跳到主要內容

臺灣博碩士論文加值系統

(54.225.48.56) 您好!臺灣時間:2022/01/19 22:12
字體大小: 字級放大   字級縮小   預設字形  
回查詢結果 :::

詳目顯示

: 
twitterline
研究生:李俊毅
研究生(外文):Chun-Yi Lee
論文名稱:基於一個線性R-D模型的快速音訊位元分配技術
論文名稱(外文):A Fast Audio Bit Allocation Technique based on A Linear R-D Model
指導教授:蔣迪豪
指導教授(外文):Tihao Chiang
學位類別:碩士
校院名稱:國立交通大學
系所名稱:電子工程系
學門:工程學門
學類:電資工程學類
論文種類:學術論文
論文出版年:2002
畢業學年度:90
語文別:英文
論文頁數:58
中文關鍵詞:音訊編碼快速演算法位元分配線性
外文關鍵詞:audioencodefast algorithmbit allocationlinearmp3MPEG
相關次數:
  • 被引用被引用:0
  • 點閱點閱:129
  • 評分評分:
  • 下載下載:10
  • 收藏至我的研究室書目清單書目收藏:1
MPEG-1 Layer III 音訊編碼方式是目前網際網路上最被廣泛使用的數位音訊格式,然而由於其編碼器的複雜性較其他層次(Layer)高,且其位元分配模組在整體運算時間中,佔有很大的比例,因此本篇論文利用一個線性模型提出一個快速的位元分配技術,在Rate Control Loop中,大幅地減少迴圈運算次數;而在Distortion Control Loop中,利用估測量化誤差的技術,以改良的NMR(Noise-to-Masking Ratio)平行法,運用單次迴圈計算出所要的scalefactors。我們所提出的位元分配技術和目前網際網路上知名的MP3編碼軟體【LAME】比較,約有五倍左右的加速。在客觀的壓縮音訊品質測量中,我們採用了三種方式來評比,分別是整體的失真頻帶(scalefactor bands)數、平均的整體NMR和客觀差異分數(Objective difference grade) [6]。我們的實驗結果顯示出我們所提出的理論能有效顯著地增加編碼速度且仍可維持一定的音訊品質而無明顯的失真發生。

The MPEG-1 Layer III audio coding is most widespread digital audio format on the Internet. Its encoder is more complicated than the other layers in the MPEG-1 audio specification, where the bit allocation constitutes significant part of the total computational load. This thesis describes a fast bit allocation technique using a novel linear model to compute the bitrate and the global gain of the inner loop (rate control loop) for the classic MP3 bit allocation problem. Estimated quantization noise is approximated with a binomial expansion for the adjustment of the scalefactors. This procedure reduces the outer loop iterations (distortion control loop) to one loop. Our bit allocation technique is about five times faster compared to the well-known LAME MP3 encoder. Based on the objective quality measure, total number of distorted bands, average total noise-to-masking ratio (NMR), and objective difference grade [6], our experimental results show that there is significant improvement in speedup of the encoding process without noticeable audio quality degradation.

中文摘要 i
英文摘要 ii
誌謝 iii
CONTENTS iv
LIST OF FIGURES vi
LIST OF TABLES vii
CHAPTER 1. INTRODUCTION 1
1.1 MOTIVATION 1
1.2 BASIC IDEA OF MPEG-1 AUDIO BIT ALLOCATION 2
1.3 ORGANIZATION 3
CHAPTER 2. MPEG-1/AUDIO LAYER III CODING 5
2.1 HISTORY 5
2.2 MAJOR CODING MODULES 6
2.2.1 Hybrid Filter Bank 7
2.2.2 Pre-Echo Control 8
2.2.3 Non-uniform Quantization 9
2.2.4 Huffman Coding 11
2.2.5 Noise Allocation 12
2.3 THE ITERATION LOOPS OF MPEG-1/AUDIO LAYER III 12
2.3.1 ISO/MPEG Specification Bit Allocation Algorithm 13
2.3.2 LAME Bit Allocation Algorithm 15
2.3.3 Related Noise Shaping for MPEG/Audio 16
2.4 PARALLEL ALGORITHM BASED ON ESTIMATED NOISE 17
2.4.1 Noise Estimation 17
2.4.2 Parallel Bit Allocation Algorithm 19
2.5 SUMMARY OF RELATED BIT ALLOCATION ALGORITHMS 20
CHAPTER 3. NEW BIT ALLOCATION MODEL 22
3.1 MODIFIED DISTORTION CONTROL ALGORITHM 22
3.1.1 Modified Noise Estimation 23
3.1.2 Weighted Importance for Different Bands 27
3.2 FAST RATE CONTROL ALGORITHM 30
3.2.1 Statistics of Quantization 30
3.2.2 A Linear Model for Rate Control Algorithm 31
3.3 SUMMARY OF PROPOSED BIT ALLOCATION ALGORITHM 34
CHAPTER 4. EXPERIMENTAL RESULTS 36
4.1 EXPERIMENT ENVIRONMENTS 36
4.1.1 Algorithm Combinations 37
4.1.2 Experiment Parameters 37
4.2 RESULTS AND REMARKS 38
4.2.1 Noise Estimation 38
4.2.2 Performance Comparisons 39
4.2.3 Objective Evaluation 40
4.3 SUMMARY OF THE EXPERIMENTAL RESULTS 43
CHAPTER 5. CONCLUSION 45
5.1 INNOVATIONS 45
5.2 FUTURE WORKS 46
BIBLIOGRAPHY 47
APPENDIX A 49
簡歷 50

[1] ISO/IEC IS 11172-3, “Coding of moving pictures and associated audio for digital storage media up to about 1.5 Mbit/s — part3: audio, ” 1992.
[2] http://www.mp3dev.org/mp3/
[3] Davis Pan, “A tutorial on MPEG/Audio Compression,” IEEE Multimedia, summer 1995, pp.60-74
[4] Painter T. and Spanias A., “Perceptual coding of digital audio,” in Proc. of the IEEE, vol. 88, pp.451-515, April. 2000
[5] K. R. Rao and J. J. Hwang, “Techniques and Standards for Image, Video, and Audio Coding”, Chapter 10, Prentice-Hall
[6] Draft ITU-T Recommendation BS.1387: “Method for objective measurements of perceived audio quality,” July. 2001.
[7] K. Brandenburg and G. Stoll, “ISO-MPEG-1 audio: a generic standard for coding of high-quality digital audio, ” J. Audio Eng. Soc., vol. 42, pp.780-792, Oct. 1994.
[8] K.-T. Fung, Y.-L. Chan, and W.-C. Siu, “A fast bit allocation algorithm for MPEG audio encoder, ” in Proc. of International Symposium on Intelligent Multimedia, Video and Speech Processing, 2001, pp. 5—8.
[9] C. Liu, C. Chen, W. Lee, and S. Lee, “A fast bit allocation method for MPEG layer III, ” in Proc. of ICCE’99, 1999, pp. 22-23.
[10] Xiang Wei, Martyn J. Shaw, and Martin R. Varley, “Optimum bit allocation and decomposition for high quality audio coding,” in Proc. of ICASSP’97, 1997, pp.315-318
[11] Hossein Najafzadeh, and Peter Kabal, “Perceptual bit allocation for low rate coding of narrowband audio,” in Proc. of ICASSP’00, 2000, pp.893-896

QRCODE
 
 
 
 
 
                                                                                                                                                                                                                                                                                                                                                                                                               
第一頁 上一頁 下一頁 最後一頁 top