbaffFrameFlag is equal to 1, num_ref_idx_l0_active_minus1 is the maximum index value for the decoding of frame macroblocks and 2 * num_ref_idx_l0_active_minus1 + 1 is the maximum index value for the decoding of field macroblocks.", it is referring to the value of num_ref_idx_l0_active_minus1 that is in effect when the value of MbaffFrameFlag is in effect. Thus it is referring to the value of num_ref_idx_l0_active_minus1 after the value in the PPS may have been overridden by a value in the slice header. If we wanted to improve upon the current text, I see two possible approaches. One is to simply delete the statement in the PPS semantics that says that "When MbaffFrameFlag is equal to 1, num_ref_idx_l0_active_minus1 is the maximum index value for the decoding of frame macroblocks and 2 * num_ref_idx_l0_active_minus1 + 1 is the maximum index value for the decoding of field macroblocks." This statement is redundant with what is stated in the slice header semantics, and is confusing since it refers to slice header decoding results despite trying to describe something in the PPS. Another possible improvement would be to rename the syntax elements in the PPS and slice header so that they have distinct names. Then instead of talking about which one is "in effect", we could talk about inferring the slice header syntax element to be equal to the PPS syntax element value when num_ref_idx_active_override_flag is 0. Best Regards, Gary Sullivan +> -----Original Message----- +> From: mp4-tech-bounces@lists.mpegif.org +> [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of +> Marco.Miehe@sci-worx.com +> Sent: Wednesday, May 10, 2024 1:45 AM +> To: Mp4-tech@lists.mpegif.org +> Subject: RE: [Mp4-tech] [H.264]Question about +> num_ref_idx_lx_active_minus1 +> +> Dear Members +> +> I post this mail again. Please can someone clarify this. +> +> -----Original Message----- +> From: mp4-tech-bounces@lists.mpegif.org +> [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of Miehe Marco +> (SCI) +> Sent: Friday, April 28, 2024 4:01 PM +> To: Mp4-tech@lists.mpegif.org +> Subject: RE: [Mp4-tech] [H.264]Question about +> num_ref_idx_lx_active_minus1 +> +> I agree with you, but that's not the point. +> Let's consider the case that MbaffFrameFlag = 1, i.e., as you say, +> mb_adaptive_frame_field_flag = 1 and field_pic_flag = 0. +> This means, we have an Mbaff Frame. Now, for a field macroblock, the +> semantics of num_ref_idx_lx_active_minus1 +> in the slice header say that the maximum index value is +> 2*num_ref_idx_lx_active_minus1 + 1, and that the range of +> num_ref_idx_lx_active_minus1 is from 0 to 15. This results +> in a maximum +> possible index value of 2*15 + 1 = 31, +> which is logical since there can be up to 32 reference fields in the +> reference list for a field MB. +> But in the semantics of the same syntax element in the +> Picture Parameter +> Set, it again says that for field MBs in Mbaff +> frames the maximum index value is 2*num_ref_idx_lx_active_minus1 + 1, +> but the range of num_ref_idx_lx_active_minus1 +> here is only limited from 0..31. This now looks as if the maximum +> possible reference index is 2*31 + 1 = 63, +> which does not makes sense regarding the maximum number of +> 32 reference +> fields. +> I believe that the semantics should be the same as for +> num_ref_idx_lx_active_minus1 in the slice header and +> everything would be clear. I think this is just an inaccurate +> description here which should be corrected. +> +> BR, +> Marco Miehe +> +> -----Original Message----- +> From: mp4-tech-bounces@lists.mpegif.org +> [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of +> Ye-Kui.Wang@nokia.com +> Sent: Wednesday, April 26, 2024 1:18 PM +> To: Mp4-tech@lists.mpegif.org +> Subject: RE: [Mp4-tech] [H.264]Question about +> num_ref_idx_lx_active_minus1 +> +> Note that MbaffFrameFlag = ( mb_adaptive_frame_field_flag && +> !field_pic_flag ), i.e. when field_pic_flag == 1, +> MbaffFrameFlag = 0. +> +> BR, YK +> +> -----Original Message----- +> From: mp4-tech-bounces@lists.mpegif.org +> [mailto:mp4-tech-bounces@lists.mpegif.org] +> Sent: 25 April, 2006 15:23 +> To: Mp4-tech@lists.mpegif.org +> Subject: [Mp4-tech] [H.264]Question about +> num_ref_idx_lx_active_minus1 +> +> Dear Members +> +> I have a question regarding the max size of the reference +> picture list. +> +> In the standard ITU-T Rec. H.264 chapter 7.4.3 (Slice header +> semantics) +> the variable +> "num_ref_idx_lx_active_minus1" says if the field_pic_flag is +> equal to 0 +> the max. size +> of the ref. pic. list is 16. And otherwise (field_pic_flag +> is equal to +> 1) the max. size +> of the ref. pic. list is 32 (num_ref_idx_lx_active_minus1 shall be in +> range of 0..31). +> +> The variable "num_ref_idx_lx_active_minus1" is also in the +> PictureParameterSet. +> I think this definition could be misunderstood. +> +> Picture parameter set semantics (chapter 7.4.2.2): +> ... When MbaffFrameFlag is equal to 1, +> num_ref_idx_l0_active_minus1 is +> the maximum index value for the +> decoding of frame macroblocks and 2 * +> num_ref_idx_l0_active_minus1 + 1 +> is the maximum index value for the +> decoding of field macroblocks. The value of +> num_ref_idx_l0_active_minus1 +> shall be in the range of 0 to 31, +> inclusive. +> +> When I read this definition I might think (altough I think it dosen't +> make sense) +> the max. size of the ref. pic list is 64. +> Up to now I thought the Max. Size of the DPB is 16 and the +> max. size of +> the reference picture list is also +> 16 or 32 (in case of fields). +> +> I'd appreciate if some one clarifies this. +> +> Best regards, +> +> Marco Miehe +> +> +> +> +> +> _______________________________________________ +> >NOTE: Please use clear subject lines for your posts. +> Include [audio, +> >[video], [systems], [general] or another apppropriate identifier to +> >indicate the type of question you have. +> > +> >Note: Conduct on the mailing list is subject to the Antitrust +> >guidelines found at +> >http://www.mpegif.org/public/documents/vault/mp-out-30042-An +> titrust.php +> > +> +> _______________________________________________ +> NOTE: Please use clear subject lines for your posts. Include [audio, +> [video], [systems], [general] or another apppropriate identifier to +> indicate the type of question you have. +> +> Note: Conduct on the mailing list is subject to the +> Antitrust guidelines +> found at +> http://www.mpegif.org/public/documents/vault/mp-out-30042-Ant +> itrust.php +> +> _______________________________________________ +> NOTE: Please use clear subject lines for your posts. Include [audio, +> [video], [systems], [general] or another apppropriate identifier to +> indicate the type of question you have. +> +> Note: Conduct on the mailing list is subject to the +> Antitrust guidelines +> found at +> http://www.mpegif.org/public/documents/vault/mp-out-30042-Ant +> itrust.php +> +> _______________________________________________ +> NOTE: Please use clear subject lines for your posts. Include +> [audio, [video], [systems], [general] or another +> apppropriate identifier to indicate the type of question you have. +> +> Note: Conduct on the mailing list is subject to the +> Antitrust guidelines found at +> http://www.mpegif.org/public/documents/vault/mp-out-30042-Ant +> itrust.php +> From pankaj_bajpai_iet operamail.com Thu May 11 05:52:22 2006 From: pankaj_bajpai_iet operamail.com (pankaj bajpai) Date: Thu May 11 13:52:06 2006 Subject: [Mp4-tech] Re: Mp4-tech Digest, Vol 34, Issue 7 Message-ID: <20060511045222.431ACCA0A4@ws5-11.us4.outblaze.com> Hi Maria, Mpeg4 (part-2) decoder cannot decode H.264 stream. Similarly, I think (let me correct if I am wrong) H264 decoder cannot decode Mpeg4 Simple profile stream. Actually the bitstream structure is entirely different. Like H264 has 4x4 and other sub partition of 16x16, while Mpeg4 has only 8x8 or 16x16. With regards > From: Farrugia, Maria, VF-Group > To: mp4-tech@lists.mpegif.org > Subject: [Mp4-tech] H.264 and MPEG-4 Video codecs compatibility > Date: Wed, 10 May 2024 09:52:18 +0100 > > > Dear all, > > Could someone please let me know if H.264 can decode video content > encoded with MPEG-4 Visual simple Profile? > And also if an MPEG-4 decoder can decode content encoded with H.264? > > Thanks in advance, > > Dr Maria Farrugia > Terminal Technologies Team > Vodafone Group Research & Development .UK > > Tel: +44 (0)1635 665886 > Fax: +44 (0)1635 676147 > Mobile: +44 (0)7919 994677 > > E-mail: maria.farrugia@vodafone.com > Pankaj Kumar Bajpai Mulitimedia Engineer India -- _______________________________________________ Surf the Web in a faster, safer and easier way: Download Opera 8 at http://www.opera.com Powered by Outblaze From dv2 naver.com Thu May 11 15:04:15 2006 From: dv2 naver.com (=?euc-kr?B?IsDMvLq/6yI=?=) Date: Thu May 11 13:52:11 2006 Subject: [Mp4-tech] [MP-tech4 ] what is mean this following? Message-ID: <4462D3DF.000001.31767@naver891> Hello? At the JM decoder 10.2. i can see that there is read_significant_coefficients() function of cabac.c. Why? coeff[i] += biari_decode_symbol (dep_dp, img->currentSlice->tex_ctx->one_contexts[type2ctx_one[type]] + ctx); So, i can't understand. Could somebody help me? Please regard. -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060511/1c045326/attachment-0001.html From maria.farrugia vodafone.com Thu May 11 09:12:37 2006 From: maria.farrugia vodafone.com (Farrugia, Maria, VF-Group) Date: Thu May 11 13:52:14 2006 Subject: [Mp4-tech] H.264 and MPEG-4 Video codecs compatibility Message-ID: Hi Gary, and all, Thank you for responses. In my second question, I was referring to MPEG-4 Visual decoder. I am aware that an MPEG-4 AVC decoder is able to decode H.264 encoded content as they are the same codec. Best regards, Maria ________________________________ From: Gary Sullivan [mailto:garysull@windows.microsoft.com] Sent: 10 May 2024 19:34 To: Farrugia, Maria, VF-Group; mp4-tech@lists.mpegif.org Subject: RE: [Mp4-tech] H.264 and MPEG-4 Video codecs compatibility The answer to your first question is somewhat a product decision question as much as it is anything else. Many products that can decode "H.264" (a.k.a. MPEG-4 AVC a.k.a. 14496-10) can also decode MPEG-4 Visual Simple Profile bitstreams. However, that is at the discretion of the product designer or the system designer. There are no requirements for such functionality in those video coding standards themselves. In your second sentence, when you refer to "an MPEG-4 decoder", are you referring to an MPEG-4 AVC decoder or an MPEG-4 Visual decoder? Best Regards, Gary Sullivan ________________________________ From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of Farrugia, Maria, VF-Group Sent: Wednesday, May 10, 2024 1:52 AM To: mp4-tech@lists.mpegif.org Subject: [Mp4-tech] H.264 and MPEG-4 Video codecs compatibility Dear all, Could someone please let me know if H.264 can decode video content encoded with MPEG-4 Visual simple Profile? And also if an MPEG-4 decoder can decode content encoded with H.264? Thanks in advance, Dr Maria Farrugia Terminal Technologies Team Vodafone Group Research & Development .UK Tel: +44 (0)1635 665886 Fax: +44 (0)1635 676147 Mobile: +44 (0)7919 994677 E-mail: maria.farrugia@vodafone.com Vodafone Group Services Limited Registered Office: Vodafone House, The Connection, Newbury, Berkshire RG14 2FN Registered in England No 3802001 -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060511/690aafac/attachment-0001.html From Alexis.Tourapis dolby.net Thu May 11 10:16:55 2006 From: Alexis.Tourapis dolby.net (Tourapis, Alexis) Date: Fri May 12 14:02:07 2006 Subject: [Mp4-tech] (no subject) Message-ID: <7272EE229DA1AA48B47EBDC47EB0C68B01F9C32C@sapphire.dolby.net> Dear Carter, I am not a CABAC expert but the basic idea is that if a coefficient is significant, then there is a very high probability for that to have a value equal to 1 or -1. Therefore, a different context is used for this case than for values larger than one (sign is encoded using a separate context (one_contexts as you see here). Is that what you are asking? Best regards, Alexis <--In Response to--> Hello? At the JM decoder 10.2. i can see that there is read_significant_coefficients() function of cabac.c. Why? coeff[i] += biari_decode_symbol (dep_dp, img->currentSlice->tex_ctx->one_contexts[type2ctx_one[type]] + ctx); So, i can't understand. Could somebody help me? Please regard. ----------------------------------------- This message (including any attachments) may contain confidential information intended for a specific individual and purpose. If you are not the intended recipient, delete this message. If you are not the intended recipient, disclosing, copying, distributing, or taking any action based on this message is strictly prohibited. From yi-jen.chiu intel.com Thu May 11 21:10:35 2006 From: yi-jen.chiu intel.com (Chiu, Yi-jen) Date: Fri May 12 14:02:11 2006 Subject: [Mp4-tech] Summer intern opportunity at Intel, Santa Clara, CA Message-ID: <2F226B6DEEDB8F4299E206C7DA5313D0064070CD@scsmsx403.amr.corp.intel.com> Hello, Below is the description about a summer internship opening at our group. Please send your resume to me at yi-jen.chiu@intel.com, thanks. Regards, Yi-Jen Chiu ------------- Immediate opening of a summer Intern: Year 2006, Intel Crop. Santa Clara, CA Responsibilities: 1. R&D various video/image processing and compression algorithms to support various video applications. 2. Assisted in the development, enhancement and verification of new product prototypes and modifications of existing products. Qualifications: Candidates are preferred to pursue the post-graduate degree in Electrical Engineer or related fields. Additional qualifications include: 1. A highly skilled and innovative fellow who is anxious to play a key role in delivering cutting edge video technologies. 