whats important: bit rate or image resolution?

[muralin]

i want to put a 120min DVD movie on SVCD.

if i use 480x480, i have to lower the bit rate to 1500 or so to fit the movie on 2 CDs.

another alternative is to have a bitrate around 1750 but change resolution to something like 352x352. Sevy has done this via his templates.

which is better? i dont want to use more than 2 CDs and i want to use SVCD.

[Visoblast]

If you are using an interlaced video source, then you'll want 480 or 240 horizontal lines. Something between the two will look funky when the image is moving.

The amount of data needed for video at a given bitrate for a given length of time is constant -- the resolution, even the video format, do not make a difference. (total data) = (bitrate) * (time). Resolution will affect video quality, but does not figure in to the amount of data.

Generally, the lower the bitrate you use, the better the video will look at a lower resolution. In my opinion, the SVCD standard doesn't allow for good quality video. Are you sure you don't want to use VCD?

[Dward]

> Resolution will affect video quality, but does not
> figure in to the amount of data.

True, but if you want to increase the resolution, you need to increase the bit rate to keep a level quality. (total data) = (bitrate) * (time), but there are almost 3 times as many pixels in a 480x480 picture than in a 352x240. Which means that for any given bitrate many more pictures can be drawn at a lower resolution than at a higher resolution.

So in a roundabout manner, a higher resolution will force you to capture more data if you want to keep quality equal.