From Andreas.Hutter mchp.siemens.de Sat Dec 1 01:59:40 2001 From: Andreas.Hutter mchp.siemens.de (Hutter Andreas) Date: Wed Jul 30 14:07:26 2003 Subject: [M4IF Technotes] Few Queries on streaming video profile!!! Message-ID: <2A8DB02E3018D411901B009027FD3A3F158F65@mchp905a.mch.sbs.de> Dear Rob, all, sorry for my delayed reply, but I just noticed the following statement: > > 2) does level 0 puts restriction on the size of frame to be > > multiple of 16 ? > > (ofcourse size should not be more that QCIF) > > yes. > > Length <= 176 > Height <= 144 > It only works in multiples of full macroblocks. > I believe we need to be more precise here: To my understanding (following a discussion arising from the interop tests)video_object_layer_width / video_object_layer_height (being the displayable area of the VOP) do not have to be multiples of 16. However, for the decoding process these values are automatically extended to full macroblocks as described in clause 6.3.3. Otherwise it would not be possible to code e.g. QSIF resolution ... Best regards, Andreas From watanka samsung.com Mon Dec 3 16:13:21 2001 From: watanka samsung.com (S.G.Chang) Date: Wed Jul 30 14:07:27 2003 Subject: [M4IF Technotes] Question on DecodeSpecificInfo Message-ID: <001801c17bc9$fda3fbf0$8ac4dba8@watankamain> Dear experts and members. I have a question on "DecodeSpecificInfo" in MPEG-4 system. As you know, the "DecoderSpecificInfo" in MPEG-4 system is needed to initialize MPEG-4 decoder. [ISO/IEC SG29/WG11, N4350, pp 478] says that VisualObjectSequence is transmitted explicitly in each DecConfigDecsr.DecSpecificInfo. This question is caused by Envivio player. According to our experiments Envivio player can't decode "VisualObjectSequenceHeader". But i can't sure that "VisualObjectSequenceHeader" must be included in "DecodeSpecificInfo" or not. If you have information on this, please know me. S.G.Chang ++++++++++++++++++++++++++++++ Seung-Gi Chang, Ph.D. Senior Engineer Mobile Solution Team, DM Lab, SAMSUNG Electronics Co ++++++++++++++++++++++++++++++ -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20011203/5336192e/attachment.html From rkoenen intertrust.com Mon Dec 3 09:31:55 2001 From: rkoenen intertrust.com (Rob Koenen) Date: Wed Jul 30 14:07:27 2003 Subject: FW: [M4IF Interop] FW: [M4IF Technotes] Question on DecodeSpecifi cInfo Message-ID: <720AE932C238D411B4D100C04F10DA6B04EB89C8@exchange.epr.com> -----Original Message----- From: Michael Ropert [mailto:mropert@envivio.fr] Sent: Tuesday, December 04, 2023 0:34 To: Rob Koenen; M4IF Interop (E-mail) Subject: RE: [M4IF Interop] FW: [M4IF Technotes] Question on DecodeSpecificInfo Hi, According to the visual standard (annex K), a DSI is composed on several elements: - VisualObjectSequence, - VisualObject, - VideoObject, - VideoObjectLayer. So what I understand, is that VisualObjectSequenceHeader must be written in the DSI. Maybe I misunderstood your question ? Michael ROPERT. www.envivio.com -----Message d'origine----- De : interop-admin@lists.m4if.org [mailto:interop-admin@lists.m4if.org]De la part de Rob Koenen Envoy? : lundi 3 d?embre 2001 18:22 ? : M4IF Interop (E-mail) Objet : [M4IF Interop] FW: [M4IF Technotes] Question on DecodeSpecificInfo Question you interop guys must be able to answer! Rob -----Original Message----- From: S.G.Chang [mailto:watanka@samsung.com] Sent: Monday, December 03, 2023 14:13 To: M4IF Subject: [M4IF Technotes] Question on DecodeSpecificInfo Dear experts and members. I have a question on "DecodeSpecificInfo" in MPEG-4 system. As you know, the "DecoderSpecificInfo" in MPEG-4 system is needed to initialize MPEG-4 decoder. [ISO/IEC SG29/WG11, N4350, pp 478] says that VisualObjectSequence is transmitted explicitly in each DecConfigDecsr.DecSpecificInfo. This question is caused by Envivio player. According to our experiments Envivio player can't decode "VisualObjectSequenceHeader". But i can't sure that "VisualObjectSequenceHeader" must be included in "DecodeSpecificInfo" or not. If you have information on this, please know me. S.G.Chang ++++++++++++++++++++++++++++++ Seung-Gi Chang, Ph.D. Senior Engineer Mobile Solution Team, DM Lab, SAMSUNG Electronics Co ++++++++++++++++++++++++++++++ -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20011203/c5e92dbe/attachment.html From sathesandeep yahoo.com Tue Dec 4 05:35:33 2001 From: sathesandeep yahoo.com (Sandeep Sathe) Date: Wed Jul 30 14:07:27 2003 Subject: [M4IF Technotes] Simple Scalability - VBV Buffer sizes distribution. Message-ID: <20011204133533.1895.qmail@web12905.mail.yahoo.com> Hi All, Standard states that if VBV parameters are absent, default values should be used. Max values mentioned for Version 1 (Table N-1) are *aggregated* for both layers. i.e. VBV size of Base Layer + VBV size of Enha. Layer = 40 (for both levels) My doubt, is what values should be allocated in case of scalable bit streams (say 2 layers), when VBV params are ABSENT. Regards, Sandeep. ps: any comments to my earler mail ([M4IF Technotes] Simple Scalable - Spatial scalability.)? __________________________________________________ Do You Yahoo!? Buy the perfect holiday gifts at Yahoo! Shopping. http://shopping.yahoo.com From arcin lumictech.com Tue Dec 4 13:31:18 2001 From: arcin lumictech.com (Arcin Bozkurt) Date: Wed Jul 30 14:07:27 2003 Subject: [M4IF Technotes] Rate Control in VM Message-ID: <3C0D1676.2030301@lumictech.com> The introduction section (15.1.1) mentions that the SRC scheme can handle I, P and B pictures and the description section is for single VO and only handles I and P pictures. My question is what "sequence" or "segment" corresponds to in the context of this SRC. From page 290 (VM16.0) : R_r : number of bits remaining for encoding this sequence (or segment) N_r : number of P frames remaining for encoding. on the next page R_p : bits to be removed from the buffer per picture is calculated as R_p : R_r / N_r which suggests that a sequence is I P P P P I P P P .... : 1 I and N_r (in this case 3) P pictures... (I know that N_r is decremented after the encoding of each frame but initially, after the encoding of the first frame, value of N_r is 3) Are my deductions correct? R_s : is the target bitrate for an IPPPPPPPPPPP sequence R_f: (bits used for the first frame) "first" frame always refers to an I picture. T_s: (number of seconds for sequence) This is the parameter that gives the information on how many P pictures follow an I picture (combined with the N_s information). This means that this SRC does not change the number of P pictures between I pictures (unless a frame is dropped). Therefore, suppose a scene change is detected. This scheme cannot be used, if the encoder forces an I picture (for quality) instead of continuing coding P pictures with small QP value (we know that SRC cannot update that value of QP more than 25% - so a degradation in quality is expected.) N_s: distance between encoded frame 4 for 7.5 fps. With N_s = 4, T_s: 10 (examples from VM) i would have 1 I, 74 P pictures in my sequence... Am I right? Arcin Bozkurt From rkoenen intertrust.com Tue Dec 4 11:59:02 2001 From: rkoenen intertrust.com (Rob Koenen) Date: Wed Jul 30 14:07:27 2003 Subject: FW: [M4IF Interop] FW: [M4IF Technotes] Question on DecodeSpecifi cInfo Message-ID: <720AE932C238D411B4D100C04F10DA6B04EB8AAB@exchange.epr.com> -----Original Message----- From: Dave Singer [mailto:singer@apple.com] Sent: Monday, December 03, 2023 16:35 To: Michael Ropert Cc: Rob Koenen; M4IF Interop (E-mail) Subject: RE: [M4IF Interop] FW: [M4IF Technotes] Question on DecodeSpecificInfo At 6:33 PM +0100 12/3/01, Michael Ropert wrote: ? Hi, According to the visual norm (annex K), a DSI is composed on several elements: - VisualObjectSequence, - VisualObject, - VideoObject, - VideoObjectLayer. So what I understand, is that VisualObjectSequenceHeader must be written in the DSI. I agree. It seems that since most of these headers contain little information, people are tempted to put in only the one that has the signficant data. But that's not what the spec says. Maybe I misunderstood your question ? Michael ROPERT. www.envivio.com -----Message d'origine----- De : interop-admin@lists.m4if.org [mailto:interop-admin@lists.m4if.org]De la part de Rob Koenen Envoy? : lundi 3 d?cembre 2001 18:22 ? : M4IF Interop (E-mail) Objet : [M4IF Interop] FW: [M4IF Technotes] Question on DecodeSpecificInfo Question you interop guys must be able to answer! Rob -----Original Message----- From: