uvc: Add API to set video format

Add a uvc_setformat() function to set the format for the UVC video
stream instead of accessing the internals of the uvc_device in
stream.c.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

4 files changed, 30 insertions, 17 deletions

diff --git a/stream.c b/stream.c
index ba9a924..d7d061a 100644
--- a/stream.c
+++ b/stream.c
@@ -167,29 +167,20 @@ void uvc_stream_enable(struct uvc_stream *stream, int enable)
 	}
 }
 
-int uvc_stream_set_format(struct uvc_stream *stream)
+int uvc_stream_set_format(struct uvc_stream *stream,
+			  const struct v4l2_pix_format *format)
 {
-	struct v4l2_device *cap = stream->cap;
-	struct uvc_device *dev = stream->uvc;
-	struct v4l2_pix_format fmt;
+	struct v4l2_pix_format fmt = *format;
 	int ret;
 
 	printf("Setting format to 0x%08x %ux%u\n",
-		dev->fcc, dev->width, dev->height);
-
-	memset(&fmt, 0, sizeof fmt);
-	fmt.width = dev->width;
-	fmt.height = dev->height;
-	fmt.pixelformat = dev->fcc;
-	fmt.field = V4L2_FIELD_NONE;
-	if (dev->fcc == V4L2_PIX_FMT_MJPEG)
-		fmt.sizeimage = dev->maxsize * 1.5;
+		format->pixelformat, format->width, format->height);
 
-	ret = v4l2_set_format(dev->vdev, &fmt);
+	ret = uvc_set_format(stream->uvc, &fmt);
 	if (ret < 0)
 		return ret;
 
-	return v4l2_set_format(cap, &fmt);
+	return v4l2_set_format(stream->cap, &fmt);
 }
 
 /* ---------------------------------------------------------------------------
diff --git a/stream.h b/stream.h
index c9694e7..6eb6731 100644
--- a/stream.h
+++ b/stream.h
@@ -23,6 +23,7 @@
 struct events;
 struct uvc_function_config;
 struct uvc_stream;
+struct v4l2_pix_format;
 
 /*
  * uvc_stream_new - Create a new UVC stream
@@ -87,13 +88,15 @@ void uvc_stream_delete(struct uvc_stream *stream);
 /*
  * uvc_stream_set_format - Set the active video format for the stream
  * @stream: the UVC stream
+ * @format: the video stream format
  *
  * This function is called from the UVC protocol handler to configure the video
  * format for 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_format(struct uvc_stream *stream);
+int uvc_stream_set_format(struct uvc_stream *stream,
+			  const struct v4l2_pix_format *format);
 
 /*
  * uvc_stream_enable - Turn on/off video streaming for the UVC stream
diff --git a/uvc.c b/uvc.c
index 0a276a4..fc28482 100644
--- a/uvc.c
+++ b/uvc.c
@@ -260,6 +260,7 @@ uvc_events_process_data(struct uvc_device *dev,
 	if (dev->control == UVC_VS_COMMIT_CONTROL) {
 		const struct uvc_function_config_format *format;
 		const struct uvc_function_config_frame *frame;
+		struct v4l2_pix_format pixfmt;
 
 		format = &dev->fc->streaming.formats[target->bFormatIndex-1];
 		frame = &format->frames[target->bFrameIndex-1];
@@ -268,7 +269,15 @@ uvc_events_process_data(struct uvc_device *dev,
 		dev->width = frame->width;
 		dev->height = frame->height;
 
-		uvc_stream_set_format(dev->stream);
+		memset(&pixfmt, 0, sizeof pixfmt);
+		pixfmt.width = frame->width;
+		pixfmt.height = frame->height;
+		pixfmt.pixelformat = format->fcc;
+		pixfmt.field = V4L2_FIELD_NONE;
+		if (format->fcc == V4L2_PIX_FMT_MJPEG)
+			pixfmt.sizeimage = dev->maxsize * 1.5;
+
+		uvc_stream_set_format(dev->stream, &pixfmt);
 	}
 }
 
@@ -320,6 +329,10 @@ static void uvc_events_process(void *d)
 	}
 }
 
+/* ---------------------------------------------------------------------------
+ * Initialization and setup
+ */
+
 void uvc_events_init(struct uvc_device *dev, struct events *events)
 {
 	struct v4l2_event_subscription sub;
@@ -346,3 +359,8 @@ void uvc_set_config(struct uvc_device *dev, struct uvc_function_config *fc)
 {
 	dev->fc = fc;
 }
+
+int uvc_set_format(struct uvc_device *dev, struct v4l2_pix_format *format)
+{
+	return v4l2_set_format(dev->vdev, format);
+}
diff --git a/uvc.h b/uvc.h
index c1138bf..f73ff70 100644
--- a/uvc.h
+++ b/uvc.h
@@ -49,5 +49,6 @@ struct uvc_device *uvc_open(const char *devname, struct uvc_stream *stream);
 void uvc_close(struct uvc_device *dev);
 void uvc_events_init(struct uvc_device *dev, struct events *events);
 void uvc_set_config(struct uvc_device *dev, struct uvc_function_config *fc);
+int uvc_set_format(struct uvc_device *dev, struct v4l2_pix_format *format);
 
 #endif /* __UVC_H__ */