John Stebbins <[email protected]> writes: > On 06/25/2012 02:42 PM, Mans Rullgard wrote: >> Module: libav >> Branch: master >> Commit: 82992604706144910f4a2f875d48cfc66c1b70d7 >> >> Author: Mans Rullgard <[email protected]> >> Committer: Mans Rullgard <[email protected]> >> Date: Sat Jun 23 19:08:11 2012 +0100 >> >> x86: fft: convert sse inline asm to yasm >> >> --- >> >> libavcodec/x86/Makefile | 1 - >> libavcodec/x86/fft_mmx.asm | 139 >> ++++++++++++++++++++++++++++++++++++++++--- >> libavcodec/x86/fft_sse.c | 110 ---------------------------------- >> 3 files changed, 129 insertions(+), 121 deletions(-) >> > > Hi, > > This commit is causing some strange interaction with libx264 in > HandBrake under certain conditions. x264 is encoding at about 1/10th > it's normal rate after updating to this commit. > > A little more background. When doing ac3 passthru HandBrake encodes a > single packet of silence data to ac3 that is uses for filling any gaps > that it detects in the audio. Encoding of this packet happens before > any other encoding or decoding starts. For some crazy reason, if we > encode this silence, we get the x264 slowdown. If we do not encode > the silence, the speed is ok. I ran gprof on the code to see where > all the time is being spent and it is all in x264. So it's not like > there is some run-away loop somewhere that is bringing everything to > it's knees. I'm guessing some cpu state must not be getting cleared > or restored properly somewhere.
I can't imagine what could possibly be causing such effects. What kind of system are you seeing this on (CPU, OS)? -- Måns Rullgård [email protected] _______________________________________________ libav-devel mailing list [email protected] https://lists.libav.org/mailman/listinfo/libav-devel