S.G.Chang [mailto:watanka@samsung.com] Sent: Monday, December 03, 2023 14:13 To: M4IF Subject: [M4IF Technotes] Question on DecodeSpecificInfo Dear experts and members. I have a question on "DecodeSpecificInfo" in MPEG-4 system. As you know, the "DecoderSpecificInfo" in MPEG-4 system is needed to initialize MPEG-4 decoder. [ISO/IEC SG29/WG11, N4350, pp 478] says that VisualObjectSequence is transmitted explicitly in each DecConfigDecsr.DecSpecificInfo. This question is caused by Envivio player. According to our experiments Envivio player can't decode "VisualObjectSequenceHeader". But i can't sure that "VisualObjectSequenceHeader" must be included in "DecodeSpecificInfo" or not. If you have information on this, please know me. S.G.Chang ++++++++++++++++++++++++++++++ Seung-Gi Chang, Ph.D. Senior Engineer Mobile Solution Team, DM Lab, SAMSUNG Electronics Co ++++++++++++++++++++++++++++++ -- David Singer Apple Computer/QuickTime -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20011204/cc9a0dbd/attachment.html From the_ether btinternet.com Tue Dec 4 23:48:38 2001 From: the_ether btinternet.com (the_ether) Date: Wed Jul 30 14:07:27 2003 Subject: [M4IF Technotes] I-block vs P-block Message-ID: <008401c17d1e$343eb420$792723d9@opsus> When signalling to the decoder what type of encoding was used, can I have just one or two blocks / macroblocks that are coded in intra mode whilst the rest are in inter (P) mode? How do I signal this? Do I specify that the VOP is a P-VOP and then the decoder assumes all MBs are of type P unless otherwise specified? To what resolution does this work? Can I specify the mode down to the block level or is it just down to the macroblock level? (ie I specify the VOP as type P-VOP and then within that just one block (or only macroblock?) is specified as being of type I-block (or only I-macroblock?)? Thanks in advance for your help. graham From peterh videospheres.com Tue Dec 4 20:30:48 2001 From: peterh videospheres.com (Peter Haighton) Date: Wed Jul 30 14:07:27 2003 Subject: [M4IF Technotes] I-block vs P-block In-Reply-To: <008401c17d1e$343eb420$792723d9@opsus> Message-ID: Graham, >When signalling to the decoder what type of encoding was used, can I have >just one or two blocks / macroblocks that are coded in intra mode whilst the >rest are in inter (P) mode? Yes, any macroblock in a P frame can be either Intra or Predictive. >How do I signal this? Do I specify that the VOP is a P-VOP and then the >decoder assumes all MBs are of type P unless otherwise specified? You specify that the VOP is a P-VOP and then every block inside gets set as either Intra macroblock Inter macroblock Inter 4MV macroblock >To what resolution does this work? Any resolution >Can I specify the mode down to the block level or is it just down to the macroblock >level? (ie I specify the VOP as type P-VOP and then within that just one block (or >only macroblock?) is specified as being of type I-block (or only I-macroblock?)? You specify that the entire macroblock is of a certain type. -- Peter Haighton VideoSpheres Inc. 84 Hines Road Kanata, Ontario Canada, K2K 3G3 Tel: (613) 270-9646 x3022 Fax: (613) 271-9442 email: peterh@VideoSpheres.com See http://www.m4if.org for the latest on MPEG-4 _______________________________________________ Technotes mailing list Technotes@lists.m4if.org http://lists.m4if.org/mailman/listinfo/technotes From dim psytel-research.co.yu Fri Dec 7 18:24:17 2001 From: dim psytel-research.co.yu (Ivan Dimkovic) Date: Wed Jul 30 14:07:28 2003 Subject: [M4IF Technotes] MPEG-4 AAC LTP Question Message-ID: <001101c17f44$025b8320$0100a8c0@hal> Dear M4IF people, I've found a constant that is used in 14496-5 reference software: NOK_MAX_LT_PRED_SFB, defining upper scalefactor band for long term prediction for long blocks. This value is set to 40 in both encoder and decoder (nok_ltp_common_internal.h) However, there is no such limit in the ISO 14496-5 standard. The question is, is there a possibility to use scalefactor bands higher than 40 for LTP? If that is the case, then ISO reference software decoder wouldn't be able to decode such AAC bitstreams. We use this limit (40) in our encoder. Best Regards, ************************************************* Ivan Dimkovic, Technical Manager PsyTEL Research Multimedia Coding Solutions Belgrade Yugoslavia phone: +381 63 264 334 phone: +381 64 11 40 600 fax: +381 11 32 25 275 email: dim@psytel-research.co.yu www: http://www.psytel-research.co.yu ************************************************* From ravi_biju yahoo.com Tue Dec 11 03:34:31 2001 From: ravi_biju yahoo.com (Biju Ravindran) Date: Wed Jul 30 14:07:28 2003 Subject: [M4IF Technotes] Quarter pel interpolation Message-ID: <20011211113431.44120.qmail@web12103.mail.yahoo.com> Hi All, Could any body give a brief description about how the quarter pel interpolation is done in Mpeg-4 for motion compensation? ===== ciao, -biju __________________________________________________ Do You Yahoo!? Check out Yahoo! Shopping and Yahoo! Auctions for all of your unique holiday gifts! Buy at http://shopping.yahoo.com or bid at http://auctions.yahoo.com From kmr iis.fhg.de Tue Dec 11 13:03:29 2001 From: kmr iis.fhg.de (Vinod Kumar) Date: Wed Jul 30 14:07:28 2003 Subject: [M4IF Technotes] Quarter pel interpolation References: <20011211113431.44120.qmail@web12103.mail.yahoo.com> Message-ID: <3C15F611.5578A80D@iis.fhg.de> Hello Biju I am forwarding a note by Gary Sullivan which helped me implement the quarter-sample interpolation Thanx Gary " I think some concrete examples are in order. Here are four. Consider macroblock (i,j) having its upper left corner at (x,y) position (i*16, j*16) in the current picture. Example 1: (MVx, MVy) = (5.25, 0.25) The integer part of the MV is (5, 0) The components of the MV are positive, so the area needed is biased to the right and below the area needed for the integer MV. Thus the area needed in the reference picture is the 16x16 area having its upper left corner at position (i*16+5, j*16), plus one extra column to the right and one extra row below that area. Thus the area needed in the reference picture is the 17x17 area having its upper left corner at position (i*16+5, j*16). Example 2: (MVx, MVy) = (-5.25, -0.25) The integer part of the MV is (-5, 0) The components of the MV are negative, so the area needed is biased to the left and above the area needed for the integer MV. Thus the area needed in the reference picture is the 16x16 area having its upper left corner at position (i+16-5, j*16), plus one extra column to the left and one extra row above that area. Thus the area needed in the reference picture is the 17x17 area having its upper left corner at position (i*16-6, j*16-1). Example 3: (MVx, MVy) = (5.25, -0.25) The area needed in the reference picture is the 17x17 area having its upper left corner at position (i*16+5, j*16-1). Example 4: (MVx, MVy) = (-5.25, 0.25) The area needed in the reference picture is the 17x17 area having its upper left corner at position (i*16-6, j*16). The same is true whether quarter pel or half pel motion is in use. Perhaps this could have been explained better by saying to get an integer motion vector by rounding the position toward negative infinity and then grabbing a 17x17 area starting from there. -Gary S. " Hope this helps Biju Ravindran wrote: > > Hi All, > Could any body give a brief description about > how the quarter pel interpolation is done in Mpeg-4 > for motion compensation? > > ===== > ciao, > -biju > > __________________________________________________ > Do You Yahoo!? > Check out Yahoo! Shopping and Yahoo! Auctions for all of > your unique holiday gifts! Buy at http://shopping.yahoo.com > or bid at http://auctions.yahoo.com > _______________________________________________ > Technotes mailing list > Technotes@lists.m4if.org > http://lists.m4if.org/mailman/listinfo/technotes -- Vinod Kumar MV Research Engineer Video Coding Group Fraunhofer Institut f?r Integrierte Schaltungen Am Weichselgarten 3, D-91058 Erlangen, Phone : +49 (0) 9131 / 776 363 Fax : +49 (0) 9131 / 776 999 From yh86us yahoo.com Wed Dec 12 10:56:40 2001 From: yh86us yahoo.com (YH) Date: Wed Jul 30 14:07:28 2003 Subject: [M4IF Technotes] Re: question Message-ID: <3C169D38.FF9031C8@yahoo.com> Hello, Are there any documents describing MPEG-4 finer granularity? Thank you. Yude From ravi_biju yahoo.com Tue Dec 11 23:59:51 2001 From: ravi_biju yahoo.com (Biju Ravindran) Date: Wed Jul 30 14:07:28 2003 