Compaction method for waveform storage
First Claim
1. A method of compactly storing and retrieving a waveform, comprising the steps of:
- (a) establishing a table containing a relatively small number of predetermined increments;
(b) storing a series of addresses, each address identifying one of said increments in said table;
(c) successively producing a series of samples representing generally the value of said waveform at time-spaced intervals, each of said samples corresponding to one of said addresses;
(d) predicting the value of each new sample to be produced, said predicted value being a fixed function of the values of at least a current and a previous sample;
(e) incrementing said predicted value by the increment identified by said address for said new sample, to produce a sample value at least approximating the actual value of said waveform at the sampling point; and
(f) reconstituting said waveform from said approximating samples.
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Accused Products
Abstract
The memory needed for the digital storage of a waveform having an amplitude range of ±128 units is compacted by nearly 50% through the use of a 16-position table containing selected increments. Each waveform sample value is first predicted from at least two prior samples by linear prediction, and the predicted value is then incremented by the most nearly accurate increment in the table to obtain an approximation of the actual waveform value at the sample point. The appropriate increment for each sample can be defined by a 4-bit table address. The best-fit increment values for any given waveform can be calculated by a reiterative trial-and-error computation process. By the use of a best-fit table, inaccuracies in the waveform reproduction can be held below audible levels.
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Citations
10 Claims
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1. A method of compactly storing and retrieving a waveform, comprising the steps of:
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(a) establishing a table containing a relatively small number of predetermined increments; (b) storing a series of addresses, each address identifying one of said increments in said table; (c) successively producing a series of samples representing generally the value of said waveform at time-spaced intervals, each of said samples corresponding to one of said addresses; (d) predicting the value of each new sample to be produced, said predicted value being a fixed function of the values of at least a current and a previous sample; (e) incrementing said predicted value by the increment identified by said address for said new sample, to produce a sample value at least approximating the actual value of said waveform at the sampling point; and (f) reconstituting said waveform from said approximating samples. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification