Jasta85 wrote:also the footage i am using right now is 16:9 so that was the dimensioned i picked when i started the amv but in order to use Xvid it says your amv must be in 4:3 dimensions,
My Body Language video is 16:9 (from a 4:3 original source, cropped) and DivX5 compatible XviD. I've never heard of XviD requiring 4:3 video to be used.
Jasta85 wrote:but if i change my amv to 4:3 wont the aspect ratio be off and the quality suffer?
Yes on both counts. Changing a 16:9 video to 4:3 without cropping would throw the aspect ratio of the video WAY off. Circles would become ovals, squares would become rectangles, and some rectangles would become squares.
Not to mention that the quality would suffer since your horizontal resolution would drop due to the loss of that many pixels. For example, full resolution square pixel 16:9 NTSC footage should be 848 x 480 as suggested by EADFAG. Changing the video to 4:3 would entail resizing or cropping the image to 640 x 480 using square pixels. According to my math, that's a 25% drop in horizontal pixel resolution.
Admittedly, DVD resolution is 720 x 480 for both standard 4:3 and
anamorphic 16:9 footage. So, for DVD sources we are already losing 15% of the horizontal pixels assuming that the original animation was produced at 848 x 480 resolution. Human vision is less perceptible of the loss of horizontal resolution which is why anamorphic techniques work very well. But lose too much and the eye may pick it out when the video is resized to its proper aspect ratio. Curved and diagonal lines may become too "jagged" after the necessary horizontal "stretch".
The one thing that you do want to keep in mind when encoding your video is to try and stay with mod16 resolutions for the best results. Since XviD and DivX typically use 16 x 16 macroblocks for encoding, keeping your resolutions to a multiple of 16 is recommended. Examples include: 640 x 480, 512 x 384, and 320 x 240 for 4:3 AR material. For 16:9 material, 848 x 480, 768 x 432, 720 x 400 (not exactly 16:9, but mod16), 704 x 400 (same as the previous), 640 x 352 (again, not 16:9 but mod16) are acceptable. Encoding with mod8 or mod4 resolutions (like 704 x 396 or 640 x 360)is possible, but wasteful. Why? Well, you could read
The Unofficial XviD FAQ's section on the subject, or bug Zero1 about it.
