保证下面的方法会执行，在该方法中对beautyManager赋值。 ``` [RongRTCAVCapturer sharedInstance].videoSendBufferCallback = ^CMSampleBufferRef_Nullable(BOOLvalid, CMSampleBufferRef _Nullable sampleBuffer) { CMSampleBufferRef processedSampleBuffer = [weakSelf.chatGPUImageHandleronGPUFilterSource:sampleBuffer]; CVPixelBufferRef pixelBuffer = CMSampleBufferGetImageBuffer(processedSampleBuffer); [self.beautyManager processWithRoatePixelBuffer:pixelBuffer]; return processedSampleBuffer;  }; ```