[camerax] Implement startVideoCapturing and onVideoRecordedEvent (flutter#4815)

Implements `startVideoCapturing` (with the image streaming option, others currently unsupported) and `onVideoRecordedEvent` (empty implementation; same as the other plugins).

Fixes flutter#126477.
Fixes flutter#127896.

Author: camsim99

packages/camera/camera_android_camerax/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.5.0+18
+
+* Implements `startVideoCapturing`.
+
 ## 0.5.0+17
 
 * Implements resolution configuration for all camera use cases.

packages/camera/camera_android_camerax/README.md

@@ -51,10 +51,12 @@ Calling `setFlashMode` with mode `FlashMode.torch` currently does nothing.
 
 `setZoomLevel` is unimplemented.
 
-### Some video capture functionality \[[Issue #127896][127896], [Issue #126477][126477]\]
+### Setting maximum duration and stream options for video capture
 
-`startVideoCapturing` is unimplemented; use `startVideoRecording` instead.
-`onVideoRecordedEvent` is also unimplemented.
+Calling `startVideoCapturing` with `VideoCaptureOptions` configured with
+`maxVideoDuration` and `streamOptions` is currently unsupported do to the
+limitations of the CameraX library and the platform interface, respectively,
+and thus, those parameters will silently be ignored.
 
 ## Contributing
 

packages/camera/camera_android_camerax/lib/src/android_camera_camerax.dart

@@ -363,6 +363,12 @@ class AndroidCameraCameraX extends CameraPlatform {
     ]);
   }
 
+  /// The camera finished recording a video.
+  @override
+  Stream<VideoRecordedEvent> onVideoRecordedEvent(int cameraId) {
+    return _cameraEvents(cameraId).whereType<VideoRecordedEvent>();
+  }
+
   /// Gets the minimum supported exposure offset for the selected camera in EV units.
   ///
   /// [cameraId] not used.
@@ -507,12 +513,23 @@ class AndroidCameraCameraX extends CameraPlatform {
   /// Note that the preset resolution is used to configure the recording, but
   /// 240p ([ResolutionPreset.low]) is unsupported and will fallback to
   /// configure the recording as the next highest available quality.
+  ///
+  /// This method is deprecated in favour of [startVideoCapturing].
   @override
   Future<void> startVideoRecording(int cameraId,
       {Duration? maxVideoDuration}) async {
-    assert(cameraSelector != null);
-    assert(processCameraProvider != null);
+    return startVideoCapturing(
+        VideoCaptureOptions(cameraId, maxDuration: maxVideoDuration));
+  }
 
+  /// Starts a video recording and/or streaming session.
+  ///
+  /// Please see [VideoCaptureOptions] for documentation on the
+  /// configuration options. Currently, maxVideoDuration and streamOptions
+  /// are unsupported due to the limitations of CameraX and the platform
+  /// interface, respectively.
+  @override
+  Future<void> startVideoCapturing(VideoCaptureOptions options) async {
     if (recording != null) {
       // There is currently an active recording, so do not start a new one.
       return;
@@ -527,6 +544,10 @@ class AndroidCameraCameraX extends CameraPlatform {
         await SystemServices.getTempFilePath(videoPrefix, '.temp');
     pendingRecording = await recorder!.prepareRecording(videoOutputPath!);
     recording = await pendingRecording!.start();
+
+    if (options.streamCallback != null) {
+      onStreamedFrameAvailable(options.cameraId).listen(options.streamCallback);
+    }
   }
 
   /// Stops the video recording and returns the file where it was saved.

packages/camera/camera_android_camerax/pubspec.yaml

@@ -2,7 +2,7 @@ name: camera_android_camerax
 description: Android implementation of the camera plugin using the CameraX library.
 repository: https://github.com/flutter/packages/tree/main/packages/camera/camera_android_camerax
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+camera%22
-version: 0.5.0+17
+version: 0.5.0+18
 
 environment:
   sdk: ">=2.19.0 <4.0.0"
@@ -19,7 +19,7 @@ flutter:
 
 dependencies:
   async: ^2.5.0
-  camera_platform_interface: ^2.2.0
+  camera_platform_interface: ^2.3.2
   flutter:
     sdk: flutter
   integration_test:

packages/camera/camera_android_camerax/test/android_camera_camerax_test.dart

@@ -785,9 +785,9 @@ void main() {
 
   group('video recording', () {
     test(
-        'startVideoRecording binds video capture use case and starts the recording',
+        'startVideoCapturing binds video capture use case and starts the recording',
         () async {
-      //Set up mocks and constants.
+      // Set up mocks and constants.
       final FakeAndroidCameraCameraX camera = FakeAndroidCameraCameraX();
       camera.processCameraProvider = MockProcessCameraProvider();
       camera.cameraSelector = MockCameraSelector();
@@ -815,7 +815,7 @@ void main() {
               camera.cameraSelector!, <UseCase>[camera.videoCapture!]))
           .thenAnswer((_) async => camera.camera!);
 
