Research On Audio Codec Algorithm And DSP Implementation

The 21st century is a digital era; all data will be represented in digital format. So, many audio compression codec algorithms have been emerged, and the MPEG family are representative.With the development of integrated circuit technology and to circuits scale, Digital Signal Processor (DSP) has been advanced enormously in many fields, such as manufacturing process, architecture. With the development of technology and the increment of capability/price, DSP has been widely used for digital signal processing applications in the fields of communication, control, multimedia and so on. Multimedia applications also greatly promote the development of DSP. Among those, middle-low end DSP is specially suitable to the audio codec fields by its flexibility and good cost-performance result.On the base of a DSP processor—MD16, which is developed by the Department of Information Science and Electronic Engineering in Zhejiang University, a hardware/software co-designed evaluating and application platform for DSP is proposed. Using reconfigurable IP module and bus-based method, Reconfigurable and reusable hardware platform was realized. Using the platform the function testing and the performance evaluating to the MD16 processor was implemented. As the same time, application research works faced the audio codecs are also carried on.MPEG1 Layer 3 was the present most popular music form, through carrying on a series of optimizations to the MP3 decoding procedure, we proposed the design methods that software/hardware co-optimized based on the DSP characteristic. By the methods , we turned the procedure to satisfy the MD16's hardware restraint, and greatly reduced the MIPs. Through this work, we can analyze the performance of MD16 processor. On the other hand, the realization of MP3 decode provides a Audio player realization plan based on MD16.AAC codec is the important components of MPEG-2 and -4 audio standards. In this article, the different audio codecs in MPEG are compared and the AAC codec algorithms is detailed analysed. Though the analysis, simplify, fixed-point processing and the modification faced the characteristics of MD16 to the AAC decode procedure, the AAC LC decode processing is realized based on MD16.