Replace all system calls with there counterpart in libv4l2.

By using the wrapper functions supplied by libv4l2 we gain
support for formats not natively supported by obs.
The library intercepts certain system calls to transparently
enable recoding.

plugins/linux-v4l2/v4l2-input.c

@@ -28,6 +28,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <sys/select.h>
 
 #include <linux/videodev2.h>
+#include <libv4l2.h>
 
 #include <util/threading.h>
 #include <util/bmem.h>
@@ -158,14 +159,14 @@ static int_fast32_t v4l2_start_capture(struct v4l2_data *data)
 		buf.memory = V4L2_MEMORY_MMAP;
 		buf.index = i;
 
-		if (ioctl(data->dev, VIDIOC_QBUF, &buf) < 0) {
+		if (v4l2_ioctl(data->dev, VIDIOC_QBUF, &buf) < 0) {
 			blog(LOG_ERROR, "unable to queue buffer");
 			return -1;
 		}
 	}
 
 	type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
-	if (ioctl(data->dev, VIDIOC_STREAMON, &type) < 0) {
+	if (v4l2_ioctl(data->dev, VIDIOC_STREAMON, &type) < 0) {
 		blog(LOG_ERROR, "unable to start stream");
 		return -1;
 	}
@@ -180,7 +181,7 @@ static int_fast32_t v4l2_stop_capture(struct v4l2_data *data)
 {
 	enum v4l2_buf_type type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 
-	if (ioctl(data->dev, VIDIOC_STREAMOFF, &type) < 0) {
+	if (v4l2_ioctl(data->dev, VIDIOC_STREAMOFF, &type) < 0) {
 		blog(LOG_ERROR, "unable to stop stream");
 	}
 
@@ -198,7 +199,7 @@ static int_fast32_t v4l2_create_mmap(struct v4l2_data *data)
 	req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 	req.memory = V4L2_MEMORY_MMAP;
 
-	if (ioctl(data->dev, VIDIOC_REQBUFS, &req) < 0) {
+	if (v4l2_ioctl(data->dev, VIDIOC_REQBUFS, &req) < 0) {
 		blog(LOG_DEBUG, "request for buffers failed !");
 		return -1;
 	}
@@ -218,13 +219,13 @@ static int_fast32_t v4l2_create_mmap(struct v4l2_data *data)
 		buf.memory = V4L2_MEMORY_MMAP;
 		buf.index = i;
 
-		if (ioctl(data->dev, VIDIOC_QUERYBUF, &buf) < 0) {
+		if (v4l2_ioctl(data->dev, VIDIOC_QUERYBUF, &buf) < 0) {
 			blog(LOG_ERROR, "failed to query buffer");
 			return -1;
 		}
 
 		data->buf[i].length = buf.length;
-		data->buf[i].start = mmap(NULL, buf.length,
+		data->buf[i].start = v4l2_mmap(NULL, buf.length,
 			PROT_READ | PROT_WRITE, MAP_SHARED,
 			data->dev, buf.m.offset);
 
@@ -244,7 +245,7 @@ static void v4l2_destroy_mmap(struct v4l2_data *data)
 {
 	for(uint_fast32_t i = 0; i < data->buf_count; ++i) {
 		if (data->buf[i].start != MAP_FAILED)
-			munmap(data->buf[i].start, data->buf[i].length);
+			v4l2_munmap(data->buf[i].start, data->buf[i].length);
 	}
 
 	data->buf_count = 0;
@@ -291,7 +292,7 @@ static void *v4l2_thread(void *vptr)
 		buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 		buf.memory = V4L2_MEMORY_MMAP;
 
-		if (ioctl(data->dev, VIDIOC_DQBUF, &buf) < 0) {
+		if (v4l2_ioctl(data->dev, VIDIOC_DQBUF, &buf) < 0) {
 			if (errno == EAGAIN)
 				continue;
 			blog(LOG_DEBUG, "failed to dequeue buffer");
@@ -310,7 +311,7 @@ static void *v4l2_thread(void *vptr)
 
 		obs_source_output_video(data->source, &out);
 
