The Design And Implementation Of Video Transmission Evaluation System

Video transmission evaluation system is a system which evaluates the state and quality of the channel by measuring the variations of the signals after going through the channel. The basic measuring method is sending a standard video test signal to the video channel and measuring the parameters of the signals using test instrument at the end of the channel. Then through the changes of the signal, we can estimate the quality of the transmission channel. In practical applications, we ensure the quality of the video and transmission by testing and maintaining the working condition of TV devices, equipments and transmission lines.This paper describes the research and implementation of the video transmission evaluation system. It elaborates the whole system including the design and implementation of the software and hardware of the sender and receiver. It first introduces the TV system, the sense of the evaluation system and the development status of it. Then the system composition, the system function and the technical difficulties of realization is described. After introducing the definition and test method of the indicator, it presents the detailed description of the design and implementation of the whole system including the signal sender and receiver. We use the RTD1073 solution for the hardware of the sender. Refer to the signals which are send by TSG95 of the Tektronix company, we carry out the simulation using matlab and realize all the signals including the basic test signals, the ITS insertion test signals and subjective test signals. The sender can send composite signal, analog component video signal and HDMI signal. The receiver uses the C727 video capture card of AVerMedia. It captures the signals and calculates the indicators such as linear and non-linear distortion and SNR, then displays the results using friendly user-interface. For the non-linear characteristics of the system hardware, we take corresponding error correction method for sender and receiver respectively. By now, the testing system has completed, all the indictors can meet the requirements defined in the national standard, and it will be sent to CTTL for testing.