[PATCH v1 2/3] libcamera: Add face detection controls

[Harvey Yang]

From: Yudhistira Erlandinata <yerlandinata at chromium.org>

Add FaceDetectMode, FaceDetectFaceRectangles, FaceDetectFaceScores,
and FaceDetectFaceLandmark. Also add ControlTypePoint for supporting
FaceDetectFaceLandmark.

BUG=b:308713855
TEST=emerge-geralt libcamera-mtkisp7

Signed-off-by: Yudhistira Erlandinata <yerlandinata at chromium.org>
Co-developed-by: becker hsieh <beckerh at chromium.org>
Co-developed-by: Harvey Yang <chenghaoyang at chromium.org>
---
 include/libcamera/controls.h        |  6 +++++
 src/libcamera/control_ids_core.yaml | 42 +++++++++++++++++++++++++++++
 src/libcamera/controls.cpp          |  6 +++++
 3 files changed, 54 insertions(+)

diff --git a/include/libcamera/controls.h b/include/libcamera/controls.h
index 7c2bb2872..bf1b8609c 100644
--- a/include/libcamera/controls.h
+++ b/include/libcamera/controls.h
@@ -34,6 +34,7 @@ enum ControlType {
 	ControlTypeString,
 	ControlTypeRectangle,
 	ControlTypeSize,
+	ControlTypePoint,
 };
 
 namespace details {
@@ -87,6 +88,11 @@ struct control_type<Size> {
 	static constexpr ControlType value = ControlTypeSize;
 };
 
+template<>
+struct control_type<Point> {
+	static constexpr ControlType value = ControlTypePoint;
+};
+
 template<typename T, std::size_t N>
 struct control_type<Span<T, N>> : public control_type<std::remove_cv_t<T>> {
 };
diff --git a/src/libcamera/control_ids_core.yaml b/src/libcamera/control_ids_core.yaml
index 6381970b4..5ff46c71e 100644
--- a/src/libcamera/control_ids_core.yaml
+++ b/src/libcamera/control_ids_core.yaml
@@ -860,6 +860,48 @@ controls:
             No further state changes or lens movements will occur until the
             AfPauseResume control is sent.
 
+  - FaceDetectMode:
+      type: uint8_t
+      description: |
+        Reporting mode of face detection.
+
+      enum:
+        - name: FaceDetectModeOff
+          value: 0
+          description: |
+            Pipeline should not report face detection result.
+        - name: FaceDetectModeSimple
+          value: 1
+          description: |
+            Pipeline should at least report faces boundary rectangles and
+            confidence score for each of them.
+
+  - FaceDetectFaceRectangles:
+      type: Rectangle
+      description: |
+        Boundary rectangle of the detected faces.
+
+      size: [n]
+
+  - FaceDetectFaceScores:
+      type: uint8_t
+      description: |
+        Confidence score of each of the detected faces by face detector.
+        The range of score is [0, 100], but usually those with low confidence
+        scores will not be included.
+        Currently identical to ANDROID_STATISTICS_FACE_SCORES.
+
+      size: [n]
+
+  - FaceDetectFaceLandmark:
+      type: Point
+      description: |
+        Array of human face landmark coordinates in format:
+        [..., left_eye_i, right_eye_i, mouth_i, left_eye_i+1, ...],
+        with i = index of face.
+
+      size: [n]
+
   - HdrMode:
       type: int32_t
       description: |
diff --git a/src/libcamera/controls.cpp b/src/libcamera/controls.cpp
index 11d35321c..ce73ae9d7 100644
--- a/src/libcamera/controls.cpp
+++ b/src/libcamera/controls.cpp
@@ -61,6 +61,7 @@ static constexpr size_t ControlValueSize[] = {
 	[ControlTypeString]		= sizeof(char),
 	[ControlTypeRectangle]		= sizeof(Rectangle),
 	[ControlTypeSize]		= sizeof(Size),
+	[ControlTypePoint]		= sizeof(Point),
 };
 
 } /* namespace */
@@ -255,6 +256,11 @@ std::string ControlValue::toString() const
 			str += value->toString();
 			break;
 		}
+		case ControlTypePoint: {
+			const Point *value = reinterpret_cast<const Point *>(data);
+			str += value->toString();
+			break;
+		}
 		case ControlTypeNone:
 		case ControlTypeString:
 			break;
-- 
2.46.0.295.g3b9ea8a38a-goog