[FFmpeg-devel] Mpeg4 audio in TS

[Nico Sabbi]

On Friday 18 April 2008 08:24:38 Vamsi Krishna wrote:
> Hello,
>
>  I am working on Mpeg-4 TS with HEAAC audio in LATM transport
> syntax ( 14496-3 ).
>
>  I tried extracting the mpeg-4 ES from the TS.  And I am unable
> decode the ES using the ISO reference software.  I tried using both
> decoders - mp4mcdec and mp4audVM_rewrite.
>
>
>  *Mp4mcdec *? results in
>
> *" ADTS Syncword error "                                    *
>
> *Warning: missing ADTS-syncword... trying RAW*
>
> *Warning: ICS - reserved bit is not set to 0           *
>
>
>
> ? this doesnot support LATM audio syntax.
>
>  And
>
>  *Mp4audVM_rewrite* ? results in the following errors:
>
>  *mp4audec: WARNING: BsOpenFileRead: magic string error (found "V?=
> ", need ".mp4")*
>
> *StreamFile:openRead(LATM): error opening bit stream for reading*
>
> *mp4audec: WARNING: BsOpenFileRead: magic string error (found "V?=
> ", need ".mp4")*
>
> *mp4audec: WARNING: StreamFile:openRead: can not determine file
> format*
>
> *mp4audec: WARNING: error decoding audio file xyz.mp4*
>
>
> My stream starts with  0x5E 0x61 ?.
>
>  I could not find the syncword 0x2B7 at the beginning of my stream.
>
>
> can you please help me out to decode the LATM audio stream.
>
> And it ll also be helpful, if you can provide some information on
> LATM syntax.
>

it's one of the  the shittiest messes ever in iso specs, with an
endless series of addenda, corrigenda and undefined configurations

>
>
> Thank you in advance.

a few steps away in the svn repository there's all the code you need:
mplayer's copy of libfaad contains the LATM demuxer (in syntax.c)
and the necessary hook in decoder.c.
But mind that I wrote it as GPL, not LGPL and I will not relicense it.