SoLoudIsolate class

Isolate-safe access to the SoLoud engine for tasks that do not require the main isolate's state.

The SoLoud engine is a singleton in C++ land and can be initialized only from the main isolate via SoLoud. Call SoLoud.instance.init in the main isolate before using this class from another isolate. Once initialized, operations can be safely performed from another isolate because they do not touch the main isolate's SoLoudLoader, AudioSource registry, filters, or playback-event streams.

SoLoudIsolate exposes only those operations. It does not expose init()/deinit(), loading, playback, filters, or the voiceEnded/fileLoaded/stateChanged event streams. Those must remain on the isolate that initialized the engine.

The primary use case is running the mixer output capture stream in a worker isolate so the main isolate stays free for UI and other tasks.

Example:

final isolateCapture = SoLoudIsolate.instance.startMixerOutputStream(
  format: MixerOutputFormat.pcmS16le,
  chunkPCMFrames: 2048,
);
isolateCapture.listen((chunk) { /* process audio bytes */ });

See also the example/lib/mixer_capture/isolate_capture_test.dart for a complete example of running mixer output capture in a separate isolate.

Annotations

• @experimental

Properties

bindings → FlutterSoLoud

The low-level platform bindings. Advanced users can use this to call methods that are safe to invoke from a non-main isolate.

no setter

hashCode → int

The hash code for this object.

no setter, inherited

isInitialized → bool

Whether the native engine is initialized.

no setter

isMixerOutputStreamRunning → bool

Whether mixer output capture is currently active.

no setter

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

getMixerOutputWavHeader() → Uint8List

Returns the current 44-byte WAV header for the active mixer output capture.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

readSamplesFromFile(String completeFileName, int numSamplesNeeded, {double startTime = 0, double endTime = -1, bool average = false}) → Future<Float32List>

//////////////////////////////////////////////// Read samples from file and memory. //////////////////////////////////////////////// This method has the same behavior as SoLoud.readSamplesFromFile (refer to it for a complete documentation) and can be safely called from a non-main isolate. Is not mandatory that the engine is initialized in the main isolate to use this method.

readSamplesFromMem(Uint8List buffer, int numSamplesNeeded, {double startTime = 0, double endTime = -1, bool average = false}) → Future<Float32List>

This method has the same behavior as SoLoud.readSamplesFromMem (refer to it for a complete documentation) and can be safely called from a non-main isolate. Is not mandatory that the engine is initialized in the main isolate to use this method.

startMixerOutputStream({MixerOutputFormat format = MixerOutputFormat.pcmF32le, int sampleRate = -1, int channels = -1, int bufferSizeBytes = 1024 * 1024, int notificationThresholdBytes = 4096, int chunkPCMFrames = -1}) → Stream<Uint8List>

Captures the master mixer output as a Stream of Uint8List chunks.

stopMixerOutputStream() → void

Stops the mixer output capture stream and releases associated resources.

toString() → String

A string representation of this object.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited

Static Properties

instance → SoLoudIsolate

The singleton instance of SoLoudIsolate.

final