网络多媒体通信——语音编码技术研究
摘要
随着LAN、Intranet、Internet在全世界的迅猛发展，IP网络的性能逐步改善，基于IP网络的多媒体通信已经成为未来通信系统重要的研究和发展方向。语音编码作为多媒体通信的一个重要环节正受到人们的广泛关注。G．729A是国际电信联盟新颁布的编码速率为8kb／s的低速率语音压缩编码标准，它是基于IP网络的多媒体会议系统标准H．323可选的语音压缩编码标准之一。本文在对IP网络的特性及G．729A编解码算法进行分析后，提出了用软件来实现语音信号编解码的方案。本方案实现时采用Microsoft公司的新版本DirectX8.0中的DirectSound技术，实现了语音信号的捕获与回放；采用G．729A编解码算法实现了语音信号压缩编解码，并提出了相应的改进措施。系统还将编码和解码部分做成动态链接库，提高了系统处理效率。
With the development of LAN, Intranet and Internet and the improvement of IP network performance, the multimedia communication based on IP network has become an important research and development branch of the future communication system. As a basis of multimedia communication, speech coding becomes the focus of discussion. The G729A, a new issued speech compressed coding standard at 8kbit/s, is one of the optional coding standards of H.323, which is multimedia meeting system standard based on IP network.
With a view to IP character and G729A coding arithmetic, a speech codec scheme in software is presented in this paper. With the DirectSound technology, an important part of DirectX 8.0, the capturing and playback of speech is achieved. The compressed encoding of speech is implemented with G729A coding arithmetic, together with some relative measures mentioned in the paper. The software module of coding and decoding are linked dynamically to improve the system processing efficiency.
With the development of LAN, Intranet and Internet and the improvement of IP network performance, the multimedia communication based on IP network has become an important research and development branch of the future communication system. As a basis of multimedia communication, speech coding becomes the focus of discussion. The G729A, a new issued speech compressed coding standard at 8kbit/s, is one of the optional coding standards of H.323, which is multimedia meeting system standard based on IP network.
With a view to IP character and G729A coding arithmetic, a speech codec scheme in software is presented in this paper. With the DirectSound technology, an important part of DirectX 8.0, the capturing and playback of speech is achieved. The compressed encoding of speech is implemented with G729A coding arithmetic, together with some relative measures mentioned in the paper. The software module of coding and decoding are linked dynamically to improve the system processing efficiency.
引文
[1] ITU-T Rec. G729, Coding of speech at 8kbit/s using conjugate-structure algebraic-code-excited linear-prediction (CS-ACELP) (03/1996) .
[2] ITU-T Rec. G.729 Annex A, Coding of speech at 8kbit/s using conjugate-structure algebraic-code-excited linear-prediction (CS-ACELP) Annex A: Reduced complexity 8kbit/s CS-ACELP speech codec (11/1996) .
[3] Coding of speech at 8kbit/s using conjugate-structure algebraic-code-excited linear-prediction (CS-ACELP), Rec. Annex B: A silence compression scheme for G.729 optimized for terminals conforming to Recommendation V.70 (11/1996) .
[4] ITU-T Rec. H.323． Packet based multimedia Communication Systems. (02/1998) .
[5] MSDN Library-April 2001 中的 Platform SDK Document DirectX 8． 0． (02/2001)
[6] Daniele Rizzetto and Claudio Catania, Hewlett-Packard Laloratories. A Voice over IP Service Architecture for Integrated Communications. IEEE Network May/June 1999,pp.34-40．
[7] Tetsuya Shimamura, Hajime Kobayashi. Weighted Autocorrelation for Pitch Extraction of Noisy Speech. IEEE Transactions on Speech and Audio Processing. Vol.9, No.7, October 2001, pp.727-730．
[8] Francesco Beritelli. A Modified CS-ACELP Algorithm for Variable-Rate Speech Coding Robust in Noisy Environments. IEEE Signal Processing Letter, Vol.6, No.2, February 1999, pp.31-34．
[9] Redwan Salami, Claude Laflamme, Jean-Pierre Adoul. Design and Description of CS-ACELP: A Toll Quality 8kb/s Speech Coder. IEEE Transactions on Speech and Audio Processing. Vol.6, No.2, March 1998, pp.116-130．
[10] Thomas J. Kostas, Michael S.Borella, Ikhlaq Sidhu. Real-Time Voice Over Packet-Switched Networks. IEEE Networks. January/February 1998． pp. 18-27．
[11] Redwan Salami, Claude Laflamme, Bruno Bessette. ITU-T G729 Annex A: Reduced Complexity 8kb/s CS-ACELP Codec for Digital Simultaneous Voice and Data. IEEE Communications Magazine. September 1997, pp.56-63．
[12] Sehyeong Cho and Youngmee Shin, Electronics and Telecommunication Research Institute(ETRI). Multimedia Service Interworking over Heterogeneous Networking Environments. IEEE Networks. March/April 1999, pp.61-69．
[13] 郭梯云,杨家玮,李建东编著.数字移动通信.第一版.人民邮电出版社,1995
[14] 蒋林涛编著.多媒体通信网.第一版.人民邮电出版社.1999
[15]王华，叶爱亮，祁立学，曹凌云编著．Visual C++6.0 编程实例与技巧．第一版．机械工业出版社．2000
[16]钟玉琢主编．多媒体技术(高级)．第一版．清华大学出版社．1999
[17]张磊 王阿禅等编著．VoIP语音技术及应用．第一版．机械工业出版社．2000．
[18]杨行峻 迟惠生等编著．语音信号数字处理．第一版．电子工业出版社．1995
[19]毕厚杰．多媒体信息的传输与处理．第一版．人民邮电出版社．1999．
[20]糜正琨编著．IP网络电话技术．第一版．人民邮电出版社．2000
[21]马鸿飞，樊昌信，宋国乡．基于小波变换和音质模型的音频编码算法研究．电子学报．2000，vol．28，No．1，pp．26-29．
[22]徐忻．Internet中数字音频技术的应用．重庆邮电学院学报．Dec．1997，vol 9，No．4，pp．49-52．
[23]周熙，李佳云．局域网会议电视及其音频技术的研究．哈尔滨师范大学自然科学学报．1999年，vol．15，No．2，pp．61-65．
[24]王黎伟，汪礼勇，丁晓明．基于IP网的可视会议系统的语音通讯．数字通信．1999年第3期，pp．11-13．
[25]王汝言．多媒体通信的信息处理技术．数字通信．2000年第2期，pp．58-61．
[26]许丽红，阚海鹰，余小清．G．729 CS-ACELP语音编码算法的优化及其DSP实现．上海大学学报．2001年2月，vol．7，No．1，pp．13-17．
[27]张继东，杨震，李晓飞．ITU-T G．729 CS-ACELP语音编码系统的性能分析．南京邮电学院学报(自然科学版)．2000年12月，vol．20，No．4，pp．91-94．
[28]唐昆，崔慧娟，刘志勇，冯重熙．高质量4kbit／s FS-ACELP语音编码算法及性能．电子学报．1999年10月，vol．27，No．10，pp．22-26．
[2] ITU-T Rec. G.729 Annex A, Coding of speech at 8kbit/s using conjugate-structure algebraic-code-excited linear-prediction (CS-ACELP) Annex A: Reduced complexity 8kbit/s CS-ACELP speech codec (11/1996) .
[3] Coding of speech at 8kbit/s using conjugate-structure algebraic-code-excited linear-prediction (CS-ACELP), Rec. Annex B: A silence compression scheme for G.729 optimized for terminals conforming to Recommendation V.70 (11/1996) .
[4] ITU-T Rec. H.323． Packet based multimedia Communication Systems. (02/1998) .
