Vladimir Dergachev ([EMAIL PROTECTED]): > > I'm talking about planning how many refreshes to show each frame. > > I'd be really surprised if you could say to the ATI card 'show this > > 2 refreshes from now'. > > The card won't do that, but the driver can. In this case what you do > is submit a frame and a number - show this frame n-vsync interrupts > from the previous one - and the driver can do the rest.
Yes, for all cards which generate an interrupt every vsync then we can make an awesome API for high quality video, so long as the driver code which copies the frame is also in the kernel, since we don't want the scheduling wait of having the X driver get loaded. Having a /dev/vsync device would give the smallest amount of code in the kernel as possible, but then you need SCHED_FIFO access to protect against scheduling delays. (read: hack) You still need calls to tell you when the timebase for the refresh is though to make sure we plan ourselves out corrrectly. Regardless that kind of information is needed for TV output if you want to get field-correctness. How do the ATI cards currently export TV output capabilities when you're writing interlaced frames? The TV output API of v4l2 looks like it might be a good start. Since the requirements for TV output sync and progressive video playback sync are so similar, I'm wondering if the frame queueing API shouldn't be the same. -- Billy Biggs [EMAIL PROTECTED] _______________________________________________ Xpert mailing list [EMAIL PROTECTED] http://XFree86.Org/mailman/listinfo/xpert
