Data compression and expansion apparatus for audio recorders

摘要

A digital audio tape recorder apparatus (DAT) for compressing and expanding digital data during LP (long play) mode recording and reproducing, and for encoding level data at a sufficient resolution, especially in the range of 0 decibels where higher resolution is required. The data is compressed into a shorter data length compared to the absolute value of the digital audio data. The apparatus includes a first shift register which receives incoming parallel data and transforms the parallel data into serial data with the MSB (most significant bit) of the loaded parallel data being retained at the register while the parallel data is shifted in a LSB (least significant bit) direction. The load signal of the first shift register is generated by a load signal generator unit which includes a first binary counter and which generates the load signal by comparing the output of the first binary counter with the input parallel data to be loaded. The output of the first shift register, which has been signal processed, is input to a second shift register which transforms the serial data into parallel data. While the serial data is shifted through the second shift register, a second load signal generator unit generates load signals to retain the output of the second shift register and the second binary counter in accordance with the output of the second shift register.