From 25f71fd71d837f7e3ac165269987624aff0c0eb5 Mon Sep 17 00:00:00 2001
From: fryshorts <leonhard@in-verted.de>
Date: Sat, 26 Jul 2014 17:26:43 +0200
Subject: [PATCH] Improved Documentation and Logging for update in v4l2 plugin.

This adds some documentation to the update function and also
improves the logging by adding some info and bumping errors
to LOG_ERROR.
---
 plugins/linux-v4l2/v4l2-input.c | 46 +++++++++++++++++++++++----------
 1 file changed, 32 insertions(+), 14 deletions(-)

diff --git a/plugins/linux-v4l2/v4l2-input.c b/plugins/linux-v4l2/v4l2-input.c
index 51e1ca84f..12fc556f3 100644
--- a/plugins/linux-v4l2/v4l2-input.c
+++ b/plugins/linux-v4l2/v4l2-input.c
@@ -714,61 +714,80 @@ static void v4l2_destroy(void *vptr)
 	bfree(data);
 }
 
+/**
+ * Initialize the v4l2 device
+ *
+ * This function:
+ * - tries to open the device
+ * - sets pixelformat and requested resolution
+ * - sets the requested framerate
+ * - maps the buffers
+ * - starts the capture thread
+ */
 static void v4l2_init(struct v4l2_data *data)
 {
 	struct v4l2_format fmt;
 	struct v4l2_streamparm par;
+	struct dstr fps;
 	int width, height;
 	int fps_num, fps_denom;
 
+	blog(LOG_INFO, "Start capture from %s", data->set_device);
 	data->dev = v4l2_open(data->set_device, O_RDWR | O_NONBLOCK);
 	if (data->dev == -1) {
-		blog(LOG_ERROR, "Unable to open device: %s", data->set_device);
+		blog(LOG_ERROR, "Unable to open device");
 		goto fail;
 	}
 
+	/* set pixel format and resolution */
 	unpack_tuple(&width, &height, data->set_res);
 	fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 	fmt.fmt.pix.width = width;
 	fmt.fmt.pix.height = height;
 	fmt.fmt.pix.pixelformat = data->set_pixfmt;
 	fmt.fmt.pix.field = V4L2_FIELD_INTERLACED;
-
 	if (v4l2_ioctl(data->dev, VIDIOC_S_FMT, &fmt) < 0) {
-		blog(LOG_DEBUG, "unable to set format");
+		blog(LOG_ERROR, "Unable to set format");
 		goto fail;
 	}
-	data->pixfmt = fmt.fmt.pix.pixelformat;
 	data->width = fmt.fmt.pix.width;
 	data->height = fmt.fmt.pix.height;
+	data->pixfmt = fmt.fmt.pix.pixelformat;
+	data->linesize = fmt.fmt.pix.bytesperline;
+	blog(LOG_INFO, "Resolution: %"PRIuFAST32"x%"PRIuFAST32,
+	     data->width, data->height);
+	blog(LOG_INFO, "Linesize: %"PRIuFAST32" Bytes", data->linesize);
 
+	/* set framerate */
 	unpack_tuple(&fps_num, &fps_denom, data->set_fps);
 	par.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 	par.parm.capture.timeperframe.numerator = fps_num;
 	par.parm.capture.timeperframe.denominator = fps_denom;
-
 	if (v4l2_ioctl(data->dev, VIDIOC_S_PARM, &par) < 0) {
-		blog(LOG_DEBUG, "unable to set params");
+		blog(LOG_ERROR, "Unable to set framerate");
 		goto fail;
 	}
+	dstr_init(&fps);
+	dstr_printf(&fps, "%.2f",
+		(float) par.parm.capture.timeperframe.denominator
+		/ par.parm.capture.timeperframe.numerator);
+	blog(LOG_INFO, "Framerate: %s fps", fps.array);
+	dstr_free(&fps);
 
-	data->linesize = fmt.fmt.pix.bytesperline;
-	blog(LOG_DEBUG, "Linesize: %"PRIuFAST32, data->linesize);
-
+	/* map buffers */
 	if (v4l2_create_mmap(data) < 0) {
-		blog(LOG_ERROR, "failed to map buffers");
+		blog(LOG_ERROR, "Failed to map buffers");
 		goto fail;
 	}
 
-	blog(LOG_INFO, "Start capturing  from %s", data->set_device);
-
+	/* start the capture thread */
 	if (os_event_init(&data->event, OS_EVENT_TYPE_MANUAL) != 0)
 		goto fail;
 	if (pthread_create(&data->thread, NULL, v4l2_thread, data) != 0)
 		goto fail;
 	return;
 fail:
-	blog(LOG_DEBUG, "initialization failed");
+	blog(LOG_ERROR, "Initialization failed");
 	v4l2_terminate(data);
 }
 
@@ -821,7 +840,6 @@ static void *v4l2_create(obs_data_t settings, obs_source_t source)
 	data->source = source;
 
 	v4l2_update(data, settings);
-	blog(LOG_DEBUG, "New input created");
 
 	return data;
 }