From bde4deb8803026ec69e11cd380d77bf5d33ee623 Mon Sep 17 00:00:00 2001 From: Paul Elder Date: Tue, 28 Aug 2018 02:17:15 -0400 Subject: 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 Reviewed-by: Laurent Pinchart Reviewed-by: Kieran Bingham --- include/uvcgadget/stream.h | 13 +++++++++++++ lib/stream.c | 6 ++++++ lib/uvc.c | 5 +++++ 3 files changed, 24 insertions(+) diff --git a/include/uvcgadget/stream.h b/include/uvcgadget/stream.h index 9ab068f..bc83cfa 100644 --- a/include/uvcgadget/stream.h +++ b/include/uvcgadget/stream.h @@ -90,6 +90,19 @@ void uvc_stream_delete(struct uvc_stream *stream); int uvc_stream_set_format(struct uvc_stream *stream, const struct v4l2_pix_format *format); +/* + * uvc_stream_set_frame_rate - Set the frame rate for the stream + * @stream: the UVC stream + * @fps: the frame rate in frames per second + * + * This function is called from the UVC protocol handler to configure the frame + * rate for the video source of the @stream. It must not be called directly by + * applications. + * + * Returns 0 on success, or a negative error code on failure. + */ +int uvc_stream_set_frame_rate(struct uvc_stream *stream, unsigned int fps); + /* * uvc_stream_enable - Turn on/off video streaming for the UVC stream * @stream: the UVC stream diff --git a/lib/stream.c b/lib/stream.c index 19f0d78..168dc71 100644 --- a/lib/stream.c +++ b/lib/stream.c @@ -156,6 +156,12 @@ int uvc_stream_set_format(struct uvc_stream *stream, return video_source_set_format(stream->src, &fmt); } +int uvc_stream_set_frame_rate(struct uvc_stream *stream, unsigned int fps) +{ + printf("=== Setting frame rate to %u fps\n", fps); + return video_source_set_frame_rate(stream->src, fps); +} + /* --------------------------------------------------------------------------- * Stream handling */ 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); } } -- cgit v1.2.3