[Ffmpeg-devel] [PATCH] Add fact chunk to non-PCM wav

[Michael Niedermayer]

Hi

On Thu, Nov 09, 2006 at 11:36:13AM +0100, Michel Bardiaux wrote:
> Michael has reported that
> 
> >>interresting, accoridng to microsofts excelent and unambigous 
> >>documentation
> >>(not kidding ...)
> >>     Fact Chunk
> >>This chunk is required for all WAVE formats other than WAVE_FORMAT_PCM. 
> >>It stores file
> >>dependent information about the contents of the WAVE data. It currently 
> >>specifies the time length of the
> >>data in samples.
> >>
> >>so this must not be under CODEC_ID_MSGSM, also it must be a seperate patch
> >>as its not CODEC_ID_MSGSM specific
> 
> I took this literally, hence CODEC_ID_PCM_ALAW and CODEC_ID_PCM_MULAW 
> will get a fact chunk too.

:)

now just take the largest pts minus the smallest pts of any packet stored
and convert that by using AVStream.time_base and AVCodecContext.sample_rate
to the number of samples and store that in the fact chunk

then run the regression tests and send a patch which updates the checksums


> 
> Note that get_wav_header does not enforce the rule on input.

thats ok

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

In the past you could go to a library and read, borrow or copy any book
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