[Ffmpeg-devel] [PATCH] DVR-MS probe audio format - was DVR-MS bug (MP2 decoding)

Michael Niedermayer michaelni
Tue Mar 27 03:32:08 CEST 2007


Hi

On Mon, Mar 26, 2007 at 04:48:35PM -0500, John Donaghy wrote:
> >remove line, and send a bugreport if it doesnt work (if ffmpeg/ffplay
> >works
> >and mplayer doesnt the bug is likely in mplayer)
> 
> 
> I'm having trouble even getting this to work in ffmpeg. The issue seems to
> be that av_read_stream_info isnt able to properly parse the audio frames
> because it is attempting to parse them when it still doesnt know what the
> audio codec is.
> 
> For a dvr_ms sample I have where the audio is mp2, if I *dont* set the audio
> codec to CODEC_ID_NONE in the asf demuxer I get this from
> av_read_frame_internal stream:
> 
> [asf @ 006F8438]av_read_frame_internal stream=1, pts=0, dts=0, size=33348
> [asf @ 006F8438]av_read_frame_internal stream=0, pts=765208, dts=765208,
> size=768
> [asf @ 006F8438]av_read_frame_internal stream=0, pts=765232, dts=765232,
> size=768
> [asf @ 006F8438]av_read_frame_internal stream=0, pts=765256, dts=765256,
> size=768
> 
> which looks ok, but if I set the audio codec to CODEC_ID_NONE I get this:
> 
> [asf @ 006F8438]av_read_frame_internal stream=1, pts=0, dts=0, size=33348
> [asf @ 006F8438]av_read_frame_internal stream=0, pts=765208, dts=765208,
> size=6144
> [asf @ 006F8438]av_read_frame_internal stream=1, pts=765516, dts=765516,
> size=15442
> 
> I think the problem is in av_read_frame_internal because "st->need_parsing"
> is 'true' but no parser can be found for CODEC_ID_NONE. Because no parser
> can be initialized  by av_parser_init for CODEC_ID_NONE, st->need_parsing
> gets set to '0'.
> 
> Is there a way to make this work? I cant see one at the minute.

hmm seems this is a missunderstanding, ive no problem with setting codec_id
to CODEC_ID_NONE
what i was complaining about was setting codec_tag to 0 which is wrong as
that might not be the codec_tag stored in the asf file ...

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Let us carefully observe those good qualities wherein our enemies excel us
and endeavor to excel them, by avoiding what is faulty, and imitating what
is excellent in them. -- Plutarch
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