cam: Make camera-related options sub-options of OptCamera

Use the new hierarchical options feature of the option parser to turn
camera-related option (--capture, --file, --stream, --strict-formats and
--metadata) into children of the --camera option. As an added bonus, we
don't need to check anymore if a camera has been specified when capture
is requested, as that's now enforced by the option parser.

This change prepares for support of multiple cameras.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

src/cam/camera_session.cpp

@@ -21,11 +21,11 @@
 using namespace libcamera;
 
 CameraSession::CameraSession(CameraManager *cm,
+			     const std::string &cameraId,
 			     const OptionsParser::Options &options)
-	: last_(0), queueCount_(0), captureCount_(0),
+	: options_(options), last_(0), queueCount_(0), captureCount_(0),
 	  captureLimit_(0), printMetadata_(false)
 {
-	const std::string &cameraId = options[OptCamera];
 	char *endptr;
 	unsigned long index = strtoul(cameraId.c_str(), &endptr, 10);
 	if (*endptr == '\0' && index > 0 && index <= cm->cameras().size())
@@ -44,7 +44,7 @@ CameraSession::CameraSession(CameraManager *cm,
 		return;
 	}
 
-	StreamRoles roles = StreamKeyValueParser::roles(options[OptStream]);
+	StreamRoles roles = StreamKeyValueParser::roles(options_[OptStream]);
 
 	std::unique_ptr<CameraConfiguration> config =
 		camera_->generateConfiguration(roles);
@@ -56,12 +56,12 @@ CameraSession::CameraSession(CameraManager *cm,
 
 	/* Apply configuration if explicitly requested. */
 	if (StreamKeyValueParser::updateConfiguration(config.get(),
-						      options[OptStream])) {
+						      options_[OptStream])) {
 		std::cerr << "Failed to update configuration" << std::endl;
 		return;
 	}
 
-	bool strictFormats = options.isSet(OptStrictFormats);
+	bool strictFormats = options_.isSet(OptStrictFormats);
 
 	switch (config->validate()) {
 	case CameraConfiguration::Valid:
@@ -134,14 +134,14 @@ void CameraSession::infoConfiguration() const
 	}
 }
 
-int CameraSession::start(const OptionsParser::Options &options)
+int CameraSession::start()
 {
 	int ret;
 
 	queueCount_ = 0;
 	captureCount_ = 0;
-	captureLimit_ = options[OptCapture].toInteger();
+	captureLimit_ = options_[OptCapture].toInteger();
-	printMetadata_ = options.isSet(OptMetadata);
+	printMetadata_ = options_.isSet(OptMetadata);
 
 	ret = camera_->configure(config_.get());
 	if (ret < 0) {
@@ -157,9 +157,9 @@ int CameraSession::start(const OptionsParser::Options &options)
 
 	camera_->requestCompleted.connect(this, &CameraSession::requestComplete);
 
-	if (options.isSet(OptFile)) {
+	if (options_.isSet(OptFile)) {
-		if (!options[OptFile].toString().empty())
+		if (!options_[OptFile].toString().empty())
-			writer_ = std::make_unique<BufferWriter>(options[OptFile]);
+			writer_ = std::make_unique<BufferWriter>(options_[OptFile]);
 		else
 			writer_ = std::make_unique<BufferWriter>();
 	}

src/cam/camera_session.h

@@ -9,6 +9,7 @@
 
 #include <memory>
 #include <stdint.h>
+#include <string>
 #include <vector>
 
 #include <libcamera/base/signal.h>
@@ -27,10 +28,12 @@ class CameraSession
 {
 public:
 	CameraSession(libcamera::CameraManager *cm,
+		      const std::string &cameraId,
 		      const OptionsParser::Options &options);
 	~CameraSession();
 
 	bool isValid() const { return config_ != nullptr; }
+	const OptionsParser::Options &options() { return options_; }
 
 	libcamera::Camera *camera() { return camera_.get(); }
 	libcamera::CameraConfiguration *config() { return config_.get(); }
@@ -39,7 +42,7 @@ public:
 	void listProperties() const;
 	void infoConfiguration() const;
 
-	int start(const OptionsParser::Options &options);
+	int start();
 	void stop();
 
 	libcamera::Signal<> captureDone;
@@ -51,6 +54,7 @@ private:
 	void requestComplete(libcamera::Request *request);
 	void processRequest(libcamera::Request *request);
 
