[camerax] Use AspectRatioStrategy and ResolutionFilter to help automatic selection of expected resolution

packages/camera/camera_android_camerax/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.6.1
+
+* Modifies resolution selection logic to use an `AspectRatioStrategy` for all aspect ratios supported by CameraX.
+
 ## 0.6.0+1
 
 * Updates `README.md` to encourage developers to opt into this implementation of the camera plugin.

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

@@ -9,10 +9,12 @@ import 'package:async/async.dart';
 import 'package:camera_platform_interface/camera_platform_interface.dart';
 import 'package:flutter/services.dart'
     show DeviceOrientation, PlatformException;
-import 'package:flutter/widgets.dart';
+import 'package:flutter/widgets.dart'
+    show Size, Texture, Widget, visibleForTesting;
 import 'package:stream_transform/stream_transform.dart';
 
 import 'analyzer.dart';
+import 'aspect_ratio_strategy.dart';
 import 'camera.dart';
 import 'camera2_camera_control.dart';
 import 'camera_control.dart';
@@ -1150,32 +1152,45 @@ class AndroidCameraCameraX extends CameraPlatform {
         ResolutionStrategy.fallbackRuleClosestLowerThenHigher;
 
     Size? boundSize;
+    int? aspectRatio;
     ResolutionStrategy? resolutionStrategy;
     switch (preset) {
       case ResolutionPreset.low:
         boundSize = const Size(320, 240);
+        aspectRatio = AspectRatio.ratio4To3;
       case ResolutionPreset.medium:
+        // TODO(camsim99): Handle the 3:2 aspect ratio case:
+        // https://github.com/flutter/flutter/issues/144363.
         boundSize = const Size(720, 480);
       case ResolutionPreset.high:
         boundSize = const Size(1280, 720);
+        aspectRatio = AspectRatio.ratio16To9;
       case ResolutionPreset.veryHigh:
         boundSize = const Size(1920, 1080);
+        aspectRatio = AspectRatio.ratio16To9;
       case ResolutionPreset.ultraHigh:
         boundSize = const Size(3840, 2160);
+        aspectRatio = AspectRatio.ratio16To9;
       case ResolutionPreset.max:
         // Automatically set strategy to choose highest available.
         resolutionStrategy =
             proxy.createResolutionStrategy(highestAvailable: true);
-        return proxy.createResolutionSelector(resolutionStrategy);
+        return proxy.createResolutionSelector(
+            resolutionStrategy, /* AspectRatioStrategy */ null);
       case null:
         // If no preset is specified, default to CameraX's default behavior
         // for each UseCase.
         return null;
     }
 
+    final AspectRatioStrategy? aspectRatioStrategy = aspectRatio == null
+        ? null
+        : proxy.createAspectRatioStrategy(
+            aspectRatio, AspectRatioStrategy.fallbackRuleAuto);
     resolutionStrategy = proxy.createResolutionStrategy(
         boundSize: boundSize, fallbackRule: fallbackRule);
-    return proxy.createResolutionSelector(resolutionStrategy);
+    return proxy.createResolutionSelector(
+        resolutionStrategy, aspectRatioStrategy);
   }
 
   /// Returns the [QualitySelector] that maps to the specified resolution

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

@@ -5,6 +5,7 @@
 import 'dart:ui' show Size;
 
 import 'analyzer.dart';
+import 'aspect_ratio_strategy.dart';
 import 'camera2_camera_control.dart';
 import 'camera_control.dart';
 import 'camera_info.dart';
@@ -59,6 +60,7 @@ class CameraXProxy {
     this.createCaptureRequestOptions = _createAttachedCaptureRequestOptions,
     this.createMeteringPoint = _createAttachedMeteringPoint,
     this.createFocusMeteringAction = _createAttachedFocusMeteringAction,
+    this.createAspectRatioStrategy = _createAttachedAspectRatioStrategy,
   });
 
   /// Returns a [ProcessCameraProvider] instance.
@@ -115,9 +117,9 @@ class CameraXProxy {
       int? fallbackRule}) createResolutionStrategy;
 
   /// Returns a [ResolutionSelector] configured with the specified
-  /// [ResolutionStrategy].
-  ResolutionSelector Function(ResolutionStrategy resolutionStrategy)
-      createResolutionSelector;
+  /// [ResolutionStrategy] and [AspectRatioStrategy].
+  ResolutionSelector Function(ResolutionStrategy resolutionStrategy,
+      AspectRatioStrategy? aspectRatioStrategy) createResolutionSelector;
 
   /// Returns a [FallbackStrategy] configured with the specified [VideoQuality]
   /// and [VideoResolutionFallbackRule].
@@ -151,7 +153,7 @@ class CameraXProxy {
   Camera2CameraControl Function(CameraControl cameraControl)
       getCamera2CameraControl;
 
-  /// Create [CapureRequestOptions] with specified options.
+  /// Create [CaptureRequestOptions] with specified options.
   CaptureRequestOptions Function(
           List<(CaptureRequestKeySupportedType, Object?)> options)
       createCaptureRequestOptions;
@@ -167,6 +169,11 @@ class CameraXProxy {
   FocusMeteringAction Function(List<(MeteringPoint, int?)> meteringPointInfos,
       bool? disableAutoCancel) createFocusMeteringAction;
 
+  /// Creates an [AspectRatioStrategy] with specified aspect ratio and fallback
+  /// rule.
+  AspectRatioStrategy Function(int aspectRatio, int fallbackRule)
+      createAspectRatioStrategy;
+
   static Future<ProcessCameraProvider> _getProcessCameraProvider() {
     return ProcessCameraProvider.getInstance();
   }
@@ -234,8 +241,11 @@ class CameraXProxy {
   }
 
   static ResolutionSelector _createAttachedResolutionSelector(
-      ResolutionStrategy resolutionStrategy) {
-    return ResolutionSelector(resolutionStrategy: resolutionStrategy);
+      ResolutionStrategy resolutionStrategy,
+      AspectRatioStrategy? aspectRatioStrategy) {
+    return ResolutionSelector(
+        resolutionStrategy: resolutionStrategy,
+        aspectRatioStrategy: aspectRatioStrategy);
   }
 
   static FallbackStrategy _createAttachedFallbackStrategy(
@@ -291,4 +301,10 @@ class CameraXProxy {
         meteringPointInfos: meteringPointInfos,
         disableAutoCancel: disableAutoCancel);
   }
+
+  static AspectRatioStrategy _createAttachedAspectRatioStrategy(
+      int preferredAspectRatio, int fallbackRule) {
+    return AspectRatioStrategy(
+        preferredAspectRatio: preferredAspectRatio, fallbackRule: fallbackRule);
+  }
 }

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: 0.6.0+1
+version: 0.6.1
 
 environment:
   sdk: ^3.1.0