System and methods for memory-constrained sound synthesis using harmonic coding

A system for use in synthesizing a sound signal with a sound synthesis engine based upon processing of a sound file, the system comprising:

• a post-compression coefficient table containing at least one set of post-compression coefficients representing a waveform in a waveform table, wherein an index of the waveform in the waveform table corresponds to the set of post-compression coefficients in the post-compression coefficient table;
• and
• a waveform module for generating at least one post-compression waveform based upon the set of post-compression coefficients at the index in the post-compression coefficient table;
• wherein each post-compression coefficient belonging to the set of post-compression coefficients has been determined by
• generating a frequency-domain representation of a periodic signal, the frequency-domain representation comprising at least one frequency-domain sample, and
• performing a threshold-based compression of frequency-domain samples if the at least one frequency-domain sample comprises a plurality of frequency-domain samples.

A computer-readable storage medium for use in synthesizing a sound signal with a sound synthesis engine in response to a processor processing a sound file, the storage medium comprising computer instructions for:

• performing a read-ahead operation on the sound file during the synthesizing of the sound signal;
• identifying an instruction in the sound file for synthesizing a waveform of a musical instrument;
• finding an index of the waveform in a waveform table used by the sound synthesis engine;
• selecting a set of post-compression coefficients in a post-compression coefficient table corresponding to the index;
• generating at least one post-compression waveform from the set of post-compression coefficients;
• placing the at least one post-compression waveform at the index in the waveform table;
• and
• supplying the at least one post-compression waveform to the sound synthesis engine in advance of the sound synthesis engine requesting the waveform;
• wherein the at least one post-compression waveform is based upon a set of post-compression coefficients, the set of post-compression coefficients having been determined by
• generating a frequency-domain representation of a periodic signal, the frequency-domain representation based upon a fast Fourier transform (FFT) of the periodic signal and comprising at least one pre-compression frequency-domain sample, and
• performing a threshold-based compression of pre-compression frequency-domain samples if the at least one pre-compression frequency-domain sample comprises a plurality of pre-compression frequency-domain samples.