[MPlayer-users] Converting DivX4 -> MPEG ?

[Tuukka Toivonen]

On Thu, 30 Oct 2003, Novak Levente wrote:

>I told about horizontal, not vertical lines, because that's how it's
>called in the VCR/camcorder world. It corresponds to the _horizontal_

Unfortunately I lost my clue. Everything I understand, is that the
more horizontal (scan)lines one has, the more vertical resolution he has.

The more vertical resolution one has, the more the display can show
distinct horizontal lines.

You are saying otherwise, but I just don't get it.

>resolution of an analog output. For most PAL Hi8 camcorders, the
>resolution is 480 analog horizontal lines per 576 of vertical scanlines

Scanlines are horizontal! From left-to-right.

>And why should you use _twice_ the analog "resolution" of your source? If
>eg. you have a Hi8-camcorder output, you have a nominal horizontal analog
>resolution of 480 lines (not vertical scanlines!). If you shoot a regular
>black-white-black-white-... pattern (one "analog pixel" per black and one
>per white component) onto tape, then during capture (A/D conversion), if
>the digitalisation is not exactly in sync and you use a horizontal
>resolution of 480 digital pixels, you won't get a black-white-black-...
>dot pattern, but a grey-grey-grey-... one: the information is lost. If you

True. In theory, if the analog device can display exactly 480 vertical
lines horizontally side-by-side, 480 pixel horizontal resolution in ADC
might or might not suffice: it's the limiting case. 481 pixels would be
enough--in theory, if ADC would have ideal filter characteristic, which is,
however, impossible. Therefore oversampling gives certainly better image
quality.