Subject: [M4IF Technotes] Spiral Search In-Reply-To: <3C15F611.5578A80D@iis.fhg.de> Message-ID: <20011212075951.79729.qmail@web12107.mail.yahoo.com> Hi All, Could anybody give some idea about how the spiral search is done for motion estimation? ===== ciao, -biju __________________________________________________ Do You Yahoo!? Check out Yahoo! Shopping and Yahoo! Auctions for all of your unique holiday gifts! Buy at http://shopping.yahoo.com or bid at http://auctions.yahoo.com From khuber sorensontech.com Wed Dec 12 09:37:37 2001 From: khuber sorensontech.com (Kris Huber) Date: Wed Jul 30 14:07:28 2003 Subject: [M4IF Technotes] Spiral Search Message-ID: <6E031E06378BD311AEF20090273CE1BA409402@el-postino.s-vision.com> Hi Biju, The basic idea of spiral search is to search in an outward-spiraling order. For example, one such possibility for the +/-1 motion search range is 7 8 9 6 1 2 5 4 3 where position "1" is the predicted position. Surely there are technical papers in journals and conference proceedings available if you search. Regards, Kris -----Original Message----- From: Biju Ravindran [mailto:ravi_biju@yahoo.com] Sent: Wednesday, December 12, 2023 1:00 AM To: technotes@lists.m4if.org Subject: [M4IF Technotes] Spiral Search Hi All, Could anybody give some idea about how the spiral search is done for motion estimation? ===== ciao, -biju __________________________________________________ Do You Yahoo!? Check out Yahoo! Shopping and Yahoo! Auctions for all of your unique holiday gifts! Buy at http://shopping.yahoo.com or bid at http://auctions.yahoo.com _______________________________________________ Technotes mailing list Technotes@lists.m4if.org http://lists.m4if.org/mailman/listinfo/technotes From arcin lumictech.com Wed Dec 12 16:48:37 2001 From: arcin lumictech.com (Arcin Bozkurt) Date: Wed Jul 30 14:07:28 2003 Subject: [M4IF Technotes] Rate Control in VM - Repost In-Reply-To: <3C0D1676.2030301@lumictech.com> References: <3C0D1676.2030301@lumictech.com> Message-ID: <0112121648370N.11629@thunderbird> The introduction section (15.1.1) mentions that the SRC scheme can handle I, P and B pictures and the description section is for single VO and only handles I and P pictures. My question is what "sequence" or "segment" corresponds to in the context of SRC. VM16.0: R_r : number of bits remaining for encoding this sequence (or segment) N_r : number of P frames remaining for encoding. R_p : bits to be removed from the buffer per picture is calculated as R_p = R_r / N_r which suggests that a sequence is I P P P P I P P P .... : 1 I and N_r (in this case 3) P pictures... ( For describing the pattern, I am assuming value of N_r is the initial value of N_r, because later N_r is decremented after the encoding of each frame) Are the following deductions correct? 1. R_s : is the target bitrate for an IPPPPPPPPPPP sequence 2. R_f: (bits used for the first frame) "first" frame always refers to an I picture. 3. T_s: (number of seconds for sequence) This is the parameter that gives the information on how many P pictures follow an I picture (combined with the N_s information). This means that this SRC does not change the number of P pictures between I pictures (unless a frame is dropped). Therefore, suppose a scene change is detected. This scheme cannot be used, if the encoder forces an I picture (for quality) instead of continuing coding P pictures with small QP value (we know that SRC cannot update that value of QP more than 25% - so a degradation in quality is expected.) N_s: distance between encoded frame 4 for 7.5 fps. With N_s = 4, T_s: 10 (examples from VM) i would have 1 I, 74 P pictures in my sequence... Am I right? Arcin Bozkurt From the_ether btinternet.com Wed Dec 12 23:28:30 2001 From: the_ether btinternet.com (the_ether) Date: Wed Jul 30 14:07:28 2003 Subject: [M4IF Technotes] Quarter pel interpolation References: <20011211113431.44120.qmail@web12103.mail.yahoo.com> <3C15F611.5578A80D@iis.fhg.de> Message-ID: <00b401c18364$bb5eb940$da1a23d9@opsus> I understand how to find the search area and how big it should be. I also understand how to work out the half-pel samples. What I don't understand is how to work out the qtr-pel samples. The description in the ISO documentation seems to suggest that in qtr-pel mode, the half-pel samples are calculated in a different way to non qtr-pel mode. Nor do I understand the use of the filter coefficients. The two books I have describe half-pel and then mention how wonderful 1/4 pel is, but neither explain how to implement it. Can someone please explain how to calculate the samples? Regards graham ----- Original Message ----- From: "Vinod Kumar" To: "Biju Ravindran" Cc: Sent: 11 December 2023 12:03 Subject: Re: [M4IF Technotes] Quarter pel interpolation Hello Biju I am forwarding a note by Gary Sullivan which helped me implement the quarter-sample interpolation Thanx Gary " I think some concrete examples are in order. Here are four. Consider macroblock (i,j) having its upper left corner at (x,y) position (i*16, j*16) in the current picture. Example 1: (MVx, MVy) = (5.25, 0.25) The integer part of the MV is (5, 0) The components of the MV are positive, so the area needed is biased to the right and below the area needed for the integer MV. Thus the area needed in the reference picture is the 16x16 area having its upper left corner at position (i*16+5, j*16), plus one extra column to the right and one extra row below that area. Thus the area needed in the reference picture is the 17x17 area having its upper left corner at position (i*16+5, j*16). Example 2: (MVx, MVy) = (-5.25, -0.25) The integer part of the MV is (-5, 0) The components of the MV are negative, so the area needed is biased to the left and above the area needed for the integer MV. Thus the area needed in the reference picture is the 16x16 area having its upper left corner at position (i+16-5, j*16), plus one extra column to the left and one extra row above that area. Thus the area needed in the reference picture is the 17x17 area having its upper left corner at position (i*16-6, j*16-1). Example 3: (MVx, MVy) = (5.25, -0.25) The area needed in the reference picture is the 17x17 area having its upper left corner at position (i*16+5, j*16-1). Example 4: (MVx, MVy) = (-5.25, 0.25) The area needed in the reference picture is the 17x17 area having its upper left corner at position (i*16-6, j*16). The same is true whether quarter pel or half pel motion is in use. Perhaps this could have been explained better by saying to get an integer motion vector by rounding the position toward negative infinity and then grabbing a 17x17 area starting from there. -Gary S. " Hope this helps Biju Ravindran wrote: > > Hi All, > Could any body give a brief description about > how the quarter pel interpolation is done in Mpeg-4 > for motion compensation? > > ===== > ciao, > -biju > > __________________________________________________ > Do You Yahoo!? > Check out Yahoo! Shopping and Yahoo! Auctions for all of > your unique holiday gifts! Buy at http://shopping.yahoo.com > or bid at http://auctions.yahoo.com > _______________________________________________ > Technotes mailing list > Technotes@lists.m4if.org > http://lists.m4if.org/mailman/listinfo/technotes -- Vinod Kumar MV Research Engineer Video Coding Group Fraunhofer Institut f?r Integrierte Schaltungen Am Weichselgarten 3, D-91058 Erlangen, Phone : +49 (0) 9131 / 776 363 Fax : +49 (0) 9131 / 776 999 _______________________________________________ Technotes mailing list Technotes@lists.m4if.org http://lists.m4if.org/mailman/listinfo/technotes From mauri.vaananen nokia.com Thu Dec 13 14:13:53 2001 From: mauri.vaananen nokia.com (mauri.vaananen@nokia.com) Date: Wed Jul 30 14:07:28 2003 Subject: [M4IF Technotes] MPEG-4 AAC LTP Question Message-ID: <58668F4DBAC34F4CBE825FDE661EC1917CB74B@trebe004.NOE.Nokia.com> Dear Mr. Dimkovic, This was an error in the (ISO 14496-3) standard. The reference software is correct, and a correction to the specification is included in the text of Draft Corrigendum approved in the last MPEG meeting. Best Regards, Mauri Vaananen -------------------------------------------- mauri.vaananen@nokia.com Nokia Research Center, Speech and Audio Systems Laboratory Visiokatu 1 (P.O. Box 100), FIN-33721 Tampere, FINLAND tel: +358 7180-35843 fax: -35899 mobile: +358 50 4835843 > -----Original Message----- > From: Ivan Dimkovic [mailto:dim@psytel-research.co.yu] > Sent: 07 December, 2001 19:24 > To: MPEG4 technical notes (E-mail) > Subject: [M4IF Technotes] MPEG-4 AAC LTP Question > > > Dear M4IF people, > > I've found a constant that is used in 14496-5 reference software: > NOK_MAX_LT_PRED_SFB, defining upper scalefactor band for long term > prediction for long blocks. > > This value is set to 40 in both encoder and decoder > (nok_ltp_common_internal.h) > > However, there is no such limit in the ISO 14496-5 standard. > The question > is, is there a possibility to use scalefactor bands higher > than 40 for LTP? > If that is the case, then ISO reference software decoder > wouldn't be able to > decode such AAC bitstreams. We use this limit (40) in our encoder. > > Best Regards, > > ************************************************* > Ivan Dimkovic, Technical Manager > > PsyTEL Research > Multimedia Coding Solutions > Belgrade Yugoslavia > > phone: +381 63 264 334 > phone: +381 64 11 40 600 > fax: +381 11 32 25 275 > > email: dim@psytel-research.co.yu > www: http://www.psytel-research.co.yu > ************************************************* > > > _______________________________________________ > Technotes mailing list > Technotes@lists.m4if.org > http://lists.m4if.org/mailman/listinfo/technotes > From arcin lumictech.com Thu Dec 13 15:28:12 2001 From: arcin lumictech.com (Arcin Bozkurt) Date: Wed Jul 30 14:07:28 2003 Subject: [M4IF Technotes] Motion Estimation Message-ID: <0112131528120T.11629@thunderbird> SAD(0,0) - (N_b / 2 +1) formula is used in the VM18.0 to get the SAD(0,0) value. It is counter-intuitive for N_b to be related to the VOP. I would espect it to be related to the number of elements being summed up in the SAD(x,y) calculation. Can someone point me to any literature or web-sites, where this subtracted number, namely, N_b/2+1 is justified? Thanks Arcin From PHosur ObjectVideo.com Thu Dec 13 15:43:19 2001 From: PHosur ObjectVideo.com (Prabhudev Hosur) Date: Wed Jul 30 14:07:28 2003 Subject: [M4IF Technotes] Motion Estimation Message-ID: <40C5B05D0F3BBD489D742090CBE34CD8034C8E@venom.atom.dbvision.net> Hi, You can design your own motion estimation algorithm for obtaining the motion vector. So you may use your own bias value for SAD(0,0), which you think is the best bias value. Prabhu -----Original Message----- From: Arcin Bozkurt [mailto:arcin@lumictech.com] Sent: Thursday, December 13, 2023 3:28 PM To: Technotes@lists.m4if.org Subject: [M4IF Technotes] Motion Estimation SAD(0,0) - (N_b / 2 +1) formula is used in the VM18.0 to get the SAD(0,0) value. It is counter-intuitive for N_b to be related to the VOP. I would espect it to be related to the number of elements being summed up in the SAD(x,y) calculation. Can someone point me to any literature or web-sites, where this subtracted number, namely, N_b/2+1 is justified? Thanks Arcin _______________________________________________ Technotes mailing list Technotes@lists.m4if.org http://lists.m4if.org/mailman/listinfo/technotes From the_ether btinternet.com Fri Dec 14 04:11:58 2001 From: the_ether btinternet.com (the_ether) Date: Wed Jul 30 14:07:28 2003 Subject: [M4IF Technotes] Chrominance positions Message-ID: <000301c18456$e57098a0$652923d9@opsus> Are the positions of the chrominance pixels in fixed positions on the screen or are they relative to the positions of VOPs. That is to say, the normal description is Y Y Y Y Y Y c c c Y Y Y Y Y Y ie one Cb and Cr per 4 Y pixels However, what if the VOP sits at position (1,0)? I presume that we would now have Y Y Y Y Y Y C C Y Y Y Y Y Y ie the C values would have to be re-calculated as they now relate to different Y pixels. So I assume that the chrominance values move relative to the VOP. In other words I cannot blindly calculate the YCbCr values for the whole screen. I have to decide on the VOP positions before calculating Cb, Cr. Is this correct? Regards graham From the_ether btinternet.com Fri Dec 14 15:27:11 2001 From: the_ether btinternet.com (the_ether) Date: Wed Jul 30 14:07:28 2003 Subject: [M4IF Technotes] Chrominance positions References: <000301c18456$e57098a0$652923d9@opsus> <0112140607350X.11629@thunderbird> Message-ID: <002101c184b3$d040bac0$dc1f23d9@opsus> Thanks for the reply. Certainly F2 appears to say that a VOP can only ever be positioned at even co-ordinates and therefore positions such as (3,2) are no-nos. I'm surprised as this would have quite a heavy restriction, also on things like BIFS. I reckon that F2 is for guidance not a rule and that odd-numbered co-ordinates are possible. Having said that I wonder what the decoder would think of all that as you would have conflicts in the calculation of the pixel value to display between the chrominance elements to the left of the luminance pixel and the 'odd numbered' ones to the right. Thinking further, the bounding region may be fixed to only even-numbered positions but the masked image could fall anywhere. The VOP position is simply just a bounding region ad will contain non object pixels as well as the 'desired' ones. I'll go with the view that a VOP has to be on an even-numbered position and so the chrominance values ca be calculated in one sweep of the screen without regard to VOPs. g. ----- Original Message ----- From: "Arcin Bozkurt" To: "the_ether" Sent: 14 December 2023 11:07 Subject: Re: [M4IF Technotes] Chrominance positions > On Thursday 13 December 2023 23:11, you wrote: > > Are the positions of the chrominance pixels in fixed positions on the > > screen or are they relative to the positions of VOPs. > > > > That is to say, the normal description is > > > > Y Y Y Y Y Y > > c c c > > Y Y Y Y Y Y > > > > ie one Cb and Cr per 4 Y pixels > > > > However, what if the VOP sits at position (1,0)? I presume that we would > > now have > > > > Y Y Y Y Y Y > > C C > > Y Y Y Y Y Y > > as far as i know, you cannot have a VOP that sits at an odd numbered topleft > corner... Or maybe I should say, you can, but as you said, you will have to > recalculate new set of C values from the originals. > > section 6.1.3.6 talks about the 420 format and refers to section F.2 for > formation of VOP. In this F2, the tightest bouding rectangle around the VOP > is chosen starting from an even numbered topleft corner. > > > > ie the C values would have to be re-calculated as they now relate to > > different Y pixels. > > > > So I assume that the chrominance values move relative to the VOP. In other > > words I cannot blindly calculate the YCbCr values for the whole screen. I > > have to decide on the VOP positions before calculating Cb, Cr. > > > > Is this correct? > > > > Regards > > > > graham > > > > > > _______________________________________________ > > Technotes mailing list > > Technotes@lists.m4if.org > > http://lists.m4if.org/mailman/listinfo/technotes From padma_volety satyam.net.in Sat Dec 15 16:21:37 2001 From: padma_volety satyam.net.in (Padmavathi Volety) Date: Wed Jul 30 14:07:29 2003 Subject: [M4IF Technotes] MPEG-4 AAC LTP Question Message-ID: <009f01c185c7$a0676000$3c0ca8c0@cspldell60> Skipped content of type multipart/alternative From ben interframemedia.com Sun Dec 16 15:53:52 2001 From: ben interframemedia.com (Ben Waggoner) Date: Wed Jul 30 14:07:29 2003 Subject: [M4IF Technotes] Preprocessing for MPEG-4 Message-ID: Hello all, I've been working on testing some MPEG-4 encoders, and it's been a difficult slog, since they all support different input formats, and often seem to be doing different kinds of color space conversions even on the same source. I long for the idea world where every encoder can use the native libraries for QuickTime and DirectShow, and can take native YUV codecs as source without any color space conversions. Anyway, I was wondering what kind of preprocessing MPEG-4 is optimized for. Most video sources will use the 601 luma range of 16-235. Most (but not all) web delivery codecs expect a luma range of 0-255, where a 0 will match RGB black elements on the same screen. How about MPEG-4? Should my black be Y=0 or Y=16? Also, I've heard that MPEG-4 has some ability to automatically compensate for different properties of the playback display, like doing different gamma compensation for Mac and PC. If this is so, could anyone offer a brief summary of how this works? Is this source tagged with what the original gamma was, so it can be corrected on playback? Ben Waggoner Interframe Media Digital Video Compression Consulting, Training, and Encoding From the_ether btinternet.com Mon Dec 17 01:29:26 2001 From: the_ether btinternet.com (the_ether) Date: Wed Jul 30 14:07:29 2003 Subject: [M4IF Technotes] Preprocessing for MPEG-4 References: Message-ID: <000b01c186a5$889868a0$8d2a23d9@opsus> You'll be further depressed to learn that MPEG-4 can take a variety of different input formats. Specifically on the dynamic range, there's a flag ('video_range') that can be set by the encoder to tell the decoder whether 0-255 or 16-235 (240 for chrominance) has been used. There are six types of RGB-YCbCr conversion supported: - ITU-R Recommendation BT.709 - Unspecified Video (Image characteristics are unknown) - FCC - ITU-R Recommendation BT.470-2 System B, G - SMPTE 170M - SMPTE 240M (1987) The default is 16-235, ITU-R Recommendation BT.709 So, the answer is, it depends on the encoder, MPEG-4 itself, allows for choice. graham ----- Original Message ----- From: "Ben Waggoner" To: Sent: 16 December 2023 23:53 Subject: [M4IF Technotes] Preprocessing for MPEG-4 > Hello all, > > I've been working on testing some MPEG-4 encoders, and it's been a > difficult slog, since they all support different input formats, and often > seem to be doing different kinds of color space conversions even on the same > source. I long for the idea world where every encoder can use the native > libraries for QuickTime and DirectShow, and can take native YUV codecs as > source without any color space conversions. > > Anyway, I was wondering what kind of preprocessing MPEG-4 is optimized > for. Most video sources will use the 601 luma range of 16-235. Most (but > not all) web delivery codecs expect a luma range of 0-255, where a 0 will > match RGB black elements on the same screen. How about MPEG-4? Should my > black be Y=0 or Y=16? > > Also, I've heard that MPEG-4 has some ability to automatically > compensate for different properties of the playback display, like doing > different gamma compensation for Mac and PC. If this is so, could anyone > offer a brief summary of how this works? Is this source tagged with what > the original gamma was, so it can be corrected on playback? > > > Ben Waggoner > Interframe Media > Digital Video Compression Consulting, Training, and Encoding > > > > _______________________________________________ > Technotes mailing list > Technotes@lists.m4if.org > http://lists.m4if.org/mailman/listinfo/technotes From ravi_biju yahoo.com Mon Dec 17 01:53:57 2001 From: ravi_biju yahoo.com (Biju Ravindran) Date: Wed Jul 30 14:07:29 2003 Subject: [M4IF Technotes] Range of Motion vectors. In-Reply-To: <000b01c186a5$889868a0$8d2a23d9@opsus> Message-ID: <20011217095357.31779.qmail@web12106.mail.yahoo.com> Hi, Could anybody explain in detail about how the range of motion vetcors is definied? In Mpeg-2 the range is given as [-8:+7.5],[-16:+15.5],[-32:+31.5],[-64:+63.5],....[-2048:+2047.5]. Normally if we take a 16x16 macro block the motion vectors will be in the range [-8:+7.5] in half pel res. + . + . + . + . + . + -1 0 1 2 3 4 where, + integer pel position. . half-pel position. What would be the search radius for other ranges such a 16,32,64...2048? What could be the size of macroblock in these cases and how the ME is found? ===== ciao, -biju __________________________________________________ Do You Yahoo!? Check out Yahoo! Shopping and Yahoo! Auctions for all of your unique holiday gifts! Buy at http://shopping.yahoo.com or bid at http://auctions.yahoo.com From khuber sorensontech.com Mon Dec 17 10:53:03 2001 From: khuber sorensontech.com (Kris Huber) Date: Wed Jul 30 14:07:29 2003 Subject: [M4IF Technotes] Range of Motion vectors. Message-ID: <6E031E06378BD311AEF20090273CE1BA409420@el-postino.s-vision.com> Hello Biju, The detailed explanation is given in clause 7.6.3 of the ISO/IEC 14496-2. Look for the corrigenda or use the 2001 version, which has the corrigenda text included, for added clarity in the explanation. Based on your summary of MPEG-2 motion vector ranges, MPEG-4 and MPEG-2 motion vector decoding are not identical. In particular, in MPEG-4 there is no vop_fcode which indicates a range as small as [-8:+7.5]. I am confused, however, by your use of a non-integer value in the upper limit of this motion vector range. If the numbers are expressed in half-pel units as you state, then +7.5 is a quarter-pel position. I did not believe MPEG-2 included quarter-pel motion compensation. Am I wrong? For MPEG-4, the size of the possible search range is indicated in Table 7-5. The intervals given there specify the range around each component of the motion vector (0,0), so the search range is a rectangular region roughly centered around (MVx, MVy)=(0,0). Note that the region is not centered around the predicted value of MV (Px,Py), nor the differential MV (MVDx, MVDy). Because of this, the useful search region depends only upon the value of vop_fcode_forward and/or vop_fcode_backward (specifically, it is not dependent upon the surrounding MV's). Also note that it is possible to reference pixels a large distance outside of the VOP boundary, in which case the motion-compensated prediction data is based on extension of the boundary pixel data. In MPEG-4 the MV decoding process is generic; it is the same for all motion vectors (e.g., 8x8, 16x16, GMC, sprite, interlace, bidirectional, etc.) except that the calculation of the MV prediction vector may be different. Chau (this is the spelling I'm familiar with), Kris -----Original Message----- From: Biju Ravindran [mailto:ravi_biju@yahoo.com] Sent: Monday, December 17, 2023 2:54 AM To: technotes@lists.m4if.org Subject: [M4IF Technotes] Range of Motion vectors. Hi, Could anybody explain in detail about how the range of motion vetcors is definied? In Mpeg-2 the range is given as [-8:+7.5],[-16:+15.5],[-32:+31.5],[-64:+63.5],....[-2048:+2047.5]. Normally if we take a 16x16 macro block the motion vectors will be in the range [-8:+7.5] in half pel res. + . + . + . + . + . + -1 0 1 2 3 4 where, + integer pel position. . half-pel position. What would be the search radius for other ranges such a 16,32,64...2048? What could be the size of macroblock in these cases and how the ME is found? ===== ciao, -biju __________________________________________________ Do You Yahoo!? Check out Yahoo! Shopping and Yahoo! Auctions for all of your unique holiday gifts! Buy at http://shopping.yahoo.com or bid at http://auctions.yahoo.com _______________________________________________ Technotes mailing list Technotes@lists.m4if.org http://lists.m4if.org/mailman/listinfo/technotes From lcheng62 yahoo.com Mon Dec 17 13:43:02 2001 From: lcheng62 yahoo.com (Liang Cheng) Date: Wed Jul 30 14:07:29 2003 Subject: [M4IF Technotes] about IM1's Linux version Message-ID: <20011217214302.70563.qmail@web21106.mail.yahoo.com> Hi, Is there any Linux/Unix based IM1 implementation currently? Thanks a lot! Liang __________________________________________________ Do You Yahoo!? Check out Yahoo! Shopping and Yahoo! Auctions for all of your unique holiday gifts! Buy at http://shopping.yahoo.com or bid at http://auctions.yahoo.com From the_ether btinternet.com Thu Dec 20 00:37:12 2001 From: the_ether btinternet.com (the_ether) Date: Wed Jul 30 14:07:29 2003 Subject: [M4IF Technotes] Location of reference software Message-ID: <008a01c188ee$f990e0a0$872d23d9@opsus> Where can I find the reference software? I have downloaded some code from the ISO site pointed to by the M4IF site, namely: http://www.iso.ch/iso/en/ittf/PubliclyAvailableStandards/14496-5_Compressed_ directories/Visual/ But I suspect that there is another version. I am specifically looking for code that implements 1/4 pel estimation but I couldn't see it in either the MoMusys or Microsoft versions. I searched for key words, skimmed through the files that looked appropriate and finally searched for the numbers 160 or -48: two of the filter coefficients used in 1/4 pel estimation. I came across ISO document N4278 from the group WG11 which referred to code video/natural/microsoft-fdam1-2.3-001213 The name of the last directory is very different to the one that comes in the zip file that can be downloaded from the ISO site pointed to by the M4IF site. The name of that directory is microsoft-vfdis-v10-990812. So all this leads me to believe that there is some more reference software somewhere. Any ideas? graham From ravi_biju yahoo.com Wed Dec 19 20:31:04 2001 From: ravi_biju yahoo.com (Biju Ravindran) Date: Wed Jul 30 14:07:29 2003 Subject: [M4IF Technotes] Location of reference software In-Reply-To: <008a01c188ee$f990e0a0$872d23d9@opsus> Message-ID: <20011220043104.21961.qmail@web12106.mail.yahoo.com> Hi Graham, The latest Mpeg-4 Video Reference Software ISO/IEC 14496 (Mpeg-4) can be downloaded from the following URL http://numbernine.net/robotbugs/mpeg4.htm The reference software from ISO is having some known bugs this one is the latest. The zip file (microsoft-fdam1-2.3-001213.zip) contains the reference software and a user manual is also available. The project files which they supplied will work on Microsoft Visual C++ 6.0, If Microsoft Visual C++5.0 is used, the project files will not work. ===== ciao, -biju __________________________________________________ Do You Yahoo!? Check out Yahoo! Shopping and Yahoo! Auctions for all of your unique holiday gifts! Buy at http://shopping.yahoo.com or bid at http://auctions.yahoo.com From mauri.vaananen nokia.com Thu Dec 20 14:00:15 2001 From: mauri.vaananen nokia.com (mauri.vaananen@nokia.com) Date: Wed Jul 30 14:07:29 2003 Subject: [M4IF Technotes] MPEG-4 AAC LTP Question Message-ID: <58668F4DBAC34F4CBE825FDE661EC1917CB76A@trebe004.NOE.Nokia.com> Dear Padmavathi, Thank you for pointing out this problem. It is a bug in the reference software, the text in the standard is correct. We are working at Nokia to provide a correction to the reference software as soon as possible. Regards, Mauri Vaananen -------------------------------------------- Mauri Vaananen mauri.vaananen@nokia.com Nokia Research Center, Speech and Audio Systems Laboratory Visiokatu 1 (P.O. Box 100), FIN-33721 Tampere, FINLAND tel: +358 7180-35843 fax: -35899 mobile: +358 50 4835843 -----Original Message----- From: ext Padmavathi Volety [mailto:padma_volety@satyam.net.in] Sent: 16 December, 2001 02:22 To: MPEG4 technical notes (E-mail) Subject: [M4IF Technotes] MPEG-4 AAC LTP Question Dear M4IF people, We found that there is difference in the extraction of ltp_short_lag field between reference software (v1refsoft990809) and standard 14496-3 (Table 4.4.28). We observed that Delay calculation of each short window is using ltp_short_lag and Delay of previous window. It is not mentioned in the same way in the standard. Can anybody provide clarification? With Regards, Padmavathi, _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Volety Padmavathi Devi CuTe Solutions Pvt. Ltd., 4-7-145/2, Nagendra Nagar Colony, Habsiguda, Hyderabad-500007, India. Ph:(W) (+)91-40-7153640, 6215879 (H) (+)91-40-7225363, 7225392 -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20011220/da0d7a93/attachment.html From the_ether btinternet.com Thu Dec 20 15:12:06 2001 From: the_ether btinternet.com (the_ether) Date: Wed Jul 30 14:07:29 2003 Subject: [M4IF Technotes] Location of reference software References: <20011220043104.21961.qmail@web12106.mail.yahoo.com> Message-ID: <002001c1896a$17f42720$a12523d9@opsus> Ah Biju, you are a life saver. I have wasted sooo much time on this. Thank you. I am just very angry that the official M4IF site points to out-of-date information. Do you know of the process whereby this code or the MoMuSys code gets updated, if any? I noted that Nokia has stated that there is a bug with AAC code in the ISO reference software and that a fix will be released ("RE: [M4IF Technotes] MPEG-4 AAC LTP Question"). Also, looking at the name of the Microsoft zip file it appears that it dates from Dec 2000 so I was wondering whether any work had been done on it since. Regards graham ----- Original Message ----- From: "Biju Ravindran" To: "the_ether" ; Sent: 20 December 2023 04:31 Subject: Re: [M4IF Technotes] Location of reference software > Hi Graham, > > The latest Mpeg-4 Video Reference Software ISO/IEC > 14496 (Mpeg-4) can be downloaded from the following > URL > http://numbernine.net/robotbugs/mpeg4.htm > > The reference software from ISO is having some known > bugs this one is the latest. > The zip file (microsoft-fdam1-2.3-001213.zip) contains > the reference software and a user manual is also > available. The project files which they > supplied will work on Microsoft Visual C++ 6.0, If > Microsoft Visual C++5.0 is used, the project files > will not work. > > ===== > ciao, > -biju > > __________________________________________________ > Do You Yahoo!? > Check out Yahoo! Shopping and Yahoo! Auctions for all of > your unique holiday gifts! Buy at http://shopping.yahoo.com > or bid at http://auctions.yahoo.com > _______________________________________________ > Technotes mailing list > Technotes@lists.m4if.org > http://lists.m4if.org/mailman/listinfo/technotes From rkoenen intertrust.com Thu Dec 20 07:48:05 2001 From: rkoenen intertrust.com (Rob Koenen) Date: Wed Jul 30 14:07:29 2003 Subject: [M4IF Technotes] Location of reference software Message-ID: <720AE932C238D411B4D100C04F10DA6B04BDA1F7@exchange.epr.com> > I am just very angry that the official M4IF site points to out-of-date > information. The pointer below is interesting, as it points to information that has ISO copyright and M4IF cannot publish without breeching copyright. I am in the process of getting an even more up-to-date version officially published. > Do you know of the process whereby this code or the MoMuSys code gets > updated, if any? I noted that Nokia has stated that there is > a bug with AAC > code in the ISO reference software and that a fix will be > released ("RE: > [M4IF Technotes] MPEG-4 AAC LTP Question"). The Reference SW is an official part of the MPEG-4 standard. It goes through the same revisions as the text. When bugs are discovered, MPEG creates a corrigendum. When new parts are added, this becomes and amendment (read: "addition") > Also, looking at the name of the Microsoft zip file it > appears that it dates > from Dec 2000 so I was wondering whether any work had been > done on it since. Definitely, this is what I was referring to above when I mentioned a new version. Best, Rob Koenen > > http://numbernine.net/robotbugs/mpeg4.htm From the_ether btinternet.com Fri Dec 21 01:12:34 2001 From: the_ether btinternet.com (the_ether) Date: Wed Jul 30 14:07:29 2003 Subject: [M4IF Technotes] Location of reference software References: <720AE932C238D411B4D100C04F10DA6B04BDA1F7@exchange.epr.com> Message-ID: <010901c189bc$a896da00$c61823d9@opsus> Thanks Rob. > The Reference SW is an official part of the MPEG-4 standard. It goes > through the same revisions as the text. When bugs are discovered, MPEG > creates a corrigendum. When new parts are added, this becomes and > amendment (read: "addition") Really? But the reference s/w available from their site appears to date from 1999 and yet it would appear that there have been many versions since then. Why then aren't these amendments available from ISO? There appears to be a disconnect between the official releases of the s/w and paper versions. Presumably this is precisely what you are about to (very kindly) enquire about as you state below. > I am in the process of getting an even more up-to-date version officially > published. > The pointer below is interesting, as it points to information that > has ISO copyright and M4IF cannot publish without breaching copyright. Well although they may own the copyright (in partnership with the contributors), the files state, "ISO/IEC gives users of MPEG-4 Video free license to this software module or modifications thereof for use in hardware or software products claiming conformance to the MPEG-4 Video" and furthermore, "Copyright is not released for non MPEG-4 Video conforming products. " and "This copyright notice must be included in all copies or derivative works." To me all this implies that we are free to copy it. We must merely repeat the copyright notice and can only use this code in MPEG-4 compliant products. No problem. And the original code was free anyway. Why so difficult to get hold of the amendments? Their copyright notice sounds very much like a type of LGPL licence - an open source licence. So really, if I have understood correctly, anyone, whether or not they are a member of M4IF or other, ought to be able to get free access to the latest version. Anyway, you've already stated that you are working on getting an even newer version released, for which I thank you. It will make my life as an individual researcher much easier. Best regards graham From cychoon hotmail.com Fri Dec 21 09:25:07 2001 From: cychoon hotmail.com (Chang Yoong Choon) Date: Wed Jul 30 14:07:29 2003 Subject: [M4IF Technotes] Reference software Error Resilient Message-ID: