函數名稱

功能簡介

speex_preprocess_state_init

創建預處理器

speex_preprocess_state_destroy

銷毀預處理器

speex_preprocess_run

處理一幀數據

speex_preprocess

處理一幀數據（廢棄的）

speex_preprocess_estimate_update

更新預處理器

speex_preprocess_ctl

設置和讀取預處理器的參數

函數原形

SpeexPreprocessState *speex_preprocess_state_init(int frame_size, int sampling_rate);

功能

創建預處理器

參數

Frmae_size   [in]每幀的大小（建議幀長為20ms）

Sample_rate  [in]采樣率（支持8k、16k、44k）

返回值

成功返回預處理器指針，失敗返回NULL

說明

加入是16k的語音數據，幀長20ms等于320個采樣

函數原形

void speex_preprocess_state_destroy(SpeexPreprocessState *st);

功能

銷毀預處理器

參數

St           [in]處理器指針

返回值

Void

說明

函數原形

int speex_preprocess_run(SpeexPreprocessState *st, spx_int16_t *x);

功能

處理一幀語音數據

參數

St           [in]處理器指針

X            [in|out]數據緩存，處理后的數據也存入該緩存中

返回值

如果VAD打開，返回值為1表示有語音，為0表示靜音或者噪音

說明

函數原形

int speex_preprocess(SpeexPreprocessState *st, spx_int16_t *x, spx_int32_t *echo);

功能

處理一幀語音數據（廢棄的函數，簡介調用speex_preprocess_run）

參數

St           [in]處理器指針

X            [in|out]數據緩存，處理后的數據也存入該緩存中     

返回值

說明

函數原形

void speex_preprocess_estimate_update(SpeexPreprocessState *st, spx_int16_t *x);

功能

更新預處理器，不會計算輸出語音

參數

St           [in]處理器指針

X            [in]數據緩存

返回值

Void

說明

函數原形

int speex_preprocess_ctl(SpeexPreprocessState *st, int request, void *ptr);

功能

設置預處理器的參數

參數

St           [in]處理器指針

Request      [in]參數的類型（由宏來代表不同的參數）

Ptr          [in|out]參數的值（設置參數時為in，獲得參數參數時為out，這個由宏決定）

返回值

成功返回0，失敗返回-1（表明未知的請求參數）

說明

以下數標識參數類型的宏

/** Set preprocessor denoiser state */

#define SPEEX_PREPROCESS_SET_DENOISE 0

/** Get preprocessor denoiser state */

#define SPEEX_PREPROCESS_GET_DENOISE 1

/** Set preprocessor Automatic Gain Control state */

#define SPEEX_PREPROCESS_SET_AGC 2

/** Get preprocessor Automatic Gain Control state */

#define SPEEX_PREPROCESS_GET_AGC 3

/** Set preprocessor Voice Activity Detection state */

#define SPEEX_PREPROCESS_SET_VAD 4

/** Get preprocessor Voice Activity Detection state */

#define SPEEX_PREPROCESS_GET_VAD 5

/** Set preprocessor Automatic Gain Control level (float) */

#define SPEEX_PREPROCESS_SET_AGC_LEVEL 6

/** Get preprocessor Automatic Gain Control level (float) */

#define SPEEX_PREPROCESS_GET_AGC_LEVEL 7

/** Set preprocessor dereverb state */

#define SPEEX_PREPROCESS_SET_DEREVERB 8

/** Get preprocessor dereverb state */

#define SPEEX_PREPROCESS_GET_DEREVERB 9

/** Set preprocessor dereverb level */

#define SPEEX_PREPROCESS_SET_DEREVERB_LEVEL 10

/** Get preprocessor dereverb level */

#define SPEEX_PREPROCESS_GET_DEREVERB_LEVEL 11

/** Set preprocessor dereverb decay */

#define SPEEX_PREPROCESS_SET_DEREVERB_DECAY 12

/** Get preprocessor dereverb decay */

#define SPEEX_PREPROCESS_GET_DEREVERB_DECAY 13

/** Set probability required for the VAD to go from silence to voice */

#define SPEEX_PREPROCESS_SET_PROB_START 14

/** Get probability required for the VAD to go from silence to voice */

#define SPEEX_PREPROCESS_GET_PROB_START 15

/** Set probability required for the VAD to stay in the voice state (integer percent) */

#define SPEEX_PREPROCESS_SET_PROB_CONTINUE 16

/** Get probability required for the VAD to stay in the voice state (integer percent) */

