Hi, On Sep 4, 2016 5:42 PM, "Timo Rothenpieler" <t...@rothenpieler.org> wrote: > > On 9/4/2016 4:06 PM, Carl Eugen Hoyos wrote: > > 2016-09-04 16:02 GMT+02:00 Timo Rothenpieler <t...@rothenpieler.org>: > >> The purpose of this patch is to make conversion from > >> yuv420p (8 bit) to p010 (10 bit) fast. > > > > Do I understand you correctly that your patch is > > faster without the change I suggested? > > With the &: > [bench @ 0x600045b80] t:0.011178 avg:0.011172 max:0.018297 min:0.010505 > > Without it: > [bench @ 0x600045b80] t:0.008455 avg:0.008517 max:0.015815 min:0.007941 > > So it is quite a bit faster. > > Tested with nvenc hevc10 encoding, and the output is visually identical, > and the file size is also exactly the same. > So it seems to cleanly ignore the unused bits. > > Also, given that at least microsoft argues with upcasting to 16 bit, the > approach without zeroing the lsb would be more accurate, as > > t << 8 | t > > is how one would convert 8 bit to 16 bit. > > > So I'd say going with the faster approach here should be fine. > If at some point someone runs into something that chokes on the bits > being non-zero, which I think is highly unlikely, it can be changed back.
Sounds good, thanks for testing and confirming. Ronald _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
