cam: Add option to disallow adjusting of requested formats

Add a '--strict-formats' option which fails the camera configuration
step if the format is adjusted,

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/cam/main.cpp

@@ -49,12 +49,15 @@ private:
 	std::shared_ptr<Camera> camera_;
 	std::unique_ptr<libcamera::CameraConfiguration> config_;
 	EventLoop *loop_;
+
+	bool strictFormats_;
 };
 
 CamApp *CamApp::app_ = nullptr;
 
 CamApp::CamApp()
-	: cm_(nullptr), camera_(nullptr), config_(nullptr), loop_(nullptr)
+	: cm_(nullptr), camera_(nullptr), config_(nullptr), loop_(nullptr),
+	  strictFormats_(false)
 {
 	CamApp::app_ = this;
 }
@@ -77,6 +80,9 @@ int CamApp::init(int argc, char **argv)
 	if (ret < 0)
 		return ret;
 
+	if (options_.isSet(OptStrictFormats))
+		strictFormats_ = true;
+
 	cm_ = new CameraManager();
 
 	ret = cm_->start();
@@ -179,6 +185,9 @@ int CamApp::parseOptions(int argc, char *argv[])
 			 "list-controls");
 	parser.addOption(OptListProperties, OptionNone, "List cameras properties",
 			 "list-properties");
+	parser.addOption(OptStrictFormats, OptionNone,
+			 "Do not allow requested stream format(s) to be adjusted",
+			 "strict-formats");
 
 	options_ = parser.parse(argc, argv);
 	if (!options_.valid())
@@ -214,6 +223,12 @@ int CamApp::prepareConfig()
 	case CameraConfiguration::Valid:
 		break;
 	case CameraConfiguration::Adjusted:
+		if (strictFormats_) {
+			std::cout << "Adjusting camera configuration disallowed by --strict-formats argument"
+				  << std::endl;
+			config_.reset();
+			return -EINVAL;
+		}
 		std::cout << "Camera configuration adjusted" << std::endl;
 		break;
 	case CameraConfiguration::Invalid:

src/cam/main.h

@@ -17,6 +17,7 @@ enum {
 	OptListProperties = 'p',
 	OptStream = 's',
 	OptListControls = 256,
+	OptStrictFormats = 257,
 };
 
 #endif /* __CAM_MAIN_H__ */