#define SPEEX_PREPROCESS_GET_PROB_CONTINUE 17

/** Set maximum attenuation of the noise in dB (negative number) */

#define SPEEX_PREPROCESS_SET_NOISE_SUPPRESS 18

/** Get maximum attenuation of the noise in dB (negative number) */

#define SPEEX_PREPROCESS_GET_NOISE_SUPPRESS 19

/** Set maximum attenuation of the residual echo in dB (negative number) */

#define SPEEX_PREPROCESS_SET_ECHO_SUPPRESS 20

/** Get maximum attenuation of the residual echo in dB (negative number) */

#define SPEEX_PREPROCESS_GET_ECHO_SUPPRESS 21

/** Set maximum attenuation of the residual echo in dB when near end is active (negative number) */

#define SPEEX_PREPROCESS_SET_ECHO_SUPPRESS_ACTIVE 22

/** Get maximum attenuation of the residual echo in dB when near end is active (negative number) */

#define SPEEX_PREPROCESS_GET_ECHO_SUPPRESS_ACTIVE 23

/** Set the corresponding echo canceller state so that residual echo suppression can be performed (NULL for no residual echo suppression) */

#define SPEEX_PREPROCESS_SET_ECHO_STATE 24

/** Get the corresponding echo canceller state */

#define SPEEX_PREPROCESS_GET_ECHO_STATE 25

/** Set maximal gain increase in dB/second (int32) */

#define SPEEX_PREPROCESS_SET_AGC_INCREMENT 26

/** Get maximal gain increase in dB/second (int32) */

#define SPEEX_PREPROCESS_GET_AGC_INCREMENT 27

/** Set maximal gain decrease in dB/second (int32) */

#define SPEEX_PREPROCESS_SET_AGC_DECREMENT 28

/** Get maximal gain decrease in dB/second (int32) */

#define SPEEX_PREPROCESS_GET_AGC_DECREMENT 29

/** Set maximal gain in dB (int32) */

#define SPEEX_PREPROCESS_SET_AGC_MAX_GAIN 30

/** Get maximal gain in dB (int32) */

#define SPEEX_PREPROCESS_GET_AGC_MAX_GAIN 31

/*  Can't set loudness */

/** Get loudness */

#define SPEEX_PREPROCESS_GET_AGC_LOUDNESS 33

/*  Can't set gain */

/** Get current gain (int32 percent) */

#define SPEEX_PREPROCESS_GET_AGC_GAIN 35

/*  Can't set spectrum size */

/** Get spectrum size for power spectrum (int32) */

#define SPEEX_PREPROCESS_GET_PSD_SIZE 37

/*  Can't set power spectrum */

/** Get power spectrum (int32[] of squared values) */

#define SPEEX_PREPROCESS_GET_PSD 39

/*  Can't set noise size */

/** Get spectrum size for noise estimate (int32)  */

#define SPEEX_PREPROCESS_GET_NOISE_PSD_SIZE 41

/*  Can't set noise estimate */

/** Get noise estimate (int32[] of squared values) */

#define SPEEX_PREPROCESS_GET_NOISE_PSD 43

/* Can't set speech probability */

/** Get speech probability in last frame (int32).  */

#define SPEEX_PREPROCESS_GET_PROB 45

/** Set preprocessor Automatic Gain Control level (int32) */

#define SPEEX_PREPROCESS_SET_AGC_TARGET 46

/** Get preprocessor Automatic Gain Control level (int32) */

#define SPEEX_PREPROCESS_GET_AGC_TARGET 47

#define NN 320

/*

    語音數據為單通道、16bit、16k

*/

int _tmain(int argc, _TCHAR* argv[])

{

     short in[NN];

     int i;

     SpeexPreprocessState *st;

     int count=0;

     float f;

     st = speex_preprocess_state_init(NN, 16000);

     i=1;

     speex_preprocess_ctl(st, SPEEX_PREPROCESS_SET_AGC, &i);

     f=16000;

     speex_preprocess_ctl(st, SPEEX_PREPROCESS_SET_AGC_LEVEL, &f);

     while (1)

     {

         int vad;

         fread(in, sizeof(short), NN, stdin);

         if (feof(stdin))

              break;

         vad = speex_preprocess_run(st, in);

         //fprintf (stderr, "%d\n", vad);

         fwrite(in, sizeof(short), NN, stdout);

         count++;

     }

     speex_preprocess_state_destroy(st);

     return 0;

}