libcamera: android: Add face detection control support

Allow Android HAL adapter to pass the face detection metadata control to
the pipeline and also send face detection metadata to the camera client
if the pipeline generates it.

Signed-off-by: Yudhistira Erlandinata <yerlandinata@chromium.org>
Co-developed-by: Harvey Yang <chenghaoyang@chromium.org>
Signed-off-by: Harvey Yang <chenghaoyang@chromium.org>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Harvey Yang <chenghaoyang@chromium.org>

2 files changed, 104 insertions, 6 deletions

diff --git a/src/android/camera_capabilities.cpp b/src/android/camera_capabilities.cpp
index 71043e12..b161bc6b 100644
--- a/src/android/camera_capabilities.cpp
+++ b/src/android/camera_capabilities.cpp
@@ -11,6 +11,7 @@
 #include <array>
 #include <cmath>
 #include <map>
+#include <stdint.h>
 #include <type_traits>
 
 #include <hardware/camera3.h>
@@ -1176,11 +1177,46 @@ int CameraCapabilities::initializeStaticMetadata()
 				  maxFrameDuration_);
 
 	/* Statistics static metadata. */
-	uint8_t faceDetectMode = ANDROID_STATISTICS_FACE_DETECT_MODE_OFF;
-	staticMetadata_->addEntry(ANDROID_STATISTICS_INFO_AVAILABLE_FACE_DETECT_MODES,
-				  faceDetectMode);
-
 	int32_t maxFaceCount = 0;
+	auto iter = camera_->controls().find(controls::draft::FaceDetectMode.id());
+	if (iter != camera_->controls().end()) {
+		const ControlInfo &faceDetectCtrlInfo = iter->second;
+		std::vector<uint8_t> faceDetectModes;
+		bool hasFaceDetection = false;
+
+		for (const auto &value : faceDetectCtrlInfo.values()) {
+			int32_t mode = value.get<int32_t>();
+			uint8_t androidMode = 0;
+
+			switch (mode) {
+			case controls::draft::FaceDetectModeOff:
+				androidMode = ANDROID_STATISTICS_FACE_DETECT_MODE_OFF;
+				break;
+			case controls::draft::FaceDetectModeSimple:
+				androidMode = ANDROID_STATISTICS_FACE_DETECT_MODE_SIMPLE;
+				hasFaceDetection = true;
+				break;
+			default:
+				LOG(HAL, Fatal) << "Received invalid face detect mode: " << mode;
+			}
+			faceDetectModes.push_back(androidMode);
+		}
+		if (hasFaceDetection) {
+			/*
+			 * \todo Create new libcamera controls to query max
+			 * possible faces detected.
+			 */
+			maxFaceCount = 10;
+			staticMetadata_->addEntry(
+				ANDROID_STATISTICS_INFO_AVAILABLE_FACE_DETECT_MODES,
+				faceDetectModes.data(), faceDetectModes.size());
+		}
+	} else {
+		uint8_t faceDetectMode = ANDROID_STATISTICS_FACE_DETECT_MODE_OFF;
+		staticMetadata_->addEntry(ANDROID_STATISTICS_INFO_AVAILABLE_FACE_DETECT_MODES,
+					  faceDetectMode);
+	}
+
 	staticMetadata_->addEntry(ANDROID_STATISTICS_INFO_MAX_FACE_COUNT,
 				  maxFaceCount);
 
diff --git a/src/android/camera_device.cpp b/src/android/camera_device.cpp
index 493f66e7..a038131a 100644
--- a/src/android/camera_device.cpp
+++ b/src/android/camera_device.cpp
@@ -22,6 +22,7 @@
 #include <libcamera/controls.h>
 #include <libcamera/fence.h>
 #include <libcamera/formats.h>
+#include <libcamera/geometry.h>
 #include <libcamera/property_ids.h>
 
 #include "system/graphics.h"
@@ -813,6 +814,11 @@ int CameraDevice::processControls(Camera3RequestDescriptor *descriptor)
 		controls.set(controls::ScalerCrop, cropRegion);
 	}
 
