[FFmpeg-trac] #4565(avformat:new): MP2 in AVI (possibly) wrong frame_size/blkalign

[FFmpeg]

#4565: MP2 in AVI (possibly) wrong frame_size/blkalign
-------------------------------------+------------------------------------
             Reporter:  darkyp       |                    Owner:
                 Type:  defect       |                   Status:  new
             Priority:  normal       |                Component:  avformat
              Version:  unspecified  |               Resolution:
             Keywords:  mp2          |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
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Comment (by darkyp):

 Now, that's an interesing one (at least for me). The binary I have on the
 raspi is avformat version 54.20.4 (seems that it is from Libav 9.18). We
 have there riff.c that must have been changed to riffenc.c later. Anyway,
 the lines there are:


 {{{
     if (enc->codec_id == AV_CODEC_ID_MP2 || enc->codec_id ==
 AV_CODEC_ID_MP3) {
         /* this is wrong, but it seems many demuxers do not work if this
 is set
            correctly */
         blkalign = frame_size;
         //blkalign = 144 * enc->bit_rate/enc->sample_rate;

 }}}

 Just recommending, in case Juango patch is approved, to have the above
 comment included but with the inversed sense.

 Out of curiousity: are there any documented decoders that have problems
 with the correct setting for blkalign?

--
Ticket URL: <https://trac.ffmpeg.org/ticket/4565#comment:9>
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