[camera] MediaSettings parameter for createCameraWithSettings (#3586)

This PR is for enabling fps and bitrate control of recorded video.
Allow users to more control over recorded video size.
`CameraPlatform.createCameraWithSettings` is added, leaving original `CameraPlatform.createCamera` commented as deprecated. So this is not breaking change.
Tested on a set of mobile devices.
Web support depends on browser (perfect with Firefox).

Fixes flutter/flutter#54339

packages/camera/camera/CHANGELOG.md

@@ -1,5 +1,6 @@
-## NEXT
+## 0.10.6
 
+* Adds support to control video fps and bitrate. See `CameraController` constructor.
 * Updates minimum supported SDK version to Flutter 3.13/Dart 3.1.
 * Updates support matrix in README to indicate that iOS 11 is no longer supported.
 * Clients on versions of Flutter that still support iOS 11 can continue to use this

packages/camera/camera/lib/src/camera_controller.dart

@@ -232,12 +232,30 @@ class CameraValue {
 /// To show the camera preview on the screen use a [CameraPreview] widget.
 class CameraController extends ValueNotifier<CameraValue> {
   /// Creates a new camera controller in an uninitialized state.
+  ///
+  /// - [resolutionPreset] affect the quality of video recording and image capture.
+  /// - [enableAudio] controls audio presence in recorded video.
+  ///
+  /// Following parameters (if present) will overwrite [resolutionPreset] settings:
+  /// - [fps] controls rate at which frames should be captured by the camera in frames per second.
+  /// - [videoBitrate] controls the video encoding bit rate for recording.
+  /// - [audioBitrate] controls the audio encoding bit rate for recording.
+
   CameraController(
     CameraDescription description,
-    this.resolutionPreset, {
-    this.enableAudio = true,
+    ResolutionPreset resolutionPreset, {
+    bool enableAudio = true,
+    int? fps,
+    int? videoBitrate,
+    int? audioBitrate,
     this.imageFormatGroup,
-  }) : super(CameraValue.uninitialized(description));
+  })  : mediaSettings = MediaSettings(
+            resolutionPreset: resolutionPreset,
+            enableAudio: enableAudio,
+            fps: fps,
+            videoBitrate: videoBitrate,
+            audioBitrate: audioBitrate),
+        super(CameraValue.uninitialized(description));
 
   /// The properties of the camera device controlled by this controller.
   CameraDescription get description => value.description;
@@ -248,10 +266,19 @@ class CameraController extends ValueNotifier<CameraValue> {
   /// if unavailable a lower resolution will be used.
   ///
   /// See also: [ResolutionPreset].
-  final ResolutionPreset resolutionPreset;
+  ResolutionPreset get resolutionPreset =>
+      mediaSettings.resolutionPreset ?? ResolutionPreset.max;
 
   /// Whether to include audio when recording a video.
-  final bool enableAudio;
+  bool get enableAudio => mediaSettings.enableAudio;
+
+  /// The media settings this controller is targeting.
+  ///
+  /// This media settings are not guaranteed to be available on the device,
+  /// if unavailable a [resolutionPreset] default values will be used.
+  ///
+  /// See also: [MediaSettings].
+  final MediaSettings mediaSettings;
 
   /// The [ImageFormatGroup] describes the output of the raw image format.
   ///
@@ -265,6 +292,7 @@ class CameraController extends ValueNotifier<CameraValue> {
 
   bool _isDisposed = false;
   StreamSubscription<CameraImageData>? _imageStreamSubscription;
+
   // A Future awaiting an attempt to initialize (e.g. after `initialize` was
   // just called). If the controller has not been initialized at least once,
   // this value is null.
@@ -313,10 +341,9 @@ class CameraController extends ValueNotifier<CameraValue> {
         );
       });
 
-      _cameraId = await CameraPlatform.instance.createCamera(
+      _cameraId = await CameraPlatform.instance.createCameraWithSettings(
         description,
-        resolutionPreset,
-        enableAudio: enableAudio,
+        mediaSettings,
       );
 
       _unawaited(CameraPlatform.instance
@@ -372,7 +399,7 @@ class CameraController extends ValueNotifier<CameraValue> {
 
   /// Pauses the current camera preview
   Future<void> pausePreview() async {
-    if (value.isPreviewPaused) {
+    if (value.isPreviewPaused || !value.isInitialized || _isDisposed) {
       return;
     }
     try {
@@ -923,7 +950,7 @@ class Optional<T> extends IterableBase<T> {
     if (_value == null) {
       throw StateError('value called on absent Optional.');
     }
-    return _value!;
+    return _value;
   }
 
   /// Executes a function if the Optional value is present.
@@ -960,7 +987,7 @@ class Optional<T> extends IterableBase<T> {
   Optional<S> transform<S>(S Function(T value) transformer) {
     return _value == null
         ? Optional<S>.absent()
-        : Optional<S>.of(transformer(_value as T));
+        : Optional<S>.of(transformer(_value));
   }
 
