| 摘要 |
PROBLEM TO BE SOLVED: To reproduce any arbitrary part from the data of audio or the like stored by an adaptive differential pulse code modulation (ADPCM) system with high quality. SOLUTION: The analog signal of an audio signal or the like is sampled and converted to a digital signal by an A/D converting part 1. This converted output is compressed by a differential compression system in a compression part 2 and stored in a first memory part 3. A memory controller 4 reads data from a predetermined starting point to an ending point out of the stored data in the first memory part 3. Besides, the A/D converted output is delayed for prescribed time by a delay part 5. These delayed data are stored in a second memory part 6 while successively updating the head of the data for one piece of sampling data. Based on the data from the first memory part 3 and one piece of data from the second memory part 6, the top of the data from the first memory part is made into one piece of data from the second memory part and outputted by an output part 7. A source signal can be reproduced without noise component because of the existence of these top data. |
