On Tue, Jul 24, 2012 at 8:05 AM, John Stebbins <stebb...@jetheaddev.com> wrote: > On 06/25/2012 02:42 PM, Mans Rullgard wrote: >> >> Module: libav >> Branch: master >> Commit: 82992604706144910f4a2f875d48cfc66c1b70d7 >> >> Author: Mans Rullgard <m...@mansr.com> >> Committer: Mans Rullgard <m...@mansr.com> >> 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. > > John
Could it have anything to do with denormals/NaN? Jason _______________________________________________ libav-devel mailing list libav-devel@libav.org https://lists.libav.org/mailman/listinfo/libav-devel