[5] MSDN Library-April 2001 中的 Platform SDK Document DirectX 8． 0． (02/2001)
[6] Daniele Rizzetto and Claudio Catania, Hewlett-Packard Laloratories. A Voice over IP Service Architecture for Integrated Communications. IEEE Network May/June 1999,pp.34-40．
[7] Tetsuya Shimamura, Hajime Kobayashi. Weighted Autocorrelation for Pitch Extraction of Noisy Speech. IEEE Transactions on Speech and Audio Processing. Vol.9, No.7, October 2001, pp.727-730．
[8] Francesco Beritelli. A Modified CS-ACELP Algorithm for Variable-Rate Speech Coding Robust in Noisy Environments. IEEE Signal Processing Letter, Vol.6, No.2, February 1999, pp.31-34．
[9] Redwan Salami, Claude Laflamme, Jean-Pierre Adoul. Design and Description of CS-ACELP: A Toll Quality 8kb/s Speech Coder. IEEE Transactions on Speech and Audio Processing. Vol.6, No.2, March 1998, pp.116-130．
[10] Thomas J. Kostas, Michael S.Borella, Ikhlaq Sidhu. Real-Time Voice Over Packet-Switched Networks. IEEE Networks. January/February 1998． pp. 18-27．
[11] Redwan Salami, Claude Laflamme, Bruno Bessette. ITU-T G729 Annex A: Reduced Complexity 8kb/s CS-ACELP Codec for Digital Simultaneous Voice and Data. IEEE Communications Magazine. September 1997, pp.56-63．
[12] Sehyeong Cho and Youngmee Shin, Electronics and Telecommunication Research Institute(ETRI). Multimedia Service Interworking over Heterogeneous Networking Environments. IEEE Networks. March/April 1999, pp.61-69．
[13] 郭梯云,杨家玮,李建东编著.数字移动通信.第一版.人民邮电出版社,1995
[14] 蒋林涛编著.多媒体通信网.第一版.人民邮电出版社.1999
[15]王华，叶爱亮，祁立学，曹凌云编著．Visual C++6.0 编程实例与技巧．第一版．机械工业出版社．2000
[16]钟玉琢主编．多媒体技术(高级)．第一版．清华大学出版社．1999
[17]张磊 王阿禅等编著．VoIP语音技术及应用．第一版．机械工业出版社．2000．
[18]杨行峻 迟惠生等编著．语音信号数字处理．第一版．电子工业出版社．1995
[19]毕厚杰．多媒体信息的传输与处理．第一版．人民邮电出版社．1999．
[20]糜正琨编著．IP网络电话技术．第一版．人民邮电出版社．2000
[21]马鸿飞，樊昌信，宋国乡．基于小波变换和音质模型的音频编码算法研究．电子学报．2000，vol．28，No．1，pp．26-29．
[22]徐忻．Internet中数字音频技术的应用．重庆邮电学院学报．Dec．1997，vol 9，No．4，pp．49-52．
[23]周熙，李佳云．局域网会议电视及其音频技术的研究．哈尔滨师范大学自然科学学报．1999年，vol．15，No．2，pp．61-65．
[24]王黎伟，汪礼勇，丁晓明．基于IP网的可视会议系统的语音通讯．数字通信．1999年第3期，pp．11-13．
[25]王汝言．多媒体通信的信息处理技术．数字通信．2000年第2期，pp．58-61．
[26]许丽红，阚海鹰，余小清．G．729 CS-ACELP语音编码算法的优化及其DSP实现．上海大学学报．2001年2月，vol．7，No．1，pp．13-17．
[27]张继东，杨震，李晓飞．ITU-T G．729 CS-ACELP语音编码系统的性能分析．南京邮电学院学报(自然科学版)．2000年12月，vol．20，No．4，pp．91-94．
[28]唐昆，崔慧娟，刘志勇，冯重熙．高质量4kbit／s FS-ACELP语音编码算法及性能．电子学报．1999年10月，vol．27，No．10，pp．22-26．