Design and implementation of a real-time MPEG-II bit rate measure system

MPEG-II transport stream delivery over a network generally requires network jitters to be kept under ±500 nsec. When the MPEG packets are transmitted in other transport formats, such as ATM, the jitter problem may become difficult to manage. In this situation, the MPEG decoding process is often complicated due to MPEG-decoder buffer under-run and over-run, consequently creating video breakup or unsynchronized audio-visual playback. Thus, developing a test tool that can monitor MPEG-II bit rate on line is an important topic. This paper presents a simple but effective method to measure bit rate at the receiver end. This method uses an off-the-shelf MPEG de-multiplexer chip together with an embedded processor to govern the time-stamps embedded in the MPEG-II stream. The collected time stamps are further used to derive the bit rate. Furthermore, the jitters as measured by comparing local clocks against the received program clock reference values in embedded MPEG streams are also calculated. A hardware test environment is set up for experiment. The results shows the usefulness of this tool in deployment