[FFmpeg-devel] Question regarding seemingly superfluous fourcc checks

[Mats Peterson]

Are the following kludges for A_QUICKTIME and V_QUICKTIME ways to 
accommodate old broken Matroska files that FFmpeg wrote in the past? I'm 
asking because in normal cases, the fourcc in A_QUICKTIME and 
V_QUICKTIME always starts at offset 4, without exception.

A_QUICKTIME:

if (ff_codec_get_id(ff_codec_movaudio_tags, 
AV_RL32(track->codec_priv.data))) {
     fourcc = AV_RL32(track->codec_priv.data);
     codec_id = ff_codec_get_id(ff_codec_movaudio_tags, fourcc);
}

V_QUICKTIME:

if (ff_codec_get_id(ff_codec_movvideo_tags, 
AV_RL32(track->codec_priv.data))) {
     fourcc = AV_RL32(track->codec_priv.data);
     codec_id = ff_codec_get_id(ff_codec_movvideo_tags, fourcc);
}

Mats