Linear Prediction filters

lpc_filter	Synthesize a signal from a single set of linear prediction coefficients and the residual values.
inv_lpc_filter	Filter the waveform using a single set of coefficients so as to produce a residual signal.
lpc_filter_1	Synthesize a signal from a track of linear prediction coefficients.
lpc_filter_fast	Synthesize a signal from a track of linear prediction coefficients.
inv_lpc_filter_ola	Produce a residual from a track of linear prediction coefficients and a signal using an overlap add technique.

The linear prediction filters are used for the analysis and synthesis of waveforms according the to linear prediction all-pole model.

The linear prediction states that the value of a signal at a given point is equal to a weighted sum of the previous P values, plus a correction value for that point:

Given a set of coefficents and the original signal, we can use this equation to work out e, the residual. Conversely given the coefficients and the residual signal, an estimation of the original signal can be calculated.

If a single set of coefficients were used for the entire waveform, the filtering process would be simple. It is usual however to have a different set of coefficients for every frame, and there are many possible ways to switch from one coefficient set to another so as not to cause discontinuities at the frame boundaries.

Alphabetic index Hierarchy of classes

This page is part of the Edinburgh Speech Tools Library documentation
Copyright University of Edinburgh 1997
Contact: speech_tools@cstr.ed.ac.uk