Cobra Voice Activity Detection
Rust API

API Reference for the Cobra Rust SDK (crates.io).

cobra::Cobra

pub struct Cobra

Struct for the Cobra VAD engine.

cobra::Cobra.new()

pub fn new<S: Into<String>>(access_key: S) -> Result<Cobra, CobraError>

Creates a new Cobra from required arguments.

Parameters

• access_key S : AccessKey obtained from Picovoice Console.

Returns

• Result<Cobra, CobraError> : If Ok, returns a new Cobra object. If Err, a CobraError object describing the error that was encountered.

cobra::Cobra.new_with_library()

pub fn new_with_library<S: Into<String>, P: Into<PathBuf>>(access_key: S, library_path: P) -> Result<Cobra, CobraError>

Creates a new Cobra from required arguments.

Parameters

• access_key S : AccessKey obtained from Picovoice Console.
• library_path P : Path to the Cobra library file.

Returns

• Result<Cobra, CobraError> : If Ok, returns a new Cobra object. If Err, a CobraError object describing the error that was encountered.

cobra::Cobra.process()

pub fn process(&self, pcm: &[i16]) -> Result<f32, CobraError>

Processes a frame of the incoming audio stream and emits the probability of voice activity.

The number of samples per frame can be attained by calling .frame_length. The incoming audio needs to have a sample rate equal to .sample_rate and be 16-bit linearly-encoded. Furthermore, Cobra operates on single-channel audio.

Parameters

• pcm &[i16] : Audio data.

Returns

• Result<f32, CobraError> : If Ok, returns the probability of voice activity. It is a floating-point number within [0, 1]. If Err, a CobraError object describing the error that was encountered.

cobra::Cobra.frame_length()

pub fn frame_length(&self) -> u32

Gets the frame length.

Returns

• u32 : Audio frame length accepted by Cobra.

cobra::Cobra.sample_rate()

pub fn sample_rate(&self) -> u32

Gets the sample rate.

Returns

• u32 : Audio sample rate accepted by Cobra.

cobra::Cobra.version()

pub fn version(&self) -> &str

Gets the Cobra version.

Returns

• &str : Cobra version string.

cobra::CobraError

pub struct CobraError

An error type describing any errors encountered by the Cobra SDK.

cobra::CobraError.new()

pub fn new(status: CobraErrorStatus, message: impl Into<String>) -> Self

Creates a new instance of CobraError

Parameters

• status CobraErrorStatus : Type of error encountered.
• message impl Into<String> : Message detailing the cause of the error.

cobra::CobraErrorStatus

pub enum CobraErrorStatus {
    LibraryError(PvStatus),
    LibraryLoadError,
    FrameLengthError,
    ArgumentError,
}

Enum describing possible error types returned from the Cobra Rust SDK.

cobra::PvStatus

pub enum PvStatus {
    SUCCESS = 0,
    OUT_OF_MEMORY = 1,
    IO_ERROR = 2,
    INVALID_ARGUMENT = 3,
    STOP_ITERATION = 4,
    KEY_ERROR = 5,
    INVALID_STATE = 6,
    PV_STATUS_RUNTIME_ERROR = 7,
    PV_STATUS_ACTIVATION_ERROR = 8,
    PV_STATUS_ACTIVATION_LIMIT_REACHED = 9,
    PV_STATUS_ACTIVATION_THROTTLED = 10,
    PV_STATUS_ACTIVATION_REFUSED = 11,
}

Error codes returned from the Cobra library.