Low encoding performance over encoding time

Discuss about generic usage of MediaCoder.

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Kitsune
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Low encoding performance over encoding time

Post by Kitsune » Thu May 01, 2014 3:51 am

Hi there! I have been using MediaCoder for quite a while. I remember stoping using it because, long ago, it wouldnt never use the 100% of my CPU and the encoding process was too slow.

But now that these problems seems fixed, I face another problem. Why does MC slows down the encoding speed the most time that past? I have a 30 minutes video and when it starts encoding it goes to 70fps and when finish it is at only 21fps. Somewhat you could think that different parts of the videos requires different speeds. But the fact is that the speed only goes down, starting at 70fps, then 60fps after 5 minutes and continuing go down. The longer the video the lowest fps you will get at the end. Also, if you even start encoding from one of those "slow" parts to see if is that just the video requires more time to process due scene complexity, you will see that it starts again at 70fps. I have an i7 950 and 12GB of RAM and while doing this I dont really run out of memory or anything and the CPU keeps at 100%. Am I missing a setting for this to not happen? The input was a high bitrate mp4 x264 file and the output was a variable bitrate mp4 x264 file using 23 as CRF.

Thanks for the awesome software and looking forward for your replies guys :).

meRobs
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Re: Low encoding performance over encoding time

Post by meRobs » Thu May 01, 2014 9:11 am

One thing to remember is that once the video and audio streams have been decoded and encoded, theyare then muxed together at the end. During muxing, the process seems to slow right down.
Have you checked out the Tips & Guides for MediaCoder? Try: http://forum.mediacoderhq.com/viewtopic.php?f=17&t=8061
Also, get older builds at: http://www.videohelp.com/tools/MediaCoder/old-versions#download

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