| 摘要 |
PURPOSE:To decode with high accuracy by transmitting an encoding data which represents a level of an input signal, together with a differential encoding signal, and correcting the cumulative distortion caused by error information of the differential encoding signal. CONSTITUTION:An audio input signal (a) is sampled by the AD converter 1 and is converted to a PCM signal of 12 bits. This 12 bit PCM signal is input to the shift register 2, and the upper rank 2 bits representing 1/2 and 1/4 of the full range are extracted to the shift register 3. A difference between the present sampled value (output of register 2) and the previous sampled value (output of shift register 4) is calculated by the subtracter 5, the 7 bit DPCM (RD) and 1 bit code (SI) showing whether the finite difference is positive or negative are obtained, and they are recorded in the disk 7 together with the outputs (RS0-RS11) of the range signal (AQ) AD converter 1 of the register 3. In this way, a stable decoding can be executed by correcting the cumulative distortion by a range code representing a level. |
