Multifunctional audio signal generation apparatus

A computer-implemented method for generating an output audio waveform signal using memory interface circuitry adapted to communicate with a memory storing original waveform data, an overlap adder configured to output a result of addition for one sample per sampling time period, and a sound system for outputting the output audio waveform signal based on said result of addition for one sample per sampling time period from said overlap adder, comprising:

• generating a waveform sample value in each of a set of channels selected from a plurality of channels, each of the plurality of channels including:
• a sample counter adapted to perform counting operation at a given rate per sampling time period and
• a read circuit adapted to retrieve a sample value of an original waveform from the memory through the memory interface circuitry based on a count value of the sample counter,
• one channel of the plurality of channels and another channel of the plurality of channels being configured to operate concurrently during an overlap time period,
• each of the set of channels being configured to generate the waveform sample value based on the sample value of the original waveform retrieved via the read circuit of the channel so that the waveform sample value for one sample is output from the channel per sampling time period, wherein the sampling time period is a sampling time period for digital/analog conversion of the output waveform sample value;
• setting, for each of the set of channels, the rate and an initial value for the sample counter of the channel and controlling start and stop of the counting operation of the sample counter, so that a partial portion of the original waveform corresponding to a count range from the set initial value to a count stop point is reproduced in the channel;
• and
• setting the initial values in individual ones of the set of channels such that sample values at different sample positions of the original waveform are simultaneously retrieved from the memory in individual ones of the set of channels, and controlling the overlap adder to add up the waveform sample values output from the set of channels in the same sampling time period, whereby sample values of an audio waveform signal with a plurality of partial portions of the original waveform, which are to be reproduced in the set of channels, partially overlapping each other are output from said overlap adder as said result of addition for one sample per sampling time period from said overlap adder,
• wherein the output audio waveform signal is to be output from the sound system based on said result of addition for one sample per sampling time period from said overlap adder.

A non-transitory computer-readable storage medium containing a group of instructions executable by a processor to implement a method for generating an output audio waveform signal using memory interface circuitry adapted to communicate with a memory storing original waveform data, an overlap adder configured to output a result of addition for one sample per sampling time period, and a sound system for outputting the output audio waveform signal based on said result of addition for one sample per sampling time period from said overlap adder, the method comprising:

• generating a waveform sample value in each of a set of channels selected from a plurality of channels, each of the plurality of channels including:
• a sample counter adapted to perform counting operation at a given rate per sampling time period and
• a read circuit adapted to retrieve a sample value of an original waveform from the memory through the memory interface circuitry based on a count value of the sample counter,
• one channel of the plurality of channels and of another channel of the plurality of channels being configured to operate concurrently during an overlap time period,
• each of the set of channels being configured to generate the waveform sample value based on the sample value of the original waveform retrieved via the read circuit of the channel so that the waveform sample value for one sample is output from the channel per sampling time period, wherein the sampling time period is a sampling time period for digital/analog conversion of the output waveform sample value;
• setting, for each of the set of channels, the rate and an initial value for the sample counter of the channel and controlling start and stop of the counting operation of the sample counter, so that a partial portion of the original waveform corresponding to a count range from the set initial value to a count stop point is reproduced in the channel;
• and
• setting the initial values in individual ones of the set of channels such that sample values at different sample positions of the original waveform are retrieved from the memory in individual ones of the set of channels, and controlling the overlap adder to add up the waveform sample values output from the set of channels in the same sampling time period, whereby sample values of an audio waveform signal with a plurality of partial portions of the original waveform, which are to be reproduced in the set of channels, partially overlapping each other are output from said overlap adder as said result of addition from said overlap adder,
• wherein the output audio waveform signal is to be output from the sound system based on said result of addition for one sample per sampling time period from said overlap adder.