   /// Transforms the Optional value.
@@ -971,7 +998,7 @@ class Optional<T> extends IterableBase<T> {
   Optional<S> transformNullable<S>(S? Function(T value) transformer) {
     return _value == null
         ? Optional<S>.absent()
-        : Optional<S>.fromNullable(transformer(_value as T));
+        : Optional<S>.fromNullable(transformer(_value));
   }
 
   @override

packages/camera/camera/pubspec.yaml

@@ -4,11 +4,11 @@ description: A Flutter plugin for controlling the camera. Supports previewing
   Dart.
 repository: https://github.com/flutter/packages/tree/main/packages/camera/camera
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+camera%22
-version: 0.10.5+9
+version: 0.10.6
 
 environment:
-  sdk: ^3.1.0
-  flutter: ">=3.13.0"
+  sdk: ^3.2.3
+  flutter: ">=3.16.6"
 
 flutter:
   plugin:
@@ -21,10 +21,10 @@ flutter:
         default_package: camera_web
 
 dependencies:
-  camera_android: ^0.10.7
-  camera_avfoundation: ^0.9.13
-  camera_platform_interface: ^2.5.0
-  camera_web: ^0.3.1
+  camera_android: ^0.10.9
+  camera_avfoundation: ^0.9.15
+  camera_platform_interface: ^2.6.0
+  camera_web: ^0.3.3
   flutter:
     sdk: flutter
   flutter_plugin_android_lifecycle: ^2.0.2

packages/camera/camera/test/camera_preview_test.dart

@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 import 'package:camera/camera.dart';
+import 'package:camera_platform_interface/camera_platform_interface.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
@@ -68,6 +69,15 @@ class FakeController extends ValueNotifier<CameraValue>
   @override
   ResolutionPreset get resolutionPreset => ResolutionPreset.low;
 
+  @override
+  MediaSettings get mediaSettings => const MediaSettings(
+        resolutionPreset: ResolutionPreset.low,
+        fps: 15,
+        videoBitrate: 200000,
+        audioBitrate: 32000,
+        enableAudio: true,
+      );
+
   @override
   Future<void> resumeVideoRecording() async {}
 

packages/camera/camera/test/camera_test.dart

@@ -111,6 +111,46 @@ void main() {
       expect(cameraController.value.isInitialized, isTrue);
     });
 
+    test('can be initialized with media settings', () async {
+      final CameraController cameraController = CameraController(
+        const CameraDescription(
+            name: 'cam',
+            lensDirection: CameraLensDirection.back,
+            sensorOrientation: 90),
+        ResolutionPreset.low,
+        fps: 15,
+        videoBitrate: 200000,
+        audioBitrate: 32000,
+        enableAudio: false,
+      );
+      await cameraController.initialize();
+
+      expect(cameraController.value.aspectRatio, 1);
+      expect(cameraController.value.previewSize, const Size(75, 75));
+      expect(cameraController.value.isInitialized, isTrue);
+      expect(cameraController.resolutionPreset, ResolutionPreset.low);
+      expect(cameraController.enableAudio, false);
+      expect(cameraController.mediaSettings.fps, 15);
+      expect(cameraController.mediaSettings.videoBitrate, 200000);
+      expect(cameraController.mediaSettings.audioBitrate, 32000);
+    });
+
+    test('default constructor initializes media settings', () async {
+      final CameraController cameraController = CameraController(
+          const CameraDescription(
+              name: 'cam',
+              lensDirection: CameraLensDirection.back,
+              sensorOrientation: 90),
+          ResolutionPreset.max);
+      await cameraController.initialize();
+
+      expect(cameraController.resolutionPreset, ResolutionPreset.max);
+      expect(cameraController.enableAudio, true);
+      expect(cameraController.mediaSettings.fps, isNull);
+      expect(cameraController.mediaSettings.videoBitrate, isNull);
+      expect(cameraController.mediaSettings.audioBitrate, isNull);
+    });
+
     test('can be disposed', () async {
       final CameraController cameraController = CameraController(
           const CameraDescription(
@@ -1429,15 +1469,20 @@ class MockCameraPlatform extends Mock
   Future<List<CameraDescription>> availableCameras() =>
       Future<List<CameraDescription>>.value(mockAvailableCameras);
 
+  @override
+  Future<int> createCameraWithSettings(
+          CameraDescription cameraDescription, MediaSettings? mediaSettings) =>
+      mockPlatformException
+          ? throw PlatformException(code: 'foo', message: 'bar')
+          : Future<int>.value(mockInitializeCamera);
+
   @override
   Future<int> createCamera(
     CameraDescription description,
     ResolutionPreset? resolutionPreset, {
     bool enableAudio = false,
   }) =>
-      mockPlatformException
-          ? throw PlatformException(code: 'foo', message: 'bar')
-          : Future<int>.value(mockInitializeCamera);
+      createCameraWithSettings(description, null);
 
   @override
   Stream<CameraInitializedEvent> onCameraInitialized(int cameraId) =>