[FFmpeg-user] Zeranoe Windows builds spiking CPU to 100% randomly

Kyle kshawkeye at gmail.com
Mon Jul 16 04:11:57 CEST 2012

On 7/13/2012 2:33 PM, Roger Pack wrote:
>> It's much easier to see the spikes with -pass 1 though.
>> ffmpeg -i 7416_20120706235700.mpg -pass 1 -c:v libx264 nul.mp4
> Ok I'm able to see it with 32-bit ffmpeg (running on 64 bit windows 7,
> with either an Athlon X2 or an i7).
> Every so often the console output "hangs" (mine uses basically 100%
> cpu the whole time, I don't see any spikes).
> Using this file: http://rogerdpack.t28.net/incoming/sintel.mpg
> zeranoe build ffmpeg-20120706-git-8293a21-win32-shared:
> ...
> (ran ffmpeg -y -i sintel.mpg -pass 1 -t 75 -c:v libx264 -an nul.mp4 [1])
> took 32.0s (showed console pause at frame 1145)
> took 35.8 (showed console pauses at frames 641, 1079)
> took 25.27s (showed no console pauses--it got lucky!)
> other build (http://x32.elijst.nl/FFmpeg-20120622.7z
> [20120622-N-41843-gc17808c-mod Jul 11 2012]):
> (ran \Downloads\FFmpeg-20120622\ffmpeg.exe -y -i sintel.mpg -pass 1 -t
> 75 -c:v libx264 -an nul.new.mp4 [2])
> took 25.6s
> took 26.6s
> took 24.5s
> (never shows console pauses)
> They make "presumably" the same file:
>    3780 -rw-r--r--    1 packrd   Administ  7739909 Jul 13 12:30 original.mp4
>    3779 -rw-r--r--    1 packrd   Administ  7739232 Jul 13 12:32 w32threads.mp4
> I don't see pauses with other codecs like mpeg4 or mpeg2video codecs, just x264.

Thank you Roger for supplying the file and command line you used.

I finally got the hang to appear and that was after completely updating 
the toolchain+x264+ffmpeg to the latest. This is in fact a issue with 
the latest of everything.

I bet the MinGW-w64 guys would know more about this issue. If someone 
could send over the information to their mailing list that would really 
help. I will if no one else can, but it might take a while.

They should help us figure out how to properly debug this.

It's odd that this error happens at random times, at least it does for 
me. It sometime would hang at the beginning, sometimes at other points.

I have a 4.0GHz i7, so if anyone needs me to run any further tests I 
would be happy to.

Best regards,
   Kyle Schwarz

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