2. Candidates are preferred with strong knowledge in video compression such as H.264, MPEG4, VC1 and MPEG2 video standards and various video codecs. Familiar with transcoding, motion estimation, rate control, and mode selection is a plus. 3. Candidates are preferred to have hands-on experience on the theory of signal processing on the areas of the pre/post-processing and display processing, specifically on noise reduction, picture enhancement, image restoration, and picture format conversion. 4. Must demonstrate excellent simulation capability with C/C++ & Matlab. Contact: Please send your resume to Yi-Jen Chiu at yi-jen.chiu@intel.com. From zhou ht-tech.com Sat May 13 09:24:23 2006 From: zhou ht-tech.com (=?UTF-8?B?5ZGo5Yqb?=) Date: Sat May 13 16:08:08 2006 Subject: [Mp4-tech] MPEG-4 Codec Choice? Message-ID: <44653547.8010202@ht-tech.com> Hello list, I work for a Chinese company who is developing a embedded software implementation of IPTV based on AVS. AVS stands for Audio Visual Systems which is new Chinese national standard approved in March 2006. As the maturity of AVS is not there yet. I am required by my employer to set up a IPTV showroom based on MPEG-4 first. Here comes some problems. There are many MPEG-4 codecs but it seems that they are not compatible to each other. For example, a MP4 file exported from QuickTime won't play with Microsoft Media Player. As I realize that MP4 is just another container format like AVI so it seems that I have to bundle the solution to a specific MPEG-4 codec. There is no single MPEG-4 decoder that can decode all the MPEG-4 variants or there is? Thanks for any advice on this. Zhou Li From lists06 wiltgen.net Sat May 13 10:48:33 2006 From: lists06 wiltgen.net (Charles) Date: Sun May 14 20:14:13 2006 Subject: [Mp4-tech] MPEG-4 Codec Choice? In-Reply-To: <44653547.8010202@ht-tech.com> Message-ID: <009601c676b5$748c7cc0$3200a8c0@maggie> > For example, a MP4 file exported from QuickTime won't play with > Microsoft Media Player. Right, because Microsoft doesn't support MPEG-4. You can just use QuickTime, or install an MPEG-4 splitter and codecs for DirectShow. -- Charles From zhou ht-tech.com Sun May 14 12:20:45 2006 From: zhou ht-tech.com (=?UTF-8?B?5ZGo5Yqb?=) Date: Sun May 14 20:14:17 2006 Subject: [Mp4-tech] MPEG-4 Codec Choice? In-Reply-To: <8A1CAD515ADC374D866A060864CD8F99033FC7@BE042.mail.lan> References: <44653547.8010202@ht-tech.com> <8A1CAD515ADC374D866A060864CD8F99033FC7@BE042.mail.lan> Message-ID: <4466B01D.3010306@ht-tech.com> Mohit Agarwal ??: > See mp4 is a container format stores MPEg4 Video.You need a player which > can play all the formats ,not the Decoder.As each Decoder work s on the Byte stream > which is same in any file format. > > You can try mplayer ,it can play all the formats you are reffering to. > Mohit > > Dear Mohit, Thanks for your input. We are doing an IPTV project in which the video output device is a good old TV, not computer monitor. The basic concept is that after equipping a TV with our Set Top box, the TV will have an IP address and can play streaming video (MPEG-4 and AVS) just like computer does. So here the decoder and player will run on an embedded processor which i am sure that mplayer doesn't support. Zhou Li From mp3.aac.mp4 gmail.com Mon May 15 10:20:42 2006 From: mp3.aac.mp4 gmail.com (tech list) Date: Mon May 15 13:03:06 2006 Subject: [Mp4-tech] MPEG-4 Codec Choice? In-Reply-To: <4466B01D.3010306@ht-tech.com> References: <44653547.8010202@ht-tech.com> <8A1CAD515ADC374D866A060864CD8F99033FC7@BE042.mail.lan> <4466B01D.3010306@ht-tech.com> Message-ID: <409a09b90605142150q37e314daofa175c8eb37bc39c@mail.gmail.com> > > So here the decoder and player will run on an embedded > processor which i am sure that mplayer doesn't support. What you need is to identify the "embedded processor" and get the codec (and parser) required for this platform. You can either buy it off the shelf or if your company has a DSP/Video group, try implementing it. There are many MPEG-4 codecs but it seems that they are not compatible to > each other. All MPEG-4 decoders would be able to play all MPEG-4 streams. There is no question of compatibility here. For example, a MP4 file exported from QuickTime won't > play with Microsoft Media Player. > That is because Microsoft's Windows Media Player does not have support for MPEG-4 files. This is not a compatibility issue. WMP does not support a lot of good formats because Mr. Gates seems to want to push WMA & WMV, but that is another issue! Use Quicktime, Nokia Multimedia Player, or Phillips Platform player for MP4 files. On 5/14/06, ?? wrote: > > Mohit Agarwal ??: > > See mp4 is a container format stores MPEg4 Video.You need a player which > > can play all the formats ,not the Decoder.As each Decoder work s on the > Byte stream > > which is same in any file format. > > > > You can try mplayer ,it can play all the formats you are reffering to. > > Mohit > > > > > Dear Mohit, > > Thanks for your input. We are doing an IPTV project in which the video > output device is a good old TV, not computer monitor. The basic concept > is that after equipping a TV with our Set Top box, the TV will have an > IP address and can play streaming video (MPEG-4 and AVS) just like > computer does. So here the decoder and player will run on an embedded > processor which i am sure that mplayer doesn't support. > > Zhou Li > > _______________________________________________ > NOTE: Please use clear subject lines for your posts. Include [audio, > [video], [systems], [general] or another apppropriate identifier to indicate > the type of question you have. > > Note: Conduct on the mailing list is subject to the Antitrust guidelines > found at > http://www.mpegif.org/public/documents/vault/mp-out-30042-Antitrust.php > -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060515/ab0f327b/attachment.html From m.semsar ece.ut.ac.ir Mon May 15 16:09:18 2006 From: m.semsar ece.ut.ac.ir (m.semsar@ece.ut.ac.ir) Date: Mon May 15 13:03:12 2006 Subject: [Mp4-tech] [MPEG4-Tech] MPEG-4 Bitstream Message-ID: <62725.217.218.37.162.1147693158.squirrel@217.218.37.162> Dear Experts, Hi, I want to recognize the header parts in MPEG-4 Bit stream, Would you let me know about the documents that explain the bit stream parsing and semantics? Best Regards, Mehdi Semsarzadeh From dv2 naver.com Mon May 15 21:51:44 2006 From: dv2 naver.com (Carter) Date: Tue May 16 12:26:08 2006 Subject: [Mp4-tech] [Question] About H.264's Macroblock Memory implementation Message-ID: <44687960.000001.20576@i5a011> HI. I'm working on the paper about "A Hardware Accelerator for Context-Based Adaptive Binary Arithmetic Decoding in H.264/AVC1" 0-7803-8834-8 and i will implementation H/W about CABAC decode in H.264. I have some Question in the paper about H.264's Macroblock Memory implementation In paper section "B. Memory System" Could you please help me ? Q1. At the paper in "B memory System" section Why the CABAC decoder start fistly to decode the twenty-fifth macroblock(A25)? Is this right? i think that the CABAC decoder start fistly to decode the first macroblock(A1)? Q2. At the same section " B memory system" section In the paper written that Motion compensation subsystem and intra prediction subsystem can read macroblocks A1,A2, and A23 from M1,M2, M23 respectively, of the macroblock memory after CABAC decoder finished reading and writing memory. Why A1,A2 and A23 ? how? Q3. What information save to Macroblock memory (M1~M24)? Q4. Why seperate two part about READ/WRITE? please help me. regard Carter -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060515/24742343/attachment-0001.html From mp4-tech-owner lists.mpegif.org Mon May 15 14:55:40 2006 From: mp4-tech-owner lists.mpegif.org (MPEGIF List Admins) Date: Tue May 16 12:26:13 2006 Subject: FW: [Mp4-tech] [H.264]Question about num_ref_idx_lx_active_minus1 Message-ID: <002001c6781e$deaefdc0$0301a8c0@corp.intertrust.com> Forwarding auto-discarded mail from non-subscribed address. -----Original Message----- From: Liyong Zhou [mailto:lzhou@pixelworks.com] Sent: Wednesday, 10 May 2024 23:55 To: Marco.Miehe@sci-worx.com; Mp4-tech@lists.mpegif.org Subject: RE: [Mp4-tech] [H.264]Question about num_ref_idx_lx_active_minus1 Marco, The index l0 and l1 are just indexes and can point to the same buffer. The number of buffers is limited to 15+1, and on top of that, profile/level also defines how many BUFFERs (through total size) you can have. -- liyong -----Original Message----- From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of Marco.Miehe@sci-worx.com Sent: Wednesday, May 10, 2024 1:45 AM To: Mp4-tech@lists.mpegif.org Subject: RE: [Mp4-tech] [H.264]Question about num_ref_idx_lx_active_minus1 Dear Members I post this mail again. Please can someone clarify this. -----Original Message----- From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of Miehe Marco (SCI) Sent: Friday, April 28, 2024 4:01 PM To: Mp4-tech@lists.mpegif.org Subject: RE: [Mp4-tech] [H.264]Question about num_ref_idx_lx_active_minus1 I agree with you, but that's not the point. Let's consider the case that MbaffFrameFlag = 1, i.e., as you say, mb_adaptive_frame_field_flag = 1 and field_pic_flag = 0. This means, we have an Mbaff Frame. Now, for a field macroblock, the semantics of num_ref_idx_lx_active_minus1 in the slice header say that the maximum index value is 2*num_ref_idx_lx_active_minus1 + 1, and that the range of num_ref_idx_lx_active_minus1 is from 0 to 15. This results in a maximum possible index value of 2*15 + 1 = 31, which is logical since there can be up to 32 reference fields in the reference list for a field MB. But in the semantics of the same syntax element in the Picture Parameter Set, it again says that for field MBs in Mbaff frames the maximum index value is 2*num_ref_idx_lx_active_minus1 + 1, but the range of num_ref_idx_lx_active_minus1 here is only limited from 0..31. This now looks as if the maximum possible reference index is 2*31 + 1 = 63, which does not makes sense regarding the maximum number of 32 reference fields. I believe that the semantics should be the same as for num_ref_idx_lx_active_minus1 in the slice header and everything would be clear. I think this is just an inaccurate description here which should be corrected. BR, Marco Miehe -----Original Message----- From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of Ye-Kui.Wang@nokia.com Sent: Wednesday, April 26, 2024 1:18 PM To: Mp4-tech@lists.mpegif.org Subject: RE: [Mp4-tech] [H.264]Question about num_ref_idx_lx_active_minus1 Note that MbaffFrameFlag = ( mb_adaptive_frame_field_flag && !field_pic_flag ), i.e. when field_pic_flag == 1, MbaffFrameFlag = 0. BR, YK -----Original Message----- From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] Sent: 25 April, 2006 15:23 To: Mp4-tech@lists.mpegif.org Subject: [Mp4-tech] [H.264]Question about num_ref_idx_lx_active_minus1 Dear Members I have a question regarding the max size of the reference picture list. In the standard ITU-T Rec. H.264 chapter 7.4.3 (Slice header semantics) the variable "num_ref_idx_lx_active_minus1" says if the field_pic_flag is equal to 0 the max. size of the ref. pic. list is 16. And otherwise (field_pic_flag is equal to 1) the max. size of the ref. pic. list is 32 (num_ref_idx_lx_active_minus1 shall be in range of 0..31). The variable "num_ref_idx_lx_active_minus1" is also in the PictureParameterSet. I think this definition could be misunderstood. Picture parameter set semantics (chapter 7.4.2.2): ... When MbaffFrameFlag is equal to 1, num_ref_idx_l0_active_minus1 is the maximum index value for the decoding of frame macroblocks and 2 * num_ref_idx_l0_active_minus1 + 1 is the maximum index value for the decoding of field macroblocks. The value of num_ref_idx_l0_active_minus1 shall be in the range of 0 to 31, inclusive. When I read this definition I might think (altough I think it dosen't make sense) the max. size of the ref. pic list is 64. Up to now I thought the Max. Size of the DPB is 16 and the max. size of the reference picture list is also 16 or 32 (in case of fields). I'd appreciate if some one clarifies this. Best regards, Marco Miehe _______________________________________________ >NOTE: Please use clear subject lines for your posts. Include [audio, >[video], [systems], [general] or another apppropriate identifier to >indicate the type of question you have. > >Note: Conduct on the mailing list is subject to the Antitrust >guidelines found at >http://www.mpegif.org/public/documents/vault/mp-out-30042-Antitrust.php > _______________________________________________ NOTE: Please use clear subject lines for your posts. Include [audio, [video], [systems], [general] or another apppropriate identifier to indicate the type of question you have. Note: Conduct on the mailing list is subject to the Antitrust guidelines found at http://www.mpegif.org/public/documents/vault/mp-out-30042-Antitrust.php _______________________________________________ NOTE: Please use clear subject lines for your posts. Include [audio, [video], [systems], [general] or another apppropriate identifier to indicate the type of question you have. Note: Conduct on the mailing list is subject to the Antitrust guidelines found at http://www.mpegif.org/public/documents/vault/mp-out-30042-Antitrust.php _______________________________________________ NOTE: Please use clear subject lines for your posts. Include [audio, [video], [systems], [general] or another apppropriate identifier to indicate the type of question you have. Note: Conduct on the mailing list is subject to the Antitrust guidelines found at http://www.mpegif.org/public/documents/vault/mp-out-30042-Antitrust.php From garysull windows.microsoft.com Mon May 15 13:54:57 2006 From: garysull windows.microsoft.com (Gary Sullivan) Date: Tue May 16 12:26:17 2006 Subject: [Mp4-tech] MPEG-4 Codec Choice? In-Reply-To: <009601c676b5$748c7cc0$3200a8c0@maggie> Message-ID: <03CB47D9C3F8074498E4653F814D6E8FAB175F@WIN-MSG-20.wingroup.windeploy.ntdev.microsoft.com> The below is somewhat of an oversimplification. Microsoft