Waveform data reproducing apparatus and digital data compression method of the musical tone control and waveform data

摘要

PURPOSE:To efficiently compress data by dividing waveform sample data into sections consisting of plural samples, detecting maximum value among the numbers of effective bits of respective data, section by section, and storing the data in the respective sections while making the data uniform to the number of bits corresponding to the maximum value. CONSTITUTION:One block of waveform sample data read out of a waveform memory 15 by a waveform read part 40 is further divided into plural sections (frame). A bit quantity detection part 56 detects the maximum values among the numbers of effective bits of the respective divided frames and a shift data generator 45 cuts the bits of the respective waveform sample data uniformly to the maximum bit length. Thus, the waveform sample data which are processed to the variable bit length are written in the waveform memory 15 again by a writing process part 58. At this time, the writing process is performed by adding various control data on the compression coefficient and weight coefficient of data used for reproduction processing, the number of bits of the waveform sample data, etc.