WebRTC Filter Example

WebRTCFilterExample.m

- (instancetype)initWithSource:(RTCVideoSource *)source {
    if (self = [super init]) {
        self.source = source;
       // CI ContextとColorSpaceを準備しておく
        self.context =
            [CIContext contextWithOptions:@{kCIContextUseSoftwareRenderer: @NO}];
        _colorSpace = CGColorSpaceCreateDeviceRGB();
        
        self.filters = @[].mutableCopy;
    }
    return self;
}

- (void)capturer:(RTCVideoCapturer *)capturer didCaptureVideoFrame:(RTCVideoFrame *)frame {
    
    // RTCVideoFrameから次のようにCVPixelBufferRefを取得できる
    CVPixelBufferRef pixelBuffer = [frame nativeHandle];
    
    // CVPixelBufferを編集する際のお決まりの処理
    CVPixelBufferLockBaseAddress(pixelBuffer, 0);
    
    CIImage *inputImage =
    [CIImage imageWithCVPixelBuffer:pixelBuffer
                            options:@{kCIImageColorSpace: (__bridge id)_colorSpace}];

    CIImage *outputImage = [self filterImage:inputImage];
    
    CVPixelBufferUnlockBaseAddress(pixelBuffer, 0);
    
    [self.context render:outputImage
         toCVPixelBuffer:pixelBuffer
                  bounds:[outputImage extent]
              colorSpace:_colorSpace];
  
    [self.source capturer:capturer didCaptureVideoFrame:frame];
}

- (CIImage *)filterImage:(CIImage *)inputImage { 
   　// あとはここで好きなようにCIFilter等を使ってフィルタ処理を書いていく
   return outputImage; 
}

- (void)dealloc {
    CGColorSpaceRelease(_colorSpace);
    self.source = nil;
    self.context = nil;
}

content _render took to much cpu