Design And Implementation Of Multi-Channel Ultra-HD Real-Time Encoding System Based On Many-Core

With the popularity of video services and continuous development of intelligence terminal devices,our demand for the quality and the resolution of video service is continually improving,which puts forward higher demand on compression ratio of video and performance of processors.As a new generation video compression standard,compared with H.264/AVC,the bit rate of HEVC reduces about 50% under the same visual quality,which has a broad prospect.Due to the high operational complexity,it is hard to implement the UHD real-time HEVC encoder.With massive parallel operation capability,many-core processor is a suitable implementation platform of UHD HEVC encoder.This thesis implement a multi-channel UHD HEVC real-time coding system based on the multichip many-core processors platform,including the capture of multi-channel UHD video,packing,multiplexing and transmission after the video encoding.Due to the bitrate's drastic changes caused by multi-channel video and UHD HEVC video coding,an effective closed-loop rate-control mechanism which achieves the accurate control for encoder's output bitrate under the help of the scene change detection is proposed by this thesis.The system's end-to-end latency can be reduced through the buffer-control mechanism proposed by the thesis which make the system steady running with lower system latency.To solve the problem of unsynchronized clocks in the system,this thesis proposes a clock synchronization mechanism used to synchronize the local clocks of video source,encoder and decoder,based on the PCR of MPEG2-TS standard.In the end,this thesis successfully sets up a multi-channel real-time system,and presents the test results with several cases.The many-core platform adopted by this thesis can capture,encode and transmit four-channel HEVC UHD video streams simultaneously.