Based On DM642 Platform Audio And Video Transmission System Research And Implementation

With the developments of multimedia technology, more and more extensive information is preferred currently. The most concerned one is how to conveniently get the multimedia information at any time and any places, such as audio and video data which should be treated seriously for us in the data acquisition, processing, and transmission. Presently, the data including audio and video transmission over the network is undoubtedly the most convenient and fast means. However, the data quantity of the original video and audio is too huge to be transmitted and stored conveniently. Therefore, the multimedia technology can only be developed quickly with the emergence of a variety of video and audio compression standards which are applied to solve the problems of transmission and storage. Applying the video compression standard of joint photographic experts group (JPEG) and audio compression standard G.723.1 in the system is one of the major content in the thesis.Digital signal Processing (DSP) devices play an important role in the filed of multimedia applications, in which DSP-based core codec is the key component. The DSP development in view of reference framework 5 (RF5) can usually maximize the code reuse and minimize the development duration. In this article, a general RF5-based developing process is briefly introduced. Based on the DM642 platform, the modules of audio and video collection, JPEG and G.723.1 en/decoding algorithm, network transmission, and video and audio playback are achieved and designed in detail. Meanwhile, both the real-time operating system DSP/BIOS and the network development kit (NDK), which are adopted for RF5, are introduced in the article, respectively. Furthermore, a secondary loader solution according to this platform is proposed, where the application program with more than on FLASH space is the major problem. Finally, the testing results and summary are provided, together with the future work.