-		if (ioctl(data->dev, VIDIOC_QBUF, &buf) < 0) {
+		if (v4l2_ioctl(data->dev, VIDIOC_QBUF, &buf) < 0) {
 			blog(LOG_DEBUG, "failed to enqueue buffer");
 			break;
 		}
@@ -366,12 +367,12 @@ static void v4l2_device_list(obs_property_t prop, obs_data_t settings)
 		dstr_resize(&device, 5);
 		dstr_cat(&device, dp->d_name);
 
-		if ((fd = open(device.array, O_RDWR | O_NONBLOCK)) == -1) {
+		if ((fd = v4l2_open(device.array, O_RDWR | O_NONBLOCK)) == -1) {
 			blog(LOG_INFO, "Unable to open %s", device.array);
 			continue;
 		}
 
-		if (ioctl(fd, VIDIOC_QUERYCAP, &video_cap) == -1) {
+		if (v4l2_ioctl(fd, VIDIOC_QUERYCAP, &video_cap) == -1) {
 			blog(LOG_INFO, "Failed to query capabilities for %s",
 			     device.array);
 		} else if (video_cap.capabilities & V4L2_CAP_VIDEO_CAPTURE) {
@@ -409,7 +410,7 @@ static void v4l2_format_list(int dev, obs_property_t prop)
 
 	obs_property_list_clear(prop);
 
-	while (ioctl(dev, VIDIOC_ENUM_FMT, &fmt) == 0) {
+	while (v4l2_ioctl(dev, VIDIOC_ENUM_FMT, &fmt) == 0) {
 		if (v4l2_to_obs_video_format(fmt.pixelformat)
 				!= VIDEO_FORMAT_NONE) {
 			obs_property_list_add_int(prop,
@@ -439,11 +440,11 @@ static void v4l2_resolution_list(int dev, uint_fast32_t pixelformat,
 
 	obs_property_list_clear(prop);
 
-	ioctl(dev, VIDIOC_ENUM_FRAMESIZES, &frmsize);
+	v4l2_ioctl(dev, VIDIOC_ENUM_FRAMESIZES, &frmsize);
 
 	switch(frmsize.type) {
 	case V4L2_FRMSIZE_TYPE_DISCRETE:
-		while (ioctl(dev, VIDIOC_ENUM_FRAMESIZES, &frmsize) == 0) {
+		while (v4l2_ioctl(dev, VIDIOC_ENUM_FRAMESIZES, &frmsize) == 0) {
 			dstr_printf(&buffer, "%dx%d", frmsize.discrete.width,
 					frmsize.discrete.height);
 			obs_property_list_add_int(prop, buffer.array,
@@ -488,11 +489,12 @@ static void v4l2_framerate_list(int dev, uint_fast32_t pixelformat,
 
 	obs_property_list_clear(prop);
 
-	ioctl(dev, VIDIOC_ENUM_FRAMEINTERVALS, &frmival);
+	v4l2_ioctl(dev, VIDIOC_ENUM_FRAMEINTERVALS, &frmival);
 
 	switch(frmival.type) {
 	case V4L2_FRMIVAL_TYPE_DISCRETE:
-		while (ioctl(dev, VIDIOC_ENUM_FRAMEINTERVALS, &frmival) == 0) {
+		while (v4l2_ioctl(dev, VIDIOC_ENUM_FRAMEINTERVALS,
+				&frmival) == 0) {
 			float fps = (float) frmival.discrete.denominator /
 				frmival.discrete.numerator;
 			int pack = pack_tuple(frmival.discrete.numerator,
@@ -529,7 +531,7 @@ static bool device_selected(obs_properties_t props, obs_property_t p,
 		obs_data_t settings)
 {
 	UNUSED_PARAMETER(p);
-	int dev = open(obs_data_getstring(settings, "device_id"),
+	int dev = v4l2_open(obs_data_getstring(settings, "device_id"),
 			O_RDWR | O_NONBLOCK);
 	if (dev == -1)
 		return false;
@@ -537,7 +539,7 @@ static bool device_selected(obs_properties_t props, obs_property_t p,
 	obs_property_t prop = obs_properties_get(props, "pixelformat");
 	v4l2_format_list(dev, prop);
 	obs_property_modified(prop, settings);
-	close(dev);
+	v4l2_close(dev);
 	return true;
 }
 
