>>> >>> …or is that really old-school and a modern compiler does all that when >>> optimising? >>> >>> Or is readability considered more important than marginal gains in >>> performance? >>> >>> Oliver (time travelling from the 1980s) >> >> You would still have to add the remaining stride. >> The linesize is usually larger than the width, so each line is properly >> aligned. >> >> So with your code, you'd still need something like >> >> dstUV += dstStride[1] / 2 - 2 * x; >> src[2] += srcStride[1] / 2 - x; >> src[2] += srcStride[1] / 2 - x; >> >> after it. > > No, the lines after it remain unchanged - only the temporary variables are > looping along the x. > > src[1] += srcStride[1] / 2; > src[2] += srcStride[2] / 2; > dstUV += dstStride[1] / 2;
It is indeed very slightly faster. Old: [bench @ 0x2cbfb20] t:0.006181 avg:0.006270 max:0.013702 min:0.006080 New: [bench @ 0x33bcb20] t:0.006195 avg:0.006225 max:0.013718 min:0.006060 It seems to be 0.5ms faster on average. _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
