SpeexPreprocessState: The Speex preprocessor


Defines

#define SPEEX_PREPROCESS_SET_DENOISE   0
#define SPEEX_PREPROCESS_GET_DENOISE   1
#define SPEEX_PREPROCESS_SET_AGC   2
#define SPEEX_PREPROCESS_GET_AGC   3
#define SPEEX_PREPROCESS_SET_VAD   4
#define SPEEX_PREPROCESS_GET_VAD   5
#define SPEEX_PREPROCESS_SET_AGC_LEVEL   6
#define SPEEX_PREPROCESS_GET_AGC_LEVEL   7
#define SPEEX_PREPROCESS_SET_DEREVERB   8
#define SPEEX_PREPROCESS_GET_DEREVERB   9
#define SPEEX_PREPROCESS_SET_DEREVERB_LEVEL   10
#define SPEEX_PREPROCESS_GET_DEREVERB_LEVEL   11
#define SPEEX_PREPROCESS_SET_DEREVERB_DECAY   12
#define SPEEX_PREPROCESS_GET_DEREVERB_DECAY   13
#define SPEEX_PREPROCESS_SET_PROB_START   14
#define SPEEX_PREPROCESS_GET_PROB_START   15
#define SPEEX_PREPROCESS_SET_PROB_CONTINUE   16
#define SPEEX_PREPROCESS_GET_PROB_CONTINUE   17
#define SPEEX_PREPROCESS_SET_NOISE_SUPPRESS   18
#define SPEEX_PREPROCESS_GET_NOISE_SUPPRESS   19
#define SPEEX_PREPROCESS_SET_ECHO_SUPPRESS   20
#define SPEEX_PREPROCESS_GET_ECHO_SUPPRESS   21
#define SPEEX_PREPROCESS_SET_ECHO_SUPPRESS_ACTIVE   22
#define SPEEX_PREPROCESS_GET_ECHO_SUPPRESS_ACTIVE   23
#define SPEEX_PREPROCESS_SET_ECHO_STATE   24
#define SPEEX_PREPROCESS_GET_ECHO_STATE   25
#define SPEEX_PREPROCESS_SET_AGC_INCREMENT   26
#define SPEEX_PREPROCESS_GET_AGC_INCREMENT   27
#define SPEEX_PREPROCESS_SET_AGC_DECREMENT   28
#define SPEEX_PREPROCESS_GET_AGC_DECREMENT   29
#define SPEEX_PREPROCESS_SET_AGC_MAX_GAIN   30
#define SPEEX_PREPROCESS_GET_AGC_MAX_GAIN   31
#define SPEEX_PREPROCESS_GET_AGC_LOUDNESS   33
#define SPEEX_PREPROCESS_GET_AGC_GAIN   35
#define SPEEX_PREPROCESS_GET_PSD_SIZE   37
#define SPEEX_PREPROCESS_GET_PSD   39
#define SPEEX_PREPROCESS_GET_NOISE_PSD_SIZE   41
#define SPEEX_PREPROCESS_GET_NOISE_PSD   43
#define SPEEX_PREPROCESS_GET_PROB   45
#define SPEEX_PREPROCESS_SET_AGC_TARGET   46
#define SPEEX_PREPROCESS_GET_AGC_TARGET   47

Typedefs

typedef SpeexPreprocessState_ SpeexPreprocessState

Functions

SpeexPreprocessStatespeex_preprocess_state_init (int frame_size, int sampling_rate)
void speex_preprocess_state_destroy (SpeexPreprocessState *st)
int speex_preprocess_run (SpeexPreprocessState *st, spx_int16_t *x)
int speex_preprocess (SpeexPreprocessState *st, spx_int16_t *x, spx_int32_t *echo)
void speex_preprocess_estimate_update (SpeexPreprocessState *st, spx_int16_t *x)
int speex_preprocess_ctl (SpeexPreprocessState *st, int request, void *ptr)

Detailed Description

This is the Speex preprocessor. The preprocess can do noise suppression, residual echo suppression (after using the echo canceller), automatic gain control (AGC) and voice activity detection (VAD).

Define Documentation

#define SPEEX_PREPROCESS_GET_AGC   3

Get preprocessor Automatic Gain Control state

#define SPEEX_PREPROCESS_GET_AGC_DECREMENT   29

Get maximal gain decrease in dB/second (int32)

#define SPEEX_PREPROCESS_GET_AGC_GAIN   35

Get current gain (int32 percent)

#define SPEEX_PREPROCESS_GET_AGC_INCREMENT   27

Get maximal gain increase in dB/second (int32)

#define SPEEX_PREPROCESS_GET_AGC_LEVEL   7

Get preprocessor Automatic Gain Control level (float)

#define SPEEX_PREPROCESS_GET_AGC_LOUDNESS   33

Get loudness

#define SPEEX_PREPROCESS_GET_AGC_MAX_GAIN   31

Get maximal gain in dB (int32)

#define SPEEX_PREPROCESS_GET_AGC_TARGET   47

Get preprocessor Automatic Gain Control level (int32)