actually does provide decoding capablity for MPEG-4 video coded using the MPEG-4 Visual Simple Profile, and has for a very long time. MPEGIF's white paper on MPEG-4 (page 34) contains an error in that regard, and I have tried to call this to the attention of MPEGIF. The Windows Media Player also has the ability to operate using installed third-party software decoders. A number of vendors offer such "plug-ins" for playing various formats including some variants of MPEG-4. But at the moment, some of the other stuff used by Quicktime (things other than MPEG-4 Simple Profile video) are not supported natively in the Windows Media Player. In particular, reading the MP4 file format is not currently a natively-supported feature. The accompanying audio format and DRM may also be issues. Best Regards, Gary Sullivan (The above is an informal description of my personal understanding and I should not be considered an official Microsoft spokesperson, although they do employ me.) +> -----Original Message----- +> From: mp4-tech-bounces@lists.mpegif.org +> [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of Charles +> Sent: Saturday, May 13, 2024 10:49 AM +> To: mp4-tech@lists.mpegif.org +> Subject: RE: [Mp4-tech] MPEG-4 Codec Choice? +> +> > For example, a MP4 file exported from QuickTime won't play with +> > Microsoft Media Player. +> +> Right, because Microsoft doesn't support MPEG-4. You can just use +> QuickTime, or install an MPEG-4 splitter and codecs for DirectShow. +> +> -- Charles +> +> +> _______________________________________________ +> NOTE: Please use clear subject lines for your posts. Include +> [audio, [video], [systems], [general] or another +> apppropriate identifier to indicate the type of question you have. +> +> Note: Conduct on the mailing list is subject to the +> Antitrust guidelines found at +> http://www.mpegif.org/public/documents/vault/mp-out-30042-Ant +> itrust.php +> From lists06 wiltgen.net Mon May 15 15:51:35 2006 From: lists06 wiltgen.net (Charles) Date: Tue May 16 12:26:21 2006 Subject: [Mp4-tech] MPEG-4 Codec Choice? In-Reply-To: <03CB47D9C3F8074498E4653F814D6E8FAB175F@WIN-MSG-20.wingroup.windeploy.ntdev.microsoft.com> Message-ID: <001301c67872$1e6777a0$3200a8c0@maggie> >> Microsoft doesn't support MPEG-4. You can just use QuickTime, or >> install an MPEG-4 splitter and codecs for DirectShow. > > The below is somewhat of an oversimplification. Microsoft actually > does provide decoding capablity for MPEG-4 video coded using the > MPEG-4 Visual Simple Profile, and has for a very long time. Yeah, I was torn between saying "Microsoft doesn't support MPEG-4" and "Microsoft has poor, pointless support for old MPEG-4 Video bitstreams, considering that Windows Media Player can't play MPEG-4 files, which even if it could, doesn't support AAC". Thanks for clearing that up. :O) > The Windows Media Player also has the ability to operate using > installed third-party software decoders. Yep, that's what I meant by "or install an MPEG-4 splitter and codecs for DirectShow". Because they're DirectShow components, they'll work not only in Windows Media Player but potentially anything that supports DirectShow (e.g. the Media Center Edition UI, etc.). Basically, download the full version of K-Lite Codec Pack and install CoreAVC, CoreAAC, and the Haali Media Splitter. You'll then be able to play MPEG-4 files in Windows Media Player. Since Apple's AVC decoder is so inefficient in comparison to CoreAVC, this configuration will allow you to smoothly play Apple's 1080p trailers on many boxes that choke and stutter when using QuickTime. Or, just use VLC. -- Charles From WJ_Liu mtk.com.tw Tue May 16 10:40:01 2006 From: WJ_Liu mtk.com.tw (WJ_Liu@mtk.com.tw) Date: Tue May 16 12:26:26 2006 Subject: [Mp4-tech] [H.264] Performance issue on reference frames and reordering of reference frames Message-ID: Dear experts, The mechanism of multiple reference frames may degrade the performance of the cache in an embedded system. Also the re-ordering of the reference frames may have the same impact. Since a frame can contain many slices and each slice can have different reference list, this may seriously downgrade the overall performance. It seems a trade-off between the encoder flexibility/capability and the system performance. Are there any information contained in the SPS/PPS/Slice header or in the spec that provide clues to improve the performance of the memory system? Did the working group ever have any discussions about this? By the way, the re-ordering mechanism can reduce the bits used to encode CAVLC of reference indexes, since most frequently referred frames can be associated with smaller indexes. Is this the main purpose for re-ordering? Or re-ordering can have other advantages? Thanks in advance. Jerry ************* Email Confidentiality Notice ******************** The information contained in this e-mail message (including any attachments) may be confidential, proprietary, privileged, or otherwise exempt from disclosure under applicable laws. It is intended to be conveyed only to the designated recipient(s). Any use, dissemination, distribution, printing, retaining or copying of this e-mail (including its attachments) by unintended recipient(s) is strictly prohibited and may be unlawful. If you are not an intended recipient of this e-mail, or believe that you have received this e-mail in error, please notify the sender immediately (by replying to this e-mail), delete any and all copies of this e-mail (including any attachments) from your system, and do not disclose the content of this e-mail to any other person. Thank you! -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060516/f96489b1/attachment-0001.html From samuel dc.fi.udc.es Tue May 16 08:30:01 2006 From: samuel dc.fi.udc.es (Samuel Rivas) Date: Tue May 16 12:26:30 2006 Subject: [Mp4-tech] [MPEG4-Tech] MPEG-4 Bitstream In-Reply-To: <62725.217.218.37.162.1147693158.squirrel@217.218.37.162> References: <62725.217.218.37.162.1147693158.squirrel@217.218.37.162> Message-ID: <20060516063001.GA10990@nodo2.lambdastream.com> m.semsar@ece.ut.ac.ir wrote: > Dear Experts, > Hi, > I want to recognize the header parts in MPEG-4 Bit stream, > Would you let me know about the documents that explain the bit stream > parsing and semantics? MPEG-4 visual streams are described in ISO-14496-2 standard. Please note that this is for MPEG-4 video, AVC is described in ISO-14496-10 or ITU H.264 standard. Regards -- Samuel From bambha vsmedia.com Tue May 16 09:05:15 2006 From: bambha vsmedia.com (Manik Bambha) Date: Wed May 17 13:14:13 2006 Subject: [Mp4-tech] MPEG4 playback in java applet Message-ID: Any ideas of how to decode MPEG4 frames in an applet? Please provide code of reference if possible. Thanks Manik Bambha -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060516/86a6dc39/attachment.html From zhang_lsv yahoo.com Wed May 17 10:28:33 2006 From: zhang_lsv yahoo.com (Xi-ao) Date: Thu May 18 12:52:08 2006 Subject: [Mp4-tech] AVC: restriction of MC in using multiple slices Message-ID: <20060517172833.1774.qmail@web54105.mail.yahoo.com> Hello, experts, Is any restriction of motion compensation when using multiple slices to code a frame? I understand the slice is a self-contained unit that can be decoded independantly. However, is it required that its reference pic. to be in a self-contained slice also? For example, if I-frame is split into 10 slices, and the following P-frame is split into 2 slices, is it allowed that MBs in P-slices use the compensated data from different I-slices freely? Thanks in advance. --------------------------------- Yahoo! Messenger with Voice. Make PC-to-Phone Calls to the US (and 30+ countries) for 2?/min or less. -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060517/6d789259/attachment.html From Wesley.DeNeve UGent.be Wed May 17 21:19:29 2006 From: Wesley.DeNeve UGent.be (Wesley De Neve) Date: Thu May 18 12:52:12 2006 Subject: [Mp4-tech] MPEG4 playback in java applet References: Message-ID: <005501c679e6$d25606d0$0200a8c0@persephone> MPEG4 playback in java appletDear Manik, It depends on how you define MPEG4 (MPEG-4 Systems, MPEG-4 Visual, H.264/MPEG-4 AVC, ...) and on your target application, but you might have a look at the following website. IBM Toolkit for MPEG-4: http://www.research.ibm.com/mpeg4/Projects/player.htm Best regards, Wesley De Neve ----- Original Message ----- From: Manik Bambha To: mp4-tech@lists.mpegif.org Sent: Tuesday, May 16, 2024 6:05 PM Subject: [Mp4-tech] MPEG4 playback in java applet Any ideas of how to decode MPEG4 frames in an applet? Please provide code of reference if possible. Thanks Manik Bambha ------------------------------------------------------------------------------ _______________________________________________ NOTE: Please use clear subject lines for your posts. Include [audio, [video], [systems], [general] or another apppropriate identifier to indicate the type of question you have. Note: Conduct on the mailing list is subject to the Antitrust guidelines found at http://www.mpegif.org/public/documents/vault/mp-out-30042-Antitrust.php -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060517/cd273160/attachment.html From dv2 naver.com Thu May 18 14:01:38 2006 From: dv2 naver.com (Carter) Date: Thu May 18 12:52:16 2006 Subject: [MP4-tech] What is relationship among ME_SearchRange, PSNR and Bitrate? Message-ID: <446BFFB2.000001.23355@nhn529> Could you please help me? Hi. What is relationship among ME_SearchRange, PSNR and Bitrate? If SearchRange is increase from 16x16 to 32x32, What happen to PSNR and Bitrate? I think that PSNR(32x32 SearchRange) is well over PSNR(16x16 SearchRange) and Bitrate(32x32 SearchRange) decrease than (16x16 SearchRange). I guess when SearchRange is 32x32, PSNR value is from 20.312 to 24.582 and Bitrate is from 300Kbps to 150Kbps. cf, This experiment environment have occur at JM 10.2 decoder. Is that Right? ------------------------------------------------------------------------ ??? ?? ??? ??, ??? http://happybean.naver.com From guha_priya yahoo.com Thu May 18 04:49:21 2006 From: guha_priya yahoo.com (guhapriya ganapathy) Date: Thu May 18 12:52:20 2006 Subject: [Mp4-tech] [Audio] Erroneous bit streams... Message-ID: <20060518114921.39373.qmail@web31806.mail.mud.yahoo.com> Dear all, Suppose you have an audio codec which is a part of a broadcast system (any system for that matter). What are the possible errors that might creep in the bitstream when it reaches the decoder? (There will be CRC check for each packet in the network layer, but I am concerned about the bitstream when it reaches the decoder.. what are the chances that the bit stream is corrupted?) Taking AAC HE as an example, Coding Technologies provides erroneous bitstreams for SBR (although SBR has CRC check) as a part of its certification package (wherein for example one bit in every third frame is corrupted ? a random corruption!), whereas ISO does not(?) provide erroneous bitstreams. Of what value are erroneous bitstreams to the decoder? Is there a value add in generating erroneous bitstreams for decoders? If so, what is the approach so that it matches what happens in the real time? Regards, Guha Priya. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060518/79fb7f46/attachment.html From bambha vsmedia.com Thu May 18 07:23:45 2006 From: bambha vsmedia.com (Manik Bambha) Date: Fri May 19 13:03:09 2006 Subject: [Mp4-tech] MPEG4 playback in java applet Message-ID: Thanks Wesley, I saw that before and the player they serve doesn't work with packet by packet processing of MPEG4 data. It actually requires a file from local or remote machine which it can play. I am getting the MPEG4 stream over TCP connection. Any ideas of how to decode MPEG4 frames in an applet without installing any additional decoder. Manik Bambha Sr. Software Engineer VS Media Inc. Phone: (818)-880-9021 x211 Fax: (818)-880-9022 ________________________________ From: Wesley De Neve [mailto:Wesley.DeNeve@UGent.be] Sent: Wednesday, May 17, 2024 12:19 PM To: Manik Bambha; mp4-tech@lists.mpegif.org Subject: Re: [Mp4-tech] MPEG4 playback in java applet Dear Manik, It depends on how you define MPEG4 (MPEG-4 Systems, MPEG-4 Visual, H.264/MPEG-4 AVC, ...) and on your target application, but you might have a look at the following website. IBM Toolkit for MPEG-4: http://www.research.ibm.com/mpeg4/Projects/player.htm Best regards, Wesley De Neve ----- Original Message ----- From: Manik Bambha To: mp4-tech@lists.mpegif.org Sent: Tuesday, May 16, 2024 6:05 PM Subject: [Mp4-tech] MPEG4 playback in java applet Any ideas of how to decode MPEG4 frames in an applet? Please provide code of reference if possible. Thanks Manik Bambha ________________________________ _______________________________________________ NOTE: Please use clear subject lines for your posts. Include [audio, [video], [systems], [general] or another apppropriate identifier to indicate the type of question you have. Note: Conduct on the mailing list is subject to the Antitrust guidelines found at http://www.mpegif.org/public/documents/vault/mp-out-30042-Antitrust.php -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060518/37a6929a/attachment.html From pankaj_bajpai_iet operamail.com Fri May 19 05:52:18 2006 From: pankaj_bajpai_iet operamail.com (pankaj bajpai) Date: Fri May 19 13:03:13 2006 Subject: [Mp4-tech] Re: Mp4-tech Digest, Vol 34, Issue 15 Message-ID: <20060519045218.880CC7ACFE@ws5-10.us4.outblaze.com> Dear Carter, Ideally the increase in search range should give better PSNR and Bitrate. But it all depends on the ME that is implemented. Depending upon the ME, sometimes, increased search range increases the PSNR slightly, but also increase the Bitrate. This may happen if the increase in bit resulted from coding longer motion vector is not taken into account. From: Carter To: mp4-tech@lists.mpegif.org Subject: [MP4-tech] What is relationship among ME_SearchRange, PSNR and Bitrate? Date: