[MPlayer-dev-eng] check recommended MPEG2 encoding options

[Rich Felker]

On Tue, Mar 06, 2007 at 12:43:25AM +0100, Reimar Döffinger wrote:
> Hello,
> http://www.mplayerhq.hu/DOCS/HTML/en/menc-feat-vcd-dvd.html
> gives this for high quality encode:
> -lavcopts vcodec=mpeg2video:vrc_buf_size=1835:vrc_maxrate=9800:vbitrate=8000:\
> keyint=15:trell:mbd=2:precmp=2:subcmp=2:cmp=2:dia=-10:predia=-10:cbp:mv0:\
> vqmin=1:lmin=1:dc=10:vstrict=0
> 
> Can someone double-check this a bit? First of all, the whole patch seems
> to miss a reference to the absolutely critical two-pass.

2pass is useless in extremely-restricted CBR.

> I have some doubts that it is a good idea to set vqmin/lmin that low,

It's necessary if you don't want the bitrate to drop in still scenes
(i.e. if you really want CBR).

> the man page says it is a bad idea. man page also suggests (by my
> reading) that negative values for dia are fast but not exactly good.
> And don't B-frames also exist for MPEG-2 and are allowed for DVD?

Required, iirc... On the other hand, lavf cannot mux them.

Rich