Hi, Am 07.10.2010 00:22, schrieb anyeos:
It applies not only for OpenGL instead in video in general. There are some encoders that can only work in some width or height multiples, like 4.
The usual 4:2:0 sampling requires that dimensions are multiples of 2. It's theoretically possible to support odd dimensions, but they many programs fail here. Usual compression methods work on 16x16 blocks internally, but all these codecs allow arbitrary *even* dimensions. They just pad the images internally. I'm not aware of any mainstream codec, which requires multiples of 4.
So you can have: 320x240, 420x480, 640x480, and so, all divisible by 4. Take care too about the aspect ratio what it is width/height in the example of 420/480 it is 0,875 not an standard one (640/480 get 1,333333 or 4:3, 320x480 the same, 720/480 is 16:9 or 1,7777777 standard NTSC and so).
You also have nonsquare pixels. All modern codecs store the pixel aspect ratio instead of the display aspect ratio. Burkhard _______________________________________________ Cinelerra mailing list [email protected] https://init.linpro.no/mailman/skolelinux.no/listinfo/cinelerra
