2016-05-23 13:44 GMT+02:00 Håvard Espeland <espel...@mixedrealities.no>:
> > > The SIMD won't be accepted if it's intrinsics. The codeword encoding is > not > > SIMD, is it? So that may be worth upstreaming. > > All optimizations we’ve done are SIMD so it does not apply. Basically what > we do for codewords is to process the shifting/masking for eight codewords > at a time. The put_bits calls are of course executed sequentially as before. > > > > When you say "no significant PSNR or file size differences", though, it > > sounds like the output changed? Did it? Can you explain why? > > For the tractor sequence we get the following results. > time ./ffmpeg -y -i ~/Downloads/tractor_1080p25.y4m -codec:v prores_aw > -an -profile:v 2 /tmp/video.mov > > ffmpeg-master: > frame= 690 fps= 22 q=-0.0 Lsize= 611897kB time=00:00:27.56 > bitrate=181881.2kbits/s speed=0.876x > video:611891kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB > muxing overhead: 0.000996% > > real 0m31.491s > user 2m3.452s > sys 0m1.168s > [Parsed_psnr_0 @ 0x3ab6da0] PSNR y:49.596357 u:54.113644 v:54.561940 > average:51.331354 min:49.684050 max:53.658792 > > AVX2 optimizations: > frame= 690 fps= 32 q=-0.0 Lsize= 611896kB time=00:00:27.56 > bitrate=181881.0kbits/s speed=1.27x > video:611890kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB > muxing overhead: 0.000996% > > real 0m23.396s > user 1m25.092s > sys 0m1.252s > [Parsed_psnr_0 @ 0x2838da0] PSNR y:49.595523 u:54.114016 v:54.562335 > average:51.330827 min:49.683836 max:53.658654 > > As you can see, there is 1kb size difference in the output file and some > minor variations in psnr. I believe the difference might be due to rounding > since we are using float point math and round towards zero, while ffmpeg > master uses fixed points for dct. If we pursue to clean up the code and > send it upstream we might also look into improving this so we get identical > results. > > Have you test your optimizations in the other prores encoder (prores kostya) (who i think have more features (interlaced encoding and 444 versions)) ? Martin _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
