An Efficient Implementation of MP3 and MPEG-4 AAC Decoder on SCREAM DSP-16

• Main Authors: Wen-jie Wu, 鄔文傑
• Other Authors: Wen Yu Su
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/45112002790267070594

碩士 === 國立成功大學 === 資訊工程學系碩博士班 === 95 === MP3(MPEG-1/Audio Layer 3)and MPEG-4 Advanced Audio Coding (AAC) is the multimedia audio compression standard defined by ISO/IEC MPEG (Moving Picture Expert Group), and it provides an outstanding coding efficiency. Now, MP3 is the most popular audio compression codec around the world.The basic structure of MPEG-4 AAC is the same as that of MPEG-2 AAC, but it has many new tools to improve its coding efficiency. For example, this thesis will introduce MPEG-1 Layer 3 and MPEG-2 AAC, then selects the implementation of MPEG-4 AAC Low Complexity Profile. There is wide demand for audio decoder built around embedded systems. In the most case, this kind of consumer electronics use a Digital Signal Processor to speed up the computation essential to decoder. SCREAM DSP-16 is a DSP based on Analog Device DSP 2191 instructions, and is developed by Scream LAB of National Cheng-Kung University. In this thesis, several techniques are proposed to implement MP3 decoder and MPEG-4 AAC decoder on SCREAM DSP-16. Computation complexity and how to use limited memory space are the most difficult problem we meet. In this thesis, we rewrite our source code in assembly language to speed up and use some technique to improve memory utilization. Finally, the speed of the MP3 decoder and MPEG-4 AAC decoder on our SCREAM DSP-16 implementation can achieve real time operation.