[ Table Of Contents | Keyword Index ]

tclassp_forest(n) 0.5 doc "tclassp - Formant estimation of a signal"


tclassp_forest - tclassp forest

Table Of Contents



Formant of estimation of a signal. ::tclassp::forest is an ASSP AOPTS command and takes the following general form .

::tclassp::forest method ?arg arg ...?

Raw resonance frequency and bandwidth values are obtained by root-solving of the Linear Prediction polynomial from the autocorrelation method with the Split-Levinson-Algorithm (SLA). Resonances are then classified as formants using the so-called Pisarenko frequencies (by-product of the SLA) and a formant frequeny range table derived from the nominal F1 frequency. The latter should be increased by about 12% for female voices (see -gender and -nominalF1 options).


All AOPTS subcommands are implemented.

::tclassp::forest cget option

Returns the current setting of the option option. option may be any option appropraite for the underlying analysis function, see OPTIONS below.

::tclassp::forest configure option ?value? ?option? ?value?

For each option-value pair sets option to value. If the last option is missing its corresponding value the current value is returned. option may be any option appropraite for the underlying analysis function, see OPTIONS below.

Currently not standard behaviour, will be changed

::tclassp::forest exec fileNameList

Performs the formant estimation on all files whose names are given in FileNameList. FileNameList must be a proper Tcl list. Returns the number of files processed successfully

::tclassp::forest info

This command returns a list of information on the AOPTS command. The first three elements of the list are

  1. the name of the analysis function

  2. the major version number

  3. the minor version number

The remaining elements consist of key-value pairs listing all available options of the analysis function and the the option type. Option type is useful for the creation of graphical user interfaces and may be:

  • bool: Options with a boolean value, best represented with check boxes

  • text: Options with a more or less free value, best represented with entry fields

  • radio: Options with a short range of fixed values, best represented by radio buttons

  • combo: Options with longer ranges of fixed values, best represented by combo boxes

  • spin: Options with continuos numerical value ranges, best represented by spin boxes

tkassp makes use of these option types to generate GUIs more or less automatically. In some cases, option type is the empty string to indicate that the option is not to be used in a GUI in the same way as the other options, see OPTIONS for details.

::tclassp::forest reset

Resets all options to the default.

::tclassp::forest version

Returns the version of the ASSP analysis function.


The following options do not affect the resulting analysis. They do not have an option type as defined for the AOPTSname info command. These options are available for all analysis commands.

-extension outputExtension

Defines the value of the output extension when the analysis result is written to file. Defaults to ".XYZ".

-outDir outputDirectory

Defines the directory in which the resulting file (if any) is stored. Defaults to the working directory (pwd).

-counter counterVariable

If counterVariable is a fully qualified variable name, it is incremented each time the AOPTSname exec command finishes processing a file. This is useful to track the progress of the analysis especially for long file lists. If counterVariable is empty (the default) no counting is performed.

-stop stopVariable

If stopVariable is a fully qualified variable name, it is read each time the AOPTSname exec command start processing a file. Setting stopVariable to true will cause the abortion of the running AOPTSname exec command. This is useful if the necessity to abort time-consuming processes of of long file lists should arise. If stopVariable is the empty string (the default) aborting processes is not possible.

The following options will affect the results of the anaysis functions. Some are available in all ASSP analysis functions but not in all of them:

-begin beginTime

Start time of the analysis in ms. Defaults to begin of signal.

-end endTime

End time of the analysis in ms. Defaults to end of signal.

-winSize windowSize

Specifies the length of the anaysis window in ms.

-effLength useEffectivLength

Boolean value determining whether -winSize is interpreted as the effective or as the exact length of the analysis window.

-winShift windowShift

Specifies the size of the window shift in ms.

-window windowFunction

Specifies the code name of the window function to use. Valid window functions are listed in the tclassp manual page.

-nominalF1 frequency

set nominal F1 frequency in Hz (default: 500.0 Hz)

-gender genderCode

sets gender specific defaults. Valid gender codes are

  • "f"emale: sets -effective true -windowSize 12.5 ms -nominalF1 560

  • "m"ale: sets -effective true -windowSize 20.0 ms -nominalF1 500

  • "u"nknown: does not change settings. This value is assumed when default settings are changed.

-estimate doEstimate

If doEstimate is true rough frequency estimates of missing formants are inserted. If doEstimate is false (the default) zeros are inserted as frequencies and bandwidths of missing formants.

-order predictionOrder

Set the number of the Linear Prediction order. Defaults to the smallest even value larger than the sample rate divided by twice the nominal F1 frequency.

-incrOrder number

Increases or decreases the linear prediction order by twice the value of number.

-numFormants number

Sets the number of output formants to number. Defaults to 4. Maximum is 8 or half the linear prediction order.

-preemphasis value

Set pre-emphasis factor to value (-1 <= value <= 0) The default dependends on the sample rate and the nominal F1 frequency.


Delsarte, P. and Genin, Y.V. (1986). "The Split Levinson Algorithm," IEEE Trans. ASSP, Vol. 34, 470-478.

Willems, L.F. (1987), "Robust formant analysis for speech synthesis applications," Proc. European Conference on Speech Technology, Vol. 1, 250-253.

Scheffers, M. and Simpson, A. (1995). "LACS: Label Assisted Copy Synthesis, " Proc. XIIIth Int. Congress of Phonetic Sciences Vol. 2, 346-349.


This document, and the package it describes, will undoubtedly contain bugs and other problems. Please report such in the category tclassp of the ASSP Library Tracker. Please also report any ideas for enhancements you may have for either package and/or documentation.

See Also