Falcon Speaker Diarization
C API

API Reference for the Falcon C SDK.

pv_falcon_t

typedef struct pv_falcon pv_falcon_t;

Container representing the Falcon Speaker Diarization object.

pv_falcon_init()

pv_status_t pv_falcon_init(
        const char *access_key,
        const char *model_path,
        const char *device,
        pv_falcon_t **object);

Creates a Falcon instance. Resources should be cleaned when you are done using the pv_falcon_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).
• device char * : String representation of the device (e.g., CPU or GPU) to use. If set to best, the most suitable device is selected automatically. If set to gpu, the engine uses the first available GPU device. To select a specific GPU device, set this argument to gpu:${GPU_INDEX}, where ${GPU_INDEX} is the index of the target GPU. If set to cpu, the engine will run on the CPU with the default number of threads. To specify the number of threads, set this argument to cpu:${NUM_THREADS}, where ${NUM_THREADS} is the desired number of threads.
• object pv_falcon_t * * : Constructed instance of Falcon.

Returns

• pv_status_t : Status code.

pv_falcon_delete()

void pv_falcon_delete(pv_falcon_t *object);

Releases resources acquired by Falcon.

Parameters

• object pv_falcon_t * : Falcon object.

pv_falcon_process()

pv_status_t pv_falcon_process(
    pv_falcon_t *object,
    const int16_t *pcm,
    int32_t num_samples,
    int32_t *num_segments,
    pv_segment_t **segments);

Processes the given audio data and returns the diarization output.

This function analyzes the provided audio data, which should be single-channel, 16-bit linearly-encoded, and have a sample rate matching pv_sample_rate(). It identifies different segments in the audio, each represented by a pv_segment_t structure. The caller is responsible for freeing the segments buffer using pv_falcon_segments_delete().

Parameters

• object pv_falcon_t * : Falcon object.
• pcm int16_t : A frame of audio samples.
• num_samples int32_t : Number of audio samples to process.
• num_segments int32_t * : Number of segments in the output.
• segments pv_segment_t * * : Array of segments in the output.

Returns

• pv_status_t : Status code.

pv_falcon_process_file()

pv_status_t pv_falcon_process_file(
    pv_falcon_t *object,
    const char *audio_path,
    int32_t *num_segments,
    pv_segment_t **segments);

Processes the given audio file and returns the diarization output. The supported formats are: 3gp (AMR), FLAC, MP3, MP4/m4a (AAC), Ogg, WAV and WebM.

It identifies different segments in the audio, each represented by a pv_segment_t structure. The caller is responsible for freeing the segments buffer using pv_falcon_segments_delete().

Parameters

• object pv_falcon_t * : Falcon object.
• audio_path const char * : Absolute path to audio file.
• num_segments int32_t * : Number of segments in the output.
• segments pv_segment_t * * : Array of segments in the output.

Returns

• pv_status_t : Status code.

pv_falcon_segments_delete()

void pv_falcon_segments_delete(pv_segment_t *segments);

Deletes words returned from pv_falcon_process() or pv_falcon_process_file().

Parameters

• segments pv_segment_t * : Array of segments returned from pv_falcon_process() or pv_falcon_process_file().

pv_falcon_version()

const char *pv_falcon_version(void);

Getter for version.

Returns

• const char * : Falcon version.

pv_sample_rate()

int32_t pv_sample_rate(void);

Audio sample rate accepted by Falcon.

Returns

• int32_t : Sample rate.

pv_falcon_list_hardware_devices()

pv_status_t pv_falcon_list_hardware_devices(
        char ***hardware_devices,
        int32_t *num_hardware_devices);

Gets a list of hardware devices that can be specified when calling pv_falcon_init().

Parameters

• hardware_devices const char * * * : Array of available hardware devices. Devices are NULL terminated strings. The array must be freed using pv_falcon_free_hardware_devices().
• num_hardware_devices int32_t * : The number of devices in the hardware_devices array.

Returns

• pv_status_t : Returned status code.

pv_falcon_free_hardware_devices()

void pv_falcon_free_hardware_devices(
        char ***hardware_devices,
        int32_t *num_hardware_devices);

This function frees the memory allocated by pv_falcon_list_hardware_devices().

Parameters

• hardware_devices const char * * * : Array of available hardware devices allocated by pv_falcon_list_hardware_devices().
• num_hardware_devices int32_t * : The number of devices in the hardware_devices array

pv_segment_t

typedef struct {
    float start_sec; /** Start time of the segment in seconds. */
    float end_sec; /** End time of the segment in seconds. */
    int32_t speaker_tag; /** Speaker tag identifier - a non-negative integer identifying unique speakers. */
} pv_segment_t;

Struct represents a segment along with its start, end, and the corresponding speaker tag.

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

• status int32_t : Status code.

Returns

• const char * : String representation of status code.

pv_get_error_stack()

pv_status_t pv_get_error_stack(
        char ***message_stack,
        int32_t *message_stack_depth);

If a function returns a failure (any pv_status_t other than PV_STATUS_SUCCESS), this function can be called to get a series of error messages related to the failure. This function can only be called only once per failure status on another function. The memory for message_stack must be freed using pv_free_error_stack.

Regardless of the return status of this function, if message_stack is not NULL, then message_stack contains valid memory. However, a failure status on this function indicates that future error messages may not be reported.

Parameters

• message_stack const char * * * : Array of messages relating to the failure. Messages are NULL terminated strings. The array and messages must be freed using pv_free_error_stack().
• message_stack_depth int32_t * : The number of messages in the message_stack array.

pv_free_error_stack()

void pv_free_error_stack(char **message_stack);

This function frees the memory used by error messages allocated by pv_get_error_stack().

Parameters

• message_stack const char * * : Array of messages relating to the failure.