Thu, 18 May 2024 14:01:38 +0900 (KST) Could you please help me? Hi. What is relationship among ME_SearchRange, PSNR and Bitrate? If SearchRange is increase from 16x16 to 32x32, What happen to PSNR and Bitrate? I think that PSNR(32x32 SearchRange) is well over PSNR(16x16 SearchRange) and Bitrate(32x32 SearchRange) decrease than (16x16 SearchRange). I guess when SearchRange is 32x32, PSNR value is from 20.312 to 24.582 and Bitrate is from 300Kbps to 150Kbps. cf, This experiment environment have occur at JM 10.2 decoder. Is that Right? Pankaj Kumar Bajpai Mulitimedia Engineer India -- _______________________________________________ Surf the Web in a faster, safer and easier way: Download Opera 8 at http://www.opera.com Powered by Outblaze From ugarg NeoMagic.com Fri May 19 14:55:24 2006 From: ugarg NeoMagic.com (Umang Garg) Date: Fri May 19 13:03:17 2006 Subject: [Mp4-tech] [Audio] Erroneous bit streams... In-Reply-To: <20060518114921.39373.qmail@web31806.mail.mud.yahoo.com> Message-ID: Hello Guha, In broadcast environment you may encounter packet loss and stream corruption as two primary errors. For HEAAC: Stream corruption may be checked via CRC. ADTS format has a CRC check along with a separate CRC check for SBR decoding. Similarly, packet loss may also have to be handled gracefully within the decoder. In case of a loss of frame(s) the simplest technique is insertion of a silence frame (to maintain synchronization) but a more appropriate technique would be gradual muting. As far as I know, the HEAAC standard does not say much about packet loss in general or the muting technique in particular. You may have to make your own decisions on that. Regards, Umang _____ From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of guhapriya ganapathy Sent: Thursday, May 18, 2024 5:19 PM To: mp4-tech@lists.mpegif.org Subject: [Mp4-tech] [Audio] Erroneous bit streams... Dear all, Suppose you have an audio codec which is a part of a broadcast system (any system for that matter). What are the possible errors that might creep in the bitstream when it reaches the decoder? (There will be CRC check for each packet in the network layer, but I am concerned about the bitstream when it reaches the decoder.. what are the chances that the bit stream is corrupted?) Taking AAC HE as an example, Coding Technologies provides erroneous bitstreams for SBR (although SBR has CRC check) as a part of its certification package (wherein for example one bit in every third frame is corrupted - a random corruption!), whereas ISO does not(?) provide erroneous bitstreams. Of what value are erroneous bitstreams to the decoder? Is there a value add in generating erroneous bitstreams for decoders? If so, what is the approach so that it matches what happens in the real time? Regards, Guha Priya. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060519/d61fe72a/attachment.html From woodsp us.ibm.com Fri May 19 09:44:41 2006 From: woodsp us.ibm.com (Steve Wood) Date: Fri May 19 14:02:08 2006 Subject: [Mp4-tech] MPEG4 playback in java applet In-Reply-To: Message-ID: Manik, the player works using any of the built-in protocols that Java supports as well as over rtsp (udp, tcp interleave, and http tunnelled). Perhaps you have a tcp connection that is not running one of the supported protocols such as http: or ftp:. Now if your tcp stream contains just a raw MPEG-4 video bitstream you should be able to use the player as long as you provide Java with a custom protocol handler, Lets say that you make your protocol tcpv: (for tcp video). By adding a custom protocol handler to Java you will be able to pass the a url like tcpv://myremotesystem.com/myvideo.m4v to the player and your custom handler would end up being called and you would open the right tcp connection through that handler and provide back an InputStream when requested through which the player can read the data. Now the player needs to know the format, which is why I ended the url with .m4v so it looks like a file of that type (ie a raw MPEG-4 video bitstream); you could also end the url with something like ?type=.m4v is you prefer. There are some tutorials on the web for custom protocols if you search around, as well a or course articles in books on Java Networking etc. Regards, Steve Wood Composite Media Technologies IBM TJ Watson Research 19 Skyline Drive, Hawthorne, NY 10532. USA "Manik Bambha" Sent by: mp4-tech-bounces@lists.mpegif.org 05/18/2006 10:23 AM To "Wesley De Neve" , cc Subject RE: [Mp4-tech] MPEG4 playback in java applet Thanks Wesley, I saw that before and the player they serve doesn?t work with packet by packet processing of MPEG4 data. It actually requires a file from local or remote machine which it can play. I am getting the MPEG4 stream over TCP connection. Any ideas of how to decode MPEG4 frames in an applet without installing any additional decoder. Manik Bambha Sr. Software Engineer VS Media Inc. Phone: (818)-880-9021 x211 Fax: (818)-880-9022 From: Wesley De Neve [mailto:Wesley.DeNeve@UGent.be] Sent: Wednesday, May 17, 2024 12:19 PM To: Manik Bambha; mp4-tech@lists.mpegif.org Subject: Re: [Mp4-tech] MPEG4 playback in java applet Dear Manik, It depends on how you define MPEG4 (MPEG-4 Systems, MPEG-4 Visual, H.264/MPEG-4 AVC, ...) and on your target application, but you might have a look at the following website. IBM Toolkit for MPEG-4: http://www.research.ibm.com/mpeg4/Projects/player.htm Best regards, Wesley De Neve ----- Original Message ----- From: Manik Bambha To: mp4-tech@lists.mpegif.org Sent: Tuesday, May 16, 2024 6:05 PM Subject: [Mp4-tech] MPEG4 playback in java applet Any ideas of how to decode MPEG4 frames in an applet? Please provide code of reference if possible. Thanks Manik Bambha _______________________________________________ NOTE: Please use clear subject lines for your posts. Include [audio, [video], [systems], [general] or another apppropriate identifier to indicate the type of question you have. Note: Conduct on the mailing list is subject to the Antitrust guidelines found at http://www.mpegif.org/public/documents/vault/mp-out-30042-Antitrust.php _______________________________________________ NOTE: Please use clear subject lines for your posts. Include [audio, [video], [systems], [general] or another apppropriate identifier to indicate the type of question you have. Note: Conduct on the mailing list is subject to the Antitrust guidelines found at http://www.mpegif.org/public/documents/vault/mp-out-30042-Antitrust.php -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060519/c63f4d02/attachment-0001.html From bambha vsmedia.com Fri May 19 07:49:26 2006 From: bambha vsmedia.com (Manik Bambha) Date: Sat May 20 15:14:05 2006 Subject: [Mp4-tech] MPEG4 playback in java applet Message-ID: Thanks, This explains a lot Manik Bambha Sr. Software Engineer VS Media Inc. Phone: (818)-880-9021 x211 Fax: (818)-880-9022 ________________________________ From: Steve Wood [mailto:woodsp@us.ibm.com] Sent: Friday, May 19, 2024 6:45 AM To: Manik Bambha Cc: mp4-tech@lists.mpegif.org Subject: RE: [Mp4-tech] MPEG4 playback in java applet Manik, the player works using any of the built-in protocols that Java supports as well as over rtsp (udp, tcp interleave, and http tunnelled). Perhaps you have a tcp connection that is not running one of the supported protocols such as http: or ftp:. Now if your tcp stream contains just a raw MPEG-4 video bitstream you should be able to use the player as long as you provide Java with a custom protocol handler, Lets say that you make your protocol tcpv: (for tcp video). By adding a custom protocol handler to Java you will be able to pass the a url like tcpv://myremotesystem.com/myvideo.m4v to the player and your custom handler would end up being called and you would open the right tcp connection through that handler and provide back an InputStream when requested through which the player can read the data. Now the player needs to know the format, which is why I ended the url with .m4v so it looks like a file of that type (ie a raw MPEG-4 video bitstream); you could also end the url with something like ?type=.m4v is you prefer. There are some tutorials on the web for custom protocols if you search around, as well a or course articles in books on Java Networking etc. Regards, Steve Wood Composite Media Technologies IBM TJ Watson Research 19 Skyline Drive, Hawthorne, NY 10532. USA "Manik Bambha" Sent by: mp4-tech-bounces@lists.mpegif.org 05/18/2006 10:23 AM To "Wesley De Neve" , cc Subject RE: [Mp4-tech] MPEG4 playback in java applet Thanks Wesley, I saw that before and the player they serve doesn't work with packet by packet processing of MPEG4 data. It actually requires a file from local or remote machine which it can play. I am getting the MPEG4 stream over TCP connection. Any ideas of how to decode MPEG4 frames in an applet without installing any additional decoder. Manik Bambha Sr. Software Engineer VS Media Inc. Phone: (818)-880-9021 x211 Fax: (818)-880-9022 ________________________________ From: Wesley De Neve [mailto:Wesley.DeNeve@UGent.be] Sent: Wednesday, May 17, 2024 12:19 PM To: Manik Bambha; mp4-tech@lists.mpegif.org Subject: Re: [Mp4-tech] MPEG4 playback in java applet Dear Manik, It depends on how you define MPEG4 (MPEG-4 Systems, MPEG-4 Visual, H.264/MPEG-4 AVC, ...) and on your target application, but you might have a look at the following website. IBM Toolkit for MPEG-4: http://www.research.ibm.com/mpeg4/Projects/player.htm Best regards, Wesley De Neve ----- Original Message ----- From: Manik Bambha To: mp4-tech@lists.mpegif.org Sent: Tuesday, May 16, 2024 6:05 PM Subject: [Mp4-tech] MPEG4 playback in java applet Any ideas of how to decode MPEG4 frames in an applet? Please provide code of reference if possible. Thanks Manik Bambha ________________________________ _______________________________________________ NOTE: Please use clear subject lines for your posts. Include [audio, [video], [systems], [general] or another apppropriate identifier to indicate the type of question you have. Note: Conduct on the mailing list is subject to the Antitrust guidelines found at http://www.mpegif.org/public/documents/vault/mp-out-30042-Antitrust.php_ ______________________________________________ NOTE: Please use clear subject lines for your posts. Include [audio, [video], [systems], [general] or another apppropriate identifier to indicate the type of question you have. Note: Conduct on the mailing list is subject to the Antitrust guidelines found at http://www.mpegif.org/public/documents/vault/mp-out-30042-Antitrust.php -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060519/ded1632b/attachment.html From gilberto ensilica.com Fri May 19 16:08:48 2006 From: gilberto ensilica.com (Gilberto Rodriguez) Date: Sat May 20 15:14:13 2006 Subject: [Mp4-tech] [H.264]NAL to mov conversion Message-ID: <000601c67b56$21f81c30$05b0a8c0@MERCURY> Hello, I am looking for a tool/script that will encapsulate the NAL output of the H.264 JM reference model into a standard .mov or .mp4 format so that it can be decoded and played back with QuickTime 7. Does anyone know if such tool or script exists and in that case can they point me to it? Thanks in advance, Gilberto -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060519/749dc898/attachment.html From Wesley.DeNeve UGent.be Sat May 20 19:32:40 2006 From: Wesley.DeNeve UGent.be (Wesley De Neve) Date: Sun May 21 17:02:05 2006 Subject: [Mp4-tech] [H.264]NAL to mov conversion References: <000601c67b56$21f81c30$05b0a8c0@MERCURY> Message-ID: <010901c67c33$65cda4b0$0200a8c0@persephone> Dear Gilberto, MP4Box (http://gpac.sourceforge.net/) and MP4Creator (http://www.mpeg4ip.net/) both have the capability to place an H.264/AVC bitstream, having the Annex B byte stream format, in an MP4 file container. The Annex B byte stream format is the output of the reference software. If desired, QuickTime can subsequently be used to transfer the H.264/AVC track from the MP4 file to a MOV container. Best regards, Wesley De Neve ----- Original Message ----- From: Gilberto Rodriguez To: Mp4-tech@lists.mpegif.org Sent: Friday, May 19, 2024 5:08 PM Subject: [Mp4-tech] [H.264]NAL to mov conversion Hello, I am looking for a tool/script that will encapsulate the NAL output of the H.264 JM reference model into a standard .mov or .mp4 format so that it can be decoded and played back with QuickTime 7. Does anyone know if such tool or script exists and in that case can they point me to it? Thanks in advance, Gilberto ------------------------------------------------------------------------------ _______________________________________________ NOTE: Please use clear subject lines for your posts. Include [audio, [video], [systems], [general] or another apppropriate identifier to indicate the type of question you have. Note: Conduct on the mailing list is subject to the Antitrust guidelines found at http://www.mpegif.org/public/documents/vault/mp-out-30042-Antitrust.php -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060520/03dfdf5c/attachment.html From dsn2603 rediffmail.com Sun May 21 11:11:52 2006 From: dsn2603 rediffmail.com (sakthi narayanan) Date: Sun May 21 17:02:10 2006 Subject: [Mp4-tech] [Audio] Erroneous bit streams... Message-ID: <20060521111021.13034.qmail@webmail67.rediffmail.com> ?Hi, AAC Provides error handling in their codes.AAC bitstreams are arranges in form of syntactic elements.So,the corrupted bitstream will throw u the proper error in real time.For example,try to corrupt the frame length or some other field in the ADTS header.Try to decoded that corrupted bitstream using ur decoder.So,the decoder will give you the apporpriate error. With Regards, Sakthi Narayanan.D On Fri, 19 May 2024 Umang Garg wrote : >Hello Guha, > >In broadcast environment you may encounter packet loss and stream corruption >as two primary errors. > >For HEAAC: > >Stream corruption may be checked via CRC. ADTS format has a CRC check along >with a separate CRC check for