Research And Implementation Of Low Delay Wideband Audio Coding Algorithms

As many low delay high efficient perceptual audio coding algorithms, a newly designed audio coding algorithm - LDX is introduced in the thesis. This low delay and wideband audio coding scheme utilizes several modified processing blocks, such as perfect psycho-acoustic model, frequency residual processing, stereo audio processing, high efficient Huffman coding and so on. As a result, it is able to provide high quality, low delay and low bit rate audio coding methods for real-time audio and multimedia communications and other related applications.This thesis illustrates how to implement the proposed low delay and high quality audio coding algorithm with the TI DM642 DSP platform, and discusses the way to optimize the code so as to run in real time on these DSPs. Firstly, this thesis discusses some of perceptual audio coding algorithms and focuses on LDX, then presents the method of fixed-point implementation of the original floating-point source code, the way to port the fixed-point algorithm to TI DM642 DSP is also addressed in the thesis. After that, the fixed-point code is optimized on the DSP to achieve the performance good enough for real-time implementation.Complete test and evaluation results have proved that, the designed audio coding algorithm has a good audio coding quality with reasonable low delay. It can be optimized on some popular DSP to provide the possibility for practical applications in audio and multimedia communication systems.