Overview
The Transcriber class is the main entry point for Moonshine Voice in Swift. It handles loading models and managing transcription sessions.
Initialization
init(modelPath:modelArch:options:)
Initialize a transcriber from model files on disk.
public init(
modelPath: String,
modelArch: ModelArch = .base,
options: [TranscriberOption]? = nil
) throws
Path to the directory containing model files (encoder_model.ort, decoder_model_merged.ort, tokenizer.bin)
Model architecture to use. Options: .tiny, .base, .tinyStreaming, .baseStreaming, .smallStreaming, .mediumStreaming
Optional transcriber options for advanced configuration
MoonshineError if the transcriber cannot be loaded
Example:
import MoonshineVoice
do {
let transcriber = try Transcriber(
modelPath: "/path/to/models",
modelArch: .base
)
} catch {
print("Failed to initialize transcriber: \(error)")
}
Non-Streaming Transcription
transcribeWithoutStreaming(audioData:sampleRate:flags:)
Transcribe audio data without streaming.
public func transcribeWithoutStreaming(
audioData: [Float],
sampleRate: Int32 = 16000,
flags: UInt32 = 0
) throws -> Transcript
Array of PCM audio samples (float values from -1.0 to 1.0)
Transcript object containing the transcription lines
Throws: MoonshineError if transcription fails
Example:
let audioData: [Float] = // ... load audio data
do {
let transcript = try transcriber.transcribeWithoutStreaming(
audioData: audioData,
sampleRate: 16000
)
for line in transcript.lines {
print("[\(line.startTime)s] \(line.text)")
}
} catch {
print("Transcription failed: \(error)")
}
Streaming Transcription (Default Stream)
The transcriber provides convenience methods that operate on a default stream:
start()
Start the default stream.
public func start() throws
MoonshineError if starting fails
stop()
Stop the default stream and process any remaining audio.
public func stop() throws
MoonshineError if stopping fails
addAudio(_:sampleRate:)
Add audio data to the default stream.
public func addAudio(_ audioData: [Float], sampleRate: Int32) throws
Array of PCM audio samples (float values from -1.0 to 1.0)
MoonshineError if adding audio fails
updateTranscription()
Manually update the transcription from the default stream.
public func updateTranscription() throws -> Transcript
MoonshineError if updating fails
Event Listeners
addListener(_:)
Add an event listener to the default stream. Supports both closure-based and protocol-based listeners.
public func addListener(_ listener: @escaping (TranscriptEvent) throws -> Void) throws
public func addListener(_ listener: TranscriptEventListener) throws
try transcriber.addListener { event in
if let lineCompleted = event as? LineCompleted {
print("Completed: \(lineCompleted.line.text)")
}
}
class MyListener: TranscriptEventListener {
func onLineStarted(_ event: LineStarted) {
print("Line started: \(event.line.text)")
}
func onLineCompleted(_ event: LineCompleted) {
print("Line completed: \(event.line.text)")
}
}
let listener = MyListener()
try transcriber.addListener(listener)
removeListener(_:)
Remove an event listener from the default stream.
public func removeListener(_ listener: @escaping (TranscriptEvent) throws -> Void) throws
public func removeListener(_ listener: TranscriptEventListener) throws
removeAllListeners()
Remove all event listeners from the default stream.
public func removeAllListeners() throws
Stream Management
createStream(updateInterval:flags:)
Create a new stream for real-time transcription.
public func createStream(
updateInterval: TimeInterval = 0.5,
flags: UInt32 = 0
) throws -> Stream
updateInterval
TimeInterval
default:"0.5"
Interval in seconds between automatic updates
Flags for stream creation
Stream object for real-time transcription
Throws: MoonshineError if stream creation fails
Example:
let stream = try transcriber.createStream(updateInterval: 0.3)
stream.addListener { event in
if let lineTextChanged = event as? LineTextChanged {
print("Updated text: \(lineTextChanged.line.text)")
}
}
try stream.start()
// Feed audio to stream
let audioData: [Float] = // ... audio data
try stream.addAudio(audioData, sampleRate: 16000)
try stream.stop()
stream.close()
getDefaultStream()
Get the default stream.
public func getDefaultStream() throws -> Stream
MoonshineError if stream creation fails
Other Methods
getVersion()
Get the version of the loaded Moonshine library.
public func getVersion() -> Int32
close()
Free the transcriber resources.
Complete Example
import MoonshineVoice
class MyListener: TranscriptEventListener {
func onLineStarted(_ event: LineStarted) {
print("Started: \(event.line.text)")
}
func onLineTextChanged(_ event: LineTextChanged) {
print("Updated: \(event.line.text)")
}
func onLineCompleted(_ event: LineCompleted) {
print("Completed: \(event.line.text)")
}
}
do {
// Initialize transcriber
let transcriber = try Transcriber(
modelPath: "/path/to/models",
modelArch: .base
)
// Add listener
let listener = MyListener()
try transcriber.addListener(listener)
// Start transcription
try transcriber.start()
// Feed audio data
let audioData: [Float] = // ... load audio
try transcriber.addAudio(audioData, sampleRate: 16000)
// Stop transcription
try transcriber.stop()
// Clean up
transcriber.close()
} catch {
print("Error: \(error)")
}