camerabin: Document requirement for PLAYING state

As described in GNOME bug 663998, the element must be in the PLAYING
state before calling capture-start.

https://bugzilla.gnome.org/show_bug.cgi?id=664048

diff --git a/gst/camerabin/gstcamerabin.c b/gst/camerabin/gstcamerabin.c
index 1a2b05f..be13b65 100644 (file)
--- a/gst/camerabin/gstcamerabin.c
+++ b/gst/camerabin/gstcamerabin.c
@@ -84,6 +84,8 @@
  * unreffed or replaced by a new user set element. Initially only elements
  * needed for view finder mode are created to speed up startup. Image bin and
  * video bin elements are created when setting the mode or starting capture.
+ * GstCameraBin must be in the PLAYING state before #GstCameraBin::capture-start
+ * is called.
  * </para>
  * </refsect2>
  * <refsect2>