[FFmpeg-devel] [PATCH] Add support for private PES streams in mpegts and support for application decoding the stream

[Baptiste Coudurier]

Sebastian Cabot wrote:
> On Sun, May 31, 2009 at 7:05 AM, Baptiste Coudurier
> <baptiste.coudurier at gmail.com> wrote:
>> Sebastian, can you please tell us what do you need to be able to handle
>> these streams outside libavformat ?
>>
> 
> Yes. No problem.
> 
> We have private streams in mpegts of type private_stream_2. I need to
> get the data with in.
> 
> At first I wrote a special codec as part of libavcodec and inside the
> TS muxer started dealing with all the stream types separately.
> 
> It occured to me that this is bad practice. Also having to recompile
> and link all the library when a change was made is not great. Further
> more since ffmpeg is LGPL it would be best not to keep private code as
> part of the main library code.
> 
> I didn't want to change mpegts muxer to return all streams without a
> codec Id or type since I didn't know what else that would break. Also
> even If I returned all streams then I would not get the stream_type
> back since that is only know once the PAT is processed.
> 
> So I got to the conclusion that separating the private code into the
> user domain would be the best approach.
> Since I couldn't find any way of dynamically loading codecs and there
> is no support for that in the ts demuxer I just chose the simplest
> way.
> 
> So I don't know what all this codec tagging is or how probe will help
> me unless of course I write my own codec. How ever I saw that at least
> in the ts demuxer only video is probed. Is this so?

Every streams are probed now, and all streams are exported with stream_type
stored in AVCodecContext->codec_tag, which should permit you to identify
streams.

-- 
Baptiste COUDURIER                              GnuPG Key Id: 0x5C1ABAAA
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FFmpeg maintainer                                  http://www.ffmpeg.org