Realization Of Speech Compression Algorithms Based On OMAP5912 Platform

With the rapid development of information and communication technology, the bandwidth efficiency and speech quality are becoming two outstanding issues. Speech coding plays a significant role in solving these issues. Particularly the low-bit-rate and high-quality speech coding algorithms, they can provide a variety of high-quality multimedia communication services in the circumstance of limited bandwidth. G.729 which is based on conjugate structure algebraic-code-excited-linear-prediction (CS-ACELP) issued by ITU-T is an excellent protocol among them. While G.729A is the reduced-complexity version of 8kbit/s speech coding algorithm based on G.729. The algorithm structure of G.729A is the same as that of G.729 and the bitstream of G.729A is interoperable with that of G.729. The speech quality produced by G.729A is equivalent to that of 32kbits/s ADPCM for most operating conditions, meeting the requirements of long-distance telephone.To realize the low-bit-rate and high-quality speech communications based on OMAP5912, this paper focuses on the G.729A speech coding standards, and makes a deep research on the hardware architecture and performance characteristics of OMAP5912. Based on these studies, this paper presents the implementation and the optimization of speech coding algorithms of G.729A on CCStudio2.21. The key algorithms in G.729A are used, including encoding and decoding. In order to improve coding speed and DSP operating efficiency, and reduce data storage space, a lot of methods are used such as the compiler level, C language level, algorithm level, and other aspects of speech coding procedures in the optimization based on the OMAP5912 platform. Finally, with the mechanism of DSP Gateway, it is achieved that the data exchange and real-time speech transmission based on the DSP and ARM dual-core processor.The experiments show that the speech coding algorithms achieve the effect of compression. And it meets the requirements of real-time communication, stable work and high-quality speech. G.729A occupies very little system resources, so it provides a guarantee to realize other functions such as image coding, system scheduling and data transmission in multimedia terminals.