Hi Laurent, Even with "nodrop=1" the framerate is still stuck at ~12fps when it should be ~30fps. I ran "/yavta -c -f Y800 -s 1280x960 /dev/video0" to test the camera fps. Here is the YAVTA output for nodrop=0: http://pastebin.com/bQZcJ0Fd Here is the YAVTA output for nodrop=1: http://pastebin.com/cFYFUrvN I used the following command to change the nodrop parameter (UVC is a built-in kernel module): echo 1 > /sys/module/uvcvideo/parameters/nodrop I also tried enabling log for the uvcvideo module: echo 0xffff > /sys/module/uvcvideo/parameters/trace And here is the corresponding part of dmesg: http://pastebin.com/eWL3GbE1 There seems to be some errors in this log (e.g. Stream 1 error event b5 e5 len 12.), but I'm not sure they could be the cause of issue or not. Thanks, Isaac On Tue, Sep 16, 2014 at 4:08 PM, Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> wrote: > Hi Isaac, > > On Sunday 14 September 2014 01:57:02 Isaac Nickaein wrote: >> Ah sorry for the confusion. The USB camera was not working on the old >> kernel of ARM board. After patching the kernel, I can grab images but >> the framerate is 1/2.5 of expected framerate. The camera works without >> any issue on my PC (with kernel 3.13) though. > > The uvcvideo driver drops erroneous frame by default. Could you please try > turning that off by setting the nodrop module parameter to 1 and check if the > frame rate changes ? Please use the yavta command line test application > (http://git.ideasonboard.org/yavta.git) as other applications might not > correctly handle frames with the error bit set, or might not take them into > account to compute the frame rate. > > The following command line should be all you need (you might want to change > the resolution and video device to match your system). > > yavta -c -f YUYV -s 640x480 /dev/video0 > > -- > Regards, > > Laurent Pinchart > -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
