Feat: ios camera best resolution

camera/example/lib/main.dart

@@ -4,6 +4,7 @@
 
 import 'dart:async';
 import 'dart:io';
+import 'dart:ui' as ui;
 
 import 'package:camera/camera.dart';
 import 'package:flutter/foundation.dart';
@@ -646,7 +647,7 @@ class _CameraExampleHomeState extends State<CameraExampleHome>
 
     final CameraController cameraController = CameraController(
       cameraDescription,
-      kIsWeb ? ResolutionPreset.max : ResolutionPreset.medium,
+      ResolutionPreset.max,
       enableAudio: enableAudio,
       imageFormatGroup: ImageFormatGroup.jpeg,
     );
@@ -729,11 +730,27 @@ class _CameraExampleHomeState extends State<CameraExampleHome>
         });
         if (file != null) {
           showInSnackBar('Picture saved to ${file.path}');
+
+          _loadImage(file.path).then((image) {
+            debugPrint(
+              'Picture resolution is ${image.height} x ${image.width}',
+            );
+          });
         }
       }
     });
   }
 
+  Future<ui.Image> _loadImage(String imagePath) async {
+    final Uint8List imageBytes = await File(imagePath).readAsBytes();
+    final Completer<ui.Image> imageCompleter = Completer();
+    ui.decodeImageFromList(imageBytes, (ui.Image image) {
+      imageCompleter.complete(image);
+    });
+
+    return imageCompleter.future;
+  }
+
   void onFlashModeButtonPressed() {
     if (_flashModeControlRowAnimationController.value == 1) {
       _flashModeControlRowAnimationController.reverse();

camera_avfoundation/ios/Classes/FLTCam.m

@@ -162,6 +162,9 @@ - (instancetype)initWithCameraName:(NSString *)cameraName
   _motionManager = [[CMMotionManager alloc] init];
   [_motionManager startAccelerometerUpdates];
 
+  _videoCaptureSession.sessionPreset = AVCaptureSessionPresetInputPriority;
+
+
   [self setCaptureSessionPreset:_resolutionPreset];
   [self updateOrientation];
 
@@ -340,10 +343,19 @@ - (NSString *)getTemporaryFilePathWithExtension:(NSString *)extension
 - (void)setCaptureSessionPreset:(FLTResolutionPreset)resolutionPreset {
   switch (resolutionPreset) {
     case FLTResolutionPresetMax:
-      if ([_videoCaptureSession canSetSessionPreset:AVCaptureSessionPresetPhoto]) {
-        _videoCaptureSession.sessionPreset = AVCaptureSessionPresetPhoto;
-        _previewSize = CGSizeMake(4032, 3024);
-        break;
+      {
+          AVCaptureDeviceFormat *bestFormat = [self getHighestResolutionFormatFor:_captureDevice];
+          if ( bestFormat ) {
+              _videoCaptureSession.sessionPreset = AVCaptureSessionPresetInputPriority;
+              if ( [_captureDevice lockForConfiguration:NULL] == YES ) {
+                  _captureDevice.activeFormat = bestFormat;
+                  [_captureDevice unlockForConfiguration];
+                  _previewSize =
+                  CGSizeMake(_captureDevice.activeFormat.highResolutionStillImageDimensions.width,
+                             _captureDevice.activeFormat.highResolutionStillImageDimensions.height);
+                  break;
+              }
+          }
       }
       if ([_videoCaptureSession canSetSessionPreset:AVCaptureSessionPreset3840x2160]) {
         _videoCaptureSession.sessionPreset = AVCaptureSessionPreset3840x2160;
@@ -405,6 +417,22 @@ - (void)setCaptureSessionPreset:(FLTResolutionPreset)resolutionPreset {
   _audioCaptureSession.sessionPreset = _videoCaptureSession.sessionPreset;
 }
 
+- (AVCaptureDeviceFormat *)getHighestResolutionFormatFor:(AVCaptureDevice*)captureDevice {
+    AVCaptureDeviceFormat *bestFormat = nil;
+    NSUInteger maxPixelCount = 0;
+    for ( AVCaptureDeviceFormat *format in [_captureDevice formats] ) {
+        CMVideoDimensions res = CMVideoFormatDescriptionGetDimensions(format.formatDescription);
+        NSUInteger height = res.height;
+        NSUInteger width = res.width;
+        NSUInteger pixelCount = height * width;
+        if ( pixelCount > maxPixelCount ) {
+          maxPixelCount = pixelCount;
+          bestFormat = format;
+        }
+    }
+    return bestFormat;
+}
+
 - (void)captureOutput:(AVCaptureOutput *)output
     didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
            fromConnection:(AVCaptureConnection *)connection {