SBR decoding. > >Similarly, packet loss may also have to be handled gracefully within the >decoder. In case of a loss of frame(s) the simplest technique is insertion >of a silence frame (to maintain synchronization) but a more appropriate >technique would be gradual muting. As far as I know, the HEAAC standard >does not say much about packet loss in general or the muting technique in >particular. You may have to make your own decisions on that. > >Regards, >Umang > > > > _____ > > From: mp4-tech-bounces@lists.mpegif.org >[mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of guhapriya ganapathy >Sent: Thursday, May 18, 2024 5:19 PM >To: mp4-tech@lists.mpegif.org >Subject: [Mp4-tech] [Audio] Erroneous bit streams... > > >Dear all, > >Suppose you have an audio codec which is a part of a broadcast system (any >system for that matter). What are the possible errors that might creep in >the bitstream when it reaches the decoder? (There will be CRC check for each >packet in the network layer, but I am concerned about the bitstream when it >reaches the decoder.. what are the chances that the bit stream is >corrupted?) >Taking AAC HE as an example, Coding Technologies provides erroneous >bitstreams for SBR (although SBR has CRC check) as a part of its >certification package (wherein for example one bit in every third frame is >corrupted - a random corruption!), whereas ISO does not(?) provide erroneous >bitstreams. Of what value are erroneous bitstreams to the decoder? Is there >a value add in generating erroneous bitstreams for decoders? If so, what is >the approach so that it matches what happens in the real time? > >Regards, >Guha Priya. > >__________________________________________________ >Do You Yahoo!? >Tired of spam? Yahoo! Mail has the best spam protection around >http://mail.yahoo.com > >_______________________________________________ >NOTE: Please use clear subject lines for your posts. Include [audio, [video], [systems], [general] or another apppropriate identifier to indicate the type of question you have. > >Note: Conduct on the mailing list is subject to the Antitrust guidelines found at http://www.mpegif.org/public/documents/vault/mp-out-30042-Antitrust.php -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060521/ed634612/attachment.html From guha_priya yahoo.com Sun May 21 22:45:29 2006 From: guha_priya yahoo.com (guhapriya ganapathy) Date: Mon May 22 12:38:08 2006 Subject: [Mp4-tech] [Audio] Erroneous bit streams... In-Reply-To: Message-ID: <20060522054529.53873.qmail@web31814.mail.mud.yahoo.com> Hi Umang, In case of a packet loss, it is fine. We may have to make our own decisions. Coming to bitstream corruption, what is the probability of the corrupted bitstream reaching the codec? When a corruption is detected at the network layer by the CRC, is it being dropped? If so, what is the need for CRC in the codec? Regards, Guha Priya. Umang Garg wrote: Hello Guha, In broadcast environment you may encounter packet loss and stream corruption as two primary errors. For HEAAC: Stream corruption may be checked via CRC. ADTS format has a CRC check along with a separate CRC check for SBR decoding. Similarly, packet loss may also have to be handled gracefully within the decoder. In case of a loss of frame(s) the simplest technique is insertion of a silence frame (to maintain synchronization) but a more appropriate technique would be gradual muting. As far as I know, the HEAAC standard does not say much about packet loss in general or the muting technique in particular. You may have to make your own decisions on that. Regards, Umang --------------------------------- From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of guhapriya ganapathy Sent: Thursday, May 18, 2024 5:19 PM To: mp4-tech@lists.mpegif.org Subject: [Mp4-tech] [Audio] Erroneous bit streams... Dear all, Suppose you have an audio codec which is a part of a broadcast system (any system for that matter). What are the possible errors that might creep in the bitstream when it reaches the decoder? (There will be CRC check for each packet in the network layer, but I am concerned about the bitstream when it reaches the decoder.. what are the chances that the bit stream is corrupted?) Taking AAC HE as an example, Coding Technologies provides erroneous bitstreams for SBR (although SBR has CRC check) as a part of its certification package (wherein for example one bit in every third frame is corrupted ? a random corruption!), whereas ISO does not(?) provide erroneous bitstreams. Of what value are erroneous bitstreams to the decoder? Is there a value add in generating erroneous bitstreams for decoders? If so, what is the approach so that it matches what happens in the real time? Regards, Guha Priya. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060521/c37a9b20/attachment-0001.html From sh upcsurpass.com Mon May 22 15:53:28 2006 From: sh upcsurpass.com (Song) Date: Mon May 22 12:38:12 2006 Subject: [Mp4-tech] [H.264] What is the difference of complementary field pairs and non-pair field? Message-ID: <006201c67d75$28a363c0$eac0a8c0@hongsong> Dear Expert, Can you explain the difference of complementary field pairs and non-pair field? I cannot understand the definition of the standard, it makes me confused for long time. Thank you and Best Regards. Song -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060522/d956a827/attachment-0001.html From padma_c79 yahoo.com Mon May 22 06:00:38 2006 From: padma_c79 yahoo.com (padma raju) Date: Tue May 23 12:38:07 2006 Subject: [Mp4-tech] NAL Decoding for MCPS mesurement Message-ID: <20060522130039.74943.qmail@web33102.mail.mud.yahoo.com> Hi All, Is NAL Unit decoding part of H264 decoder? Should we consider NAL decoding for MCPS mesurement of H264 decoder? Regards Padma --------------------------------- How low will we go? Check out Yahoo! Messenger?s low PC-to-Phone call rates. -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060522/737c5a3f/attachment.html From ESRIS ntu.edu.sg Mon May 22 22:49:33 2006 From: ESRIS ntu.edu.sg (%Sriskanthan Nadarajah) Date: Tue May 23 12:38:12 2006 Subject: [Mp4-tech] [Audio] Erroneous bit streams... References: <20060522054529.53873.qmail@web31814.mail.mud.yahoo.com> Message-ID: <64B39DEF28C45C40AA854FE1857BF2E3010B1024@MBox1.assoc.main.ntu.edu.sg> Hi Guha Priya. The CRC should be checked and error passed before passing the stream to the Codec. Sris WINUX Interfacing Technology Pte. Ltd. Tele: (65) 6794-3069 H/P 92763116 Com. Reg. No: 200303307W www.winux-it.com ________________________________ From: mp4-tech-bounces@lists.mpegif.org on behalf of guhapriya ganapathy Sent: Mon 5/22/2006 1:45 PM To: mp4-tech@lists.mpegif.org Subject: RE: [Mp4-tech] [Audio] Erroneous bit streams... Hi Umang, In case of a packet loss, it is fine. We may have to make our own decisions. Coming to bitstream corruption, what is the probability of the corrupted bitstream reaching the codec? When a corruption is detected at the network layer by the CRC, is it being dropped? If so, what is the need for CRC in the codec? Regards, Guha Priya. Umang Garg wrote: Hello Guha, In broadcast environment you may encounter packet loss and stream corruption as two primary errors. For HEAAC: Stream corruption may be checked via CRC. ADTS format has a CRC check along with a separate CRC check for SBR decoding. Similarly, packet loss may also have to be handled gracefully within the decoder. In case of a loss of frame(s) the simplest technique is insertion of a silence frame (to maintain synchronization) but a more appropriate technique would be gradual muting. As far as I know, the HEAAC standard does not say much about packet loss in general or the muting technique in particular. You may have to make your own decisions on that. Regards, Umang ________________________________ From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of guhapriya ganapathy Sent: Thursday, May 18, 2024 5:19 PM To: mp4-tech@lists.mpegif.org Subject: [Mp4-tech] [Audio] Erroneous bit streams... Dear all, Suppose you have an audio codec which is a part of a broadcast system (any system for that matter). What are the possible errors that might creep in the bitstream when it reaches the decoder? (There will be CRC check for each packet in the network layer, but I am concerned about the bitstream when it reaches the decoder.. what are the chances that the bit stream is corrupted?) Taking AAC HE as an example, Coding Technologies provides erroneous bitstreams for SBR (although SBR has CRC check) as a part of its certification package (wherein for example one bit in every third frame is corrupted - a random corruption!), whereas ISO does not(?) provide erroneous bitstreams. Of what value are erroneous bitstreams to the decoder? Is there a value add in generating erroneous bitstreams for decoders? If so, what is the approach so that it matches what happens in the real time? Regards, Guha Priya. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060522/7ce39741/attachment.html From dhanashrik acmet.com Tue May 23 15:25:18 2006 From: dhanashrik acmet.com (Dhanashri K) Date: Tue May 23 12:38:16 2006 Subject: [Mp4-tech] RE: regarding h.264 Bitrate In-Reply-To: <005701c67e43$7b932fb0$0301a8c0@corp.intertrust.com> Message-ID: <200605231000.k4NA0iC17710@alice.acmet.com> Hello Everybody, 1) What is the maximum bitrate allowed for a file per frame for H.264 baseline and level 1 encoder.? 2) In H.264 decoder , input data(frames) coming from encoder is first stored in buffer and then it is Displayed. What is time duration for which one frame should be stored in buffer before displaying.? Dhanashri k. _____ -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060523/17fe0457/attachment.html From kaustubh.patankar vsnl.net Tue May 23 18:21:47 2006 From: kaustubh.patankar vsnl.net (kaustubh.patankar@vsnl.net) Date: Wed May 24 12:52:07 2006 Subject: [Mp4-tech] NAL Decoding for MCPS mesurement In-Reply-To: <20060522130039.74943.qmail@web33102.mail.mud.yahoo.com> References: <20060522130039.74943.qmail@web33102.mail.mud.yahoo.com> Message-ID: Hi Padma Yes you should consider this for MCPS measurement regards Kaustubh -------------- next part -------------- Skipped content of type multipart/alternative-------------- next part -------------- _______________________________________________ NOTE: Please use clear subject lines for your posts. Include [audio, [video], [systems], [general] or another apppropriate identifier to indicate the type of question you have. Note: Conduct on the mailing list is subject to the Antitrust guidelines found at http://www.mpegif.org/public/documents/vault/mp-out-30042-Antitrust.php From mykerekes eml.cc Tue May 23 21:34:53 2006 From: mykerekes eml.cc (hungary) Date: Wed May 24 12:52:12 2006 Subject: [Mp4-tech] RE: regarding h.264 Bitrate In-Reply-To: <200605231000.k4NA0iC17710@alice.acmet.com> References: <200605231000.k4NA0iC17710@alice.acmet.com> Message-ID: <1148445293.25824.262183675@webmail.messagingengine.com> Hi Dhanashri, I am not sure of the question you are asking about. The maximum bitrate supported page no. (Table A-1-Level limits) of the H.264 latest standard, All things like bitrate ,max frame size et.c are clearly mentioned. Regards Hungary On Tue, 23 May 2024 15:25:18 +0530, "Dhanashri K" said: > Hello Everybody, > > > > > > 1) What is the maximum bitrate allowed for a file per frame for H.264 > baseline and level 1 encoder.? > > > > 2) In H.264 decoder , input data(frames) coming from encoder is first > stored in buffer and then it is > > Displayed. What is time duration for which one frame should be > stored > in buffer before displaying.? > > > > > > Dhanashri k. > > > > _____ > > > > > > > -- hungary mykerekes@eml.cc -- http://www.fastmail.fm - Same, same, but different From ugarg NeoMagic.com Wed May 24 12:42:45 2006 From: ugarg NeoMagic.com (Umang Garg) Date: Wed May 24 12:52:16 2006 Subject: [Mp4-tech] [Audio] Erroneous bit streams... In-Reply-To: <64B39DEF28C45C40AA854FE1857BF2E3010B1024@MBox1.assoc.main.ntu.edu.sg> Message-ID: Guha, Sris While HEAAC for broadcast environments mandates the CRC check in ADTS format, it usage appears to be quite redundant with little practical advantage. It existence may have more to do with legacy reasons. The redundancy arises from the fact that the CRC validation of the bitstream cannot happen untill the stream has been parsed upto a specified number of bits. If the bitstream is corrupted in the 'right' places then it is possible that the parsing process can go haywire. This implies that you may not interpret the bits correctly and the parsing may take a completely different control flow path. It is a chicken-and-egg situation. Your best bet lies in the ability to handle serious corruption issues at network level. Minor bitstream distortions can then be handled inside the decoder by having a robust error handling mechanism along with CRC check. Regards, Umang _____ From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of %Sriskanthan Nadarajah Sent: Monday, May 22, 2024 8:20 PM To: guhapriya ganapathy; mp4-tech@lists.mpegif.org Subject: RE: [Mp4-tech] [Audio] Erroneous bit streams... Hi Guha Priya. The CRC should be checked and error passed before passing the stream to the Codec. Sris WINUX Interfacing Technology Pte. Ltd. Tele: (65) 6794-3069 H/P 92763116 Com. Reg. No: 200303307W www.winux-it.com _____ From: mp4-tech-bounces@lists.mpegif.org on behalf of guhapriya ganapathy Sent: Mon 5/22/2006 1:45 PM To: mp4-tech@lists.mpegif.org Subject: RE: [Mp4-tech] [Audio] Erroneous bit streams... Hi Umang, In case of a packet loss, it is fine. We may have to make our own decisions. Coming to bitstream corruption, what is the probability of the corrupted bitstream reaching the codec? When a corruption is detected at the network layer by the CRC, is it being dropped? If so, what is the need for CRC in the codec? Regards, Guha Priya. Umang Garg wrote: Hello Guha, In broadcast environment you may encounter packet loss and stream corruption as two primary errors. For HEAAC: Stream corruption may be checked via CRC. ADTS format has a CRC check along with a separate CRC check for SBR decoding. Similarly, packet loss may also have to be handled gracefully within the decoder. In case of a loss of frame(s) the simplest technique is insertion of a silence frame (to maintain synchronization) but a more appropriate technique would be gradual muting. As far as I know, the HEAAC standard does not say much about packet loss in general or the muting technique in particular. You may have to make your own decisions on that. Regards, Umang _____ From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of guhapriya ganapathy Sent: Thursday, May 18, 2024 5:19 PM To: mp4-tech@lists.mpegif.org Subject: [Mp4-tech] [Audio] Erroneous bit streams... Dear all, Suppose you have an audio codec which is a part of a broadcast system (any system for that matter). What are the possible errors that might creep in the bitstream when it reaches the decoder? (There will be CRC check for each packet in the network layer, but I am concerned about the bitstream when it reaches the decoder.. what are the chances that the bit stream is corrupted?) Taking AAC HE as an example, Coding Technologies provides erroneous bitstreams for SBR (although SBR has CRC check) as a part of its certification package (wherein for example one bit in every third frame is corrupted - a random corruption!), whereas ISO does not(?) provide erroneous bitstreams. Of what value are erroneous bitstreams to the decoder? Is there a value add in generating erroneous bitstreams for decoders? If so, what is the approach so that it matches what happens in the real time? Regards, Guha Priya. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060524/56644639/attachment-0001.html From robin94539 yahoo.com Wed May 24 02:15:51 2006 From: robin94539 yahoo.com (Robin Zoo) Date: Wed May 24 12:52:21 2006 Subject: [Mp4-tech] output of deblocking filter In-Reply-To: <200605231607.k4NG7jQt010860@lists1.magma.ca> Message-ID: <20060524091551.28203.qmail@web52404.mail.yahoo.com> Dear experts: I noticed the following descriptions in MPEG2 standard: "The output of the decoding process, for interlaced sequences, consists of a series of reconstructed fields that are separated in time by a field period" "In progressive sequences each picture in the sequence shall be a frame picture. The sequence, at the output of the decoding process, consists of a series of reconstructed frames that are separated in time by a frame period" I think the statements are true in H.264 decoding process though I didn't found similar description. Here is my question, for H.264 interlaced sequences, if PAFF and MBAFF are in use, the output of deblocking filter are mixed frame and field pictures which even include frames containing mixed field or frame macroblock pairs. Interlacing of frame or macroblock pairs has to be done before sending the decoded pixel for display. Is it true? thanks a lot! Robinstain __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com From guha_priya yahoo.com Wed May 24 04:28:19 2006 From: guha_priya yahoo.com (guhapriya ganapathy) Date: Wed May 24 12:52:25 2006 Subject: [Mp4-tech] [Audio] Erroneous bit streams... In-Reply-To: Message-ID: <20060524112819.20272.qmail@web31801.mail.mud.yahoo.com> Hi Umang, That being the case, why aren't there any erroneous bitstreams available in the market to validate the robustness of the decoder? Only CT provides a set of erroneous bitstreams for SBR part of HEAAC as a part of its certification package. As such, ISO has no erroneous bitstreams for AAC. Regards, Guha Priya. Umang Garg wrote: Guha, Sris While HEAAC for broadcast environments mandates the CRC check in ADTS format, it usage appears to be quite redundant with little practical advantage. It existence may have more to do with legacy reasons. The redundancy arises from the fact that the CRC validation of the bitstream cannot happen untill the stream has been parsed upto a specified number of bits. If the bitstream is corrupted in the 'right' places then it is possible that the parsing process can go haywire. This implies that you may not interpret the bits correctly and the parsing may take a completely different control flow path. It is a chicken-and-egg situation. Your best bet lies in the ability to handle serious corruption issues at network level. Minor bitstream distortions can then be handled inside the decoder by having a robust error handling mechanism along with CRC check. Regards, Umang --------------------------------- From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of %Sriskanthan Nadarajah Sent: Monday, May 22, 2024 8:20 PM To: guhapriya ganapathy; mp4-tech@lists.mpegif.org Subject: RE: [Mp4-tech] [Audio] Erroneous bit streams... Hi Guha Priya. The CRC should be checked and error passed before passing the stream to the Codec. Sris WINUX Interfacing Technology Pte. Ltd. Tele: (65) 6794-3069 H/P 92763116 Com. Reg. No: 200303307W www.winux-it.com --------------------------------- From: mp4-tech-bounces@lists.mpegif.org on behalf of guhapriya ganapathy Sent: Mon 5/22/2006 1:45 PM To: mp4-tech@lists.mpegif.org Subject: RE: [Mp4-tech] [Audio] Erroneous bit streams... Hi Umang, In case of a packet loss, it is fine. We may have to make our own decisions. Coming to bitstream corruption, what is the probability of the corrupted bitstream reaching the codec? When a corruption is detected at the network layer by the CRC, is it being dropped? If so, what is the need for CRC in the codec? Regards, Guha Priya. Umang Garg wrote: Hello Guha, In broadcast environment you may encounter packet loss and stream corruption as two primary errors. For HEAAC: Stream corruption may be checked via CRC. ADTS format has a CRC check along with a separate CRC check for SBR decoding. Similarly, packet loss may also have to be handled gracefully within the decoder. In case of a loss of frame(s) the simplest technique is insertion of a silence frame (to maintain synchronization) but a more appropriate technique would be gradual muting. As far as I know, the HEAAC standard does not say much about packet loss in general or the muting technique in particular. You may have to make your own decisions on that. Regards, Umang --------------------------------- From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of guhapriya ganapathy Sent: Thursday, May 18, 2024 5:19 PM To: mp4-tech@lists.mpegif.org Subject: [Mp4-tech] [Audio] Erroneous bit streams... Dear all, Suppose you have an audio codec which is a part of a broadcast system (any system for that matter). What are the possible errors that might creep in the bitstream when it reaches the decoder? (There will be CRC check for each packet in the network layer, but I am concerned about the bitstream when it reaches the decoder.. what are the chances that the bit stream is corrupted?) Taking AAC HE as an example, Coding Technologies provides erroneous bitstreams for SBR (although SBR has CRC check) as a part of its certification package (wherein for example one bit in every third frame is corrupted ? a random corruption!), whereas ISO does not(?) provide erroneous bitstreams. Of what value are erroneous bitstreams to the decoder? Is there a value add in generating erroneous bitstreams for decoders? If so, what is the approach so that it matches what happens in the real time? Regards, Guha Priya. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060524/68567304/attachment-0001.html From garysull windows.microsoft.com Wed May 24 11:11:31 2006 From: garysull windows.microsoft.com (Gary Sullivan) Date: Thu May 25 15:32:05 2006 Subject: [Mp4-tech] output of deblocking filter In-Reply-To: <20060524091551.28203.qmail@web52404.mail.yahoo.com> Message-ID: <03CB47D9C3F8074498E4653F814D6E8FC5B2FE@WIN-MSG-20.wingroup.windeploy.ntdev.microsoft.com> I believe the answer to this question is not quite so simple. See remarks below. Best Regards, Gary Sullivan +> -----Original Message----- +> From: mp4-tech-bounces@lists.mpegif.org +> [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of Robin Zoo +> Sent: Wednesday, May 24, 2024 2:16 AM +> To: mp4-tech@lists.mpegif.org +> Subject: [Mp4-tech] output of deblocking filter +> +> Dear experts: +> +> I noticed the following descriptions in MPEG2 +> standard: +> +> "The output of the decoding process, for interlaced +> sequences, consists of a series of reconstructed +> fields that are separated in time by a field period" +> +> "In progressive sequences each picture in the sequence +> shall be a frame picture. The sequence, at the output +> of the decoding process, consists of a series of +> reconstructed frames that are separated in time by a +> frame period" I believe neither of those statements are actually necessarily true in the MPEG2 low delay mode of operation. They may be true outside of low-delay operation. +> +> I think the statements are true in H.264 decoding +> process though I didn't found similar description. This is not the case. My advice is to not try to take statements out of one standard and apply them to another. Even if you could find some case where an out-of-context quote may apply, the underlying definitions of terms may differ. In the case of H.264/MPEG-4 AVC, the output of the decoding process is a series of pictures. Pictures can be frames or fields. There is no definition of an "interlaced sequence" or a "progressive sequence" in H.264/AVC. When fixed_frame_rate_flag is equal to 1, there are some strict constraints on the relative timing of the output of pictures in H.264/AVC. When it is not, there aren't. Also, I believe there is more of a notion of multiple sequences within a single bitstream in the case of AVC than there is in MPEG-2. +> +> Here is my question, for H.264 interlaced sequences, +> if PAFF and MBAFF are in use, the output of deblocking +> filter are mixed frame and field pictures which even +> include frames containing mixed field or frame +> macroblock pairs. Interlacing of frame or macroblock +> pairs has to be done before sending the decoded pixel +> for display. Is it true? It is difficult to understand this question. Anyhow, display is outside of the scope of the standard. +> +> thanks a lot! +> +> Robinstain +> +> __________________________________________________ +> Do You Yahoo!? +> Tired of spam? Yahoo! Mail has the best spam protection around +> http://mail.yahoo.com +> _______________________________________________ +> NOTE: Please use clear subject lines for your posts. Include +> [audio, [video], [systems], [general] or another +> apppropriate identifier to indicate the type of question you have. +> +> Note: Conduct on the mailing list is subject to the +> Antitrust guidelines found at +> http://www.mpegif.org/public/documents/vault/mp-out-30042-Ant +> itrust.php +> From robin94539 yahoo.com Wed May 24 20:42:32 2006 From: robin94539 yahoo.com (Robin Zoo) Date: Thu May 25 15:32:11 2006 Subject: [Mp4-tech] output of deblocking filter In-Reply-To: <03CB47D9C3F8074498E4653F814D6E8FC5B2FE@WIN-MSG-20.wingroup.windeploy.ntdev.microsoft.com> Message-ID: <20060525034232.32872.qmail@web52409.mail.yahoo.com> Dear Gary, Thank you for your reply! Maybe I didn't make myself understood. I'd like to ask my question in a simple way. First, a H.264 standard compliance encoder is used to encode an interlaced video clip and make sure that PAFF and MBAFF are in use. Then a compliance decoder is used to decode the bit-stream. Is the output of the decoder a field picture sequence or a mixed field and frame picture sequence? Is the deblocking filtering the last decoding step in H.264? thanks a lot! Robin --- Gary Sullivan wrote: > > I believe the answer to this question is not quite > so simple. See > remarks below. > > Best Regards, > > Gary Sullivan > > +> -----Original Message----- > +> From: mp4-tech-bounces@lists.mpegif.org > +> [mailto:mp4-tech-bounces@lists.mpegif.org] On > Behalf Of Robin Zoo > +> Sent: Wednesday, May 24, 2024 2:16 AM > +> To: mp4-tech@lists.mpegif.org > +> Subject: [Mp4-tech] output of deblocking filter > +> > +> Dear experts: > +> > +> I noticed the following descriptions in MPEG2 > +> standard: > +> > +> "The output of the decoding process, for > interlaced > +> sequences, consists of a series of reconstructed > +> fields that are separated in time by a field > period" > +> > +> "In progressive sequences each picture in the > sequence > +> shall be a frame picture. The sequence, at the > output > +> of the decoding process, consists of a series of > +> reconstructed frames that are separated in time > by a > +> frame period" > > I believe neither of those statements are actually > necessarily true in > the MPEG2 low delay mode of operation. They may be > true outside of > low-delay operation. > > > +> > +> I think the statements are true in H.264 decoding > +> process though I didn't found similar > description. > > This is not the case. My advice is to not try to > take statements out of > one standard and apply them to another. Even if you > could find some > case where an out-of-context quote may apply, the > underlying definitions > of terms may differ. > > In the case of H.264/MPEG-4 AVC, the output of the > decoding process is a > series of pictures. > Pictures can be frames or fields. > > There is no definition of an "interlaced sequence" > or a "progressive > sequence" in H.264/AVC. > > When fixed_frame_rate_flag is equal to 1, there are > some strict > constraints on the relative timing of the output of > pictures in > H.264/AVC. When it is not, there aren't. > > Also, I believe there is more of a notion of > multiple sequences within a > single bitstream in the case of AVC than there is in > MPEG-2. > > > +> > +> Here is my question, for H.264 interlaced > sequences, > +> if PAFF and MBAFF are in use, the output of > deblocking > +> filter are mixed frame and field pictures