[camera_android] Don't override default fps range when not recording

packages/camera/camera_android/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.10.10+2
+
+* Don't set the FPS range unless video recording. It can cause dark image previews on some devices becuse the auto exposure algorithm is more constrained after fixing the min/max FPS range to the same value. This change has the side effect that providing the `fps` parameter will not affect the camera preview when not video recording. And if you need a lower frame rate in your image streaming handler, you can skip frames by checking the time it passed since the last frame.
+
 ## 0.10.10+1
 
 * Updates compileSdk 34 to flutter.compileSdkVersion.

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

@@ -225,30 +225,6 @@ public Camera(
             dartMessenger,
             videoCaptureSettings.resolutionPreset);
 
-    Integer recordingFps = null;
-
-    if (videoCaptureSettings.fps != null && videoCaptureSettings.fps.intValue() > 0) {
-      recordingFps = videoCaptureSettings.fps;
-    } else {
-
-      if (SdkCapabilityChecker.supportsEncoderProfiles()) {
-        EncoderProfiles encoderProfiles = getRecordingProfile();
-        if (encoderProfiles != null && encoderProfiles.getVideoProfiles().size() > 0) {
-          recordingFps = encoderProfiles.getVideoProfiles().get(0).getFrameRate();
-        }
-      } else {
-        CamcorderProfile camcorderProfile = getRecordingProfileLegacy();
-        recordingFps = null != camcorderProfile ? camcorderProfile.videoFrameRate : null;
-      }
-    }
-
-    if (recordingFps != null && recordingFps.intValue() > 0) {
-
-      final FpsRangeFeature fpsRange = new FpsRangeFeature(cameraProperties);
-      fpsRange.setValue(new Range<Integer>(recordingFps, recordingFps));
-      this.cameraFeatures.setFpsRange(fpsRange);
-    }
-
     // Create capture callback.
     captureTimeouts = new CaptureTimeoutsWrapper(3000, 3000);
     captureProps = new CameraCaptureProperties();
@@ -326,6 +302,36 @@ private void prepareMediaRecorder(String outputFilePath) throws IOException {
             .build();
   }
 
+  /**
+   * Updates the FpsRange camera features with the appropriate FPS range. It sets the minimum and
+   * maximum fps range to the same value, as that's what is recommended for video recording.
+   */
+  private void setFpsCameraFeatureForRecording(CameraProperties cameraProperties) {
+    Integer recordingFps = null;
+
+    if (videoCaptureSettings.fps != null && videoCaptureSettings.fps.intValue() > 0) {
+      recordingFps = videoCaptureSettings.fps;
+    } else {
+
+      if (SdkCapabilityChecker.supportsEncoderProfiles()) {
+        EncoderProfiles encoderProfiles = getRecordingProfile();
+        if (encoderProfiles != null && encoderProfiles.getVideoProfiles().size() > 0) {
+          recordingFps = encoderProfiles.getVideoProfiles().get(0).getFrameRate();
+        }
+      } else {
+        CamcorderProfile camcorderProfile = getRecordingProfileLegacy();
+        recordingFps = null != camcorderProfile ? camcorderProfile.videoFrameRate : null;
+      }
+    }
+
+    if (recordingFps != null && recordingFps.intValue() > 0) {
+
+      final FpsRangeFeature fpsRange = new FpsRangeFeature(cameraProperties);
+      fpsRange.setValue(new Range<Integer>(recordingFps, recordingFps));
+      this.cameraFeatures.setFpsRange(fpsRange);
+    }
+  }
+
   @SuppressLint("MissingPermission")
   public void open(Integer imageFormatGroup) throws CameraAccessException {
     this.imageFormatGroup = imageFormatGroup;
@@ -851,6 +857,9 @@ public String stopVideoRecording() {
     // Re-create autofocus feature so it's using continuous capture focus mode now.
     cameraFeatures.setAutoFocus(
         cameraFeatureFactory.createAutoFocusFeature(cameraProperties, false));
+    // Reset to non recording fps range (the default)
+    cameraFeatures.setFpsRange(cameraFeatureFactory.createFpsRangeFeature(cameraProperties));
+
     recordingVideo = false;
     try {
       closeRenderer();
@@ -1252,6 +1261,8 @@ void prepareRecording() {
     // Re-create autofocus feature so it's using video focus mode now.
     cameraFeatures.setAutoFocus(
         cameraFeatureFactory.createAutoFocusFeature(cameraProperties, true));
+    // Update camera features with the desired fps range
+    setFpsCameraFeatureForRecording(cameraProperties);
   }
 
   private void setStreamHandler(EventChannel imageStreamChannel) {
@@ -1375,6 +1386,7 @@ public void setDescriptionWhileRecording(CameraProperties properties) {
             videoCaptureSettings.resolutionPreset);
     cameraFeatures.setAutoFocus(
         cameraFeatureFactory.createAutoFocusFeature(cameraProperties, true));
+    setFpsCameraFeatureForRecording(cameraProperties);
     try {
       open(imageFormatGroup);
     } catch (CameraAccessException e) {

packages/camera/camera_android/android/src/test/java/io/flutter/plugins/camera/CameraTest_getRecordingProfileTest.java

@@ -86,10 +86,7 @@ public void getRecordingProfileLegacy() {
 
     CamcorderProfile actualRecordingProfile = camera.getRecordingProfileLegacy();
 
-    // First time: getRecordingProfileLegacy() is called in `before()` when
-    // camera constructor tries to determine default recording Fps.
-    // Second time: in this test case.
-    verify(mockResolutionFeature, times(2)).getRecordingProfileLegacy();
+    verify(mockResolutionFeature, times(1)).getRecordingProfileLegacy();
     assertEquals(mockCamcorderProfile, actualRecordingProfile);
   }
 
@@ -104,7 +101,7 @@ public void getRecordingProfile() {
 
     EncoderProfiles actualRecordingProfile = camera.getRecordingProfile();
 
-    verify(mockResolutionFeature, times(2)).getRecordingProfile();
+    verify(mockResolutionFeature, times(1)).getRecordingProfile();
     assertEquals(mockRecordingProfile, actualRecordingProfile);
   }
 

packages/camera/camera_android/pubspec.yaml

@@ -3,7 +3,7 @@ description: Android implementation of the camera plugin.
 repository: https://github.com/flutter/packages/tree/main/packages/camera/camera_android
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+camera%22
 
-version: 0.10.10+1
+version: 0.10.10+2
 
 environment:
   sdk: ^3.6.0