[Ffmpeg-devel] MPEG 2 Quality Issues

[Guillaume POIRIER]

Hi,

On 12/1/06, V?ctor Paesa <wzrlpy at arsystel.com> wrote:
> Hi,
>
> >
> > ffmpeg -i TestforMPG-Short.avi -vcodec mpeg2video -minrate 7000k
> > -maxrate 7000k -b 7000k -bufsize 5000k -bf 2 -flags +qprd+ildct -flags2
> > +ivlc+sgop -mbd rd -sc_threshold 10000000 -lmin 1 -mblmin 1 -lmax
> > '340*QP2LAMBDA' -f vob -ab 192 ffmpeg.mpg
> >
> > Feel free to add +trell.
> >
> > You must know that every encoder around WILL activate qprd. You can
> > detect it by using -debug 16, if macroblocks have differents values then
> > qprd is activated.
> >
> > Always try to use the largest bufsize for rc, the bigger buffer is, the
> > more rc will be efficient.
> >
>
> I noticed that ffmpeg -h offers no help for mbd, rd:
>
> -mbd               <int>   E.V..
>    rd                      E.V..
>
> Since you have just suggested them, could you please explain in
> a few words what they do?

MEncoder man page has all the details:

      mbd=<0-2>
              Macroblock decision algorithm (high quality mode),
encode each macro block in all modes and choose the best.  This is
slow but results in better quality and file size.
                 0    Use mbcmp (default).
                 1    Select the MB mode which needs the fewest bits (=vhq).
                 2    Select the MB mode which has the best rate distortion.

Guillaume
-- 
An association of men who will not quarrel with one another is a thing
which has never yet existed, from the greatest confederacy of nations
down to a town meeting or a vestry.
 -- Thomas Jefferson
(when interviewed about MPlayer ML flamewars)
http://www.brainyquote.com/quotes/quotes/t/thomasjeff157207.html