Hi, On Thursday 24 September 2009 11:14:35 Bo Liu wrote: > Hi, All > > I have a question about VIDIOC_S_FMT? > > Gstreamer will ioctl(VIDIOC_STREAMINGOFF）， then ioctl(VIDIOC_S_FMT), > then ioctl(VIDIOC_STREAMINGON) > > The newest's code have these patch: > > diff --git a/drivers/media/video/uvc/uvc_v4l2.c > b/drivers/media/video/uvc/uvc_v4l2.c index 507542d..f8b94d6 100644 (file) > --- a/drivers/media/video/uvc/uvc_v4l2.c > +++ b/drivers/media/video/uvc/uvc_v4l2.c > @@ -251,7 +251,7 @@ static int uvc_v4l2_set_format(struct uvc_video_device > *video, if (fmt->type != video->streaming->type) > return -EINVAL; > > - if (uvc_queue_streaming(&video->queue)) > + if (uvc_queue_allocated(&video->queue)) > return -EBUSY; > > ret = uvc_v4l2_try_format(video, fmt, &probe, &format, &frame); > > > > And, I found after this patch ioctl(VIDIOC_S_FMT) will failed at > uvc_queue_allocated(it won't failed at uvc_queue_streaming). > > So, Now Can Gstreamer set the format(use ioctl(VIDIOC_STREAMINGOFF）， > then ioctl(VIDIOC_S_FMT), then ioctl(VIDIOC_STREAMINGON)) after open the > device(doesn't close) ? If not, How to implement this?
You can't change the format while buffers are allocated. You need to free the buffers before, using VIDIOC_REQBUFS with a buffer count of 0. -- Regards, Laurent Pinchart _______________________________________________ Linux-uvc-devel mailing list [email protected] https://lists.berlios.de/mailman/listinfo/linux-uvc-devel