@@ -548,7 +550,7 @@ static bool format_selected(obs_properties_t props, obs_property_t p,
 		obs_data_t settings)
 {
 	UNUSED_PARAMETER(p);
-	int dev = open(obs_data_getstring(settings, "device_id"),
+	int dev = v4l2_open(obs_data_getstring(settings, "device_id"),
 			O_RDWR | O_NONBLOCK);
 	if (dev == -1)
 		return false;
@@ -557,7 +559,7 @@ static bool format_selected(obs_properties_t props, obs_property_t p,
 	v4l2_resolution_list(dev, obs_data_getint(settings, "pixelformat"),
 			prop);
 	obs_property_modified(prop, settings);
-	close(dev);
+	v4l2_close(dev);
 	return true;
 }
 
@@ -569,7 +571,7 @@ static bool resolution_selected(obs_properties_t props, obs_property_t p,
 {
 	UNUSED_PARAMETER(p);
 	int width, height;
-	int dev = open(obs_data_getstring(settings, "device_id"),
+	int dev = v4l2_open(obs_data_getstring(settings, "device_id"),
 			O_RDWR | O_NONBLOCK);
 	if (dev == -1)
 		return false;
@@ -580,7 +582,7 @@ static bool resolution_selected(obs_properties_t props, obs_property_t p,
 	v4l2_framerate_list(dev, obs_data_getint(settings, "pixelformat"),
 			width, height, prop);
 	obs_property_modified(prop, settings);
-	close(dev);
+	v4l2_close(dev);
 	return true;
 }
 
@@ -639,7 +641,7 @@ static void v4l2_terminate(struct v4l2_data *data)
 		v4l2_destroy_mmap(data);
 
 	if (data->dev != -1) {
-		close(data->dev);
+		v4l2_close(data->dev);
 		data->dev = -1;
 	}
 }
@@ -663,7 +665,7 @@ static void v4l2_init(struct v4l2_data *data)
 	struct v4l2_format fmt;
 	struct v4l2_streamparm par;
 
-	data->dev = open(data->device, O_RDWR | O_NONBLOCK);
+	data->dev = v4l2_open(data->device, O_RDWR | O_NONBLOCK);
 	if (data->dev == -1) {
 		blog(LOG_ERROR, "Unable to open device: %s", data->device);
 		goto fail;
@@ -675,7 +677,7 @@ static void v4l2_init(struct v4l2_data *data)
 	fmt.fmt.pix.pixelformat = data->pixelformat;
 	fmt.fmt.pix.field = V4L2_FIELD_INTERLACED;
 
-	if (ioctl(data->dev, VIDIOC_S_FMT, &fmt) < 0) {
+	if (v4l2_ioctl(data->dev, VIDIOC_S_FMT, &fmt) < 0) {
 		blog(LOG_DEBUG, "unable to set format");
 		goto fail;
 	}
@@ -687,7 +689,7 @@ static void v4l2_init(struct v4l2_data *data)
 	par.parm.capture.timeperframe.numerator = data->fps_numerator;
 	par.parm.capture.timeperframe.denominator = data->fps_denominator;
 
-	if (ioctl(data->dev, VIDIOC_S_PARM, &par) < 0) {
+	if (v4l2_ioctl(data->dev, VIDIOC_S_PARM, &par) < 0) {
 		blog(LOG_DEBUG, "unable to set params");
 		goto fail;
 	}