[iOS] Robustness for video renderer. (flutter-webrtc#1751)

* Robustness for video renderer.

* update.

Author: cloudwebrtc

common/darwin/Classes/FlutterRTCMediaStream.m

@@ -65,35 +65,38 @@ - (RTCMediaConstraints*)defaultMediaStreamConstraints {
 
 
 - (NSArray<AVCaptureDevice*> *) captureDevices {
-    NSArray<AVCaptureDeviceType> *deviceTypes = @[
+    if (@available(iOS 13.0, macOS 10.15, macCatalyst 14.0, tvOS 17.0, *)) {
+        NSArray<AVCaptureDeviceType> *deviceTypes = @[
 #if TARGET_OS_IPHONE
-        AVCaptureDeviceTypeBuiltInTripleCamera,
-        AVCaptureDeviceTypeBuiltInDualCamera,
-        AVCaptureDeviceTypeBuiltInDualWideCamera,
-        AVCaptureDeviceTypeBuiltInWideAngleCamera,
-        AVCaptureDeviceTypeBuiltInTelephotoCamera,
-        AVCaptureDeviceTypeBuiltInUltraWideCamera,
+            AVCaptureDeviceTypeBuiltInTripleCamera,
+            AVCaptureDeviceTypeBuiltInDualCamera,
+            AVCaptureDeviceTypeBuiltInDualWideCamera,
+            AVCaptureDeviceTypeBuiltInWideAngleCamera,
+            AVCaptureDeviceTypeBuiltInTelephotoCamera,
+            AVCaptureDeviceTypeBuiltInUltraWideCamera,
 #else
-        AVCaptureDeviceTypeBuiltInWideAngleCamera,
+            AVCaptureDeviceTypeBuiltInWideAngleCamera,
 #endif
-    ];
-
+        ];
+        
 #if !defined(TARGET_OS_IPHONE)
-    if (@available(macOS 13.0, *)) {
-        deviceTypes = [deviceTypes arrayByAddingObject:AVCaptureDeviceTypeDeskViewCamera];
-    }
+        if (@available(macOS 13.0, *)) {
+            deviceTypes = [deviceTypes arrayByAddingObject:AVCaptureDeviceTypeDeskViewCamera];
+        }
 #endif
 
-    if (@available(iOS 17.0, macOS 14.0, tvOS 17.0, *)) {
-        deviceTypes = [deviceTypes arrayByAddingObjectsFromArray: @[
-            AVCaptureDeviceTypeContinuityCamera,
-            AVCaptureDeviceTypeExternal,
-        ]];
-    }
+        if (@available(iOS 17.0, macOS 14.0, tvOS 17.0, *)) {
+            deviceTypes = [deviceTypes arrayByAddingObjectsFromArray: @[
+                AVCaptureDeviceTypeContinuityCamera,
+                AVCaptureDeviceTypeExternal,
+            ]];
+        }
 
-    return [AVCaptureDeviceDiscoverySession discoverySessionWithDeviceTypes:deviceTypes
-                                                                     mediaType:AVMediaTypeVideo
-                                                                      position:AVCaptureDevicePositionUnspecified].devices;
+        return [AVCaptureDeviceDiscoverySession discoverySessionWithDeviceTypes:deviceTypes
+                                                                      mediaType:AVMediaTypeVideo
+                                                                       position:AVCaptureDevicePositionUnspecified].devices;
+    }
+    return @[];
 }
 
 /**

common/darwin/Classes/FlutterRTCVideoRenderer.m

@@ -25,6 +25,7 @@ @implementation FlutterRTCVideoRenderer {
 @synthesize textureId = _textureId;
 @synthesize registry = _registry;
 @synthesize eventSink = _eventSink;
+@synthesize videoTrack = _videoTrack;
 
 - (instancetype)initWithTextureRegistry:(id<FlutterTextureRegistry>)registry
                               messenger:(NSObject<FlutterBinaryMessenger>*)messenger {
@@ -75,13 +76,14 @@ - (void)dispose {
 
 - (void)setVideoTrack:(RTCVideoTrack*)videoTrack {
   RTCVideoTrack* oldValue = self.videoTrack;
-
   if (oldValue != videoTrack) {
+    os_unfair_lock_lock(&_lock);
+    _videoTrack = videoTrack;
+    os_unfair_lock_unlock(&_lock);
     _isFirstFrameRendered = false;
     if (oldValue) {
       [oldValue removeRenderer:self];
     }
-    _videoTrack = videoTrack;
     _frameSize = CGSizeZero;
     _renderSize = CGSizeZero;
     _rotation = -1;
@@ -192,6 +194,10 @@ - (void)copyI420ToCVPixelBuffer:(CVPixelBufferRef)outputPixelBuffer
 - (void)renderFrame:(RTCVideoFrame*)frame {
 
   os_unfair_lock_lock(&_lock);
+  if(_videoTrack == nil) {
+    os_unfair_lock_unlock(&_lock);
+    return;
+  }
   if(!_frameAvailable && _pixelBufferRef) {
     [self copyI420ToCVPixelBuffer:_pixelBufferRef withFrame:frame];
     if(_textureId != -1) {

common/darwin/Classes/FlutterWebRTCPlugin.h

@@ -49,8 +49,8 @@ typedef void (^CapturerStopHandler)(CompletionHandler _Nonnull handler);
 @property(nonatomic, strong) FlutterRTCFrameCapturer* _Nullable frameCapturer;
 @property(nonatomic, strong) AVAudioSessionPort _Nullable preferredInput;
 