#define SPEEX_PREPROCESS_GET_DENOISE   1

Get preprocessor denoiser state

#define SPEEX_PREPROCESS_GET_DEREVERB   9

Get preprocessor dereverb state

#define SPEEX_PREPROCESS_GET_DEREVERB_DECAY   13

Get preprocessor dereverb decay

#define SPEEX_PREPROCESS_GET_DEREVERB_LEVEL   11

Get preprocessor dereverb level

#define SPEEX_PREPROCESS_GET_ECHO_STATE   25

Get the corresponding echo canceller state

#define SPEEX_PREPROCESS_GET_ECHO_SUPPRESS   21

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

#define SPEEX_PREPROCESS_GET_ECHO_SUPPRESS_ACTIVE   23

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

#define SPEEX_PREPROCESS_GET_NOISE_PSD   43

Get noise estimate (int32[] of squared values)

#define SPEEX_PREPROCESS_GET_NOISE_PSD_SIZE   41

Get spectrum size for noise estimate (int32)

#define SPEEX_PREPROCESS_GET_NOISE_SUPPRESS   19

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

#define SPEEX_PREPROCESS_GET_PROB   45

Get speech probability in last frame (int32).

#define SPEEX_PREPROCESS_GET_PROB_CONTINUE   17

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

#define SPEEX_PREPROCESS_GET_PROB_START   15

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

#define SPEEX_PREPROCESS_GET_PSD   39

Get power spectrum (int32[] of squared values)

#define SPEEX_PREPROCESS_GET_PSD_SIZE   37

Get spectrum size for power spectrum (int32)

#define SPEEX_PREPROCESS_GET_VAD   5

Get preprocessor Voice Activity Detection state

#define SPEEX_PREPROCESS_SET_AGC   2

Set preprocessor Automatic Gain Control state

#define SPEEX_PREPROCESS_SET_AGC_DECREMENT   28

Set maximal gain decrease in dB/second (int32)

#define SPEEX_PREPROCESS_SET_AGC_INCREMENT   26

Set maximal gain increase in dB/second (int32)

#define SPEEX_PREPROCESS_SET_AGC_LEVEL   6

Set preprocessor Automatic Gain Control level (float)

#define SPEEX_PREPROCESS_SET_AGC_MAX_GAIN   30

Set maximal gain in dB (int32)

#define SPEEX_PREPROCESS_SET_AGC_TARGET   46

Set preprocessor Automatic Gain Control level (int32)

#define SPEEX_PREPROCESS_SET_DENOISE   0

Set preprocessor denoiser state

#define SPEEX_PREPROCESS_SET_DEREVERB   8

Set preprocessor dereverb state

#define SPEEX_PREPROCESS_SET_DEREVERB_DECAY   12

Set preprocessor dereverb decay

#define SPEEX_PREPROCESS_SET_DEREVERB_LEVEL   10

Set preprocessor dereverb level

#define SPEEX_PREPROCESS_SET_ECHO_STATE   24

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_SUPPRESS   20

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

#define SPEEX_PREPROCESS_SET_ECHO_SUPPRESS_ACTIVE   22

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

#define SPEEX_PREPROCESS_SET_NOISE_SUPPRESS   18

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

#define SPEEX_PREPROCESS_SET_PROB_CONTINUE   16

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

#define SPEEX_PREPROCESS_SET_PROB_START   14

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

#define SPEEX_PREPROCESS_SET_VAD   4

Set preprocessor Voice Activity Detection state


Typedef Documentation

typedef struct SpeexPreprocessState_ SpeexPreprocessState

State of the preprocessor (one per channel). Should never be accessed directly.


Function Documentation

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

Preprocess a frame (deprecated, use speex_preprocess_run() instead)

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

Used like the ioctl function to control the preprocessor parameters

Parameters:
st Preprocessor state
request ioctl-type request (one of the SPEEX_PREPROCESS_* macros)
ptr Data exchanged to-from function
Returns:
0 if no error, -1 if request in unknown

void speex_preprocess_estimate_update ( SpeexPreprocessState st,
spx_int16_t *  x 
)

Update preprocessor state, but do not compute the output

Parameters:
st Preprocessor state
x Audio sample vector (in only). Must be same size as specified in speex_preprocess_state_init().

int speex_preprocess_run ( SpeexPreprocessState st,
spx_int16_t *  x 
)

Preprocess a frame

Parameters:
st Preprocessor state
x Audio sample vector (in and out). Must be same size as specified in speex_preprocess_state_init().
Returns:
Bool value for voice activity (1 for speech, 0 for noise/silence), ONLY if VAD turned on.

void speex_preprocess_state_destroy ( SpeexPreprocessState st  ) 

Destroys a preprocessor state

Parameters:
st Preprocessor state to destroy

SpeexPreprocessState* speex_preprocess_state_init ( int  frame_size,
int  sampling_rate 
)

Creates a new preprocessing state. You MUST create one state per channel processed.

Parameters:
frame_size Number of samples to process at one time (should correspond to 10-20 ms). Must be the same value as that used for the echo canceller for residual echo cancellation to work.
sampling_rate Sampling rate used for the input.
Returns:
Newly created preprocessor state


Generated on Sat Dec 6 22:03:23 2008 for Speex by  doxygen 1.5.1