cam: Add --info option to print information about stream(s)

Add a new option to the cam tool that prints information about the
configuration supplied by the user. If the option is specified,
information about the configuration is printed after the configuration
has been verified and possibly adjusted by the camera.

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

src/cam/main.cpp

@@ -5,6 +5,7 @@
  * main.cpp - cam - The libcamera swiss army knife
  */
 
+#include <iomanip>
 #include <iostream>
 #include <signal.h>
 #include <string.h>
@@ -34,6 +35,7 @@ public:
 private:
 	int parseOptions(int argc, char *argv[]);
 	int prepareConfig();
+	int infoConfiguration();
 	int run();
 
 	static CamApp *app_;
@@ -169,6 +171,8 @@ int CamApp::parseOptions(int argc, char *argv[])
 			 "Set configuration of a camera stream", "stream", true);
 	parser.addOption(OptHelp, OptionNone, "Display this help message",
 			 "help");
+	parser.addOption(OptInfo, OptionNone,
+			 "Display information about stream(s)", "info");
 	parser.addOption(OptList, OptionNone, "List all cameras", "list");
 
 	options_ = parser.parse(argc, argv);
@@ -258,8 +262,40 @@ int CamApp::prepareConfig()
 	return 0;
 }
 
+int CamApp::infoConfiguration()
+{
+	if (!config_) {
+		std::cout << "Cannot print stream information without a camera"
+			  << std::endl;
+		return -EINVAL;
+	}
+
+	unsigned int index = 0;
+	for (const StreamConfiguration &cfg : *config_) {
+		std::cout << index << ": " << cfg.toString() << std::endl;
+
+		const StreamFormats &formats = cfg.formats();
+		for (unsigned int pixelformat : formats.pixelformats()) {
+			std::cout << " * Pixelformat: 0x" << std::hex
+				  << std::setw(8) << pixelformat << " "
+				  << formats.range(pixelformat).toString()
+				  << std::endl;
+
+			for (const Size &size : formats.sizes(pixelformat))
+				std::cout << "  - " << size.toString()
+					  << std::endl;
+		}
+
+		index++;
+	}
+
+	return 0;
+}
+
 int CamApp::run()
 {
+	int ret;
+
 	if (options_.isSet(OptList)) {
 		std::cout << "Available cameras:" << std::endl;
 
@@ -270,6 +306,12 @@ int CamApp::run()
 		}
 	}
 
+	if (options_.isSet(OptInfo)) {
+		ret = infoConfiguration();
+		if (ret)
+			return ret;
+	}
+
 	if (options_.isSet(OptCapture)) {
 		Capture capture(camera_.get(), config_.get());
 		return capture.run(loop_, options_);

src/cam/main.h

@@ -12,6 +12,7 @@ enum {
 	OptCapture = 'C',
 	OptFile = 'F',
 	OptHelp = 'h',
+	OptInfo = 'I',
 	OptList = 'l',
 	OptStream = 's',
 };