[MEncoder-users] crf, qp, pass params (was - how do u set H264 video ID?)

[Goga777]

> > =================================================================
> > mencoder -v -v ?-msglevel all=9
> > /home/gat/DIESEL/TEST_FP24/PF24_10Seconds.MTS -mc 0 -noskip -fps 30000/1001
> > -delay -0.222 -oac copy -vf pullup,softskip,harddup,scale=1920:1080 -ofps
> > 24000/1001 -vid 4113 -ovc x264 -x264encopts
> > bitrate=24000:qp=5:pass=2:nointerlaced:log=3:frameref=2 -o a.avi
> > =================================================================
> 
> Your options are kinda silly. why do you use two different encoding
> modes together? You use qp=5 with pass=2. Those are two different
> modes - either choose the one or the other. Also, qp should never be
> used. Use crf instead or pass=2


as far as I understand the crf and bitrate options is not compatible. 
Good discussion about of crf, qp, pass, bitrate you can find in MPlayer list here is

http://lists.mplayerhq.hu/pipermail/mplayer-users/2007-January/065203.html

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Here's what _I_ think:
- crf provides very good quality and allows to make do without 2 pass,
which is cool.
However, you can't control how big the encode will end up.
- two pass both allow you to control the target bitrate, and allows to
make a smarter use of the bits you throw at it. Each now pass somewhat
improves quality over the previous one.
- qp is really meant to be used if you know what you do, if you need
to us lossless mode, or if you really want to _force_ low quants.

My ranking (in decreasing order of quality):
2-pass>crf>qp

In terms of speed:
crf,qp>2-pass.


Guillaume

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