[MPlayer-users] Converting DivX4 -> MPEG ?

[D Richard Felker III]

On Thu, Oct 30, 2003 at 12:50:49PM +0200, Tuukka Toivonen wrote:
> [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
> On Mon, 27 Oct 2003, Levente Novák wrote:
> 
> >>IMO SVCD should *never* be used for archival or distribution purposes
> 
> Never say never... anything might be good in some special situation.
> 
> >For archival purposes, the best option is to use a lossless codec (like
> >HuffYUV, FFV1, LJPEG) at a resolution at least the Nyquist frequency of
> 
> Yes, if you have the space. Or even completely uncompressed video.
> 
> >your source (generally twice that of the number of analog "lines" your
> >capture standard uses). Unfortunately they all give huge files. But you
> 
> No, the same number of lines. Nyquist frequency corresponds to half of

"Lines" doesn't mean scan lines. Read the literature. The meaning is
the maximum number of lines that can be displayed on the screen
without them "blurring together" (aliasing), which is exactly the
Nyquist frequency. And I think it's used for measuring horizontal
resolution, not vertical, since vertical resolution is very discrete
and has nothing to do with sampling theory.

> >For distribution, it's right that MPEG-4 compresses better than MPEG-2.
> >With camcorder (moderately noisy) sources however, I prefer sometimes
> >MPEG-2 to the less blocky MPEG-4 but where blocks tend often to "stick"
> >to the foreground on scenes when the camcorder is moving while shooting.
> 
> I have noticed this too, often it looks just like the "motion blur"
> effect in Dubius demos from few years ago... increasing bitrate helps.

Also try mpeg_quant option to lavc.

Rich