[FFmpeg-devel] [PATCH] avformat/riff: remove useless tag correlation 'mpg2' --> AV_CODEC_ID_MPEG1VIDEO.

Александр Слободенюк alexander.slobodeniuk at bramtech.ru
Fri Jul 14 13:42:45 EEST 2017


Also  if  you  will  write an mpeg1video , it will be created with tag
'mpg1',    not    'mpg2'    in    all   cases   (because   correlation
AV_CODEC_ID_MPEG1_VIDEO   --  'mpg1')  stands  before  'mpg2'  tag  in
ff_codec_bmp_tags:

ffmpeg -i whatever.mov -vcodec mpeg1video test.avi
    (output)
    ...
    (output)
    Stream #0:0: Video: mpeg1video (mpg1 / 0x3167706D),

> This is actually a bug, that just doesn't affect anything.
> First  of all, the logic of functions that work with ff_codec_bmp_tags
> is "One tag -- one codec id".
> Also  if  you  write  this tag as MPEG2VIDEO, and then read the header
> (all by ffmpeg), it will interpret as MPEG1VIDEO:

> ffmpeg -i whatever.mxf -vcodec mpeg2video test.avi
> && gdb ffprobe_g

> (gdb) break avi_read_header
> (gdb) r -i test.avi
> (gdb) finish
(gdb) p s->>streams[0]->codecpar->codec_id
> $1 = AV_CODEC_ID_MPEG1VIDEO



-- 
С уважением,
 Александр                          mailto:alexander.slobodeniuk at bramtech.ru



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