| #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 struct SpeexPreprocessState_ SpeexPreprocessState | 
State of the preprocessor (one per channel). Should never be accessed directly.
| 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
| st | Preprocessor state | |
| request | ioctl-type request (one of the SPEEX_PREPROCESS_* macros) | |
| ptr | Data exchanged to-from function | 
| void speex_preprocess_estimate_update | ( | SpeexPreprocessState * | st, | |
| spx_int16_t * | x | |||
| ) | 
Update preprocessor state, but do not compute the output
| 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
| st | Preprocessor state | |
| x | Audio sample vector (in and out). Must be same size as specified in speex_preprocess_state_init(). | 
| void speex_preprocess_state_destroy | ( | SpeexPreprocessState * | st | ) | 
Destroys a preprocessor state
| 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.
| 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. | 
 1.5.1