[FFmpeg-devel] lpcm in mov default to big endian

[Yusuke Nakamura]

2013/11/1 Mark Himsley <mark at mdsh.com>

> It is my understanding that "Unless otherwise stated, all data in a
> QuickTime movie is stored in big-endian byte ordering" [1] in MOV files.
>
> I have a couple of thousand files, which technically are invalid because
> their sound sample description element 4CC is 'lpcm' but its version is 0 -
> and "Version 0 supports only uncompressed audio in raw ('raw ') or
> twos-complement ('twos') format" [2]
>
> Because isom.c only contains a mapping for 4CC 'lpcm' to
> AV_CODEC_ID_PCM_S16LE, these files have their audio decoded as LE when it
> is actually BE.
>
> Attached patch adds AV_CODEC_ID_PCM_S16BE as the first match for 4CC
> 'lpcm'.
>
> This is not tested for regressions in fate, but makes 4CC 'lpcm' match
> many other 4CCs in isom.c, and makes my files decode correctly.
>
> Please comment.
>
> [1] https://developer.apple.com/**library/mac/documentation/**
> quicktime/QTFF/qtff.pdf<https://developer.apple.com/library/mac/documentation/quicktime/QTFF/qtff.pdf>page 21
> [2] https://developer.apple.com/**library/mac/documentation/**
> quicktime/QTFF/qtff.pdf<https://developer.apple.com/library/mac/documentation/quicktime/QTFF/qtff.pdf>page 178
>
> --
> Mark
>
>
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>

The patch itself, LGTM.

Can you share one of such sample?