| 摘要 |
A speech coding apparatus includes driving excitation coding units, a comparator and a selecting unit. The driving excitation coding units encode in respective excitation modes a target signal to be encoded that is obtained from the input speech, and output coding distortions involved in the encoding. The comparator compares at least one of the coding distortions involved in the encoding with a fixed threshold value or with a threshold value that is determined in response to signal power of the input speech or with a threshold value that is determined in response to signal power of the target signal to be encoded. The selecting unit selects the excitation mode in response to the coding distortions and a compared result of the comparator. The speech coding apparatus can select a more favorable excitation that will provide better speech quality, thereby being able to improve the subjective quality of the speech it outputs by decoding resultant speech code.
|
