博碩士論文 975203024 詳細資訊


姓名 童閏煜(Run-yu Tong)  查詢紙本館藏   畢業系所 通訊工程學系
論文名稱 參數立體音訊編碼之低複雜解碼方法
(Low Complexity Decoding in Parametric Stereo Audio Coding Scheme)
檔案 [Endnote RIS 格式]    [Bibtex 格式]    [檢視]  [下載]
  1. 本電子論文使用權限為同意立即開放。
  2. 已達開放權限電子全文僅授權使用者為學術研究之目的,進行個人非營利性質之檢索、閱讀、列印。
  3. 請遵守中華民國著作權法之相關規定,切勿任意重製、散佈、改作、轉貼、播送,以免觸法。

摘要(中) 參數立體聲 (Parametric Stereo, PS) 音訊編碼為2004年在ISO/MPEG 制定的HE-AAC v2標準下定義的一音訊編解碼物件。傳統音訊編碼標準MP3 (MPEG-1 Layer 3)、AAC (Advanced Audio Coding)的壓縮技術主要利用聲響心理模型 (Psycoaustic Model)、遮蔽效應(Masking Effect)來提高資料壓縮率,編碼過程仍以個別聲道獨立處理。PS則利用聲道間音訊的特徵關係,可節省將近一半的資料量,使傳統音訊利於以更低位元率在網路傳輸或儲存。
由於傳統PS解碼端複雜度比編碼端複雜度高出幾近兩倍,對使用者的可攜式裝置電力是一很大負擔。因此本論文提出一低複雜解碼的PS編解碼架構以降低解碼端複雜度為目標,先在編碼端利用對冗餘訊號抽取空間參數的方法傳送冗餘訊號參數,然後解碼端利用單聲道訊號重建冗餘訊號後,會進行偵測與評估其暫態訊號對重建冗餘訊號的影響,並使用能量補償演算法,對重建的冗餘訊號補償暫態訊號
所造成的失真。
最後使得解碼後的音訊品質客觀評分工具(Objective Difference Grade,ODG )分數上升約0.6分,並討論與MPEG-4 AAC結合的效能,其低複雜解碼的PS架構也利於對AAC在低位元率時傳輸。
摘要(英) The Parametric Stereo (PS) audio coding is an audio coding object of High Efficiency Advanced Audio Coding version 2 (HE-AAC v2) which was standardized by ISO/MPEG in 2004. Traditional audio codec, e.g. MP3 or AAC, utilize “Psycoaustic Model” and “Masking Effect” to achieve high compression efficiency. However, they mainly process the signal with single channel. Different from traditional audio codec, the PS audio coding incorporates the characteristics of two channels, to extract spatial parameters and to down-mixes stereo signals into a mono signal. The PS can save almost half data size which provides great help in storage and transmission.
Nevertheless, the complexity of PS decoder is nearly twice larger than that of PS encoder, which causes a serious problem in implementing PS on portable devices. Therefore, this thesis proposes a modified PS coding scheme to reduce the complexity of decoder. The encoder extracts and transmits the additional residual parameters from the residual signal and the mono signal. On the contrary, the decoder reconstructs the residual signal by the mono signal and the transmitted residual parameters. In addition, we detect the existence of transient signal and measure the artifact of reconstructed residual signal. Finally, “Energy compesated algorithm” is proposed to reduce the artifact produced by the transient signal.
The proposed scheme can improve the Objective Difference Grade (ODG) of audio quality measurement “EAQUAL” with 0.6 score. Combining with audio coder AAC, the modified PS coding scheme still maintains a good performance at low coding bitrates.
關鍵字(中) ★ 空間音訊編碼
★ 參數立體聲
★ 空間參數
★ 冗餘訊號編碼
★ 解相關濾波器
關鍵字(英) ★ residual coding
★ decorrelation filter
★ spatial parameter
★ spatial audio coding
★ Parametric Stereo
論文目次 摘 要 I
Abstract II
誌 謝 III
目 錄 IV
附圖索引                VI
附表索引             VIII
第一章 緒論                1
1.1 研究背景                1
1.2 研究動機                2
1.3 論文架構 3
第二章 空間聽覺特徵與參數立體聲編解碼架構 4
2.1 雙耳聽覺空間特徵參數      4
2.1.1 單音源音場:方向角定位特徵參數 5
