[Mp4-tech] info/links needed regarding packetizing, muxing
bdr bdr
gemini.bdr gmail.com
Thu Dec 1 12:35:36 ESTEDT 2005
Hi Praveen ,
currently iam working on mpeg-2 transport stream(demux) , i
have few quries regarding this ,how to identify version changes , what
parameters should be considered in identifying the version changes .i hope
you can clear me from your earlier knowledge on mpeg-2 muxing .
waiting for your reply .
Rgds
gemini.
On 11/30/05, mp4-tech-request lists.mpegif.org <
mp4-tech-request lists.mpegif.org> wrote:
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> Today's Topics:
>
> 1. (no subject) (Qiu Qiuping)
> 2. [Mp4-tech][systems][ISO-fileformat] timescale in mvhd and
> mdhd (Girish Shenoy)
> 3. Re: mp4v content in 3gp files (Magnus Hoem)
> 4. Re: mp4v content in 3gp files (Girish Shenoy)
> 5. info/links needed regarding packetizing, muxing mpeg4 a/v
> streams and AVI format (Praveen SINGH)
> 6. [MP4 Format] Number of chunks in the last run of STSC atom
> (Jayant Chauhan)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Wed, 30 Nov 2023 11:09:50 +0800
> From: "Qiu Qiuping" <qpqiu trident.com.cn>
> Subject: [Mp4-tech] (no subject)
> To: <mp4-tech lists.mpegif.org>
> Message-ID: <707EF4D95EF97A44B63D407B7953306501AC6780 tmtpms.TMT.COM>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Dear Experts,
> I have a question regarding h.264 decoder implementation. How to output
> pictures in DPB to display, especially, when there is no SEI information
> available?
> Who can help me, thanks.
>
> Qiuping Qiu
>
>
> ------------------------------
>
> Message: 2
> Date: Wed, 30 Nov 2023 10:57:31 +0530
> From: Girish Shenoy <girish dgbmicro.com>
> Subject: [Mp4-tech][systems][ISO-fileformat] timescale in mvhd and
> mdhd
> To: mp4-tech lists.mpegif.org
> Message-ID: <438D3843.5050908 dgbmicro.com>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Hi All,
>
> In the case where an iso format file has multiple tracks what would be
> the value of timescale field in mvhd?
>
> The following possibilities cross my mind:
> 1. It has to be the LCM of the timescales in the mdhd box with the
> respective mdhd boxes maintaining their natural timescales.
> 2. Use the LCM of timescales of all tracks to populate mvhd and all
> mdhd boxes (ie all the mdhd and mvhd in the file have the same value in
> timescale field; namely the LCM) and the decode/composition deltas for
> each track need to be multiplied with the factor obtained by dividing
> the LCM-Timescale with the track's natural timescale.
> 3. Mvhd timescale is not too relevant. The mdhd timescales need to
> necessarily match the natural timescales of the corresponding track.
> Timescale in mvhd does not matter.
>
> Which one of the above (or otherwise) is the accepted way to populate
> mvhd and mdhd timescales?
>
> Regards,
> Girish
>
> ------------------------------
>
> Message: 3
> Date: Wed, 30 Nov 2023 07:34:15 +0100
> From: Magnus Hoem <magnus.hoem popwire.com>
> Subject: Re: [Mp4-tech] mp4v content in 3gp files
> To: Girish Shenoy <girish dgbmicro.com>
> Cc: mp4-tech lists.mpegif.org
> Message-ID: <A1CA4001-4BAB-464C-B044-05D2318F90C0 popwire.com>
> Content-Type: text/plain; charset=ISO-8859-1; delsp=yes; format=flowed
>
> Hi Girish,
> mp4 and 3gpp are basically the same format, but there are minor
> diifferences. In mp4 the iods-box is mandatory (if I remember
> correctly), and it is not in 3gp. It is however not surprising that
> QT can play both (they claim to support both, and can create both
> types correctly). Mp4 supports mpeg4 and H264 video along with AAC
> audio. 3gpp can also contain H263 video and AMR audio, (which is not
> supported in mp4).
>
> About the mp4v-file. Since the release of the video-enabled iPod
> there is some confusion about this extension. It used to be a 14496-2
> (mpeg4) elementary stream, but now Apple uses it for a more or less
> regular mov/3gpp-file with mpeg4 or h264 content (along with AAC
> audio) to be played on the iPod. Which one are you refering to? I
> think QT will have a problem playing the elementary stream, but if
> you insert it correctly into a mov, 3gp or mp4 container it should
> not be a problem at all. The iPod file should of course not cause a
> problem in QT.