An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20011221/f647dd8c/attachment.html From rkoenen intertrust.com Thu Dec 20 17:48:03 2001 From: rkoenen intertrust.com (Rob Koenen) Date: Wed Jul 30 14:07:29 2003 Subject: [M4IF Technotes] Location of reference software Message-ID: <720AE932C238D411B4D100C04F10DA6B04BDA226@exchange.epr.com> > Their copyright notice sounds very much like a type of LGPL licence - an > open source licence. So really, if I have understood correctly, anyone, > whether or not they are a member of M4IF or other, ought to be able to get > free access to the latest version. What was also on that site is the text of the standard (outdated btw). It doens't come with such a copyright notice. The difference is not whether you are an M4IF member or not. M4IF members have definite benefits, but access to ISO copyrighted material is not among them. Note that there is a crucial difference between this copyright statement and a GPL license. You can take the MPEG-4 Ref Soft, turn it upside down, change it inside out, add al sorts of fancy stuff, etc., WITHOUT ANY FURTHER OBLIGATION - as long as it is used for implementing MPEG-4 compliant products. The requirements of a GPL are very different. Best, Rob From lmwang hf.tvia.com Fri Dec 21 17:08:22 2001 From: lmwang hf.tvia.com (lmwang) Date: Wed Jul 30 14:07:30 2003 Subject: [M4IF Technotes] where is the latest system reference code? Message-ID: <005501c189ff$0a411df0$6902a8c0@hf.tvia.com> Hi people, Who know where can download the latest system reference code, I think the reference code which m4if link to is too old and have many bugs, thanks, Limin Wang, -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20011221/e95018f2/attachment.html From lmwang hf.tvia.com Fri Dec 21 17:22:52 2001 From: lmwang hf.tvia.com (lmwang) Date: Wed Jul 30 14:07:30 2003 Subject: [M4IF Technotes] where is the latest system reference code? References: Message-ID: <005b01c18a01$10d7e7f0$6902a8c0@hf.tvia.com> hi Vinayagam.M, Thanks for your immediate answer, but I want system part reference code, your linking support video part only. Do you know where to get it or send me one copy directly. thanks , have a good Xmas, Limin Wang, Software Department ----- Original Message ----- From: To: "lmwang" Sent: Friday, December 21, 2023 5:18 PM Subject: Re: [M4IF Technotes] where is the latest system reference code? > > Hi Limin Wang, > Please use the latest release of this software which has many problems > solved and has more documentation. You can get it from > http://numbernine.net/robotbugs/mpeg4.htm > > Regards, > Vinayagam.M > L&T Infotech > Chennai, Tamil Nadu, > India > > > > > "lmwang" > To: > Sent by: cc: > technotes-admin@list Subject: [M4IF Technotes] where is the latest > s.m4if.org system reference code? > > > 12/21/01 02:38 PM > > > > > > > Hi people, > > Who know where can download the latest system reference code, I think the > reference code which m4if link to is too old and have many bugs, > > thanks, > Limin Wang, > > > From jtavares av.it.pt Fri Dec 21 16:44:46 2001 From: jtavares av.it.pt (Joao Tavares) Date: Wed Jul 30 14:07:30 2003 Subject: [M4IF Technotes] Reference software Error Resilient References: Message-ID: <004101c18a3e$ccdb15c0$a95c88c1@av.it.pt> Dear Chang: Error concealment is implementation specific, although ISO MPEG-4 supports it. For instance, Synchronization Markers, Data Partitioning, RVLC and HEC field allow for error concealment mechanisms to be implemented in the decoder. Microsoft MPEG-4 Visual reference software does not have error concealment functions implement but MoMuSys does. MoMuSys software can't also decode bitstreams with errors. Important checks for error detection are missing in both the software packages. _______________________________ Joao Tavares IT - Instituto das Telecomunicacoes Universidade de Aveiro Campus Universitario de Santiago 3810-193 AVEIRO - PORTUGAL Tel +351 234 377900 Fax +351 234 377901 ________________________________ ----- Original Message ----- From: Chang Yoong Choon To: technotes@lists.m4if.org Sent: Friday, December 21, 2023 1:25 AM Subject: [M4IF Technotes] Reference software Error Resilient Dear All: I am using Microsoft ISO MPEG-4 reference software. Whenever I try to decode MPEG-4 bitstream with errors, the decoder will crash or stop decoding. According to ISO MPEG-4 reference software manual, the current decoder supports error resilient bitstream but does not have error recovery, error detection, error concealment functions. In other words, whenever the decoder encounter bitstream error during decoding process, it will stop decoding. Where can I find MPEG-4 decoder that support error resilient and have error detection, error detection, error recovery, error concealment functions? How can I modify the Microsoft MPEG-4 refernece software so that it can decode bitstream with errors? Which file in the source code should I modify? Does MoMuSys MPEG-4 reference software decoder support error resilient functions? Can the decoder decode MPEG-4 bitstream with errors? Many thanks for your help. regards Yoong-Choon Chang ------------------------------------------------------------------------------ Get your FREE download of MSN Explorer at http://explorer.msn.com. _______________________________________________ Technotes mailing list Technotes@lists.m4if.org http://lists.m4if.org/mailman/listinfo/technotes -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20011221/dc96dcfc/attachment.html From khuber sorensontech.com Fri Dec 21 09:47:40 2001 From: khuber sorensontech.com (Kris Huber) Date: Wed Jul 30 14:07:30 2003 Subject: [M4IF Technotes] Reference software Error Resilient Message-ID: <6E031E06378BD311AEF20090273CE1BA409430@el-postino.s-vision.com> Hello Yoong-Choon, Yes, I think what you say is true of the reference software not handling bitstreams with errors. Many parts of error resilience you are free to do as you wish, as there are various ways of doing it. I'm sure there are technical papers and likely companies and consultants that can help figure out how to do that, or to do it outright. At some point during the standardization process I think there were experiments to prove that the error-resilient syntax elements provided were sufficient to implement effective error resilience (or something sufficient to achieve consensus on the technical merit of the syntax), but the reference software does not necessarily include non-normative features. A conformant a decoder is free to crash in the case of a bitstream error, just as the reference software does, or it may do something very simple like produce black VOPs until the next video sequence comes along. What the conformant decoder (of profiles including the error-resilience tools) must do is to properly decode the error-resilient syntax when there are no bitstream errors. This ensures that encoders can safely use the error-resilient syntax in the broadcast situation, for example, instead of having to transmit a version for the reliable channels and another version for the error-prone channels. Such an approach has the potential to be more bandwidth-efficient overall (the dual-channel approach is still possible using MPEG video, of course). For decoders operating at the end of an error-prone link, what is done with the syntax elements designed to enable error-resilience becomes more important. But what is appropriate is an implementation decision that depends upon how much computation and memory is available at the decoder, not to mention the error characteristics of the particular channel and the encoder's usage of the syntax. The market is left to sort out and ultimately decide among the numerous possibilities for the error-resient decoder functionality. Regards, Kris -----Original Message----- From: Chang Yoong Choon [mailto:cychoon@hotmail.com] Sent: Thursday, December 20, 2023 6:25 PM To: technotes@lists.m4if.org Subject: [M4IF Technotes] Reference software Error Resilient Dear All: I am using Microsoft ISO MPEG-4 reference software. Whenever I try to decode MPEG-4 bitstream with errors, the decoder will crash or stop decoding. According to ISO MPEG-4 reference software manual, the current decoder supports error resilient bitstream but does not have error recovery, error detection, error concealment functions. In other words, whenever the decoder encounter bitstream error during decoding process, it will stop decoding. Where can I find MPEG-4 decoder that support error resilient and have