Camera2: Use face priority scene mode when face detect is enabled.

Per API specs, enabled face detection implies that metering, etc is
done based on faces.

Bug: 6243944
Change-Id: Ie35162226d70cc0f437e92e37be138e71e45e738

1 files changed, 14 insertions, 10 deletions

diff --git a/services/camera/libcameraservice/camera2/Parameters.cpp b/services/camera/libcameraservice/camera2/Parameters.cpp
index 71aa39b..f490b2a 100644
--- a/services/camera/libcameraservice/camera2/Parameters.cpp
+++ b/services/camera/libcameraservice/camera2/Parameters.cpp
@@ -1360,17 +1360,23 @@ status_t Parameters::updateRequest(CameraMetadata *request) const {
             &antibandingMode, 1);
     if (res != OK) return res;
 
-    uint8_t reqControlMode =
-            (sceneMode == ANDROID_CONTROL_SCENE_MODE_UNSUPPORTED) ?
-            ANDROID_CONTROL_AUTO : ANDROID_CONTROL_USE_SCENE_MODE;
+    // android.hardware.Camera requires that when face detect is enabled, the
+    // camera is in a face-priority mode. HAL2 splits this into separate parts
+    // (face detection statistics and face priority scene mode). Map from other
+    // to the other.
+    uint8_t reqControlMode = ANDROID_CONTROL_AUTO;
+    if (enableFaceDetect || sceneMode != ANDROID_CONTROL_SCENE_MODE_UNSUPPORTED) {
+        reqControlMode = ANDROID_CONTROL_USE_SCENE_MODE;
+    }
     res = request->update(ANDROID_CONTROL_MODE,
             &reqControlMode, 1);
     if (res != OK) return res;
-    if (reqControlMode == ANDROID_CONTROL_USE_SCENE_MODE) {
-        res = request->update(ANDROID_CONTROL_SCENE_MODE,
-                &sceneMode, 1);
-        if (res != OK) return res;
-    }
+
+    uint8_t reqSceneMode = enableFaceDetect ?
+            (uint8_t)ANDROID_CONTROL_SCENE_MODE_FACE_PRIORITY : sceneMode;
+    res = request->update(ANDROID_CONTROL_SCENE_MODE,
+            &reqSceneMode, 1);
+    if (res != OK) return res;
 
     uint8_t reqFlashMode = ANDROID_FLASH_OFF;
     uint8_t reqAeMode;
@@ -1515,8 +1521,6 @@ status_t Parameters::updateRequest(CameraMetadata *request) const {
             reqCropRegion, 3);
     if (res != OK) return res;
 
-    // TODO: Decide how to map recordingHint, or whether just to ignore it
-
     uint8_t reqVstabMode = videoStabilization ?
             ANDROID_CONTROL_VIDEO_STABILIZATION_ON :
             ANDROID_CONTROL_VIDEO_STABILIZATION_OFF;