| 摘要 |
PURPOSE: To provide a voice coding device by which good voice quality can be obtained without degrading voice quality by temporal variation for discriminating a mode even if a frame length is shortened to 5ms-10ms or less in order to make low delay. CONSTITUTION: A hearing sense weighing signal is inputted from an input terminal 2010 with a unit of a frame, and a spectrum parameter is inputted from an input terminal 2020. A feature quantity calculating circuit A 2030 calculates, for example, pitch prediction gain PG as feature quantity and outputs it. A feature quantity calculating circuit B 3040 calculates short time prediction gain SG as feature quantity and output it. A mode discriminating circuit 2050 compares an output value PG of the input terminal 2020 and an output value SG of the input terminal 2030 with plural threshold values previously decided in accordance with mode information of a frame of one frame before stored in a delay circuit 2060, performs mode discrimination, and outputs mode information. |