-      await camera.startVideoRecording(cameraId);
+      await camera.startVideoCapturing(const VideoCaptureOptions(cameraId));
 
       verify(camera.processCameraProvider!.bindToLifecycle(
           camera.cameraSelector!, <UseCase>[camera.videoCapture!]));
@@ -824,9 +824,9 @@ void main() {
     });
 
     test(
-        'startVideoRecording binds video capture use case and starts the recording'
+        'startVideoCapturing binds video capture use case and starts the recording'
         ' on first call, and does nothing on second call', () async {
-      //Set up mocks and constants.
+      // Set up mocks and constants.
       final FakeAndroidCameraCameraX camera = FakeAndroidCameraCameraX();
       camera.processCameraProvider = MockProcessCameraProvider();
       camera.cameraSelector = MockCameraSelector();
@@ -854,14 +854,14 @@ void main() {
               camera.cameraSelector!, <UseCase>[camera.videoCapture!]))
           .thenAnswer((_) async => camera.camera!);
 
-      await camera.startVideoRecording(cameraId);
+      await camera.startVideoCapturing(const VideoCaptureOptions(cameraId));
 
       verify(camera.processCameraProvider!.bindToLifecycle(
           camera.cameraSelector!, <UseCase>[camera.videoCapture!]));
       expect(camera.pendingRecording, equals(mockPendingRecording));
       expect(camera.recording, mockRecording);
 
-      await camera.startVideoRecording(cameraId);
+      await camera.startVideoCapturing(const VideoCaptureOptions(cameraId));
       // Verify that each of these calls happened only once.
       verify(mockSystemServicesApi.getTempFilePath(camera.videoPrefix, '.temp'))
           .called(1);
@@ -872,6 +872,55 @@ void main() {
       verifyNoMoreInteractions(mockPendingRecording);
     });
 
+    test(
+        'startVideoCapturing called with stream options starts image streaming',
+        () async {
+      // Set up mocks and constants.
+      final FakeAndroidCameraCameraX camera =
+          FakeAndroidCameraCameraX(shouldCreateDetachedObjectForTesting: true);
+      final MockProcessCameraProvider mockProcessCameraProvider =
+          MockProcessCameraProvider();
+      camera.processCameraProvider = mockProcessCameraProvider;
+      camera.cameraSelector = MockCameraSelector();
+      camera.recorder = camera.testRecorder;
+      camera.videoCapture = camera.testVideoCapture;
+      camera.imageAnalysis = camera.testImageAnalysis;
+      camera.camera = MockCamera();
+      final MockPendingRecording mockPendingRecording = MockPendingRecording();
+      final TestSystemServicesHostApi mockSystemServicesApi =
+          MockTestSystemServicesHostApi();
+      TestSystemServicesHostApi.setup(mockSystemServicesApi);
+
+      const int cameraId = 17;
+      const String outputPath = '/temp/MOV123.temp';
+      final Completer<CameraImageData> imageDataCompleter =
+          Completer<CameraImageData>();
+      final VideoCaptureOptions videoCaptureOptions = VideoCaptureOptions(
+          cameraId,
+          streamCallback: (CameraImageData imageData) =>
+              imageDataCompleter.complete(imageData));
+
+      // Mock method calls.
+      when(camera.processCameraProvider!.isBound(camera.videoCapture!))
+          .thenAnswer((_) async => true);
+      when(mockSystemServicesApi.getTempFilePath(camera.videoPrefix, '.temp'))
+          .thenReturn(outputPath);
+      when(camera.testRecorder.prepareRecording(outputPath))
+          .thenAnswer((_) async => mockPendingRecording);
+      when(mockProcessCameraProvider.bindToLifecycle(any, any))
+          .thenAnswer((_) => Future<Camera>.value(camera.camera));
+      when(camera.camera!.getCameraInfo())
+          .thenAnswer((_) => Future<CameraInfo>.value(MockCameraInfo()));
+
+      await camera.startVideoCapturing(videoCaptureOptions);
+
+      final CameraImageData mockCameraImageData = MockCameraImageData();
+      camera.cameraImageDataStreamController!.add(mockCameraImageData);
+
+      expect(imageDataCompleter.future, isNotNull);
+      await camera.cameraImageDataStreamController!.close();
+    });
+
     test('pauseVideoRecording pauses the recording', () async {
       final AndroidCameraCameraX camera = AndroidCameraCameraX();
       final MockRecording recording = MockRecording();