Hi,
On Friday 21 December 2007, Plooij wrote:
> I have some news on this issue: after an update from Ubuntu last Wednesday,
> both cameras work fine simultaneously. They even continue to work fine
> after rebooting, so the problem seems to be solved permanently (there's
> nothing worse than problems that occur only sometimes). The Ubuntu update
> contained an updated kernel.
>
> Sorry, I forgot rule nr. 1 in bug reporting: use the latest version of the
> program. I downloaded a recent version of your driver from SVN. Should I
> use that one instead of the one from Ubuntu that seems to work now?
Given that the Ubuntu package will probably follow the driver's development, I
would at least try the SVN version to discover bugs before it's too late :-)
> After the update, I still can't set the frame rate parameter. I've added my
> code below (irrelevant code is replaced by text between [] brackets). This
> is the output of the code section:
>
> Parameter getting not supported.
> Parameter setting not supported.
See comment below.
> Do you think it is possible to make a driver that skips frames in case of
> insufficient bandwidth, instead of giving corrupted frames to applications?
For YUV video streams that would be possible, as images have a fixed size. For
MJPEG video streams there is no way to detect packet loss.
> void CGrabber_Implementation::init_device()
> {
> struct v4l2_capability cap;
> struct v4l2_cropcap cropcap;
> struct v4l2_crop crop;
> struct v4l2_streamparm streamparm;
> struct v4l2_format fmt;
> unsigned int min;
>
> [Capability checks]
>
> [Cropping settings]
>
> //Parameters
> CLEAR(streamparm);
Set streamparm.type to V4L2_BUF_TYPE_VIDEO_CAPTURE. That should solve your
problem.
> if (-1 == xioctl (fd, VIDIOC_G_PARM, &streamparm))
> {
> switch (errno)
> {
> case EINVAL:
> printf("Parameter getting not supported.\n");
> break;
> default:
> errno_exit ("VIDIOC_G_PARM");
> break;
> }
> }
>
> streamparm.parm.capture.timeperframe.numerator = 1;
> streamparm.parm.capture.timeperframe.denominator = 15;
>
> if (-1 == xioctl (fd, VIDIOC_S_PARM, &streamparm))
> {
> switch (errno)
> {
> case EINVAL:
> printf("Parameter setting not supported.\n");
> break;
> default:
> errno_exit ("VIDIOC_S_PARM");
> break;
> }
> }
>
> //Format
> CLEAR (fmt);
>
> fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
> fmt.fmt.pix.width = 640;
> fmt.fmt.pix.height = 480;
> fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_YUYV;
> fmt.fmt.pix.field = V4L2_FIELD_NONE;
>
> if (-1 == xioctl (fd, VIDIOC_S_FMT, &fmt))
> errno_exit ("VIDIOC_S_FMT");
>
> [Format checks]
>
> [More initialization]
>
> [Camera control settings]
> }
Best regards,
Laurent Pinchart
_______________________________________________
Linux-uvc-devel mailing list
[email protected]
https://lists.berlios.de/mailman/listinfo/linux-uvc-devel
