[yavta PATCH 5/9] Allow passing file descriptors to yavta

[Sakari Ailus <sakari.ailus@xxxxxx>]

Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxx>
---
 yavta.c |   63 +++++++++++++++++++++++++++++++++++++++++++--------------------
 1 file changed, 43 insertions(+), 20 deletions(-)

diff --git a/yavta.c b/yavta.c
index 870682e..a9b192a 100644
--- a/yavta.c
+++ b/yavta.c
@@ -62,6 +62,7 @@ struct buffer
 struct device
 {
 	int fd;
+	int opened;
 
 	enum v4l2_buf_type type;
 	enum v4l2_memory memtype;
@@ -180,13 +181,8 @@ static unsigned int v4l2_format_code(const char *name)
 	return 0;
 }
 
-static int video_open(struct device *dev, const char *devname, int no_query)
+static int video_open(struct device *dev, const char *devname)
 {
-	dev->fd = -1;
-	dev->memtype = V4L2_MEMORY_MMAP;
-	dev->buffers = NULL;
-	dev->type = (enum v4l2_buf_type)-1;
-
 	dev->fd = open(devname, O_RDWR);
 	if (dev->fd < 0) {
 		printf("Error opening device %s: %s (%d).\n", devname,
@@ -196,6 +192,16 @@ static int video_open(struct device *dev, const char *devname, int no_query)
 
 	printf("Device %s opened.\n", devname);
 
+	dev->opened = 1;
+
+	return 0;
+}
+
+static int video_querycap(struct device *dev, int no_query) {
+	struct v4l2_capability cap;
+	unsigned int capabilities;
+	int ret;
+
 	if (no_query) {
 		/* Assume capture device. */
 		dev->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
@@ -215,9 +221,7 @@ static int video_open(struct device *dev, const char *devname, int no_query)
 	else if (capabilities & V4L2_CAP_VIDEO_OUTPUT)
 		dev->type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
 	else {
-		printf("Error opening device %s: neither video capture "
-			"nor video output supported.\n", devname);
-		close(dev->fd);
+		printf("Device supports neither capture nor output.\n");
 		return -EINVAL;
 	}
 
@@ -231,7 +235,8 @@ static void video_close(struct device *dev)
 {
 	free(dev->pattern);
 	free(dev->buffers);
-	close(dev->fd);
+	if (dev->opened)
+		close(dev->fd);
 }
 
 static unsigned int get_control_type(struct device *dev, unsigned int id)
@@ -1246,6 +1251,7 @@ static void usage(const char *argv0)
 	printf("-w, --set-control 'ctrl value'	Set control 'ctrl' to 'value'\n");
 	printf("    --enum-formats		Enumerate formats\n");
 	printf("    --enum-inputs		Enumerate inputs\n");
+	printf("    --fd                        Use a numeric file descriptor insted of a device\n");
 	printf("    --no-query			Don't query capabilities on open\n");
 	printf("    --offset			User pointer buffer offset from page start\n");
 	printf("    --requeue-last		Requeue the last buffers before streamoff\n");
@@ -1262,6 +1268,7 @@ static void usage(const char *argv0)
 #define OPT_USERPTR_OFFSET	261
 #define OPT_REQUEUE_LAST	262
 #define OPT_STRIDE		263
+#define OPT_FD			264
 
 static struct option opts[] = {
 	{"capture", 2, 0, 'c'},
@@ -1269,6 +1276,7 @@ static struct option opts[] = {
 	{"delay", 1, 0, 'd'},
 	{"enum-formats", 0, 0, OPT_ENUM_FORMATS},
 	{"enum-inputs", 0, 0, OPT_ENUM_INPUTS},
+	{"fd", 1, 0, OPT_FD},
 	{"file", 2, 0, 'F'},
 	{"fill-frames", 0, 0, 'I'},
 	{"format", 1, 0, 'f'},
@@ -1297,7 +1305,11 @@ static struct option opts[] = {
 int main(int argc, char *argv[])
 {
 	struct sched_param sched;
-	struct device dev = { 0 };
+	struct device dev = {
+		.fd = -1,
+		.memtype = V4L2_MEMORY_MMAP,
+		.type = (enum v4l2_buf_type)-1,
+	};
 	int ret;
 
 	/* Options parsings */
@@ -1452,6 +1464,14 @@ int main(int argc, char *argv[])
 		case OPT_ENUM_INPUTS:
 			do_enum_inputs = 1;
 			break;
+		case OPT_FD:
+			dev.fd = atoi(optarg);
+			if (dev.fd < 0) {
+				printf("Bad file descriptor %d\n", dev.fd);
+				return 1;
+			}
+			printf("Using file descriptor %d\n", dev.fd);
+			break;
 		case OPT_NO_QUERY:
 			no_query = 1;
 			break;
@@ -1482,18 +1502,21 @@ int main(int argc, char *argv[])
 		return 1;
 	}
 
-	if (optind >= argc) {
-		usage(argv[0]);
-		return 1;
-	}
-
 	if (!do_file)
 		filename = NULL;
 
-	/* Open the video device. If the device type isn't recognized, set the
-	 * --no-query option to avoid querying V4L2 subdevs.
-	 */
-	ret = video_open(&dev, argv[optind], no_query);
+	if (dev.fd == -1) {
+		if (optind >= argc) {
+			usage(argv[0]);
+			return 1;
+		} else {
+			ret = video_open(&dev, argv[optind]);
+			if (ret < 0)
+				return 1;
+		}
+	}
+
+	ret = video_querycap(&dev, no_query);
 	if (ret < 0)
 		return 1;
 
-- 
1.7.10.4

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