>
> Best regards,
> Magnus
>
> On 28 nov 2005, at 15.21, Girish Shenoy wrote:
>
> > Hi All,
> >
> > First, I note that Quicktime (and also RealPlayer) plays .mp4 files
> > (i played some mp4 files successfully).
> > Also both these are able to play .3gp files with non-mp4 content (I
> > played some files successfully here too).
> > In fact the 3gp file format uses the format defined my mp4 to store
> > the mpeg-4 content.
> >
> > I noticed that I am not able to play 3gp files with mp4v content
> > using either of the players. Quicktime gives me an error -2010
> > "movie contains some invalid data" (quicktime player 7.0.3).
> >
> > Certain other open source (linux based) players are however able to
> > play the same files. Theoretically any player able to play 3gp file
> > and mp4 files should be able to play mp4v content from a 3gp
> > file.Since both 3gp and mp4 files are essentially the same base
> > format, I examined the mp4 file that was played successfully. The
> > only difference I found was that this mp4 file had an additional
> > "iods" box/atom.
> >
> > But the "iods" box/atom is not a mandatory box and in fact the 3gpp
> > file format spec mentions that these mpeg-4 architectural elements
> > need not be present and shall be ignored.
> >
> > Am I wrong in saying that iods is not required, is this the problem?
> > Has anyone else faced this problem? Anybody know any answers?
> >
> > I would be grateful to any information on the above.
> >
> > Thanks in advance,
> > Girish
> > _______________________________________________
> > 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
>
> **********************************************
> Popwire Technology
> Magnus Hoem
> Senior Research Engineer
> magnus.hoem popwire.com
> Årstaängsvägen 19 B
> Box 47612
> SE-117 94 Stockholm, Sweden
>
> Phone: +46 8 579 116 00
> Direct: +46 8 579 112 12
> Mobile: +46 733 25 44 34
>
> http://www.popwire.com
> ***********************************************
>
> This message, including any attachments may contain confidential and
> privileged material; it is intended only for the person to whom it is
> addressed. Its contents do not constitute a commitment by Popwire except
> where provided for in a written and undersigned agreement.
>
>
>
>
>
> ------------------------------
>
> Message: 4
> Date: Wed, 30 Nov 2023 12:47:02 +0530
> From: Girish Shenoy <girish dgbmicro.com>
> Subject: Re: [Mp4-tech] mp4v content in 3gp files
> To: Magnus Hoem <magnus.hoem popwire.com>
> Cc: mp4-tech lists.mpegif.org
> Message-ID: <438D51EE.2010901 dgbmicro.com>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Thanks Magnus !
>
> As it always happens, one struggles for an answer for days and finally
> decides to write to a forum to get help. Just after that is done, one
> finds his answer.
>
> I did not have any mp4v files. I was having a .3gp file with mp4v
> content and a .mp4 file with mp4v content.
> .mp4 plays OK.
> .3gp had a problem.
>
> The answer to the problem as I discovered was simple. There seems to be
> a problem with the decoder-specific-info (the concatenated VO headers)
> in the problematic file. Just out of curiosity I just replaced the
> decoder specific info in the problematic file with the same from the
> file which was being successfully played by QT. Although in a strict
> sense, the exercise I did was outrageous, the results were pleasing.
> (Probably because the video in both files had similar properties). And
> lo!! QT started playing the file.
>
> Now I am in the process of analyzing both decoder specific info from
> both files to get to the bottom of it. Once that happens, I guess I will
> update this thread with the root cause (if it is relevant to the members).
>
> Btw!! thanks a lot Magnus for all that information. I was not aware of
> many of the facts you presented.
>
> Thanks,
> Girish
>
>
> Magnus Hoem wrote:
>
> > Hi Girish,
> > mp4 and 3gpp are basically the same format, but there are minor
> > diifferences. In mp4 the iods-box is mandatory (if I remember
> > correctly), and it is not in 3gp. It is however not surprising that
> > QT can play both (they claim to support both, and can create both
> > types correctly). Mp4 supports mpeg4 and H264 video along with AAC
> > audio. 3gpp can also contain H263 video and AMR audio, (which is not
> > supported in mp4).
> >
> > About the mp4v-file. Since the release of the video-enabled iPod
> > there is some confusion about this extension. It used to be a 14496-2
> > (mpeg4) elementary stream, but now Apple uses it for a more or less
> > regular mov/3gpp-file with mpeg4 or h264 content (along with AAC
> > audio) to be played on the iPod. Which one are you refering to? I
> > think QT will have a problem playing the elementary stream, but if
> > you insert it correctly into a mov, 3gp or mp4 container it should
> > not be a problem at all. The iPod file should of course not cause a
> > problem in QT.
