Hi Paulo, On Tuesday 25 November 2008, Paulo Assis wrote: > Hi, > While performing some tests on the latest svn revision of guvcview > I've notice some strange behaviour from the uvc driver dispatched > with Ubuntu latest kernel (2.6.27-8). > After starting guvcview in MJPEG mode everything is working fine, I then > proceed into changing the imput mode to yuv, also everything is working OK. > But now if I set it back to MJPEG mode, I get a select timeout, meaning > that no frames are available. > With luvcview, that doesn't implement a select prior to the VIDIOC_DQBUF > ioctl, it just hangs waiting for a frame. > > If I had to guess I would say that after geting into yuv (uncompressed) > mode incomplete frame drop gets activated, but after getting back into > MJPEG mode it doesn't get deactivated, and since MJPEG data is smaller in > size than yuv then the driver just confuses the MJPEG frame with a > incomplete yuv frame. > > Like I said it's just a wild guess based on the driver behaviour :-). > I will only have time to debug this properly in the next weekend.
And that's a good guess :-) The problem is fixed in 2.6.28. In the meantime you can download, build and install the latest driver source (see http://linux-uvc.berlios.de/ for instructions). Best regards, Laurent Pinchart _______________________________________________ Linux-uvc-devel mailing list [email protected] https://lists.berlios.de/mailman/listinfo/linux-uvc-devel
