[FFmpeg-devel] MP4A-LATM support?

[Alex Converse]

On Wed, Nov 11, 2009 at 8:54 AM, Luca Abeni <lucabe72 at email.it> wrote:
> Hi all,
>
> a patch was recently posted to implement support for MP4A-LATM in RTP.
> I am currently working on that patch, and I am trying to understand
> what's the better way to implement such functionality...
>
> In order to avoid duplicate work and to prepare a patch that is not
> consistent with the rest of ffmpeg, I have some questions about
> MP4A-LATM:
> 1) It seems to me that libavformat and libavcodec do not currently
> ? support it... Is anyone working on LATM support?

Some guy was working on LATM demux in the past but we haven't heard
from him in a while. Still, he sent some code to ffmpeg-devel that you
might be able to salvage.

> 2) Does anyone know where can I find some freely available information
> ? about LATM?

No way, by making the standards cost money, they can justify delaying
publication to give MPEG members a huge leg up implementing these
standards.

> 3) The submitted patch rework the RTP muxer to accept "regular" AAC, and
> ? to add some LATM header to it before RTP packetisation. But I got the
> ? impression that maybe a bitstream filter can be a better idea...
> ? Can anyone with some experience with LATM comment on this? If LATM
> ? support for other formats will be implemented, how will it work?
> ? Through a bitstream filter, or directly in the muxer?
>

In the past, the consensus has been bitstream filter.