error detection, error detection, error recovery, error concealment functions? How can I modify the Microsoft MPEG-4 refernece software so that it can decode bitstream with errors? Which file in the source code should I modify? Does MoMuSys MPEG-4 reference software decoder support error resilient functions? Can the decoder decode MPEG-4 bitstream with errors? Many thanks for your help. regards Yoong-Choon Chang _____ Get your FREE download of MSN Explorer at http://explorer.msn.com . _______________________________________________ Technotes mailing list Technotes@lists.m4if.org http://lists.m4if.org/mailman/listinfo/technotes -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20011221/95e84c7b/attachment.html From tomotohara yahoo.com Fri Dec 21 09:08:35 2001 From: tomotohara yahoo.com (Tomo) Date: Wed Jul 30 14:07:30 2003 Subject: [M4IF Technotes] Reference software Error Resilient In-Reply-To: <6E031E06378BD311AEF20090273CE1BA409430@el-postino.s-vision.com> Message-ID: <20011221170835.54751.qmail@web10507.mail.yahoo.com> Hello. I think this is one of the portions left open to "decoder system" designer and it is one of the technologies that each indivisual or corporation can add proprietary algorithm. There are several technical papers. Even MPEG-2, I noticed certian DVD players are very stable against stream errors, but some not-well-designed DVD players hang up very miserablly. --- Kris Huber wrote: > Hello Yoong-Choon, > > Yes, I think what you say is true of the reference software not > handling > bitstreams with errors. Many parts of error resilience you are free > to do > as you wish, as there are various ways of doing it. I'm sure there > are > technical papers and likely companies and consultants that can help > figure > out how to do that, or to do it outright. At some point during the > standardization process I think there were experiments to prove that > the > error-resilient syntax elements provided were sufficient to implement > effective error resilience (or something sufficient to achieve > consensus on > the technical merit of the syntax), but the reference software does > not > necessarily include non-normative features. A conformant a decoder > is free > to crash in the case of a bitstream error, just as the reference > software > does, or it may do something very simple like produce black VOPs > until the > next video sequence comes along. What the conformant decoder (of > profiles > including the error-resilience tools) must do is to properly decode > the > error-resilient syntax when there are no bitstream errors. This > ensures > that encoders can safely use the error-resilient syntax in the > broadcast > situation, for example, instead of having to transmit a version for > the > reliable channels and another version for the error-prone channels. > Such an > approach has the potential to be more bandwidth-efficient overall > (the > dual-channel approach is still possible using MPEG video, of course). > For > decoders operating at the end of an error-prone link, what is done > with the > syntax elements designed to enable error-resilience becomes more > important. > But what is appropriate is an implementation decision that depends > upon how > much computation and memory is available at the decoder, not to > mention the > error characteristics of the particular channel and the encoder's > usage of > the syntax. The market is left to sort out and ultimately decide > among the > numerous possibilities for the error-resient decoder functionality. > > Regards, > Kris > > -----Original Message----- > From: Chang Yoong Choon [mailto:cychoon@hotmail.com] > Sent: Thursday, December 20, 2023 6:25 PM > To: technotes@lists.m4if.org > Subject: [M4IF Technotes] Reference software Error Resilient > > > Dear All: > > I am using Microsoft ISO MPEG-4 reference software. Whenever I try to > decode > MPEG-4 bitstream with errors, the decoder will crash or stop > decoding. > According to ISO MPEG-4 reference software manual, the current > decoder > supports error resilient bitstream but does not have error recovery, > error > detection, error concealment functions. In other words, whenever the > decoder > encounter bitstream error during decoding process, it will stop > decoding. > > Where can I find MPEG-4 decoder that support error resilient and have > error > detection, error detection, error recovery, error concealment > functions? > > How can I modify the Microsoft MPEG-4 refernece software so that it > can > decode bitstream with errors? Which file in the source code should I > modify? > > Does MoMuSys MPEG-4 reference software decoder support error > resilient > functions? Can the decoder decode MPEG-4 bitstream with errors? > > Many thanks for your help. > > regards > Yoong-Choon Chang > > _____ > > Get your FREE download of MSN Explorer at http://explorer.msn.com > . > _______________________________________________ Technotes mailing > list > Technotes@lists.m4if.org > http://lists.m4if.org/mailman/listinfo/technotes > > ===== Tomo __________________________________________________ Do You Yahoo!? Check out Yahoo! Shopping and Yahoo! Auctions for all of your unique holiday gifts! Buy at http://shopping.yahoo.com or bid at http://auctions.yahoo.com From rkoenen intertrust.com Fri Dec 21 14:30:57 2001 From: rkoenen intertrust.com (Rob Koenen) Date: Wed Jul 30 14:07:30 2003 Subject: [M4IF Technotes] Reference software Error Resilient Message-ID: <720AE932C238D411B4D100C04F10DA6B04BDA254@exchange.epr.com> Exactly. It should be clear that the objective of providing reference code is not to help everyone in business with highly optimized software at no cost. While setting an interoperable standard, MPEG must leave room for competition between vendors, and must also see to it that contributors to the standard are not asked to give away their competitive advantages. Only the elements needed for interoperability are standardized. Hence: - there is no standardized encoder, and don't expect the reference encoder to be optimized (Although there is another part of the MPEG-4 Standard, part 7, which *will* provide a video encoder that is optimized. This is going to be published early next year.) - Do not expect reference decoders to be optimized beyond what it normative. Error resilience tools are there to help a decoder cope with non-compliant bitstreams that can occur as a result of errors. The response to such non-compliant bitstreams is not normatively prescribed in the standard. The tools have been shown to allow implementations to do a pretty decent job at coping with errors, but these implementations are private to the companies that built them. Rob > -----Original Message----- > From: Tomo [mailto:tomotohara@yahoo.com] > Sent: Friday, December 21, 2023 9:09 > To: Kris Huber; 'Chang Yoong Choon' > Cc: technotes@lists.m4if.org > Subject: RE: [M4IF Technotes] Reference software Error Resilient > > > Hello. > > I think this is one of the portions left open to "decoder system" > designer and it is one of the technologies that each indivisual > or corporation can add proprietary algorithm. There are several > technical papers. > > Even MPEG-2, I noticed certian DVD players are very stable against > stream errors, but some not-well-designed DVD players hang up > very miserablly. > > From cychoon hotmail.com Sat Dec 22 08:44:19 2001 From: cychoon hotmail.com (Chang Yoong Choon) Date: Wed Jul 30 14:07:30 2003 Subject: [M4IF Technotes] Reference software Error Resilient Message-ID: An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20011222/8e920c95/attachment.html From lmwang hf.tvia.com Sun Dec 23 18:54:38 2001 From: lmwang hf.tvia.com (lmwang) Date: Wed Jul 30 14:07:30 2003 Subject: [M4IF Technotes] where can get The latest version of the 2D player (source+binary)? Message-ID: <000e01c18ba0$37d579d0$6902a8c0@hf.tvia.com> Hi folks, Now I cann't visit http://www.cselt.it/ufv/im1/ website, I don't know what's happened, who can tell me a new link to get 2D player or send me one copy directly, thanks, Limin Wang, software engineer -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20011223/104734d2/attachment.html From cychoon hotmail.com Fri Dec 21 09:25:07 2001 From: cychoon hotmail.com (Chang Yoong Choon) Date: Wed Jul 30 14:07:50 2003 Subject: [M4IF Technotes] Reference software Error Resilient Message-ID: An HTML attachment was scrubbed... URL: /pipermail/mp4-tech/attachments/20011221/f647dd8c/attachment-0001.html