[MPlayer-users] Greyscale "tricks"

[Meino Christian Cramer]

From: Jan Knutar <jknutar at nic.fi>
Subject: Re: [MPlayer-users] Greyscale "tricks"
Date: Thu, 15 Jul 2004 06:43:37 +0300

> 
> >  Are there any more options to mencoder to save file size/to increase
> >  quality others than the grayscale encoding option for the lavcodec --
> >  not only concerning colorspace?
> 
> Well, what options are you using?
> 
> As Matthew already said, the colourspace normally used is YUV, in which 
> Y already is "Black and White". The human eye/mind doesn't really 
> distinguish colour all that good, so the UV of YUV is already quarter 
> resolution compared to Y, even before getting compressed, so you don't 
> save as much space on leaving out colour.

I use this to encode (extracted parts of my script):

export LAMEOPTS=mode=3:vbr=2:q=7
export TIMESLICE="-ss 00:01:00 -endpos 00:02:00"
export OPTS="-vf denoise3d=0:0:0:hqdn3d=0:0:0:crop=700:576:12:0 -mc 0 -noskip -skiplimit 0"
export CMP=2; export SUBCMP=$CMP; export PRECMP=$CMP;export 
export LAVOPTS=cbp:psnr:mbd=2:gray:vcodec=mpeg4:vpass=#PASS#:vbitrate=1500:trell:autoaspect

# modifying for Pass1/pass2
export PASS1LAVOPTS=`echo $LAVOPTS | sed 's|#PASS#|1|'`
export PASS2LAVOPTS=`echo $LAVOPTS | sed 's|#PASS#|2|'`

(( cat $VOBDIR/*.vob | \
mencoder $OPTS $TS -oac copy \
-ovc lavc \
-lavcopts ${PASS1LAVOPTS} - ) >> PASS1.log 2>&1)

What do you think?
Do I have implemented any """feature""" (== bug ;)

I am using mplayer on Linux 2.6.7. i386