[MPlayer-users] variable bitrate for the video?

[Fabio Papa (MCE)]

On Wed, 23 Apr 2003 13:33:46 +0200
"Wendy Tromp" <wendy at snuffel.net> wrote:

> [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
> > Hm? Bitrate should be variable by default with most of the codecs. What
> > codec are you trying? Normally you have to specify parameters to make the
> > bitrate constant.
> 
> I realise now that 2-pass encoding is for variable bitrates, but I don't
> quite get how that works. I know that the first pass is for getting
> information about the movie and that in the second pass this information is
> used. I am now doing the following commands:
> 
> mencoder -ovc lavc -lavcopts
> vcodec=mpeg4:vhq:vpass=1:vbitrate=1200:v4mv -passlogfile=/mnt/log.log -oac
> mp3lame -lameopts br=192 movie.avi -o movie_encoded.avi
> 
> and
> 
> mencoder -ovc lavc -lavcopts
> vcodec=mpeg4:vhq:vpass=1:vbitrate=1200:v4mv -passlogfile=/mnt/log.log -oac
> mp3lame -lameopts br=192 movie.avi -o movie_encoded.avi
> 
> Now this results in a movie of about 10 megs per minute, and decent quality,
> but I actually have no idea what I am doing. I am very curious about the
> vbitrate part, what it does, and when it is useful to specify it. Does it
> indicate the minumum bitrate or the maximum or what?
I suggest you to read encoding-tips.txt, which is in the DOCS/tech subdir of
the MPlayer source.
And anyway, variable bitrate is not only in 2pass encoding; 1 pass encoding is
variable as well, only not that much optimized for quality.

> 
> can anyone help me with this?
> Wendy
I hope I just did!

> 
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-- 
Fabio Papa - italian LTSP translator