cPorcupine - C API

API Reference for the Porcupine C SDK.


pv_porcupine_t

typedef struct pv_porcupine pv_porcupine_t;

Container representing the Porcupine wake word engine.


pv_porcupine_init()

pv_status_t pv_porcupine_init(
const char *access_key,
const char *model_path,
int32_t num_keywords,
const char *const *keyword_paths,
const float *sensitivities,
pv_porcupine_t **object);

Create a Porcupine instance. Resources should be cleaned when you are done using the pv_porcupine_delete() function.

Parameters

  • access_key const char * : AccessKey obtained from Picovoice Console.
  • model_path const char * : Absolute path to the file containing model parameters (.pv).
  • num_keywords int32_t : Number of keywords to monitor.
  • keyword_paths const char *const * : Absolute paths to keyword model files (.ppn).
  • sensitivities float * : Sensitivities for detecting keywords. Each value should be a number within [0, 1]. A higher sensitivity results in fewer misses at the cost of increasing the false alarm rate.
  • object pv_porcupine_t * * : Constructed instance of Porcupine.

Returns


pv_porcupine_delete()

void pv_porcupine_delete(pv_porcupine_t *object);

Releases resources acquired by Porcupine.

Parameters


pv_porcupine_process()

pv_status_t pv_porcupine_process(pv_porcupine_t *object, const int16_t *pcm, int32_t *keyword_index);

Processes a frame of the incoming audio stream and emits the detection result. The number of samples per frame can be attained by calling pv_porcupine_frame_length(). The incoming audio needs to have a sample rate equal to pv_sample_rate() and be 16-bit linearly-encoded. Porcupine operates on single-channel audio.

Parameters

  • object pv_porcupine_t * : Porcupine object.
  • pcm int16_t : A frame of audio samples.
  • keyword_index int32_t * : Index of observed keyword at the end of the current frame. Indexing is 0-based and matches the ordering of keyword models provided to pv_porcupine_init(). If no keyword is detected then it is set to -1.

Returns


pv_porcupine_version()

const char *pv_porcupine_version(void);

Getter for version.

Returns

  • char * : Porcupine version.

pv_porcupine_frame_length()

int32_t pv_picovoice_frame_length(void);

Getter for number of audio samples per frame.

Returns

  • int32_t : Frame length.

pv_sample_rate()

int32_t pv_sample_rate(void);

Audio sample rate accepted by Porcupine.

Returns

  • int32_t : Sample rate.

pv_status_t

typedef enum {
PV_STATUS_SUCCESS = 0,
PV_STATUS_OUT_OF_MEMORY,
PV_STATUS_IO_ERROR,
PV_STATUS_INVALID_ARGUMENT,
PV_STATUS_STOP_ITERATION,
PV_STATUS_KEY_ERROR,
PV_STATUS_INVALID_STATE,
PV_STATUS_RUNTIME_ERROR,
PV_STATUS_ACTIVATION_ERROR,
PV_STATUS_ACTIVATION_LIMIT_REACHED,
PV_STATUS_ACTIVATION_THROTTLED,
PV_STATUS_ACTIVATION_REFUSED
} pv_status_t;

Status code enum.


pv_status_to_string()

const char *pv_status_to_string(pv_status_t status);

Parameters

  • int32_t : Returned status code.

Returns

  • char * : String representation.


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