stream, uvc: add uvc_stream_set_frame_rate

We would like to be able to set the frame rate of the video source of a
stream. This patch adds such a function to set the source's frame rate
from the stream. The frame rate is set right after the format is set.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/lib/uvc.c b/lib/uvc.c
index 695db5b..ab03f0e 100644
--- a/lib/uvc.c
+++ b/lib/uvc.c
@@ -269,6 +269,7 @@ uvc_events_process_data(struct uvc_device *dev,
 		const struct uvc_function_config_format *format;
 		const struct uvc_function_config_frame *frame;
 		struct v4l2_pix_format pixfmt;
+		unsigned int fps;
 
 		format = &dev->fc->streaming.formats[target->bFormatIndex-1];
 		frame = &format->frames[target->bFrameIndex-1];
@@ -286,6 +287,10 @@ uvc_events_process_data(struct uvc_device *dev,
 			pixfmt.sizeimage = dev->maxsize * 1.5;
 
 		uvc_stream_set_format(dev->stream, &pixfmt);
+
+		/* fps is guaranteed to be non-zero and thus valid. */
+		fps = 1.0 / (target->dwFrameInterval / 10000000.0);
+		uvc_stream_set_frame_rate(dev->stream, fps);
 	}
 }