[FFmpeg-devel] [PATCH] lavf/matroskadec: SMI to SVQ3

Mats Peterson matsp888 at yahoo.com
Wed Jan 6 10:57:05 CET 2016

On 01/06/2016 10:41 AM, wm4 wrote:
> On Wed, 6 Jan 2016 04:33:16 +0100
> Mats Peterson <matsp888-at-yahoo.com at ffmpeg.org> wrote:
>> At least in this case, MPlayer seems to look at the codec tag rather
>> than the codec ID in order to determine the codec. Therefore, the
>> 'fourcc' variable needs to be set to 'SVQ3' as well, which is later
>> copied to st->codec->codec_tag in matroskadec.c.
> You should fix mplayer instead. FFmpeg API users are not supposed to
> use fourcc fields to identify codecs. The fourcc variable in
> matroskadec.c is copied to AVCodecContext.codec_tag, which is not
> necessarily a fourcc (depends on the CODEC_ID; most time it's unused),
> and the svq3 decoder in libavcodec doesn't read it.
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:) In any case, the fourcc should be SVQ3 and not SMI, regardless of 
what MPlayer is doing.


Mats Peterson

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