[FFmpeg-devel] [PATCH] lavf/matroskadec: A_QUICKTIME and AV_CODEC_ID_NONE

Mats Peterson matsp888 at yahoo.com
Mon Jan 4 22:17:26 CET 2016

In many older QuickTime files, the audio format, or "fourcc", is
0x00000000 (AV_CODEC_ID_NONE). The QuickTime File Format Specification
states the following regarding this situation:

"This format descriptor should not be used, but may be found in some
files. Samples are assumed to be stored in either 'raw ' or 'twos'
format, depending on the sample size field in the sound description."

MPlayer handles this logic by itself, but FFmpeg/FFplay currently does

I have also removed some superfluous checks for the format/fourcc at the
very start of the private data for A_QUICKTIME and V_QUICKTIME. This
shouldn't happen, since the private data always starts with the sample
description size, *then* the format/fourcc, in a Matroska file.


Mats Peterson
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