core: Add flicker correction control

Allow user to set the flicker period through the --flicker-period command line argument. Signed-off-by: Naushir Patuck <[email protected]>
naushir · Jul 25, 2023 · 09a3ffa · 09a3ffa
1 parent 9e17265
commit 09a3ffa
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Showing 3 changed files with 17 additions and 0 deletions.
diff --git a/core/libcamera_app.cpp b/core/libcamera_app.cpp
@@ -620,6 +620,14 @@ void LibcameraApp::StartCamera()
 		controls_.set(controls::LensPosition, f);
 	}
 
+	if (options_->flicker_period && !controls_.get(controls::AeFlickerMode) &&
+		camera_->controls().find(&controls::AeFlickerMode) != camera_->controls().end() &&
+		camera_->controls().find(&controls::AeFlickerPeriod) != camera_->controls().end())
+	{
+		controls_.set(controls::AeFlickerMode, controls::FlickerManual);
+		controls_.set(controls::AeFlickerPeriod, options_->flicker_period.get<std::chrono::microseconds>());
+	}
+
 	if (camera_->start(&controls_))
 		throw std::runtime_error("failed to start camera");
 	controls_.clear();

diff --git a/core/options.cpp b/core/options.cpp
@@ -132,6 +132,7 @@ bool Options::Parse(int argc, char *argv[])
 	// Convert time strings to durations
 	timeout.set(timeout_);
 	shutter.set(shutter_);
+	flicker_period.set(flicker_period_);
 
 	// HDR control. Set this before opening or listing any cameras.
 	// Currently this does not exist in libcamera, so go directly to V4L2
@@ -440,6 +441,8 @@ void Options::Print() const
 		std::cerr << "    gain: " << gain << std::endl;
 	std::cerr << "    metering: " << metering << std::endl;
 	std::cerr << "    exposure: " << exposure << std::endl;
+	if (flicker_period)
+		std::cerr << "    flicker period: " << flicker_period.get() << "us" << std::endl;
 	std::cerr << "    ev: " << ev << std::endl;
 	std::cerr << "    awb: " << awb << std::endl;
 	if (awb_gain_r && awb_gain_b)

diff --git a/core/options.hpp b/core/options.hpp
@@ -205,6 +205,10 @@ struct Options
 			 "Save captured image metadata to a file or \"-\" for stdout")
 			("metadata-format", value<std::string>(&metadata_format)->default_value("json"),
 			 "Format to save the metadata in, either txt or json (requires --metadata)")
+			("flicker-period", value<std::string>(&flicker_period_)->default_value("0s"),
+			 "Manual flicker correction period"
+			 "\nSet to 10000us to cancel 50Hz flicker."
+			 "\nSet to 8333us to cancel 60Hz flicker.\n")
 			;
 		// clang-format on
 	}
@@ -277,6 +281,7 @@ struct Options
 	std::string metadata;
 	std::string metadata_format;
 	bool hdr;
+	TimeVal<std::chrono::microseconds> flicker_period;
 
 	virtual bool Parse(int argc, char *argv[]);
 	virtual void Print() const;
@@ -292,4 +297,5 @@ struct Options
 	std::string lens_position_;
 	std::string timeout_;
 	std::string shutter_;
+	std::string flicker_period_;
 };