2.1.2 單音源音場:相似性特徵參數 7
2.1.3 雙音源音場 8
2.2 參數立體聲編碼架構 10
2.2.1 時域/頻域分析 10
2.2.2 特徵參數抽取及降混音 14
2.3 參數立體聲解碼架構 17
2.3.1 解相關濾波器 17
2.3.2 空間音場合成 21
2.3.3 複雜度分析與軟體實作考量 24
2.4 冗餘訊號編解 35
第三章 參數立體音訊低複雜解碼方法 39
3.1 系統架構簡介 39
3.2 低複雜冗餘訊號重建 41
3.2.1冗餘訊號特徵參數 41
3.2.2冗餘訊號重建係數 42
3.3 暫態訊號能量補償 45
3.3.1暫態訊號內插參數失真 45
3.3.2暫態訊號能量補償演算法 49
第四章 實驗結果與討論 52
4.1 客觀音訊品質評量工具 52
4.2 複雜度-位元率-音訊品質探討 54
4.3 結合AAC編碼位元率與品質表現 74
第五章 結論與未來工作       80
參考文獻
參考文獻 [1] Johnston and Ferreira, “Sum-Difference Stereo Transform Coding, ” Proc. ICASSP, pp.569- 571, May 1992
[2] Chi-Min Liu, Wen-Chieh Lee, and Yo-Hua Hsiao, “M/S coding based on allocation entropy, ” Proc. of the 6th Int. Conference on Digital Audio Effects, London, UK, Sep. 11~18, 2003.
[3] Lord Rayleigh (J.W. Strutt), “On our perception of sound direction,”
Philosophical Magazine, 13:214–232, 1907.
[4] C. Faller, “Parametric coding of spatial audio,” Proc. of the 7th International Conference on Digital Audio Effects (DAFx’04), Naples, Italy, October 5-8, 2004.
[5] ISO/IEC JTC1/SC29/WG11, “Text of ISO/IEC 14496-3:2001/FPDAM2 (parametric coding for high quality audio),” ISO/IEC JTC1/SC29/WG11 N5713, July 2003.
[6] E. Schuijers, J. Breebaart, H. Purnhagen, and J. Engdeg˙ard, “Low complexity parametric stereo coding,” in Proc. 116th AES Convention, Berlin, Germany, May 2004.
[7] J. Hall and M. Fernandes, “The role of monaural frequency selectivity in binaural analysis,” in J. Acoust. Soc. Amer., 1984, vol. 76, pp. 435 – 439.
[8] J. Engdegard, H. Purnhagen, J. Roden, and L. Liljeryd, “Sythetic ambience in parametric stereo coding,” in Proc. 116th AES Convention, Berlin, Germany, May 2004, pp.1-12.
[9] M. R. Schroeder and B. F. Logan, “Colorless Artificial Reverberation”, J. Audio Eng. Soc., vol. 9, no. 3, pp. 192-197, July 1961.
[10] J. Breebaart, S. van de Par, A. Kohlrausch, and E. Schuijers, “High-quality parametric spatial audio coding at low bitrates,” in Proc. 116th AES Convention, Berlin, Germany, May 2004.
[11] R. Irwan and R. M. Aarts, “Two-to-five channel sound processing,” Journal of the Audio Engineering Society, vol. 50, no. 11, pp. 914–926, 2002.
[12] T.C. Li, and P.C. Chang, “Spatial characteristic based scalable audio coding structure, “ in Proc. of National Symposium on Tele- communications (NST), Taipei, Taiwan, pp. 452-456, Dec. 2009.
[13] J. Breebaart, S. van de Par, A. Kohlrausch, and E. Schuijers “Parametric coding of stereo audio”, EURASIP Journal, Applied Signal Processing 9:1305-1322, 2005.
[14] J. Breebaart and C. Faller, Spatial Audio Processing, ed.1,WILEY, 2007,p82-84
[15] ITU-R Recommendation BS.1387, Method for Objective Measurements of Perceived Audio Quality, Dec. 1998.
指導教授 張寶基(Pao-chi Chang) 審核日期 2010-7-26
推文 facebook   plurk   twitter   funp   google   live   udn   HD   myshare   reddit   netvibes   friend   youpush   delicious   baidu   

若有論文相關問題,請聯絡國立中央大學圖書館推廣服務組 TEL:(03)422-7151轉57407,或E-mail聯絡