[camera] Pause/resume video recording for Android & iOS

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

@@ -166,6 +166,16 @@ public void onMethodCall(MethodCall call, final Result result) {
           camera.stopVideoRecording(result);
           break;
         }
+      case "pauseVideoRecording":
+        {
+          camera.pauseVideoRecording(result);
+          break;
+        }
+      case "resumeVideoRecording":
+        {
+          camera.resumeVideoRecording(result);
+          break;
+        }
       case "startImageStream":
         {
           try {
@@ -702,6 +712,34 @@ private void stopVideoRecording(@NonNull final Result result) {
       }
     }
 
+    private void pauseVideoRecording(@NonNull final Result result) {
+      if (!recordingVideo) {
+        result.success(null);
+        return;
+      }
+
+      try {
+        mediaRecorder.pause();
+        result.success(null);
+      } catch (IllegalStateException e) {
+        result.error("videoRecordingFailed", e.getMessage(), null);
+      }
+    }
+
+    private void resumeVideoRecording(@NonNull final Result result) {
+      if (!recordingVideo) {
+        result.success(null);
+        return;
+      }
+
+      try {
+        mediaRecorder.resume();
+        result.success(null);
+      } catch (IllegalStateException e) {
+        result.error("videoRecordingFailed", e.getMessage(), null);
+      }
+    }
+
     private void startPreview() throws CameraAccessException {
       closeCaptureSession();
 

packages/camera/example/lib/main.dart

@@ -206,6 +206,19 @@ class _CameraExampleHomeState extends State<CameraExampleHome>
               ? onVideoRecordButtonPressed
               : null,
         ),
+        IconButton(
+          icon: controller != null && controller.value.isRecordingPaused
+              ? Icon(Icons.play_arrow)
+              : Icon(Icons.pause),
+          color: Colors.blue,
+          onPressed: controller != null &&
+                  controller.value.isInitialized &&
+                  controller.value.isRecordingVideo
+              ? (controller != null && controller.value.isRecordingPaused
+                  ? onResumeButtonPressed
+                  : onPauseButtonPressed)
+              : null,
+        ),
         IconButton(
           icon: const Icon(Icons.stop),
           color: Colors.red,
@@ -308,6 +321,20 @@ class _CameraExampleHomeState extends State<CameraExampleHome>
     });
   }
 
+  void onPauseButtonPressed() {
+    pauseVideoRecording().then((_) {
+      if (mounted) setState(() {});
+      showInSnackBar('Video recording paused');
+    });
+  }
+
+  void onResumeButtonPressed() {
+    resumeVideoRecording().then((_) {
+      if (mounted) setState(() {});
+      showInSnackBar('Video recording resumed');
+    });
+  }
+
   Future<String> startVideoRecording() async {
     if (!controller.value.isInitialized) {
       showInSnackBar('Error: select a camera first.');
@@ -349,6 +376,32 @@ class _CameraExampleHomeState extends State<CameraExampleHome>
     await _startVideoPlayer();
   }
 
+  Future<void> pauseVideoRecording() async {
+    if (!controller.value.isRecordingVideo) {
+      return null;
+    }
+
+    try {
+      await controller.pauseVideoRecording();
+    } on CameraException catch (e) {
+      _showCameraException(e);
+      return null;
+    }
+  }
+
+  Future<void> resumeVideoRecording() async {
+    if (!controller.value.isRecordingVideo) {
+      return null;
+    }
+
+    try {
+      await controller.resumeVideoRecording();
+    } on CameraException catch (e) {
+      _showCameraException(e);
+      return null;
+    }
+  }
+
   Future<void> _startVideoPlayer() async {
     final VideoPlayerController vcontroller =
         VideoPlayerController.file(File(videoPath));

packages/camera/ios/Classes/CameraPlugin.m

@@ -139,6 +139,7 @@ @interface FLTCam : NSObject <FlutterTexture,
 @property(strong, nonatomic) AVCaptureVideoDataOutput *videoOutput;
 @property(strong, nonatomic) AVCaptureAudioDataOutput *audioOutput;
 @property(assign, nonatomic) BOOL isRecording;
+@property(assign, nonatomic) BOOL isRecordingPaused;
 @property(assign, nonatomic) BOOL isAudioSetup;
 @property(assign, nonatomic) BOOL isStreamingImages;
 @property(nonatomic) CMMotionManager *motionManager;
@@ -365,7 +366,7 @@ - (void)captureOutput:(AVCaptureOutput *)output
       CVPixelBufferUnlockBaseAddress(pixelBuffer, kCVPixelBufferLock_ReadOnly);
     }
   }
-  if (_isRecording) {
+  if (_isRecording && !_isRecordingPaused) {
     if (_videoWriter.status == AVAssetWriterStatusFailed) {
       _eventSink(@{
         @"event" : @"error",
@@ -474,6 +475,7 @@ - (void)startVideoRecordingAtPath:(NSString *)path result:(FlutterResult)result
       return;
     }
     _isRecording = YES;
+    _isRecordingPaused = NO;
     result(nil);
   } else {
     _eventSink(@{@"event" : @"error", @"errorDescription" : @"Video is already recording!"});
@@ -504,6 +506,14 @@ - (void)stopVideoRecordingWithResult:(FlutterResult)result {
   }
 }
 
