| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method and apparatus for using coding scheme selection patterns in a predictive speech coder to reduce sensitivity to frame error conditions. <P>SOLUTION: The apparatus includes a speech coder configured to select from among various predictive coding modes. After a predefined number of speech frames have been predictively coded, the speech coder codes one frame with a nonpredictive coding mode or a mildly predictive coding mode. The predefined number of frames can be determined in advance from the subjective standpoint of a listener. The predefined number of frames may be varied periodically. An average coding bit rate can be maintained for the speech coder by ensuring that an averaged coding bit rate is maintained for each successive pattern, or group, of predictively coded speech frames including at least one nonpredictively coded or mildly predictively coded speech frame. <P>COPYRIGHT: (C)2012,JPO&INPIT |
