| G.723.1语音编码算法闭环基音搜索的低复杂度算法 |
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| 引用本文： | 张春茂,唐昆,崔慧娟,杜文,李敬. G.723.1语音编码算法闭环基音搜索的低复杂度算法[J]. 计算机工程与应用, 2003, 39(29): 78-79,95 |
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| 作者姓名： | 张春茂 唐昆 崔慧娟 杜文 李敬 |
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| 作者单位： | 清华大学电子工程系微波与数字通信国家重点实验室,北京,100084 |
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| 基金项目： | 清华大学“985”项目 |
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| 摘 要： | 由于ITU-TG.723.1语音编码算法具有较高的算法复杂度,故而在应用与实现时受到了很多的限制。该文提出一种低复杂度闭环基音搜索算法,该算法仍以5阶基音预测器为基础,但在求取5个基音预测增益时不是采用原算法中对20维矢量码本进行搜索的方法,而是利用这个20维矢量组成一个Wiener-Hopf方程,并利用语音的短时平稳特性将该方程简化为一个Toeplitz线性代数方程组,方程组的解就是所求的基音预测增益。对该增益进行5维码本矢量量化,从而用5维矢量码本搜索代替了原来的20维矢量码本搜索。这样使闭环基音搜索部分的运算量降低了一半,语音质量只有略微下降,同时与G.723.1算法码流兼容。
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| 关 键 词： | G.723.1闭环基音搜索 基音预测器 算法复杂度 |
| 文章编号： | 1002-8331-(2003)29-0078-02 |
Low Complexity Algorithm of Close-Loop Pitch Search in G.723.1 Speech Codec |
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| Zhang Chunmao Tang Kun Cui Huijuan Du Wen Li Jing. Low Complexity Algorithm of Close-Loop Pitch Search in G.723.1 Speech Codec[J]. Computer Engineering and Applications, 2003, 39(29): 78-79,95 |
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| Authors: | Zhang Chunmao Tang Kun Cui Huijuan Du Wen Li Jing |
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| Abstract: | The application and implementation of ITU-T G.723.1speech codec is narrowly limited because of the high computational complexity.A new close-loop pitch search algorithm is presented in this paper.This algorithm is still based on the5-order pitch predictor.A Wiener-Hopf equation is established from the20-dimention vector which is used in the20-dimention codebook search in G.723.1algorithm.The equation solution is exactly the optimal pitch gain and is vector quantized with a5-dimention vector codebook.The synthesized speech quality degrades slightly and the code is compatible with the G.723.1algorithm while the computational complexity decreases near a half. |
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| Keywords: | G.723.1 close-loop pitch search pitch predictor computational complexity |
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