Hi Philipp, On Tuesday 04 December 2007, Philipp Kolmann wrote: > Hi, > > I have a Logitech QuickCam 9000 which works really nice during daylight > with Skype 2.0 Beta. > > Skype starts the Video-Calls with 15fps settings (dwFrameInterval: 666666) > wich works nicely. After some time, it changes the fps to 30fps > (dwFrameInterval: 333333) and the cam locks up.
Changing the frame rate from 15fps to 30fps would exceed the allocated bus bandwidth. That's not allowed by the UVC spec. Changing from 30fps to 15fps might be legal but I'm not sure about it. > The only possibility to solve this issue is to unplug the cam completely > from the computer. The device shouldn't deadlock, that might be a device bug. > I have added a few lines of debug code to the uvc module I will attach to > this report. Additional I have attached the output of these debug lines to > syslog. > > Maybe you have an idea, what's going wrong here. Skype told me to get in > touch with you, since it works during daylight but not with bad light > during the night. > > If you would have any patches to test, I am more then willing to test them. > > I hope you can help me with this issue, The application should stop video streaming before changing the frame rate. Could you add debug messages to VIDIOC_STREAMOFF and see if it gets called before changing the frame rate ? If it doesn't, I'm not sure who is to blame. V4L2 doesn't clearly state if changing the frame rate during video streaming is allowed or not. I will raise the issue on the video4linux mailing list if you confirm that Skype doesn't stop streaming before changing the frame rate. Best regards, Laurent Pinchart _______________________________________________ Linux-uvc-devel mailing list Linux-uvc-devel@lists.berlios.de https://lists.berlios.de/mailman/listinfo/linux-uvc-devel
