发明名称 |
Audio coding and decoding methods and apparatuses and recording medium having recorded thereon programs for implementing them |
摘要 |
In the CELP coding system a low-order synthesis filter and a cascade-connected synthesis filter formed by a cascade connection of low- and high-order synthesis filters are provided, a synthesized acoustic signal is estimated in a mode decision part for an input acoustic signal, and the estimated synthesized acoustic signal is subjected to inverse filtering by an inverse filter corresponding to the low-order synthesis filter and an inverse filter corresponding to the cascade-connected synthesis filter to obtain residual signals. That one of the synthesis filters which corresponds to the residual signal of smaller power is selected by a switch, and a codebook is searched for indices which will minimize the error between the output synthesized acoustic signal by the selected synthesis filter and the input acoustic signal.
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申请公布号 |
US6810381(B1) |
申请公布日期 |
2004.10.26 |
申请号 |
US20000568810 |
申请日期 |
2000.05.11 |
申请人 |
NIPPON TELEGRAPH AND TELEPHONE CORPORATION |
发明人 |
SASAKI SHIGEAKI;MANO KAZUNORI;HAYASHI SHINJI |
分类号 |
G10L19/06;G10L19/14;G10L19/18;(IPC1-7):G10L19/00 |
主分类号 |
G10L19/06 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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