> bttv 0.8.x tries to do zerocopy reads, i.e. you can pass the shm segment > pointer to read() syscall. > > Gerd So would it perhaps be faster to get your shared memory segments from X, and the do reads and display that memory? I have driver version num..0.8.31. Is there a way to know if the memory segment is dma-able? On my nvideo card, I can use the v4l2 YUV420 pixel format along with the NV10 overlay port with format 0x30323449, fourcc code I420. No colorspace conversion necessary. It is pretty sweet, only uses <10% processor as reported by top. Chris