+	if (settings.getEntry(ANDROID_STATISTICS_FACE_DETECT_MODE, &entry)) {
+		const uint8_t *data = entry.data.u8;
+		controls.set(controls::draft::FaceDetectMode, data[0]);
+	}
+
 	if (settings.getEntry(ANDROID_SENSOR_TEST_PATTERN_MODE, &entry)) {
 		const int32_t data = *entry.data.i32;
 		int32_t testPatternMode = controls::draft::TestPatternModeOff;
@@ -1540,8 +1546,9 @@ CameraDevice::getResultMetadata(const Camera3RequestDescriptor &descriptor) cons
 	value32 = ANDROID_SENSOR_TEST_PATTERN_MODE_OFF;
 	resultMetadata->addEntry(ANDROID_SENSOR_TEST_PATTERN_MODE, value32);
 
-	value = ANDROID_STATISTICS_FACE_DETECT_MODE_OFF;
-	resultMetadata->addEntry(ANDROID_STATISTICS_FACE_DETECT_MODE, value);
+	if (settings.getEntry(ANDROID_STATISTICS_FACE_DETECT_MODE, &entry))
+		resultMetadata->addEntry(ANDROID_STATISTICS_FACE_DETECT_MODE,
+					 entry.data.u8, 1);
 
 	value = ANDROID_STATISTICS_LENS_SHADING_MAP_MODE_OFF;
 	resultMetadata->addEntry(ANDROID_STATISTICS_LENS_SHADING_MAP_MODE,
@@ -1580,6 +1587,61 @@ CameraDevice::getResultMetadata(const Camera3RequestDescriptor &descriptor) cons
 		resultMetadata->addEntry(ANDROID_SENSOR_FRAME_DURATION,
 					 *frameDuration * 1000);
 
+	const auto &faceDetectRectangles =
+		metadata.get(controls::draft::FaceDetectFaceRectangles);
+	if (faceDetectRectangles) {
+		std::vector<int32_t> flatRectangles;
+		for (const Rectangle &rect : *faceDetectRectangles) {
+			flatRectangles.push_back(rect.x);
+			flatRectangles.push_back(rect.y);
+			flatRectangles.push_back(rect.x + rect.width);
+			flatRectangles.push_back(rect.y + rect.height);
+		}
+		resultMetadata->addEntry(
+			ANDROID_STATISTICS_FACE_RECTANGLES, flatRectangles);
+	}
+
+	const auto &faceDetectFaceScores =
+		metadata.get(controls::draft::FaceDetectFaceScores);
+	if (faceDetectRectangles && faceDetectFaceScores) {
+		if (faceDetectFaceScores->size() != faceDetectRectangles->size()) {
+			LOG(HAL, Error) << "Pipeline returned wrong number of face scores; "
+					<< "Expected: " << faceDetectRectangles->size()
+					<< ", got: " << faceDetectFaceScores->size();
+		}
+		resultMetadata->addEntry(ANDROID_STATISTICS_FACE_SCORES,
+					 *faceDetectFaceScores);
+	}
+
+	const auto &faceDetectFaceLandmarks =
+		metadata.get(controls::draft::FaceDetectFaceLandmarks);
+	if (faceDetectRectangles && faceDetectFaceLandmarks) {
+		size_t expectedLandmarks = faceDetectRectangles->size() * 3;
+		if (faceDetectFaceLandmarks->size() != expectedLandmarks) {
+			LOG(HAL, Error) << "Pipeline returned wrong number of face landmarks; "
+					<< "Expected: " << expectedLandmarks
+					<< ", got: " << faceDetectFaceLandmarks->size();
+		}
+
+		std::vector<int32_t> androidLandmarks;
+		for (const Point &landmark : *faceDetectFaceLandmarks) {
+			androidLandmarks.push_back(landmark.x);
+			androidLandmarks.push_back(landmark.y);
+		}
+		resultMetadata->addEntry(
+			ANDROID_STATISTICS_FACE_LANDMARKS, androidLandmarks);
+	}
+
+	const auto &faceDetectFaceIds = metadata.get(controls::draft::FaceDetectFaceIds);
+	if (faceDetectRectangles && faceDetectFaceIds) {
+		if (faceDetectFaceIds->size() != faceDetectRectangles->size()) {
+			LOG(HAL, Error) << "Pipeline returned wrong number of face ids; "
+					<< "Expected: " << faceDetectRectangles->size()
+					<< ", got: " << faceDetectFaceIds->size();
+		}
+		resultMetadata->addEntry(ANDROID_STATISTICS_FACE_IDS, *faceDetectFaceIds);
+	}
+
 	const auto &scalerCrop = metadata.get(controls::ScalerCrop);
 	if (scalerCrop) {
 		const Rectangle &crop = *scalerCrop;