which > even > +> include frames containing mixed field or frame > +> macroblock pairs. Interlacing of frame or > macroblock > +> pairs has to be done before sending the decoded > pixel > +> for display. Is it true? > > It is difficult to understand this question. > Anyhow, display is outside of the scope of the > standard. > > > +> > +> thanks a lot! > +> > +> Robinstain > +> > +> > __________________________________________________ > +> Do You Yahoo!? > +> Tired of spam? Yahoo! Mail has the best spam > protection around > +> http://mail.yahoo.com > +> _______________________________________________ > +> NOTE: Please use clear subject lines for your > posts. Include > +> [audio, [video], [systems], [general] or another > +> apppropriate identifier to indicate the type of > question you have. > +> > +> Note: Conduct on the mailing list is subject to > the > +> Antitrust guidelines found at > +> > http://www.mpegif.org/public/documents/vault/mp-out-30042-Ant > +> itrust.php > +> > __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com From nitinmpai gmail.com Thu May 25 10:13:23 2006 From: nitinmpai gmail.com (Nitin PAI) Date: Thu May 25 15:32:15 2006 Subject: [Mp4-tech] Question regarding slice groups Message-ID: Hi, I want to know the significance of introducing slice groups. I understand that the slices are needed for error resilience. Does slice groups serve only the need of grouping the slices in raster order or ease of specifiying the slice group map? Or is there any other things like a slice group is an independent decodable entity ( i mean the motion vectors should be constrained to lie inside the slice group only?) Thanks, Nitin -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060525/84f77038/attachment.html From garysull windows.microsoft.com Thu May 25 11:26:35 2006 From: garysull windows.microsoft.com (Gary Sullivan) Date: Fri May 26 18:44:10 2006 Subject: [Mp4-tech] Question regarding slice groups In-Reply-To: Message-ID: <03CB47D9C3F8074498E4653F814D6E8FCE14BB@WIN-MSG-20.wingroup.windeploy.ntdev.microsoft.com> The (only) purpose of slice groups is to specify the slice group map, which determines which macroblocks are included in the scan of macroblocks for each slice. A slice starts with a macroblock that is identified by the syntax element first_mb_in_slice, and then includes some number of subsequent macroblocks in raster scan order within the same slice group as the first macroblock of the slice. The slices of the current picture can be decoded independently of each other. However, this says nothing about which reference pictures or which parts of the reference pictures are used in the decoding of those slices. The slice group concept enables a number of functionalities. One of them is error resilience. Another is enhanced-efficiency for region-of-interest coding. Another is enabling encoders to create what you're calling an "independent decodable entity" -- however, the independence would need to be established separately -- for example, by use of the "motion-constrained slice group set SEI message" (see subclauses D.1.19 and D.2.19). Best Regards, Gary Sullivan ________________________________ From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of Nitin PAI Sent: Wednesday, May 24, 2024 9:43 PM To: mp4-tech@lists.mpegif.org Subject: [Mp4-tech] Question regarding slice groups Hi, I want to know the significance of introducing slice groups. I understand that the slices are needed for error resilience. Does slice groups serve only the need of grouping the slices in raster order or ease of specifiying the slice group map? Or is there any other things like a slice group is an independent decodable entity ( i mean the motion vectors should be constrained to lie inside the slice group only?) Thanks, Nitin -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060525/8989199d/attachment-0001.html From Ye-Kui.Wang nokia.com Thu May 25 22:59:01 2006 From: Ye-Kui.Wang nokia.com (Ye-Kui.Wang@nokia.com) Date: Fri May 26 18:44:19 2006 Subject: [Mp4-tech] Question regarding slice groups In-Reply-To: Message-ID: <1C1F3D15859526459B4DD0A7A9B2268B022061EA@trebe101.NOE.Nokia.com> Slice groups can be used to improve error resilience as well as to realize other functionalities, including region-of-interest spatial scalable coding, random access from inter pictures, and so on. BR, YK ________________________________ From: mp4-tech-bounces@lists.mpegif.org [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of ext Nitin PAI Sent: Thursday, May 25, 2024 7:43 AM To: mp4-tech@lists.mpegif.org Subject: [Mp4-tech] Question regarding slice groups Hi, I want to know the significance of introducing slice groups. I understand that the slices are needed for error resilience. Does slice groups serve only the need of grouping the slices in raster order or ease of specifiying the slice group map? Or is there any other things like a slice group is an independent decodable entity ( i mean the motion vectors should be constrained to lie inside the slice group only?) Thanks, Nitin -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060525/485a2171/attachment-0001.html From Wesley.DeNeve UGent.be Thu May 25 22:59:51 2006 From: Wesley.DeNeve UGent.be (Wesley De Neve) Date: Fri May 26 18:44:23 2006 Subject: [Mp4-tech] Question regarding slice groups References: Message-ID: <14d301c6803e$50010690$0200a8c0@persephone> Dear Nitin, The main incentive behind the introduction of slice groups is to enable a coding tool called Flexible Macroblock Ordering (FMO). There are already quite some publications available that deal with this subject. The following manuscript might be of particular interest to you: Peter Lambert et al., Flexible macroblock ordering in H.264/AVC. Journal of Visual Communication & Image Representation. Elsevier. Vol. 17. 2006. pp. 358 - 375 Regarding your last question: motion vectors can point to macroblocks that belong to other slice groups. However, an encoder may use the motion-constrained slice group set SEI (Supplemental Enhancement Information) message to signal to the decoder that it has restricted motion vectors in this way. This might be useful for content adaptation purposes (ROI extraction), etc. Best regards, -Wesley ----- Original Message ----- From: Nitin PAI To: mp4-tech@lists.mpegif.org Sent: Thursday, May 25, 2024 6:43 AM Subject: [Mp4-tech] Question regarding slice groups Hi, I want to know the significance of introducing slice groups. I understand that the slices are needed for error resilience. Does slice groups serve only the need of grouping the slices in raster order or ease of specifiying the slice group map? Or is there any other things like a slice group is an independent decodable entity ( i mean the motion vectors should be constrained to lie inside the slice group only?) Thanks, Nitin ------------------------------------------------------------------------------ _______________________________________________ NOTE: Please use clear subject lines for your posts. Include [audio, [video], [systems], [general] or another apppropriate identifier to indicate the type of question you have. Note: Conduct on the mailing list is subject to the Antitrust guidelines found at http://www.mpegif.org/public/documents/vault/mp-out-30042-Antitrust.php -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060525/5af055ea/attachment-0001.html From xie_yg2000 yahoo.com.cn Thu May 25 17:32:21 2006 From: xie_yg2000 yahoo.com.cn (yaguang xie) Date: Fri May 26 18:44:27 2006 Subject: [Mp4-tech] [H.264] What is the difference of complementary field pairs and non-pair field? In-Reply-To: <006201c67d75$28a363c0$eac0a8c0@hongsong> Message-ID: <20060526003221.57895.qmail@web15707.mail.cnb.yahoo.com> hi Song, As my comprehension, there are two kinds of complementary field pairs, complementary reference field pairs(both of the two fields are reference picture) and complementary non-ref field pairs(both of the fields are non-reference picture). If the two fields of a frame is different for reference property,for example, one is reference picture and the other is non-reference picture,either of the field is non-paird field. the reference one is called non-paired reference field, and the non-reference one is called non-paired non-reference field. B.R. Song wrote: Dear Expert, Can you explain the difference of complementary field pairs and non-pair field? I cannot understand the definition of the standard, it makes me confused for long time. Thank you and Best Regards. Song _______________________________________________ NOTE: Please use clear subject lines for your posts. Include [audio, [video], [systems], [general] or another apppropriate identifier to indicate the type of question you have. Note: Conduct on the mailing list is subject to the Antitrust guidelines found at http://www.mpegif.org/public/documents/vault/mp-out-30042-Antitrust.php --------------------------------- Sneak preview the all-new Yahoo.com. It's not radically different. Just radically better. -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060525/1b789a64/attachment-0001.html From garima.singh tivr.co.in Fri May 26 04:46:36 2006 From: garima.singh tivr.co.in (Garima Singh) Date: Fri May 26 18:44:33 2006 Subject: [Mp4-tech] Audio/Video Sync in MPEG-4 Systems In-Reply-To: <20060407030316.12873.qmail@web8413.mail.in.yahoo.com> Message-ID: <20060526114636.54240.qmail@web201.biz.mail.re2.yahoo.com> Hi All, I am trying to sync audio and video data available in MPEG-4 SL. I have composition time stamps values of both audio and video elementary streams and OCR values with me but I am seeing that OCR values are greater than individual time stamps. Why is it so? Shouldn't I just subtract OCR value from the individual times stamp values to get the synchronization. Please explain me the method if i am wrong. Regards, Garima Regards, Garima Singh TIVR Communications - Delivering Efficient Solutions for Mobile Multimedia www.tivr.co.in -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060526/8d18e5ff/attachment-0001.html From eechyang gmail.com Sat May 27 17:43:56 2006 From: eechyang gmail.com (Cheng Yang) Date: Sun May 28 10:14:10 2006 Subject: [Mp4-tech] Where can I get common test error patterns descripted in VCEG-M77? Message-ID: <2e282fb70605270243r44ad51f5uf12eebf3ae0e7b39@mail.gmail.com> Dear experts: I need error patterns of common test conditions descripted in VCEG-M77 to do some experiments. While I got some package error patterns of 3GPP2, I need some more accurate bit error patterns. Can anyone tell me how to get them? Can I download them from ftp3.itu.ch? It seems that the ftp site need an account to log in. Thanks for replying in advance! -- Best regards! Cheng Yang E.E. Department Fudan University Shanghai, China -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060527/316d4688/attachment.html From dv2 naver.com Mon May 29 21:43:48 2006 From: dv2 naver.com (Carter) Date: Tue May 30 15:20:11 2006 Subject: [Mp4-tech] Why I or B frame can have one fixed QP? Message-ID: <447AEC84.000001.06510@naver891> Hello? I have working on JM10.2 decoder S/W Reference. BTW, What is mean? "remaining_mode_selector" of the function readIntraPredMode_CABAC() In cabac.c Please help me.. Best Regrad -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060529/5a7b1971/attachment.html From sejudge gmail.com Mon May 29 19:34:52 2006 From: sejudge gmail.com (Steve Judge) Date: Tue May 30 15:20:18 2006 Subject: [Mp4-tech] Non-Tech post: SW Eng Job opportunity at Richard Texas start-up Message-ID: <652bafb60605291734u6f314c35r41f8812596699984@mail.gmail.com> Ambrado has a job opening for a SW engineer in this field. If there is a more appropriate list for posting jobs in this field, please advise. *Lead Software Engineer *Richardson Texas based start-up has an immediate need for a DSP SW engineer. This position is responsible for group leadership and software engineering of signal, video, image and audio processing algorithms. Duties include design, implementation, and performance optimization of software modules on embedded DSPs; programming embedded DSP and/or parallel media processor architectures in C/C++ and low-level assembly; implementation of signal processing algorithms, such as FFT, DCT, and convolution in a real-world product offering; comprehension of published digital processing standards, such as MPEG-2, or H.264. Experience with real-time OS is a bonus. A working knowledge of video and image processing algorithms such as JPEG/MPEG is also a bonus. Requirements: BS/MS (MS preferred) with 5 years relevant experience. Video and signal processing algorithm researchers with limited software experience will also be considered. Some international travel will be required. Competitive stock options, salary, and benefits. Please forward resume and salary requirement to the Director of Engineering: Steve Judge Director of Engineering steve.judge@ambrado.com > > -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060529/305c003e/attachment.html From mayank_2001 hotmail.com Tue May 30 17:37:26 2006 From: mayank_2001 hotmail.com (Mayank Agarwal) Date: Tue May 30 15:20:22 2006 Subject: [Mp4-tech] H.264 Decoder Implementation Message-ID: Hi all, I want to implement the H.264 decoder in C language according to ITU-T H.264 standard. >From where i will get the encoded h.264 streams which can be used as an input to the decoder. Further are there any links which can really help in implementing the decoder in C language. Thanks and Regards, Mayank _________________________________________________________________ NRIs: Still paying for money transfers? Now send Money2India for FREE! http://ads.mediaturf.net/event.ng/Type=click&FlightID=20273&AdID=65990&TargetID=11172&Targets=11172&Values=202,414,1093,1264,3122&Redirect=http:%2F%2Fwww.icicinri.net%2Fmoney2india%2F%3Fm2i%3DBAC-MSN%26att%3DMSNTLM2I70CHAR%26rfr%3DMSNTLM2I70CHAR From senthilr_pava rediffmail.com Tue May 30 15:45:58 