[FFmpeg-devel] [PATCH] Fix VP3 dequantization matrices when an IDCT permutation is used
David Conrad
lessen42
Wed Sep 17 21:36:37 CEST 2008
On Sep 17, 2008, at 6:53 AM, Michael Niedermayer wrote:
> On Wed, Sep 17, 2008 at 01:07:47AM -0400, David Conrad wrote:
>> Hi,
>>
>> It appears that the reason why the VP3 SSE/MMX IDCTs weren't
>> bitexact to
>> the C version was because the dct coefficients weren't being
>> dequantized
>> correctly when a permutation was needed. The coefficients are
>> permutated
>> correctly in unpack_vlcs() but the dequantization matrices are built
>> assuming no permutation. This fix allows both the SSE2 and MMX IDCTs
>> produce bitexact output for the VP3 and Theora samples I have.
>
> patches look ok
Applied.
I also forgot to mention that it doesn't change VP5 or VP6
bitexactness either.
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