v4l2: v4l2_calls: add gst_v4l2_clone

Signed-off-by: Michael Olbrich <m.olbrich@pengutronix.de>

2 files changed, 50 insertions, 31 deletions

diff --git a/sys/v4l2/v4l2_calls.c b/sys/v4l2/v4l2_calls.c
index 4ace236ac..72a639580 100644
--- a/sys/v4l2/v4l2_calls.c
+++ b/sys/v4l2/v4l2_calls.c
@@ -470,12 +470,13 @@ gst_v4l2_empty_lists (GstV4l2Object * v4l2object)
 }
 
 /******************************************************
- * gst_v4l2_open():
- *   open the video device (v4l2object->videodev)
+ * gst_v4l2_clone():
+ *   clone the video device from the other object,
+ *   or open a video device (v4l2object->videodev)
  * return value: TRUE on success, FALSE on error
  ******************************************************/
 gboolean
-gst_v4l2_open (GstV4l2Object * v4l2object)
+gst_v4l2_clone (GstV4l2Object * v4l2object, GstV4l2Object * other)
 {
   struct stat st;
   int libv4l2_fd;
@@ -487,34 +488,39 @@ gst_v4l2_open (GstV4l2Object * v4l2object)
   GST_V4L2_CHECK_NOT_OPEN (v4l2object);
   GST_V4L2_CHECK_NOT_ACTIVE (v4l2object);
 
-  /* be sure we have a device */
-  if (!v4l2object->videodev)
-    v4l2object->videodev = g_strdup ("/dev/video");
-
-  /* check if it is a device */
-  if (stat (v4l2object->videodev, &st) == -1)
-    goto stat_failed;
-
-  if (!S_ISCHR (st.st_mode))
-    goto no_device;
-
-  /* open the device */
-  v4l2object->video_fd =
-      open (v4l2object->videodev, O_RDWR /* | O_NONBLOCK */ );
-
-  if (!GST_V4L2_IS_OPEN (v4l2object))
-    goto not_open;
-
-  libv4l2_fd = v4l2_fd_open (v4l2object->video_fd,
-      V4L2_ENABLE_ENUM_FMT_EMULATION);
-  /* Note the v4l2_xxx functions are designed so that if they get passed an
-     unknown fd, the will behave exactly as their regular xxx counterparts, so
-     if v4l2_fd_open fails, we continue as normal (missing the libv4l2 custom
-     cam format to normal formats conversion). Chances are big we will still
-     fail then though, as normally v4l2_fd_open only fails if the device is not
-     a v4l2 device. */
-  if (libv4l2_fd != -1)
-    v4l2object->video_fd = libv4l2_fd;
+  if (!other) {
+    /* be sure we have a device */
+    if (!v4l2object->videodev)
+      v4l2object->videodev = g_strdup ("/dev/video");
+
+    /* check if it is a device */
+    if (stat (v4l2object->videodev, &st) == -1)
+      goto stat_failed;
+
+    if (!S_ISCHR (st.st_mode))
+      goto no_device;
+
+    /* open the device */
+    v4l2object->video_fd =
+        open (v4l2object->videodev, O_RDWR /* | O_NONBLOCK */ );
+
+    if (!GST_V4L2_IS_OPEN (v4l2object))
+      goto not_open;
+
+    libv4l2_fd = v4l2_fd_open (v4l2object->video_fd,
+        V4L2_ENABLE_ENUM_FMT_EMULATION);
+    /* Note the v4l2_xxx functions are designed so that if they get passed an
+       unknown fd, the will behave exactly as their regular xxx counterparts, so
+       if v4l2_fd_open fails, we continue as normal (missing the libv4l2 custom
+       cam format to normal formats conversion). Chances are big we will still
+       fail then though, as normally v4l2_fd_open only fails if the device is not
+       a v4l2 device. */
+    if (libv4l2_fd != -1)
+      v4l2object->video_fd = libv4l2_fd;
+  } else {
+    v4l2object->video_fd = v4l2_dup (other->video_fd);
+    v4l2object->videodev = g_strdup (other->videodev);
+  }
 
   v4l2object->can_poll_device = TRUE;
 
@@ -605,6 +611,17 @@ error:
 
 
 /******************************************************
+ * gst_v4l2_open():
+ *   open the video device (v4l2object->videodev)
+ * return value: TRUE on success, FALSE on error
+ ******************************************************/
+gboolean
+gst_v4l2_open (GstV4l2Object * v4l2object)
+{
+  return gst_v4l2_clone (v4l2object, NULL);
+}
+
+/******************************************************
  * gst_v4l2_close():
  *   close the video device (v4l2object->video_fd)
  * return value: TRUE on success, FALSE on error
diff --git a/sys/v4l2/v4l2_calls.h b/sys/v4l2/v4l2_calls.h
index 11d16b6ab..cac963bac 100644
--- a/sys/v4l2/v4l2_calls.h
+++ b/sys/v4l2/v4l2_calls.h
@@ -90,6 +90,8 @@
 
 
 /* open/close the device */
+gboolean	gst_v4l2_clone			(GstV4l2Object *v4l2object,
+						 GstV4l2Object *other);
 gboolean	gst_v4l2_open			(GstV4l2Object *v4l2object);
 gboolean	gst_v4l2_close			(GstV4l2Object *v4l2object);