[MEncoder-users] Fwd: Questions on Mencoder performace

[Dominik 'Rathann' Mierzejewski]

On Tuesday, 06 June 2006 at 01:02, Phil Ehrens wrote:
> larrystotler at netscape.net wrote:
> > 
> >  mencoder file -alang en -oac mp3lame -ovc xvid -xvidencopts 
> > pass=1(pass=2:bitrate=1536) -o file
> > 
> >  On my Xeon system, I get 49% CPU usage, but I can start 2 encodings at 
> > one time. I generally get about 10 frames first pass, 5 2nd pass.
> >  On my P3-900, I get similar results. This mobile proc has 100Mhz 
> > external bus
> >  On my CeleronM 2.4Ghz, I get 13-15 frames first pass and then 13-15 
> > frames second pass.
> > 
> > My questions are:
> > 
> >  How much does L2 cache impact performance? Is 512k L2 a huge benefit 
> > over 256k? Would a real P4 be better than the Celeron Mobile?
> >  How much does memory speed impact performance? Would switching the 
> > CeleronM to DDR make a small or huge difference?
> >  How much does Hard Drive speed affect performance? I have a SATA and 
> > SCSI 10k/80M/s drives in my Xeon, and ATA100s in the other 2
> > Are there further command line arguements that I need?
> 
> 
> None of these things will give you as big a performance boost as
> switching from xvid to lavc will. Using '-oac copy' will also give
> you a performance (and quality) boost. Good starting options for
> lavc:
> 
> -lavcopts vcodec=mpeg4:nr=1000:mbd=2:v4mv:trell:vpass=N:vbitrate=1800

nr=1000 is a bit too much. I wouldn't go higher than 400, 600 tops.
I'd also add mv0 and cbp to the mix.

Regards,
R.

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