julius/wav2mfcc.c File Reference

Convert speech waveform to MFCC parameter vector sequence. More...

#include <julius.h>
#include <sys/stat.h>

Include dependency graph for wav2mfcc.c:

Go to the source code of this file.

Functions
HTK_Param *	new_wav2mfcc (SP16 speech[], int speechlen)

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Detailed Description

Convert speech waveform to MFCC parameter vector sequence.

Author:

Akinobu Lee

Date:

Sun Sep 18 19:40:34 2005

Parameter vector sequence extraction of input speech is done here. The supported parameter is MFCC, with any combination of all the qualifiers in HTK: _0, _E, _D, _A, _Z, _N. Acoustic model for recognition should be trained with the same parameter type. You can specify other parameters such as window size, frame shift, high/low frequency cut-off via runtime options. At startup, Julius will check for the parameter types of acoustic model if it conforms the limitation, and determine whether other additional processing is needed such as Cepstral Mean Normalization.

Functions below are used to convert fully buffered whole sentence utterance, and typically used for audio file input. When input is concurrently processed with recognition process at 1st pass, in case of microphone input, the MFCC computation will be done within functions in realtime-1stpass.c instead of these.

Revision

1.7

Definition in file wav2mfcc.c.

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Function Documentation

HTK_Param* new_wav2mfcc	(	SP16	speech[],
		int	speechlen
	)

Extract MFCC parameters with sentence CMN from given waveform.

Parameters:

	speech	[in] buffer of speech waveform
	speechlen	[in] length of speech in samples

Returns:

pointer to newly allocated parameter structure data with extracted MFCC vector sequence.

Definition at line 79 of file wav2mfcc.c.

Referenced by main_recognition_loop().

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