Study On Metrics And Tests Of Video Streaming Performance

With the development of network technology, IPTV, mobile TV, Internet video the value-added services that related to the video streaming is arising significantly. It can be predicted that the network video market has great room for development in the future. Network video streaming is a kind of concrete use of video technology. However, video streaming data will produce a wide range of distortion during collection, compression, processing, transmission, recovery process. In order to reduce the bandwidth of data storage and transmission, video quality will be reduced in the quantization process. In the error channel (e.g. radio channel) transmission, the letter channel errors and data loss will increase the video distortion after decoded; in packet-switched networks (such as the Internet) transmission, access network congestion caused large data loss and delay, it also will increase the distortion.To make video streaming business such as IPTV has been running well, it must ensure network video quality to meet the requirement quality of service (QoS), as provide high-quality of video streaming experience (QoE). Therefore, we must provide a valid video streaming quality assessment method to what used to analyze system operation prior to encoding/decoding algorithm/format, also to monitor the quality of the video stream in the system run-time. In most applications, the end of the video quality is a measure of system performance, a key indicator of the merits. The video service system must be able to grasp the decline in the quality of the video stream, and through the necessary means to maintain and enhance. Therefore, it is essential to find an effective method to degree the amount of video stream quality.This paper is aimed to study on metrics and tests of video streaming performance during network transmission. The article outlined the concept of network video streaming, described some of the key technologies and network architectures in detail, classified and organized video streaming services on the quality of the names and business concepts, surveyed the quality of the video stream at home and abroad research progress, including the use of specific methods, the effect and characteristics of what is, which aspects should be improved and studied. Then, selected the most suitable for network video streaming performance indicators MDI and did the development and testing experimental. Considered PSNR and MDI indicators together, to improve MDI-based indicators methods, proposed an improved method based on the quality of the video itself and network effects on the quality of the video streaming, and it is verified by experiment that the new way of measuring MDI is superior to considering only target. Video streaming quality tests and analysis is very important to understand the operation of the network to provide better quality and network services for IPTV and other video streaming business services'development.The author is a graduate student primarily involved in the Beijing University of Posts and Communications Tests Technology Research Center of testing video streaming performance metrics. This paper is the period conclusion of the theory in graduate research and development experience, also a detailed description of the research project. The main aspects related to the following:1. Studied on video streaming transmission in networks, analyzed the composition of the network video system and its way of work. Described the video streaming technology and network features of video streaming, and analyzed various factors of the impact on video quality.2. Studied on existing subjective and objective video quality measurement method. Understand the current measurement methods, and the scope of each method, advantages and disadvantages of several existing methods to evaluate video quality metrics. MDI index mainly reflects the jitter and packet loss characteristics of the video streaming, is a simple and extensible standard, the most suitable for assessing the transmission network of video streaming and the quality of end-user experience.3. Selected MDI-based indicators to analyze the substance and designed the video streaming performance monitoring system for the package format of TS/RTP/UDP/IP to calculate the video streaming MLR: DF value. Build the test environment, through the designed system to measure indicators of MOS and MDI, then analyze the experimental results, prove the validity of testing methods.4. Studied on the injury reasons of video streaming transmitted in the network before, during and after three main stages, and quantify the relationship between the performances of video streaming and the damage factor. PSNR for the measure is based on the video stream itself, while the MDI index consider only the impact of the network, the paper proposes an improved MDI algorithm, considering both the video streaming itself and network conditions, the experiment verified the QoE effectiveness of the new method.