+	const OptionsParser::Options &options_;
 	std::shared_ptr<libcamera::Camera> camera_;
 	std::unique_ptr<libcamera::CameraConfiguration> config_;
 

src/cam/main.cpp

@@ -113,19 +113,6 @@ int CamApp::parseOptions(int argc, char *argv[])
 	parser.addOption(OptCamera, OptionString,
 			 "Specify which camera to operate on, by id or by index", "camera",
 			 ArgumentRequired, "camera");
-	parser.addOption(OptCapture, OptionInteger,
-			 "Capture until interrupted by user or until <count> frames captured",
-			 "capture", ArgumentOptional, "count");
-	parser.addOption(OptFile, OptionString,
-			 "Write captured frames to disk\n"
-			 "If the file name ends with a '/', it sets the directory in which\n"
-			 "to write files, using the default file name. Otherwise it sets the\n"
-			 "full file path and name. The first '#' character in the file name\n"
-			 "is expanded to the stream name and frame sequence number.\n"
-			 "The default file name is 'frame-#.bin'.",
-			 "file", ArgumentOptional, "filename");
-	parser.addOption(OptStream, &streamKeyValue,
-			 "Set configuration of a camera stream", "stream", true);
 	parser.addOption(OptHelp, OptionNone, "Display this help message",
 			 "help");
 	parser.addOption(OptInfo, OptionNone,
@@ -138,12 +125,32 @@ int CamApp::parseOptions(int argc, char *argv[])
 	parser.addOption(OptMonitor, OptionNone,
 			 "Monitor for hotplug and unplug camera events",
 			 "monitor");
+
+	/* Sub-options of OptCamera: */
+	parser.addOption(OptCapture, OptionInteger,
+			 "Capture until interrupted by user or until <count> frames captured",
+			 "capture", ArgumentOptional, "count", false,
+			 OptCamera);
+	parser.addOption(OptFile, OptionString,
+			 "Write captured frames to disk\n"
+			 "If the file name ends with a '/', it sets the directory in which\n"
+			 "to write files, using the default file name. Otherwise it sets the\n"
+			 "full file path and name. The first '#' character in the file name\n"
+			 "is expanded to the stream name and frame sequence number.\n"
+			 "The default file name is 'frame-#.bin'.",
+			 "file", ArgumentOptional, "filename", false,
+			 OptCamera);
+	parser.addOption(OptStream, &streamKeyValue,
+			 "Set configuration of a camera stream", "stream", true,
+			 OptCamera);
 	parser.addOption(OptStrictFormats, OptionNone,
 			 "Do not allow requested stream format(s) to be adjusted",
-			 "strict-formats");
+			 "strict-formats", ArgumentNone, nullptr, false,
+			 OptCamera);
 	parser.addOption(OptMetadata, OptionNone,
 			 "Print the metadata for completed requests",
-			 "metadata");
+			 "metadata", ArgumentNone, nullptr, false,
+			 OptCamera);
 
 	options_ = parser.parse(argc, argv);
 	if (!options_.valid())
@@ -192,7 +199,10 @@ int CamApp::run()
 	std::unique_ptr<CameraSession> session;
 
 	if (options_.isSet(OptCamera)) {
-		session = std::make_unique<CameraSession>(cm_.get(), options_);
+		const OptionValue &camera = options_[OptCamera];
+		session = std::make_unique<CameraSession>(cm_.get(),
+							  camera.toString(),
+							  camera.children());
 		if (!session->isValid()) {
 			std::cout << "Failed to create camera session" << std::endl;
 			return -EINVAL;
@@ -223,13 +233,8 @@ int CamApp::run()
 	}
 
 	/* 4. Start capture. */
-	if (options_.isSet(OptCapture)) {
+	if (session && session->options().isSet(OptCapture)) {
-		if (!session) {
+		ret = session->start();
-			std::cout << "Can't capture without a camera" << std::endl;
-			return -ENODEV;
-		}
-
-		ret = session->start(options_);
 		if (ret) {
 			std::cout << "Failed to start camera session" << std::endl;
 			return ret;
@@ -253,7 +258,7 @@ int CamApp::run()
 		loop_.exec();
 
 	/* 6. Stop capture. */
-	if (options_.isSet(OptCapture))
+	if (session && session->options().isSet(OptCapture))
 		session->stop();
 
 	return 0;