| 摘要 |
PURPOSE:To shorten a mean code length and to make a memory into a low- capacity by restricting the number of codes to be outputted per one sample based on a code string outputted just before when a difference value is not within an analysis coding range. CONSTITUTION:A code output restricting circuit 7 restricts the number of the codes to be outputted per one sample based on the size of an adjoining sound signal sampled by an A/D converter 1 and on the code outputted before a present sampling time. A coder 3 outputs the code to indicate the difference value of one or above per one sample and executes the coding of a variable length according to the number of the codes to be outputted per one sample restricted by the circuit 7. When the code to indicate the difference value coded by the coding part 3 is inputted to a decoder 121, the difference value of the adjoining sound signal is calculated based on the code, and decoded to a synthesized voice. Thus, the output of an excessive marker code can be eliminated, the mean code length can be shortened, and the memory can be made into the low-capacity. |
