Frederik Deweerdt <frederik.deweerdt@xxxxxxxxxxx> writes: > I've tried then to use several buffers (four). I then call four times > VIDIOCMCAPTURE and then call VIDIOCSYNC four times. The first call to > VIDIOCSYNC still takes about 100ms, and the subsequent calls take a bit > less than 40ms. This is too slow for a TV app too. > My understanding is that when you call VIDIOCMCAPTURE, it starts the > capture on the device, so why do the 2nd, 3rd and 4th frames take so > long to grab? One second splitted into 25 frames/sec are 40ms delay per frame... VIDIOSYNC just sits and waits until the frame capture is finished by the hardware. It does not need 40ms *CPU* time, it just hangs around idle. If you want to use the time to let the CPU do something else just do that before calling the SYNC ioctl. Being able to do that is one of the reasons of splitting the capture into two ioctls (MCAPTURE+SYNC) in the first place ... Gerd -- You have a new virus in /var/mail/kraxel