+- (void)pauseVideoRecording {
+  _isRecordingPaused = YES;
+}
+
+- (void)resumeVideoRecording {
+  _isRecordingPaused = NO;
+}
+
 - (void)startImageStreamWithMessenger:(NSObject<FlutterBinaryMessenger> *)messenger {
   if (!_isStreamingImages) {
     FlutterEventChannel *eventChannel =
@@ -725,6 +735,10 @@ - (void)handleMethodCallAsync:(FlutterMethodCall *)call result:(FlutterResult)re
   } else if ([@"stopImageStream" isEqualToString:call.method]) {
     [_camera stopImageStream];
     result(nil);
+  } else if ([@"pauseVideoRecording" isEqualToString:call.method]) {
+    [_camera pauseVideoRecording];
+  } else if ([@"resumeVideoRecording" isEqualToString:call.method]) {
+    [_camera resumeVideoRecording];
   } else {
     NSDictionary *argsMap = call.arguments;
     NSUInteger textureId = ((NSNumber *)argsMap[@"textureId"]).unsignedIntegerValue;

packages/camera/lib/camera.dart

@@ -130,14 +130,17 @@ class CameraValue {
     this.isRecordingVideo,
     this.isTakingPicture,
     this.isStreamingImages,
-  });
+    bool isRecordingPaused,
+  }) : _isRecordingPaused = isRecordingPaused;
 
   const CameraValue.uninitialized()
       : this(
-            isInitialized: false,
-            isRecordingVideo: false,
-            isTakingPicture: false,
-            isStreamingImages: false);
+          isInitialized: false,
+          isRecordingVideo: false,
+          isTakingPicture: false,
+          isStreamingImages: false,
+          isRecordingPaused: false,
+        );
 
   /// True after [CameraController.initialize] has completed successfully.
   final bool isInitialized;
@@ -151,6 +154,11 @@ class CameraValue {
   /// True when images from the camera are being streamed.
   final bool isStreamingImages;
 
+  final bool _isRecordingPaused;
+
+  /// True when camera [isRecordingVideo] and recording is paused.
+  bool get isRecordingPaused => isRecordingVideo && _isRecordingPaused;
+
   final String errorDescription;
 
   /// The size of the preview in pixels.
@@ -172,6 +180,7 @@ class CameraValue {
     bool isStreamingImages,
     String errorDescription,
     Size previewSize,
+    bool isRecordingPaused,
   }) {
     return CameraValue(
       isInitialized: isInitialized ?? this.isInitialized,
@@ -180,6 +189,7 @@ class CameraValue {
       isRecordingVideo: isRecordingVideo ?? this.isRecordingVideo,
       isTakingPicture: isTakingPicture ?? this.isTakingPicture,
       isStreamingImages: isStreamingImages ?? this.isStreamingImages,
+      isRecordingPaused: isRecordingPaused ?? _isRecordingPaused,
     );
   }
 
@@ -446,7 +456,7 @@ class CameraController extends ValueNotifier<CameraValue> {
         'startVideoRecording',
         <String, dynamic>{'textureId': _textureId, 'filePath': filePath},
       );
-      value = value.copyWith(isRecordingVideo: true);
+      value = value.copyWith(isRecordingVideo: true, isRecordingPaused: false);
     } on PlatformException catch (e) {
       throw CameraException(e.code, e.message);
     }
@@ -477,6 +487,56 @@ class CameraController extends ValueNotifier<CameraValue> {
     }
   }
 
+  /// Pause recording.
+  Future<void> pauseVideoRecording() async {
+    if (!value.isInitialized || _isDisposed) {
+      throw CameraException(
+        'Uninitialized CameraController',
+        'pauseVideoRecording was called on uninitialized CameraController',
+      );
+    }
+    if (!value.isRecordingVideo) {
+      throw CameraException(
+        'No video is recording',
+        'pauseVideoRecording was called when no video is recording.',
+      );
+    }
+    try {
+      value = value.copyWith(isRecordingPaused: true);
+      await _channel.invokeMethod<void>(
+        'pauseVideoRecording',
+        <String, dynamic>{'textureId': _textureId},
+      );
+    } on PlatformException catch (e) {
+      throw CameraException(e.code, e.message);
+    }
+  }
+
+  /// Resume recording.
+  Future<void> resumeVideoRecording() async {
+    if (!value.isInitialized || _isDisposed) {
+      throw CameraException(
+        'Uninitialized CameraController',
+        'resumeVideoRecording was called on uninitialized CameraController',
+      );
+    }
+    if (!value.isRecordingVideo) {
+      throw CameraException(
+        'No video is recording',
+        'resumeVideoRecording was called when no video is recording.',
+      );
+    }
+    try {
+      value = value.copyWith(isRecordingPaused: false);
+      await _channel.invokeMethod<void>(
+        'resumeVideoRecording',
+        <String, dynamic>{'textureId': _textureId},
+      );
+    } on PlatformException catch (e) {
+      throw CameraException(e.code, e.message);
+    }
+  }
+
   /// Releases the resources of this camera.
   @override
   Future<void> dispose() async {