-@property(nonatomic, strong) NSString *focusMode;
-@property(nonatomic, strong) NSString *exposureMode;
+@property(nonatomic, strong) NSString * _Nonnull focusMode;
+@property(nonatomic, strong) NSString * _Nonnull exposureMode;
 
 @property(nonatomic) BOOL _usingFrontCamera;
 @property(nonatomic) NSInteger _lastTargetWidth;

common/darwin/Classes/FlutterWebRTCPlugin.m

@@ -585,6 +585,10 @@ - (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
       for (RTCVideoTrack* track in stream.videoTracks) {
         [_localTracks removeObjectForKey:track.trackId];
         RTCVideoTrack* videoTrack = (RTCVideoTrack*)track;
+        FlutterRTCVideoRenderer *renderer = [self findRendererByTrackId:videoTrack.trackId];
+        if(renderer != nil) {
+          renderer.videoTrack = nil;
+        }
         CapturerStopHandler stopHandler = self.videoCapturerStopHandlers[videoTrack.trackId];
         if (stopHandler) {
           shouldCallResult = NO;
@@ -699,6 +703,10 @@ - (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
     if (audioTrack) {
       [self ensureAudioSession];
     }
+    FlutterRTCVideoRenderer *renderer = [self findRendererByTrackId:trackId];
+    if(renderer != nil) {
+      renderer.videoTrack = nil;
+    }
     result(nil);
   } else if ([@"restartIce" isEqualToString:call.method]) {
     NSDictionary* argsMap = call.arguments;
@@ -746,9 +754,11 @@ - (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
     NSDictionary* argsMap = call.arguments;
     NSNumber* textureId = argsMap[@"textureId"];
     FlutterRTCVideoRenderer* render = self.renders[textureId];
-    render.videoTrack = nil;
-    [render dispose];
-    [self.renders removeObjectForKey:textureId];
+    if(render != nil) {
+      render.videoTrack = nil;
+      [render dispose];
+      [self.renders removeObjectForKey:textureId];
+    }
     result(nil);
   } else if ([@"videoRendererSetSrcObject" isEqualToString:call.method]) {
     NSDictionary* argsMap = call.arguments;
@@ -826,8 +836,10 @@ - (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
       NSDictionary* argsMap = call.arguments;
       NSNumber* viewId = argsMap[@"viewId"];
       FlutterRTCVideoPlatformViewController* render = _platformViewFactory.renders[viewId];
-      render.videoTrack = nil;
-      [_platformViewFactory.renders removeObjectForKey:viewId];
+      if(render != nil) {
+        render.videoTrack = nil;
+        [_platformViewFactory.renders removeObjectForKey:viewId];
+      }
       result(nil);
     }
 #endif
@@ -2283,4 +2295,13 @@ - (NSDictionary*)transceiverToMap:(RTCRtpTransceiver*)transceiver {
   };
   return params;
 }
+
+- (FlutterRTCVideoRenderer *)findRendererByTrackId:(NSString *)trackId {
+    for (FlutterRTCVideoRenderer *renderer in self.renders.allValues) {
+        if (renderer.videoTrack != nil && [renderer.videoTrack.trackId isEqualToString:trackId]) {
+            return renderer;
+        }
+    }
+    return nil;
+}
 @end

ios/Classes/FlutterRTCVideoPlatformView.h

@@ -10,7 +10,7 @@
 
 - (void)renderFrame:(nullable RTC_OBJC_TYPE(RTCVideoFrame) *)frame;
 
-- (instancetype)initWithFrame:(CGRect)frame;
+- (instancetype _Nonnull)initWithFrame:(CGRect)frame;
 
 - (void)setSize:(CGSize)size;
 

ios/Classes/FlutterRTCVideoPlatformView.m

@@ -49,9 +49,13 @@ - (void)renderFrame:(nullable RTC_OBJC_TYPE(RTCVideoFrame) *)frame {
 
   CMSampleBufferRef sampleBuffer = [self sampleBufferFromPixelBuffer:pixelBuffer];
   if (sampleBuffer) {
-    if([_videoLayer requiresFlushToResumeDecoding]) {
-      [_videoLayer flushAndRemoveImage];
-    }
+      if (@available(iOS 14.0, *)) {
+          if([_videoLayer requiresFlushToResumeDecoding]) {
+              [_videoLayer flushAndRemoveImage];
+          }
+      } else {
+          // Fallback on earlier versions
+      }
     [_videoLayer enqueueSampleBuffer:sampleBuffer];
     CFRelease(sampleBuffer);
   }