[发明专利]从带宽有限音频信号生成带宽扩展信号的设备和方法

说明书

技术领域

本发明涉及音频信号处理，具体涉及用于从带宽有限音频信号生成带宽扩展信号的设备和方法。

背景技术

音频信号的存储或传输常常受到严格的比特率约束的影响。过去，当仅极低的比特率可用时，编码者被迫大幅度地减少要传送的音频带宽。现在，现代音频编解码器可以通过使用带宽扩展(BWE)方法来对宽带信号进行编码，这些带宽扩展方法如下所述：M.Dietz,L.Liljeryd,K. and O.Kunz,“Spectral Band Replication,a novel approach in audio coding,”in 112th AES Convention,Munich,May 2002；S.Meltzer,R. and F.Henn,“SBR enhanced audio codecs for digital broadcasting such as“Digital Radio Mondiale”(DRM),”in 112th AES Convention,Munich,May 2002；T.Ziegler,A.Ehret,P.Ekstrand and M.Lutzky,“Enhancing mp3with SBR:Features and Capabilities of the new mp3PRO Algorithm,”in 112th AES Convention,Munich,May 2002；International Standard ISO/IEC 14496-3:2001/FPDAM 1,“Bandwidth Extension,”ISO/IEC,2002.Speech bandwidth extension method and apparatus,Vasu Iyengar et al；E.Larsen,R.M.Aarts,and M.Danessis.Efficient high-frequency bandwidth extension of music and speech.In AES 112th Convention,Munich,Germany,May 2002；R.M.Aarts,E.Larsen,and O.Ouweltjes.A unified approach to low-and high frequency bandwidth extension.In AES 115th Convention,New York,USA,October 2003；K. A Robust Wideband Enhancement for Narrowband Speech Signal.Research Report,Helsinki University of Technology,Laboratory of Acoustics and Audio Signal Processing,2001；E.Larsen and R.M.Aarts.Audio Bandwidth Extension-Application to psychoacoustics,Signal Processing and Loudspeaker Design.John Wiley&Sons,Ltd,2004；E.Larsen,R.M.Aarts,and M.Danessis.Efficient high-frequency bandwidth extension of music and speech.In AES 112th Convention,Munich,Germany,May 2002；J.Makhoul.Spectral Analysis of Speech by Linear Prediction.IEEE Transactions on Audio and Electroacoustics,AU-21(3),June 1973；United States Patent Application08/951,029,Ohmori,et al.,Audio band width extending system and method；and United States Patent 6895375,Malah,D&Cox,R.V.:System for bandwidth extension of Narrow-band speech.这些算法依赖于高频成分(HF)的参数表现，该高频内容借助于移项进入高频频谱区(“修补”)和参数驱动的后处理的应用而从解码信号的低频部分(LF)生成。该低频部分使用任何音频或语音编码器来编码。例如，带宽扩展方法如下所述：M.Dietz,L.Liljeryd,K. and O.Kunz,“Spectral Band Replication,a novel approach in audio coding,”in 112th AES Convention,Munich,May 2002；S.Meltzer,R. and F.Henn,“SBR enhanced audio codecs for digital broadcasting such as“Digital Radio Mondiale”(DRM),”in 112th AES Convention,Munich,May 2002；T.Ziegler,A.Ehret,P.Ekstrand and M.Lutzky,“Enhancing mp3with SBR:Features and Capabilities of the new mp3PRO Algorithm,”in 112th AES Convention,Munich,May 2002；and International Standard ISO/IEC14496-3:2001/FPDAM 1,“Bandwidth Extension,”ISO/IEC,2002。由Vasu Iyengar等人所提出的语音带宽扩展方法和设备依赖于单边带调制(SSB)，其也常被称为“复制”方法，用于生成多重HF修补。