[Ffmpeg-devel] [PATCH] lowres chroma bug

[Oleg Metelitsa]

Hello Trent,

>> Of course that would only be done for avg_h264_chroma_mc2_mmx2, not for
>> avg_h264_chroma_mc{4,8}_mmx2.  Maybe this is faster than the using the
>> 16-bit move?  The same can be done for the put version too:
>>
>> @@ -1376,1 +1376,2 @@
>> -#define H264_CHROMA_OP4(S,D,T)
>> +#define H264_CHROMA_OP4(S,D,T) "movd 2+" #S ", " #T "\n\t"\
>> +                               "punpcklwd " #T ", " #D "\n\t"


Why do not use one SSE integer instruction instead of two MMX
instructions?

So we will have:

#define H264_CHROMA_OP2(S,D,T)   "pinsrw $1, 2+" #S ", " #D " \n\t"

instead of

>> +#define H264_CHROMA_OP2(S,D,T) "movd 2+" #S ", " #T "\n\t"\
>> +                               "punpcklwd " #T ", " #D "\n\t"


Oleg