Linear Predictive Analysis

LP Analysis

The linear predictive analysis window provides an interface to the lpanal utility program, which is documented in the Csound manual. The results of analysis can be used for resynthesis in Csound via the opcodes lpread and lpreson.

The window contains the following controls:

Sound Input File
The name of the file containing the sound to be analyzed.
This is a mandatory entry field.
Analysis Output File
The name of the generated file containing the resulting data.
This is a mandatory entry field.
File Comment
A string which is written into the header of the generated output file.
Sample Rate
If present, indicates the sample rate of the sound input file. If omitted, the sample rate in the sound file's header is used. For headerless files, analysis assumes a default sample rate of 10000Hz.
Channel Number
Selects one of the channels in the sound input file. Default is channel 1.
Begin Time
Offset (in seconds) from the start of the input file to the start of the segment to be analyzed.
Duration
Length (in seconds) of the analyzed segment of the input file. If this parameter is omitted, analysis proceeds to the end of the file.
Number of Poles
Number of poles for analysis. If omitted, a default value of 34 is used. The maximum number allowed is 50.
Hop Size
Hop size between frames of analysis, measured in samples. The default is 200, the maximum 500.
Minimum Frequency
Lowest frequency (measured in Hz) of pitch tracking. A value of 0 disables pitch tracking; the default is 70Hz.
Maximum Frequency
Highest frequency of pitch tracking, defaulting to 200Hz.
Messages
Select one of these radio buttons to control the number of diagnostic messages printed during analysis.
Analyze
Clicking on this button (when enabled) starts analysis using the given parameters.
Abort
Clicking on this button (when enabled) causes a running analysis to be aborted.