Hi, I think I can add this to guvcview and run some tests, but I would like some info on the v4l2_jpegcompression struct, especially on the **jpeg_markers flag, I believe for mjpeg I should set all flags, except V4l2_JPEG_MARKER_DHT, since huffman tables are not included in the video stream, is this correct, or it just doesn't make any difference? Also is the correct aproach a call to VIDIOC_G_JPEGCOMP for filling the struct and then just change the quality entry and call VIDIOC_S_JPEGCOMP?
Best regards, Paulo 2009/6/2 Jon Fairbairn <[email protected]> > Hi Laurent, > Laurent Pinchart <[email protected]> writes: > > Here's a patch that implements VIDIOC_[GS]_JPEGCOMP. It seems to work > with a > > Logitech QuickCam Pro for Notebooks. Could you please test it with your > > camera(s) and report the results ? > > Thanks. I downloaded the source for the kernel I'm running, > applied the patch (it applied cleanly), so I built it and > insmodded it, and ran motion -- this message > > motion: [1] VIDIOC_G_JPEGCOMP not supported but it should > be (does your webcam driver support this ioctl?) > > no longer appears, but I still get > > motion: [1] Video device fatal error - Closing video > device > > That might be bug in motion, but I'm not sure what else to > use to test it. mplayer with -tv mjpeg says (inter alia) > > Selected driver: v4l2 > name: Video 4 Linux 2 input > author: Martin Olschewski <[email protected]> > comment: first try, more to come ;-) > v4l2: video fd: /dev/video0: 3 > v4l2: your device driver does not support VIDIOC_G_STD ioctl, VIDIOC_G_PARM > was used instead. > Selected device: Live! Cam Optia > Capabilites: video capture streaming > supported norms: > inputs: 0 = Camera 1; > Current input: 0 > Format MJPEG ( 0 bits, MJPEG): Unknown 0x47504a4d > Format YUYV (16 bits, YUV 4:2:2 (YUYV)): Packed YUY2 > Current format: YUYV > v4l2: set format: YVU420 > v4l2: ioctl set format failed: Invalid argument > v4l2: set format: YUV420 > v4l2: ioctl set format failed: Invalid argument > v4l2: set format: UYVY > v4l2: ioctl set format failed: Invalid argument > v4l2: set format: YUYV > v4l2: set input: 0 > > which doesn't look right -- it doesn't say "set format: > MJPEG". xawtv just gives me a black window on my vncsession. > luvcview and mjpeg-streamer work in MJPEG mode, but they did > before the patch, so that's no test either. > > What would be the right way to test this? > > Kernel is 2.6.27.24-78.2.53.fc9.x86_64 > > > -- > Jón Fairbairn [email protected] > http://www.chaos.org.uk/~jf/Stuff-I-dont-want.html<http://www.chaos.org.uk/%7Ejf/Stuff-I-dont-want.html> > (updated 2009-01-31) > > _______________________________________________ > Linux-uvc-devel mailing list > [email protected] > https://lists.berlios.de/mailman/listinfo/linux-uvc-devel >
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