Hi Cédric, On Thursday 19 March 2009 09:27:07 [email protected] wrote: > Hi, > > This is my problem, I don't have any errors. V4L2 API says that when you > ask for a Width and Heigth, the driver will give you the max ones below > the values you asked for. Meaning if you ask for 817x616, it will set > 800x600 without returning any errors. > > My DMESG (no pb, I have got my "/dev/video0"): > > usb 1-2: new full speed USB device using ohci_hcd and address 3 > usb 1-2: configuration #1 chosen from 1 choice > uvcvideo: Found UVC 1.00 device <unnamed> (046d:0991) > input: UVC Camera (046d:0991) as > /devices/pci0000:00/0000:00:02.2/usb1/1-2/1-2:1.0/input/input9 > > > An extract of my code, taken from the web (Capture.c): > > CLEAR (fmt); > > fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; > if (-1 == xioctl (fd, VIDIOC_G_FMT, &fmt)) > errno_exit ("VIDIOC_G_FMT"); > > fmt.fmt.pix.width = WB_FRAME_WIDTH; // 800 > fmt.fmt.pix.height = WB_FRAME_HEIGHT; // 600 > fmt.fmt.pix.pixelformat = WB_COLOR_FORMAT; // YUYV which is perfect for me > fmt.fmt.pix.field = V4L2_FIELD_INTERLACED; > > // Note VIDIOC_S_FMT may change width and height > // So I check the *new* values > > fprintf (stderr, > "width: %d\n" > "height: %d\n", > fmt.fmt.pix.width, > fmt.fmt.pix.height); > > It prints 176 by 144! What am I doing wrong? > (later, I check the buffer size allocated via MMAP: 50688 => 176 x 144 x 2) > > Any ideas? Where could be the problem?
Try to set the trace parameter to UVC_TRACE_FORMAT (8). The driver will print debug messages to the kernel log with the format requested by the application. echo 8 > /sys/modules/uvcvideo/parameters/trace Best regards, Laurent Pinchart _______________________________________________ Linux-uvc-devel mailing list [email protected] https://lists.berlios.de/mailman/listinfo/linux-uvc-devel