2006 From: senthilr_pava rediffmail.com (senthil k) Date: Wed May 31 12:52:08 2006 Subject: [Mp4-tech] (no subject) Message-ID: <20060530154422.25846.qmail@webmail46.rediffmail.com> ? hi! I am trying to find mpeg2.5 specification to purchase, but i am not able to find right website for that, can any body tell where can i get it? It will be helpful to me. Thanks Senthil. -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060530/92a306e2/attachment.html From Srivaishnav_Rajagopal sdesigns.com Tue May 30 10:27:54 2006 From: Srivaishnav_Rajagopal sdesigns.com (Srivaishnav Rajagopal) Date: Wed May 31 12:52:14 2006 Subject: [Mp4-tech] DMB related question Message-ID: <5DF100B598199744B111FCEA5222E78A5D718B@sigma-exch1.sdesigns.com> Hi, Could someone pls help me with SL header parsing. If I parse with the SL descriptor information I end up in the middle of a byte of much before the start of the PES payload. It would be great if you could provide me with some information/pointers on how to parse it. Thanks Sri -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060530/9a0c2b73/attachment.html From guha_priya yahoo.com Tue May 30 20:26:34 2006 From: guha_priya yahoo.com (guhapriya ganapathy) Date: Wed May 31 12:52:19 2006 Subject: [Mp4-tech] H.264 Decoder Implementation In-Reply-To: Message-ID: <20060531032634.58890.qmail@web31806.mail.mud.yahoo.com> Hi Mayank, You can get the encoded bitstreams at http://ftp3.itu.ch/av-arch/jvt-site/draft_conformance/ Regards, Guha Priya. Mayank Agarwal wrote: Hi all, I want to implement the H.264 decoder in C language according to ITU-T H.264 standard. >From where i will get the encoded h.264 streams which can be used as an input to the decoder. Further are there any links which can really help in implementing the decoder in C language. Thanks and Regards, Mayank __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060530/ada993c5/attachment.html From samuel dc.fi.udc.es Wed May 31 09:18:40 2006 From: samuel dc.fi.udc.es (Samuel Rivas) Date: Wed May 31 12:52:23 2006 Subject: [Mp4-tech] H.264 Decoder Implementation In-Reply-To: References: Message-ID: <20060531071840.GC17691@nodo2.lambdastream.com> Mayank Agarwal wrote: > Hi all, > I want to implement the H.264 decoder in C language according to ITU-T > H.264 standard. > From where i will get the encoded h.264 streams which can be used as an > input to the decoder. > Further are there any links which can really help in implementing the > decoder in C language. > Thanks and Regards, > Mayank You can use the reference implementation both to leaf through the code and to encode your own test streams http://standards.iso.org/ittf/PubliclyAvailableStandards/c039593_ISO_IEC_14496-5_2001_Amd_6_2005(E)_Reference_Software.zip Regards -- Samuel From mykerekes eml.cc Wed May 31 07:09:19 2006 From: mykerekes eml.cc (hungary) Date: Wed May 31 15:08:09 2006 Subject: [Mp4-tech] B picture with all Intra MB's ? In-Reply-To: <20060530154422.25846.qmail@webmail46.rediffmail.com> References: <20060530154422.25846.qmail@webmail46.rediffmail.com> Message-ID: <1149084559.2470.262718880@webmail.messagingengine.com> Dear experts, Is it permitted to code all MBs as intra and still have the picture type as for B picture ? Though the picture type is B but still as per i see the standard doesnot tell anything regarding this. According to the standard it should decode. Plz clarify if i am wrong ! Regards Hungary -- hungary mykerekes@eml.cc -- http://www.fastmail.fm - Same, same, but different From Martin.Lange sci-worx.com Wed May 31 16:13:59 2006 From: Martin.Lange sci-worx.com (Martin.Lange@sci-worx.com) Date: Wed May 31 15:08:13 2006 Subject: [Mp4-tech] [H.264] purpose of non-existing pictures Message-ID: <7E6219E8CD869D4186B919B0DCF127C0013A861F@hajse201.eu.infineon.com> Hello everyone, a thing which I was always wondering is the purpose of non-existing pictures. What is a scenario in which an encoder would decide to intentionally introduce gaps in frame_num, thus producing non-existing pictures? The only effect I see is that they make other pictures fall out of the decoded picture buffer and that they also get incorporated into reference lists, thus changing the reference indices other pictures would have without their presence. Can this lead to any gain in coding efficiency? Can anybody comment on what was the intention of this tool? If this is a question which has already been posted in the past, I would be happy if anyone could point me to some kind of FAQ of this forum, if it exists (does it?). Best regards, Martin Lange From senthilr_pava rediffmail.com Wed May 31 18:22:32 2006 From: senthilr_pava rediffmail.com (senthil k) Date: Wed May 31 18:38:06 2006 Subject: [Mp4-tech] mpeg2.5 specification Message-ID: <20060531182055.21770.qmail@webmail27.rediffmail.com> ? Hi mayank! Thanks for your kind response. in ISO website it is not there, Moreover MPEG2.5 Layer 3 is not a mpeg standard, It is proprietary extension developed by Fraunhofer, you can refer this link for more information. http://www.iis.fraunhofer.de/amm/projects/mp3/index.html I would like to know from where i can get the format specification. Thanks senthil. On Wed, 31 May 2024 Mayank Agarwal wrote : > >I think you can log on to www.iso.org > >Regards, >Mayank > >> From: "senthil k" >>Reply-To: senthil k >>To: "MPEG4" >>Subject: [Mp4-tech] (no subject) >>Date: 30 May 2024 15:44:22 -0000 >> >> ?hi! >> >> I am trying to find mpeg2.5 specification to purchase, >>but i am not able to find right website for that, can any body tell >>where can i get it? It will be helpful to me. >> >>Thanks >>Senthil. > > >>_______________________________________________ >>NOTE: Please use clear subject lines for your posts. Include [audio, [video], [systems], [general] or another apppropriate identifier to indicate the type of question you have. >> >>Note: Conduct on the mailing list is subject to the Antitrust guidelines found at http://www.mpegif.org/public/documents/vault/mp-out-30042-Antitrust.php > >_________________________________________________________________ >Fall in Love... Get married! Join FREE! http://www.shaadi.com/ptnr.php?ptnr=msnhottag > -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060531/942a628e/attachment.html From garysull windows.microsoft.com Wed May 31 13:14:39 2006 From: garysull windows.microsoft.com (Gary Sullivan) Date: Thu Jun 1 09:51:09 2006 Subject: [Mp4-tech] [H.264] purpose of non-existing pictures In-Reply-To: <7E6219E8CD869D4186B919B0DCF127C0013A861F@hajse201.eu.infineon.com> Message-ID: <03CB47D9C3F8074498E4653F814D6E8FD958B7@WIN-MSG-20.wingroup.windeploy.ntdev.microsoft.com> Martin et al, One type of use of this feature is to enable a form of temporal bitstream scalability in which some reference pictures can be removed from the bitstream without harming the ability to decode the remaining pictures. For example, I suggest reading the information in the standard relating to "sub-sequence" concepts (esp. D.2.11 through D.2.13). I believe this is the primary purpose. Also, it can provide a form of robustness to transmission-channel losses of some reference pictures. If a reference picture becomes "non-existing" due to packet losses, the remaining pictures in the bitstream may still be decodable. This definition provides a well-defined decoder behavior for environments in which in the system operation may result in the loss of some reference pictures. For such a case, it might not really be necessary to specify how the decoder would respond to a picture loss -- however, this feature allows the encoder to decide whether the decoder should flag the loss of a picture as a real problem or not (by setting the value of the gaps_in_frame_num_value_allowed_flag to 0 or 1) and allows the encoder to understand how the decoder will respond to such events, which can be beneficial to know for various purposes. In fact, the way the decoder responds to a missing reference picture when gaps_in_frame_num_value_allowed_flag is equal to 1 may often also be a good way for the decoder to respond to a missing reference picture when gaps_in_frame_num_value_allowed_flag is equal to 0 as well. But when when gaps_in_frame_num_value_allowed_flag is equal to 0, it is up to the individual product designer to decide how the decoder should respond to missing reference pictures. Best Regards, Gary Sullivan +> -----Original Message----- +> From: mp4-tech-bounces@lists.mpegif.org +> [mailto:mp4-tech-bounces@lists.mpegif.org] On Behalf Of +> Martin.Lange@sci-worx.com +> Sent: Wednesday, May 31, 2024 7:14 AM +> To: mp4-tech@lists.mpegif.org +> Subject: [Mp4-tech] [H.264] purpose of non-existing pictures +> +> Hello everyone, +> +> a thing which I was always wondering is the purpose of non-existing +> pictures. What is a scenario in which an encoder would decide to +> intentionally introduce gaps in frame_num, thus producing +> non-existing +> pictures? The only effect I see is that they make other pictures fall +> out of the decoded picture buffer and that they also get incorporated +> into reference lists, thus changing the reference indices +> other pictures +> would have without their presence. Can this lead to any gain +> in coding +> efficiency? Can anybody comment on what was the intention of +> this tool? +> +> If this is a question which has already been posted in the +> past, I would +> be happy if anyone could point me to some kind of FAQ of +> this forum, if +> it exists (does it?). +> +> Best regards, +> Martin Lange +> +> _______________________________________________ +> NOTE: Please use clear subject lines for your posts. Include +> [audio, [video], [systems], [general] or another +> apppropriate identifier to indicate the type of question you have. +> +> Note: Conduct on the mailing list is subject to the +> Antitrust guidelines found at +> http://www.mpegif.org/public/documents/vault/mp-out-30042-Ant +> itrust.php +> From Srivaishnav_Rajagopal sdesigns.com Wed May 31 13:26:37 2006 From: Srivaishnav_Rajagopal sdesigns.com (Srivaishnav Rajagopal) Date: Thu Jun 1 09:51:15 2006 Subject: [Mp4-tech] OD stream config Message-ID: <5DF100B598199744B111FCEA5222E78A5D718F@sigma-exch1.sdesigns.com> Hi all, I am looking for the DecoderSpecificInfo format, which is present in the OD stream of MPEG4. The reason I need it since it contains the start code information needed to parse a transport stream. Thanks Sri -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20060531/bf9394b7/attachment-0001.html From Wesley.DeNeve UGent.be Wed May 31 23:46:40 2006 From: Wesley.DeNeve UGent.be (Wesley De Neve) Date: Thu Jun 1 09:51:22 2006 Subject: [Mp4-tech] [H.264] purpose of non-existing pictures References: <7E6219E8CD869D4186B919B0DCF127C0013A861F@hajse201.eu.infineon.com> Message-ID: <0d6b01c684f3$51c433d0$7301a8c0@persephone> Dear Martin, I think you rather have to look at "non-existing" frames from a decoder point of view. Then, temporal scalability is a possible scenario in which gaps might be introduced in frame_num. Frame loss due to packet dropping in a congested network is another one. When no gaps in frame_num are allowed (the value of gaps_in_frame_num_value_allowed_flag is equal to zero), decoders infer disposed reference frames from gaps in the frame_num syntax element and insert a "non-existing'' frame to the reference picture buffer as if the frame was received and decoded. This procedure guarantees that the contents of and the picture order in the reference picture buffer remain unchanged when it comes to the decoding of the remaining pictures. This process is not executed when gaps in frame_num are allowed (the value of gaps_in_frame_num_value_allowed_flag is equal to one). The latter is for instance useful when temporal scalability is implemented by making use of sub-sequences. The sub-sequence feature of H.264/AVC enables hierarchical temporal scalability, which allows disposal of reference pictures from a coded bitstream without affecting the decoding of the remaining pictures in the bitstream (hereby intentionally introducing gaps in frame_num when reference pictures are dropped). The latter is also discussed in the following papers: [1] Dong Tian et al.: Sub-Sequence Video Coding for Improved Temporal Scalability; [2] Ville-Pekka Limnell et al.: Quality Scalability in H.264-AVC Video Coding. >From an encoder perspective, "non-existing" frames will typically be created by using skipped slices in order to achieve bit rate savings (or to keep the amount of pictures in the coded bitstream the same after offline exploitation of temporal scalability, something that significantly eases the synchronization with an audio stream when varying coding patterns are in use). Best regards, Wesley De Neve Martin.Lange@sci-worx.com wrote: > Hello everyone, > > a thing which I was always wondering is the purpose of non-existing > pictures. What is a scenario in which an encoder would decide to > intentionally introduce gaps in frame_num, thus producing non-existing > pictures? The only effect I see is that they make other pictures fall > out of the decoded picture buffer and that they also get incorporated > into reference lists, thus changing the reference indices other > pictures > would have without their presence. Can this lead to any gain in coding > efficiency? Can anybody comment on what was the intention of this > tool? > > If this is a question which has already been posted in the past, I > would > be happy if anyone could point me to some kind of FAQ of this forum, > if > it exists (does it?). > > Best regards, > Martin Lange > > _______________________________________________ > NOTE: Please use clear subject lines for your posts. Include [audio, > [video], [systems], [general] or another apppropriate identifier to > indicate the type of question you have. > > Note: Conduct on the mailing list is subject to the Antitrust > guidelines found at > http://www.mpegif.org/public/documents/vault/mp-out-30042-Antitrust.php