Em Qua, 2003-08-27 às 17:17, Joëlle Nakhlé escreveu: > What is a sdl surface? > I use 32 bits to display on screen. The image from the camera is > stored in a 32 bits bitmap at 30 fps. I don't know what alpha > information is, so I can't tell if there is any or not. SDL stands for Simple Directmedia Layer. It's similar to directdraw in windows environment. You create a surface (which is a memory area) and just put your bytes there... sdl takes care of displaying it FAST :-) As you may know, images use 24 bits for colors. Human eye normally won't recognize more than this. 32-bit color screen modes wastes 1 byte per pixel, but is faster because of the simple fact that your computer is probably optimized for 32-bit thoughput. Of course, this is not the only scenario. You can also have 24 bits (8 for each color component: r g b) for color and 8 for what they call ALPHA channel. This extra channel can be used for, say, transparency, a extra bump map in a 3d surface, or extra data in other forms which doesn't come to my mind now. You can find sdl information at your favorite distribution's sdl-devel package, and at http://www.libsdl.org/
