[libcamera-devel] [PATCH 8/8] cam: Add support for viewfinder through DRM/KMS

[Laurent Pinchart]

Use the KMSSink class to display the viewfinder stream, if any, through
DRM/KMS. The output connector is selected through the new -D/--display
argument.

Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
---
 src/cam/capture.cpp | 21 +++++++++++++++++++++
 src/cam/main.cpp    | 11 +++++++++++
 src/cam/main.h      |  1 +
 3 files changed, 33 insertions(+)

diff --git a/src/cam/capture.cpp b/src/cam/capture.cpp
index 6982d89fabe7..5b25b2c239f8 100644
--- a/src/cam/capture.cpp
+++ b/src/cam/capture.cpp
@@ -13,6 +13,9 @@
 
 #include "capture.h"
 #include "file_sink.h"
+#ifdef HAVE_KMS
+#include "kms_sink.h"
+#endif
 #include "main.h"
 
 using namespace libcamera;
@@ -46,6 +49,24 @@ int Capture::run(EventLoop *loop, const OptionsParser::Options &options)
 
 	camera_->requestCompleted.connect(this, &Capture::requestComplete);
 
+#ifdef HAVE_KMS
+	if (options.isSet(OptDisplay)) {
+		if (config_->size() != 1) {
+			std::cout << "Display doesn't support multiple streams"
+				  << std::endl;
+			return -EINVAL;
+		}
+
+		if (roles_[0] != StreamRole::Viewfinder) {
+			std::cout << "Display requires a viewfinder stream"
+				  << std::endl;
+			return -EINVAL;
+		}
+
+		sink_ = new KMSSink(options[OptDisplay].toString());
+	}
+#endif
+
 	if (options.isSet(OptFile)) {
 		if (!options[OptFile].toString().empty())
 			sink_ = new FileSink(options[OptFile]);
diff --git a/src/cam/main.cpp b/src/cam/main.cpp
index cdd29d500202..5cd1e929bd88 100644
--- a/src/cam/main.cpp
+++ b/src/cam/main.cpp
@@ -78,6 +78,12 @@ int CamApp::init(int argc, char **argv)
 	if (ret < 0)
 		return ret;
 
+	if (options_.isSet(OptDisplay) && options_.isSet(OptFile)) {
+		std::cout << "--display and --file options are mutually exclusive"
+			  << std::endl;
+		return -EINVAL;
+	}
+
 	cm_ = new CameraManager();
 
 	ret = cm_->start();
@@ -164,6 +170,11 @@ int CamApp::parseOptions(int argc, char *argv[])
 			 ArgumentRequired, "camera");
 	parser.addOption(OptCapture, OptionNone,
 			 "Capture until interrupted by user", "capture");
+#ifdef HAVE_KMS
+	parser.addOption(OptDisplay, OptionString,
+			 "Display viewfinder through DRM/KMS on specified connector",
+			 "display", ArgumentOptional, "connector");
+#endif
 	parser.addOption(OptFile, OptionString,
 			 "Write captured frames to disk\n"
 			 "The first '#' character in the file name is expanded to the stream name and frame sequence number.\n"
diff --git a/src/cam/main.h b/src/cam/main.h
index 4a130d8dd290..57eece507a16 100644
--- a/src/cam/main.h
+++ b/src/cam/main.h
@@ -10,6 +10,7 @@
 enum {
 	OptCamera = 'c',
 	OptCapture = 'C',
+	OptDisplay = 'D',
 	OptFile = 'F',
 	OptHelp = 'h',
 	OptInfo = 'I',
-- 
Regards,

Laurent Pinchart