libsent/src/anlz/strip_mfcc.c

MFCC列からゼロサンプル列を取り除く [詳細]

#include <sent/stddefs.h>
#include <sent/htk_param.h>
#include <sent/mfcc.h>

strip_mfcc.cのインクルード依存関係図

ソースコードを見る。

マクロ定義
#define	IS_INVALID_FRAME_MFCC(A)   ((A) < -30.0 || (A) > 30.0)
	Invalid log value range to detect zero sample frame.
関数
static int	guess_abs_e_location (HTK_Param *param)
boolean	param_strip_zero (HTK_Param *param)

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説明

MFCC列からゼロサンプル列を取り除く

作者:

Akinobu LEE

日付:

Tue Feb 15 00:38:57 2005

エネルギー項の値からゼロサンプルのフレームを検出します．

The detection is done by setting valid range of log energy.

However, since HTK parameter file has no information for framesize or frequency, defining precise upper bound of power is impossible.

Guess the power that is in log scale as described below,

framesize : 1 100 400 1000 10000(can't be!) upper bound: 20.794 25.400 26.786 27.702 30.005

Thus it can be said that the range of [0..30] will work.

When energy normalization was on, the parameters are normalized to:

1.0 - (Emax - value) * ESCALE

So the range becomes [1.0-Emax*ESCALE..1.0]. But the engine cannot know whether the ENORMALIZE was on for given parameters.

As a conclusion, the safe bit is to set the range of log energy to [-30..30] hoping that escale is less than 1.0 (the HTK's default is 0.1).

But remember, there are no guarantee that valid segments is not misdetected. When the misdetection frequently occurs on your MFCC file, please try "-nostrip" option to turn off the stripping.

Revision

1.4

strip_mfcc.c で定義されています。

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関数

static int guess_abs_e_location

(

HTK_Param *

param

)

[static]

Guess where the absolute energy coefficient is.

引数:

param

[in] parameter data

戻り値:

the guessed dimension number of energy coefficient, -1 on failure.

strip_mfcc.c の 69 行で定義されています。

参照元 param_strip_zero().

boolean param_strip_zero

(

HTK_Param *

param

)

Strip zero frames from MFCC data.

引数:

param

[in] parameter data

戻り値:

TRUE on success, FALSE on failure.

strip_mfcc.c の 98 行で定義されています。

参照元 main_recognition_loop().

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