[MEncoder-users] MPEG2 quality

[Reimar Döffinger]

Hello,
On Mon, Mar 05, 2007 at 09:45:17PM +0100, Konrad Dubiel wrote:
> When encoding DV video into MPEG2 I get blocky compression artifacts
> in flat coloured areas. They are clearly visible and very annoying.
> 
> My -lavcopts are:
> vcodec=mpeg2video:\
> trell:mbd=2:precmp=2:subcmp=2:cmp=2:dia=-10:predia=-10:cbp:mv0:\
> vqmin=1:lmin=1:dc=10:vstrict=0:\
> vrc_buf_size=1835:\
> keyint=12:\
> vrc_maxrate=9800:\
> vbitrate=8000:\
> aspect=16/9:\
> acodec=ac3:abitrate=224
> 
> Is this really the best quality mencoder can achieve? It is very poor
> when compared to MainActor for example.

I really wonder where you got those from, many of those are likely to
decrease quality, esp. the dia, predia, dc, vqmin, lmin options seem
like a very bad idea. About the cmp settings I have my doubts as well.
But anyway, one-pass bitrate-based encoding will almost always result in
crap, you must do at least two passes.
And why not using vmax_b_frames and vb_strategy?

Greetings,
Reimar Döffinger