hi Michael, On Thu, 2002-11-28 at 16:09, Michael Hunold wrote: > Because all opens on the device have equal rights, there is a need to > specify some sort of importance or "order" of the different things. > > First of all, we have to define what the different things are: > - overlay video: clear. > - streaming capture: full fps capture via REQBUFS, STREAMON, QBUF, > DQBUF, STREAMOFF > - read() capture: capture via read() system call. I've always considered streaming capture to be of main importance, since that one is lockable. So streaming capture is always most important. Only one source can do streaming capture, and it gets all the frames. If the driver can do it, it should also keep the overlay uptodate, though that isn't strictly necessary. If no streaming capture is active, read() is preferred above overlay, but the same goes - if the driver can do it, overlay should be kept up. > First question: should capture via read() be able to deliver all frames > (ie 25fps for PAL) by definition? No, since you can't lock read() for one source specifically, so you can queue from > 1 sources. Both get half of the framerate then. Just mho. ;-). -- Ronald Bultje <rbultje@xxxxxxxxxxxxxxxxxxx> Linux Video/Multimedia developer
