apps: cam: Add option to set stream orientation

Add a '--orientation|-o' option to the cam test application to set
an orientation to the image stream.

Supported values are the ones obtained by applying flips to the camera
sensor:
- rot0: no rotation
- rot180: rotate 180 degrees
- flip: vertical flip
- mirror: horizontal flip

Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: David Plowman <david.plowman@raspberrypi.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/apps/cam/main.cpp

@@ -133,6 +133,11 @@ int CamApp::parseOptions(int argc, char *argv[])
 			 "Capture until interrupted by user or until <count> frames captured",
 			 "capture", ArgumentOptional, "count", false,
 			 OptCamera);
+
+	parser.addOption(OptOrientation, OptionString,
+			 "Desired image orientation (rot0, rot180, mirror, flip)",
+			 "orientation", ArgumentRequired, "orientation", false,
+			 OptCamera);
 #ifdef HAVE_KMS
 	parser.addOption(OptDisplay, OptionString,
 			 "Display viewfinder through DRM/KMS on specified connector",