[MEncoder-users] new doom9 codec comparission

Corey Hickey bugfood-ml at fatooh.org
Sat Dec 3 22:41:33 CET 2005

Rich Felker wrote:
>>for i in $1 $2 ; do
>>  mencoder ~/dumpstream/matrix.vob -aid 128 -oac copy \
>>  -vf crop=718:356:0:60,scale=640:272 -ovc lavc -lavcopts \
>>  vcodec=mpeg4:threads=2:vbitrate=581:vratetol=1000:1:mbd=2:mv0:trell:\
>                  ^^^^^^^^^
> multithreaded decoding is known to reduce psnr, albeit only very
> slightly. is it really worth it? imo tests should be on single-cpu
> anyway for fairness.

Michael said the tests would be done on a dual-core CPU. Once I get the
best single-threaded command line I can, I'll try threads=2 and see if
there's a big PSNR drop. Also, see Michael's email to this thread on
Fri, 2 Dec 2005 17:57:33 +0100.

If threads=2 ends up being bad, then I can probably omit it and we'll
still do pretty well in the performance department. The machine I'm
testing on is roughly equivalent to the Athlon64 3500+ used in the 2004
comparison. Although the movie in that case was The Matrix Revolutions,
the resolution is the same and framerates should be roughly equal. The
fastest codecs listed were 58.99 fps (HDX4), 50.76 fps (3ivX), and 50.12
(XviD). By using turbo for the first pass, I'm getting an average of
77.18 fps.


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