[MEncoder-users] MPEG1 with constant bitrate

[Rich Felker]

On Mon, Jun 06, 2005 at 11:49:31AM +0200, Jan Paul Schmidt wrote:
> 
> Am 06.06.2005 um 01:57 schrieb Rich Felker:
> 
> >On Sun, Jun 05, 2005 at 09:57:24PM +0200, Jan Paul Schmidt wrote:
> >>Hi there,
> >>
> >>I'm trying to get a MPEG1 video with constant bitrate with lavc. The
> >>lavc options are:
> >>
> >>	vcodec=mpeg1video:vbitrate=600:vrc_maxrate=600:vrc_minrate=600
> >
> >You forgot vrc_buf_size. Without specifying a buffer size, there's no
> >such thing as min/max rate. The concepts don't even make sense.
> 
> I stripped down the lavc options to where it does not make any 
> difference. I had vrc_buf_size in it, but that did not have any notable 
> effect to me, so I throw it out to let mencoder use some kind of 
> default.

There is no default. You really must specify a buffer size, which is
the window within which you want your bitrate to be constant.
Otherwise the buffer size is the whole file, meaning that min/max rate
only need to be met for the average over the whole file.

Rich