> >
> > Best regards,
> > Magnus
> >
> > On 28 nov 2005, at 15.21, Girish Shenoy wrote:
> >
> >> Hi All,
> >>
> >> First, I note that Quicktime (and also RealPlayer) plays .mp4 files
> >> (i played some mp4 files successfully).
> >> Also both these are able to play .3gp files with non-mp4 content (I
> >> played some files successfully here too).
> >> In fact the 3gp file format uses the format defined my mp4 to store
> >> the mpeg-4 content.
> >>
> >> I noticed that I am not able to play 3gp files with mp4v content
> >> using either of the players. Quicktime gives me an error -2010
> >> "movie contains some invalid data" (quicktime player 7.0.3).
> >>
> >> Certain other open source (linux based) players are however able to
> >> play the same files. Theoretically any player able to play 3gp file
> >> and mp4 files should be able to play mp4v content from a 3gp
> >> file.Since both 3gp and mp4 files are essentially the same base
> >> format, I examined the mp4 file that was played successfully. The
> >> only difference I found was that this mp4 file had an additional
> >> "iods" box/atom.
> >>
> >> But the "iods" box/atom is not a mandatory box and in fact the 3gpp
> >> file format spec mentions that these mpeg-4 architectural elements
> >> need not be present and shall be ignored.
> >>
> >> Am I wrong in saying that iods is not required, is this the problem?
> >> Has anyone else faced this problem? Anybody know any answers?
> >>
> >> I would be grateful to any information on the above.
> >>
> >> Thanks in advance,
> >> Girish
> >> _______________________________________________
> >> 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
> >
> >
> > **********************************************
> > Popwire Technology
> > Magnus Hoem
> > Senior Research Engineer
> > magnus.hoem popwire.com
> > Årstaängsvägen 19 B
> > Box 47612
> > SE-117 94 Stockholm, Sweden
> >
> > Phone: +46 8 579 116 00
> > Direct: +46 8 579 112 12
> > Mobile: +46 733 25 44 34
> >
> > http://www.popwire.com
> > ***********************************************
> >
> > This message, including any attachments may contain confidential and
> > privileged material; it is intended only for the person to whom it is
> > addressed. Its contents do not constitute a commitment by Popwire except
> > where provided for in a written and undersigned agreement.
> >
> >
> >
> >
>
>
> ------------------------------
>
> Message: 5
> Date: Wed, 30 Nov 2023 15:31:35 +0530
> From: Praveen SINGH <praveen.singh st.com>
> Subject: [Mp4-tech] info/links needed regarding packetizing, muxing
> mpeg4 a/v streams and AVI format
> To: <mp4-tech lists.mpegif.org>
> Message-ID: <004801c5f595$0cd2a1f0$1216b40a dlh.st.com>
> Content-Type: text/plain; charset="utf-8"
>
> Hello,
>
> I have just started with MPEG-4. It would be very kind if someone can send
> some basic materials and/or links for the below.
>
> 1) AVI format.
> 2) Packetising & Multiplexing mpeg4 video and audio.
>
>
> Thanks and Best Regards,
> Praveen
> PS: I have earlier knowledge for mpeg2 pes and muxing.
>
>
>
> ------------------------------
>
> Message: 6
> Date: Wed, 30 Nov 2023 15:42:54 +0530
> From: Jayant Chauhan <gripened gmail.com>
> Subject: [Mp4-tech] [MP4 Format] Number of chunks in the last run of
> STSC atom
> To: mp4-tech lists.mpegif.org
> Message-ID:
> <5b996acb0511300212h5eafdb67u2e24fce1d4a173cf mail.gmail.com>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Hey guys,
> Just wondering, is there an easier and coherent way of finding out the
> number of Chunks for the last run of similar chunks in an MP4 file from
> the
> STSC atom?! Because, to find the number of chunks in a particular run, we
> need the index for the current and the next run. But for the last run, we
> have no further info, so we need to know the number of samples before hand
> to be able to do this right ?!? Can somebody please tell me how to do it
> if
> we dont have prior knowledge of the Total Sample numbers in a track?!
>
> regards
> Jayant
>
> PS - Btw, does ne one have a MP4 parser which can parse an MP4 file if we
> just pass it a fixed size of packets from the file, instead of having the
> complete file to parse at a time ?! Am trying to make a filter for the
> parser, but the DirectShow requires that I pass the Parser filter a fixed
> size from the FileSourceFilter (IAsyncReader)
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> ------------------------------
>
> _______________________________________________
> 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.
>
> 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
>
> End of Mp4-tech Digest, Vol 28, Issue 28
> ****************************************
>
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