Research And Implementation Of Video Intercom System Based On WebRTC

As people’s living standards continue to improve and demand for life and living is also rising. People pay more and more attention on the safety and convenience of the community, video intercom system has gradually become intelligent terminal equipment, it required to meet people wisdom of life.Traditional video intercom of single function, multimedia function is poor, especially the voice quality is not high, there are echoes, distortion, etc. In this paper, the Web Real-Time Communication technology is applied to the video intercom, and design a video intercom system based on WebRTC. The main work includes:Analyze the WebRTC technology architecture, research the working principle of three modules, including audio engine, video engine and network transmission module. Aiming at the problem of echo in video intercom system, analysis and simulation for LMS, NLMS, RLS, PNLMS these types of echo cancellation algorithm. Propose improved algorithm based on the original algorithm, and carry on the simulation and analysis. Finally, the improved algorithm is transplanted into the WebRTC. We completed the construction of the video intercom system embedded hardware platform, mainly including hardware circuit design and PCB design of the door machine and Smart base. The door machine with high integration of A20 processor as the core, carry the Android operating system. The processor is based on dual ARM architecture (A7 CPU architecture, can very good support Android4.2 system, including its multimedia processing ability. Smart base adopts TI CC2530 as the processor, which is based on the ZigBee wireless solution chip, this also provides a good space for us to develop smart home late expansion. To participate in the door machine client software design, including audio and video module software, control module software, cancel and echo algorithm for software implementation.Finally, we tested the entire video intercom system functionality and performance, the key is to the door machine voice performance test. Test results show that the system image and voice quality has reached the design requirements. The video intercom system performance and multimedia processing capabilities is good. It has good practical application value.