| 摘要 |
PROBLEM TO BE SOLVED: To prevent data from being absent even when variation in a difference of a sound signal is small when the sound signal is compressed. SOLUTION: When a sound signal is sampled and converted from analog to digital and compressed, differences between the sampled data are found one after another and the quantity of variation between last and current differences is monitored. When this variation quantity becomes large, the sampling frequency is increased. When this variation quantity decreases, the sampling frequency is lowered. The data hold the repetition frequency of data having the same difference as the last one and the same data are repeated to save the memory. |
