[libcamera-devel] [PATCH v2 6/6] cam: Add command line option to test IspCrop control

[David Plowman]

This allows the user to request digital zoom by adding, for example,
"-z 0.25,0.25,0.5,0.5" which would give a 2x zoom, still centred in
the middle of the image.

Signed-off-by: David Plowman <david.plowman at raspberrypi.com>
---
 src/cam/capture.cpp | 25 +++++++++++++++++++++++--
 src/cam/capture.h   |  2 +-
 src/cam/main.cpp    |  3 +++
 src/cam/main.h      |  1 +
 4 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/src/cam/capture.cpp b/src/cam/capture.cpp
index 5510c00..3b50c59 100644
--- a/src/cam/capture.cpp
+++ b/src/cam/capture.cpp
@@ -10,6 +10,9 @@
 #include <limits.h>
 #include <sstream>
 
+#include <libcamera/control_ids.h>
+#include <libcamera/property_ids.h>
+
 #include "capture.h"
 #include "main.h"
 
@@ -58,7 +61,7 @@ int Capture::run(const OptionsParser::Options &options)
 
 	FrameBufferAllocator *allocator = new FrameBufferAllocator(camera_);
 
-	ret = capture(allocator);
+	ret = capture(allocator, options);
 
 	if (options.isSet(OptFile)) {
 		delete writer_;
@@ -70,7 +73,7 @@ int Capture::run(const OptionsParser::Options &options)
 	return ret;
 }
 
-int Capture::capture(FrameBufferAllocator *allocator)
+int Capture::capture(FrameBufferAllocator *allocator, const OptionsParser::Options &options)
 {
 	int ret;
 
@@ -120,6 +123,24 @@ int Capture::capture(FrameBufferAllocator *allocator)
 		requests.push_back(request);
 	}
 
+	/* Set up digital zoom if it was requested on the command line. */
+	if (options.isSet(OptZoom)) {
+		std::string zoom = options[OptZoom].toString();
+		float x, y, width, height;
+
+		if (sscanf(zoom.c_str(), "%f,%f,%f,%f", &x, &y, &width, &height) == 4) {
+			Size sensorArea = camera_->properties().get(properties::SensorOutputSize);
+			Rectangle crop(x * sensorArea.width,
+				       y * sensorArea.height,
+				       width * sensorArea.width,
+				       height * sensorArea.height);
+
+			requests.front()->controls().set(controls::IspCrop, crop);
+		} else {
+			std::cout << "Invalid zoom values - ignoring" << std::endl;
+		}
+	}
+
 	ret = camera_->start();
 	if (ret) {
 		std::cout << "Failed to start capture" << std::endl;
diff --git a/src/cam/capture.h b/src/cam/capture.h
index 0aebdac..5280616 100644
--- a/src/cam/capture.h
+++ b/src/cam/capture.h
@@ -29,7 +29,7 @@ public:
 
 	int run(const OptionsParser::Options &options);
 private:
-	int capture(libcamera::FrameBufferAllocator *allocator);
+	int capture(libcamera::FrameBufferAllocator *allocator, const OptionsParser::Options &options);
 
 	void requestComplete(libcamera::Request *request);
 
diff --git a/src/cam/main.cpp b/src/cam/main.cpp
index 244720b..8f326d9 100644
--- a/src/cam/main.cpp
+++ b/src/cam/main.cpp
@@ -201,6 +201,9 @@ int CamApp::parseOptions(int argc, char *argv[])
 	parser.addOption(OptStrictFormats, OptionNone,
 			 "Do not allow requested stream format(s) to be adjusted",
 			 "strict-formats");
+	parser.addOption(OptZoom, OptionString,
+			 "Specify digital zoom by supplying IspCrop control as x,y,width,height e.g. 0.25,0.25,0.5,0.5",
+			 "zoom", ArgumentRequired, "zoom");
 
 	options_ = parser.parse(argc, argv);
 	if (!options_.valid())
diff --git a/src/cam/main.h b/src/cam/main.h
index ea8dfd3..a1fd899 100644
--- a/src/cam/main.h
+++ b/src/cam/main.h
@@ -17,6 +17,7 @@ enum {
 	OptListProperties = 'p',
 	OptMonitor = 'm',
 	OptStream = 's',
+	OptZoom = 'z',
 	OptListControls = 256,
 	OptStrictFormats = 257,
 };
-- 
2.20.1