[FFmpeg-devel] port mplayer eq filter to libavfilter
Ronald S. Bultje
Wed Dec 8 13:16:40 CET 2010
On Tue, Dec 7, 2010 at 2:01 PM, Stefano Sabatini
<stefano.sabatini-lala at poste.it> wrote:
> On date Tuesday 2010-12-07 10:00:26 +0800, William Yu encoded:
>> 2010/12/4 Michael Niedermayer <michaelni at gmx.at>:
>> > On Fri, Dec 03, 2010 at 02:47:58AM +0100, Michael Niedermayer wrote:
>> > [...]
>> >> > +
>> >> > + ? ?__asm__ volatile (
>> >> > + ? ? ? ?"movd %3, %%mm3 \n\t"
>> >> > + ? ? ? ?"movd %4, %%mm4 \n\t"
>> >> > + ? ? ? ?"punpcklwd %%mm3, %%mm3 \n\t"
>> >> > + ? ? ? ?"punpcklwd %%mm4, %%mm4 \n\t"
>> >> > + ? ? ? ?"punpckldq %%mm3, %%mm3 \n\t"
>> >> > + ? ? ? ?"punpckldq %%mm4, %%mm4 \n\t"
>> >> > + ? ? ? ?"1: \n\t"
>> >> > + ? ? ? ?"pxor %%mm0, %%mm0 \n\t"
>> >> > + ? ? ? ?"mov %2, %%"REG_c" \n\t"
>> >> > + ? ? ? ?"sar $3, %%"REG_c" \n\t"
>> >> > + ? ? ? ?"2: \n\t"
>> >> > + ? ? ? ?"movq (%0), %%mm1 \n\t"
>> >> > + ? ? ? ?"movq %%mm1, %%mm2 \n\t"
>> >> have you benchmarked changeing this one from mplayer?
>> > note, you can trivially benchmark code by putting START/STOP_TIMER around
>> > code that you want to benchmark
>> Thanks for your help. I optimizing it.
>> Should i revert assembly code to original mplayer code
>> before i can finding out a better way?
> Please try to change the code as little as you can, this is a *port*,
> further optimizations can be done later (that also means less work for
> you and for the reviewers).
Most of my suggested changes clearly make it faster and better. Anyone
can confirm that without needing to time it. We don't accept broken
ports, but likewise we should not expect broken mplayer code. Being in
mplayer in no way guarantees being perfect.
Please keep the changes, except for that one line pointed out by
Michael because that one should potentially be checked.
(The problem I see here is tons of broken ports going into our broken
SVN, and then people that complain about brokenness - like me or Mans
in the past - will be expected to fix it. Or worse, it just won't
happen, and ffmpeg will become as broken as mplayer is today.)
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