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Old 07-20-11, 12:19 PM   #8
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Join Date: Dec 2010
Posts: 15
Default Re: vdpau + ffmpeg - no workie ???

Originally Posted by crisalide View Post
MLT does, but do not expect a big speed increase, because in the transcoding chain, decoding is not the big part and because vram to sysram copy requires approx as much cpu time as soft decoding. In short, don't count on vdpau to speed up transcoding significantly.
well, you guys and crisilide were right. To satisfy my curiosity bug i went ahead and compiled the vlc + vaapi and vdpau. And here are my results:

I ran
 cvlc --ffmpeg-hw A_File.avi --sout='#transcode{vcodec=mp1v,vb=1024,acodec=mpga,ab=128}:std{access=file,mux=ts,dst=./Trans_hw.mpg}'
cvlc A_File.avi --sout='#transcode{vcodec=mp1v,vb=1024,acodec=mpga,ab=128}:std{access=file,mux=ts,dst=./Trans.mpg}'
Here are some metrics:
to convert 668Mb avi file to mpg on 2Gb AMD Sempron 3200 system"
HW enabled transcoding ~ 40 minutes, CPU utilization ~80%
no HW enabled ~30 minutes, CPU utilization ~ 97% ( full load).

Thank you for your help and advise!

P.S. Link to vlc forums with my steps ( to get vlc _ vdpau working) and some discussion.

Last edited by DBabo; 07-20-11 at 12:22 PM. Reason: added link to vlc forum
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