[FFmpeg-user] ffv1.3 memory overflow

Johann Rekowski johann.rekowski at googlemail.com
Mon Mar 11 22:34:57 CET 2013

On 03/11/2013 09:55 PM, Nicolas George wrote:
> Le primidi 21 ventôse, an CCXXI, Johann Rekowski a écrit :
>> 				 utvideo doesn't cause ALSA buffer
>> xrun with proper buffer_size and period_size settings, ffv1.3 does
>> though, and the more slices I add to it, the more extreme it gets.
> You should investigate the source of the problem. I suspect this is related
> to CPU usage: I suggest you try encoding from a file and compare the CPU
> usage of ffv1.3 and utvideo.
>> Since ffv1.3 currently causes a memory overflow in the master
>> branch, testing newer changes is impossible right now (at least for
>> me). So this'll have to wait.
> I posted a patch on the mailing list:
> http://ffmpeg.org/pipermail/ffmpeg-devel/2013-March/140331.html
> It may fix your memory consumption problem.
> Regards,
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I've been trying to find out the source of the problem. It seems that 
even utvideo and huffyuv start doing ALSA xruns if I let them record for 
like 5 minutes.
Comparing utvideo and ffv1.3 had almost the same results. utvideo does 
around 55 - 70 % CPU usage, while ffv1.3 does 65 - 80 % CPU usage on 
average. (using 8 cores) This is just the recording of my desktop, once 
I start my game to record it, all the ALSA xruns start rolling high, 
utvideo just delays them for 5 minutes and then the whole video gets 
destroyed. Even only one xrun causes complete desync in the video.

If I use less cores, the ALSA xruns happen instantly. If I increase 
slices on less cores, ALSA xruns still happen once I start my game.
Is there anybody that knows of a good lossless codec that doesn't cause 
much heat on the cpu, while still doing some compressing, because my HDD 
isn't that fast to be able to write 1080p raw 30fps input in time.
Or any setting in ffv1 or such codecs that could help me reducing cpu usage?

- Johann Rekowski

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