> > 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. That would avoid the memcpy, yes. On the other hand you can't double-buffer with read() calls, i.e. you probably don't get the full frame rate. If all you want do is displaying video you can also simply use the Xvideo Extention. The X-Server will ask the grabber card to xfer the data directly to the vga cards memory, which needs 0% CPU time. > Is there a way to know if the memory segment is dma-able? On ia32: In theory all memory below 4GB. For now bttv will DMA to non-highmem pages. Gerd -- #include </dev/tty>
