WebRTC code reading (11): video_coding module analysis, webrtcvideo_coding

WebRTC code reading (11): video_coding module analysis, webrtcvideo_coding
1. videoCodingModuleImpl: IncomingPacket, the package receiving and processing interfaces are provided. After the RTP parsing process, the callback: Decode is called to process the decoded interface VCMReceiveCallback. The callback interface VideoCodingModuleImpl is :: addVideoFrame sends the frame interface. The original video data I420 VCMPacketizationCallback is provided to the external callback interface after the encoding is complete.
2. videoCodingModuleImpl, module processing and control class, manages and maintains VideoSender and VideoReceiver, Video receiving and decoding processes, and CALLS DecodedImageCallback to decode VCMReceiver and video receiving packets, manage VCMJitterBuffer, video buffer, group sequence, out-of-order, jitter, and other processing VideoSender, specific video sending classes, VCMGenericEncoder Interface Class VCMGenericEncoder, and specific management encoding classes, maintain VideoEncoder VCMEncodedFrameCallback and implement the callback interface provided by the Encode module for processing VP8Encoder/VP8Decoder /..., encoding/decoding and encapsulation 3. main functions: Processing jitterbuffer, group compaction, jitter, and out-of-order processing; processing of encoding and decoding; managing video encoding and decoding processes