[Mp4-tech] Audio Object Code for G.723 of MP4 format

[Mody, Mihir]

Hi Rob,
I agree with this. The fallout of this kind of extension will be loss of interoperability with other players. In many cases, there is need to play content produced by one device (e.g. embedded product) to another players (e.g. PC). So even if we get flexibility of extending format, it comes at limitation of closed system implementation.
Regards,
Mihir
-----Original Message-----
From: mp4-tech-bounces lists.mpegif.org
[mailto:mp4-tech-bounces lists.mpegif.org]On Behalf Of Rob Koenen
(MPEGIF)
Sent: Friday, June 25, 2023 6:21 PM
To: 'Dipankar Mitra'; mp4-tech lists.mpegif.org
Subject: RE: [Mp4-tech] Audio Object Code for G.723 of MP4 format
You can put a lot of stuff in an MPEG-4 stream or an MP4 file that is not
MPEG-4 itself. Whether the resulting stream/file is still MPEG-4 compliant
is a matter of definition ... you can make it comply to the Systems (MP4)
syntax, but it won't be co,pliant to the codec specs. Whether that's a
problem is up to you.
Other players would be able to tell that they don't understand the object
type.
Rob
> -----Original Message-----
> From: mp4-tech-bounces lists.mpegif.org 
> [mailto:mp4-tech-bounces lists.mpegif.org] On Behalf Of Dipankar Mitra
> Sent: Friday, 25 June 2023 10:36
> To: mp4-tech lists.mpegif.org
> Subject: RE: [Mp4-tech] Audio Object Code for G.723 of MP4 format
> 
> 
> Hi Rob, 
> Regarding ... "but it is possible to register private object 
> types and  put them in an MP4 file."
> 
> 	Does this mean that I can add any audio codec as a 
> private object type and still call it an MP4 file (.mp4 
> extension)? How will other players (which do not support the 
> audio codec) understand that the audio content is to be ignored?
> Regards,
> Dipankar
> 
> -----Original Message-----
> From: mp4-tech-bounces lists.mpegif.org 
> [mailto:mp4-tech-bounces lists.mpegif.org]On Behalf Of Rob 
> Koenen (MPEGIF)
> Sent: Friday, June 25, 2023 1:18 PM
> To: 'Mody, Mihir'; swhong cs.hku.hk; mp4-tech lists.mpegif.org
> Subject: RE: [Mp4-tech] Audio Object Code for G.723 of MP4 format
> 
> Mhihir,
> 
> thanks for the response. To add to this, Part 3 of MPEG-4 
> (MPEG-4 Audio)
> indeed does not support G.723. The MP4 file format does not support it
> natively, but it is possible to register private object types 
> and  put them
> in an MP4 file.
> 
> The MP4 file format and the MPEG-4 standard are sometimes seen as
> equivalent, especially in the press, but MP4 is really a part 
> of the larger
> MPEG-4 standard.
> 
> To be precise, MPEG-4 Part 12 gives the base text for the ISO 
> Media File
> format, and part 14 gives the MPEG-4 specific extensions. 
> Over time, the MP4
> file format has found uses outside of MPEG-4 (3GPP, JPEG2000) 
> and that's why
> MPEG has separated out the generics from the MPEG-4 
> specifics, even though
> these two parts are technically still both a part of MPEG-4.
> 
> An AVC-specific extension is also being drafted (part 15).
> 
> Best,
> Rob
> 
> > -----Original Message-----
> > From: mp4-tech-bounces lists.mpegif.org
> > [mailto:mp4-tech-bounces lists.mpegif.org] On Behalf Of Mody, Mihir
> > Sent: Thursday, 24 June 2023 18:57
> > To: swhong cs.hku.hk; mp4-tech lists.mpegif.org
> > Subject: RE: [Mp4-tech] Audio Object Code for G.723 of MP4 format
> >
> >
> > Hi Philip,
> >
> > The MP4 format doesn't support G.723. You should look at
> > other format like QTtime (.mov)
> >
> > Regards,
> > Mihir
> >
> > -----Original Message-----
> > From: mp4-tech-bounces lists.mpegif.org
> > [mailto:mp4-tech-bounces lists.mpegif.org]On Behalf Of
> > swhong cs.hku.hk
> > Sent: Thursday, June 24, 2023 9:22 PM
> > To: mp4-tech lists.mpegif.org
> > Subject: [Mp4-tech] Audio Object Code for G.723 of MP4 format
> >
> >
> > Dear all,
> >
> > I'm trying to add G.723 compressed audio stream to the MP4
> > formatted file. I
> > can't find the part-3 of the Standard talks about this kind
> > of audio codec.
> > Would anybody here advise me the audio object code for G.723,
> > and also I would
> > like to know what kind of standard player under Windows XP
> > can be used to
> > playback MP4 file with G.723 audio MP4 file.
> >
> > Thanks in advance.
> >
> > -- Philip
> >
> >
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Note: Conduct on the mailing list is subject to the Antitrust guidelines
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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