cam: Add camera index to file name of capture frames

To prepare for multi-camera support, extend the file naming scheme for
captured frames to include the camera index in addition to the stream
name and frame number.

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

src/cam/camera_session.cpp

@@ -22,9 +22,11 @@ using namespace libcamera;
 
 CameraSession::CameraSession(CameraManager *cm,
 			     const std::string &cameraId,
+			     unsigned int cameraIndex,
 			     const OptionsParser::Options &options)
-	: options_(options), last_(0), queueCount_(0), captureCount_(0),
-	  captureLimit_(0), printMetadata_(false)
+	: options_(options), cameraIndex_(cameraIndex), last_(0),
+	  queueCount_(0), captureCount_(0), captureLimit_(0),
+	  printMetadata_(false)
 {
 	char *endptr;
 	unsigned long index = strtoul(cameraId.c_str(), &endptr, 10);
@@ -152,7 +154,8 @@ int CameraSession::start()
 	streamName_.clear();
 	for (unsigned int index = 0; index < config_->size(); ++index) {
 		StreamConfiguration &cfg = config_->at(index);
-		streamName_[cfg.stream()] = "stream" + std::to_string(index);
+		streamName_[cfg.stream()] = "cam" + std::to_string(cameraIndex_)
+					  + "-stream" + std::to_string(index);
 	}
 
 	camera_->requestCompleted.connect(this, &CameraSession::requestComplete);

src/cam/camera_session.h

@@ -28,7 +28,7 @@ class CameraSession
 {
 public:
 	CameraSession(libcamera::CameraManager *cm,
-		      const std::string &cameraId,
+		      const std::string &cameraId, unsigned int cameraIndex,
 		      const OptionsParser::Options &options);
 	~CameraSession();
 
@@ -60,6 +60,8 @@ private:
 
 	std::map<const libcamera::Stream *, std::string> streamName_;
 	std::unique_ptr<BufferWriter> writer_;
+	unsigned int cameraIndex_;
+
 	uint64_t last_;
 
 	unsigned int queueCount_;

src/cam/main.cpp

@@ -136,7 +136,7 @@ int CamApp::parseOptions(int argc, char *argv[])
 			 "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"
+			 "is expanded to the camera index, stream name and frame sequence number.\n"
 			 "The default file name is 'frame-#.bin'.",
 			 "file", ArgumentOptional, "filename", false,
 			 OptCamera);
@@ -201,7 +201,7 @@ int CamApp::run()
 	if (options_.isSet(OptCamera)) {
 		const OptionValue &camera = options_[OptCamera];
 		session = std::make_unique<CameraSession>(cm_.get(),
-							  camera.toString(),
+							  camera.toString(), 0,
 							  camera.children());
 		if (!session->isValid()) {
 			std::cout << "Failed to create camera session" << std::endl;