[FFmpeg-devel] [PATCH] H.264: x264 SSE2 iDCT functions

Jason Garrett-Glaser darkshikari
Sat Jan 3 01:44:54 CET 2009


On Fri, Jan 2, 2009 at 6:12 PM, Michael Niedermayer <michaelni at gmx.at> wrote:
> On Fri, Jan 02, 2009 at 04:36:11PM -0500, Jason Garrett-Glaser wrote:
>> On Fri, Jan 2, 2009 at 4:14 PM, Guillaume POIRIER <poirierg at gmail.com> wrote:
>> > Hello,
>> >
>> > On Fri, Jan 2, 2009 at 9:37 PM, Jason Garrett-Glaser
>> > <darkshikari at gmail.com> wrote:
>> >
>> >> Patch attached.
>> >
>> >> +#if defined(CONFIG_GPL) && defined(HAVE_YASM)
>> >> +static void ff_h264_idct_dc_add8_mmx2(uint8_t *dst, int16_t *block, int stride)
>> >> +{
>> >>
>> >
>> > This is just to avoid having unreferenced code, right? I assume you're
>> > not doing to license ff_h264_idct_dc_add8_mmx2 under GPL...
>>
>> Yes, of course.  I can't license it under GPL, it's basically copied
>> from the original idct_dc.
>>
>> Also, Michael, why isn't idct_add8 (the chroma 8-4x4idct function)
>> used at all?  Did you forget to insert it when you added
>> add16/add16_intra into h264.c?
>
> i benchmarked it, and it was slower, thats why its not in svn ...
> I dont know why it was slower ...

Is it slower if you use the SSE2 iDCT functions?

The current one is almost surely slower as it only uses the MMX ones...

Dark Shikari




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