Update FPS range on Android to have correct brightness

Author: mvanbeusekom

packages/camera/camera/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.6.4+2
+
+* Detect if selected camera supports auto focus and act accordingly on Android. This solves a problem where front facing cameras are not capturing the picture because auto focus is not supported.
+
 ## 0.6.4+1
 
 * Added closeCaptureSession() to stopVideoRecording in Camera.java to fix an Android 6 crash

packages/camera/camera/android/src/main/java/io/flutter/plugins/camera/Camera.java

@@ -33,6 +33,7 @@
 import android.os.Build.VERSION_CODES;
 import android.os.Handler;
 import android.os.Looper;
+import android.util.Log;
 import android.util.Range;
 import android.util.Rational;
 import android.util.Size;
@@ -96,6 +97,7 @@ public class Camera {
   private CameraRegions cameraRegions;
   private int exposureOffset;
   private boolean useAutoFocus;
+  private Range<Integer> fpsRange;
 
   public Camera(
       final Activity activity,
@@ -131,6 +133,7 @@ public void onOrientationChanged(int i) {
     orientationEventListener.enable();
 
     cameraCharacteristics = cameraManager.getCameraCharacteristics(cameraName);
+    initFps(cameraCharacteristics);
     sensorOrientation = cameraCharacteristics.get(CameraCharacteristics.SENSOR_ORIENTATION);
     isFrontFacing =
         cameraCharacteristics.get(CameraCharacteristics.LENS_FACING) == CameraMetadata.LENS_FACING_FRONT;
@@ -145,6 +148,26 @@ public void onOrientationChanged(int i) {
             cameraCharacteristics.get(CameraCharacteristics.SCALER_AVAILABLE_MAX_DIGITAL_ZOOM));
   }
 
+  private void initFps(CameraCharacteristics cameraCharacteristics){
+    try {
+      Range<Integer>[] ranges = cameraCharacteristics.get(CameraCharacteristics.CONTROL_AE_AVAILABLE_TARGET_FPS_RANGES);
+      if(ranges != null) {
+        for (Range<Integer> range : ranges) {
+          int upper = range.getUpper();
+          Log.i("Camera", "[FPS Range Available] is:" + range);
+          if (upper >= 10) {
+            if (fpsRange == null || upper < fpsRange.getUpper()) {
+              fpsRange = range;
+            }
+          }
+        }
+      }
+    } catch (Exception e) {
+      e.printStackTrace();
+    }
+    Log.i("Camera", "[FPS Range] is:" + fpsRange);
+  }
+
   private void prepareMediaRecorder(String outputFilePath) throws IOException {
     if (mediaRecorder != null) {
       mediaRecorder.release();
@@ -268,9 +291,10 @@ public void onConfigured(@NonNull CameraCaptureSession session) {
               }
               cameraCaptureSession = session;
 
+              updateFpsRange();
               updateAutoFocus();
-              updateExposure(exposureMode);
               updateFlash(flashMode);
+              updateExposure(exposureMode);
 
               refreshPreviewCaptureSession(
                   onSuccessCallback,
@@ -589,8 +613,14 @@ public void stopVideoRecording(@NonNull final Result result) {
 
     try {
       recordingVideo = false;
-      closeCaptureSession();
-      mediaRecorder.stop();
+
+      try {
+        cameraCaptureSession.abortCaptures();
+        mediaRecorder.stop();
+      } catch (CameraAccessException | IllegalStateException e) {
+        // Ignore exceptions and try to continue (changes are camera session already aborted capture)
+      }
+
       mediaRecorder.reset();
       startPreview();
       result.success(videoRecordingFile.getAbsolutePath());
@@ -865,6 +895,14 @@ public void setZoomLevel(@NonNull final Result result, float zoom) throws Camera
     result.success(null);
   }
 
+  private void updateFpsRange() {
+    if (fpsRange == null) {
+      return;
+    }
+
+    captureRequestBuilder.set(CaptureRequest.CONTROL_AE_TARGET_FPS_RANGE, fpsRange);
+  }
+
   private void updateAutoFocus() {
     if (useAutoFocus) {
       int[] modes = cameraCharacteristics.get(

packages/camera/camera/pubspec.yaml

@@ -2,7 +2,7 @@ name: camera
 description: A Flutter plugin for getting information about and controlling the
   camera on Android and iOS. Supports previewing the camera feed, capturing images, capturing video,
   and streaming image buffers to dart.
-version: 0.6.4+1
+version: 0.6.4+2
 homepage: https://github.com/flutter/plugins/tree/master/packages/camera/camera
 
 dependencies: