[MPlayer-users] Converting DivX4 -> MPEG ?

[Tuukka Toivonen]

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
the number of video scan lines. Why? Imagine that every other line
is black and every other white. This is the maximum frequency that can
presented. What is this frequency? 0.5, i.e. every full wave with
one black and one white line takes in total two lines.

>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.