VoxaTrace/com.musicmuni.voxatrace.sonix/SonixLessonSynthesizer

SonixLessonSynthesizer

Synthesizes audio lessons from note sequences.

What is Lesson Synthesis?

A lesson is a sequence of notes (e.g. Sa, Re, Ga, Ma, Pa, Dha, Ni in Indian classical practice), each with its own audio recording. This synthesizer:

Combines individual note recordings into a complete lesson
Applies proper timing based on beat length
Handles crossfades and loop smoothing
Adds configurable silence at start/end

When to Use

Scenario	Use This?	Why
Generate lesson audio	Yes	Core use case
Create practice tracks	Yes	From note sequence
Synthesize from MIDI	No	Use `SonixMidiSynthesizer`
Play existing audio	No	Use `SonixPlayer`

Quick Start

Kotlin

val notes = listOf(
    LessonNote(
        noteName = "Sa",
        noteLabel = "S",
        noteAudioFilePath = "/path/to/sa.wav",
        numBeats = 2,
        numSamplesConsonant = 100
    ),
    LessonNote(
        noteName = "Re",
        noteLabel = "R",
        noteAudioFilePath = "/path/to/re.wav",
        numBeats = 2,
        numSamplesConsonant = 100
    )
)

val synth = SonixLessonSynthesizer.create(
    notes = notes,
    beatLengthMs = 500
)

if (synth.loadAudioSync()) {
    val audioData = synth.synthesize()
    // audioData is ready to play or save
}

synth.release()

Swift

let notes = [
    LessonNote(
        noteName: "Sa",
        noteLabel: "S",
        noteAudioFilePath: "/path/to/sa.wav",
        numBeats: 2,
        numSamplesConsonant: 100
    ),
    LessonNote(
        noteName: "Re",
        noteLabel: "R",
        noteAudioFilePath: "/path/to/re.wav",
        numBeats: 2,
        numSamplesConsonant: 100
    )
]

let synth = SonixLessonSynthesizer.create(
    notes: notes,
    beatLengthMs: 500
)

// Load audio (async)
if await synth.loadAudio() {
    if let audioData = synth.synthesize() {
        // audioData is ready to play or save
    }
}

synth.release()

Builder Pattern (Advanced)

Kotlin

val synth = SonixLessonSynthesizer.Builder()
    .notes(noteList)
    .beatLengthMs(500)
    .silenceBeats(start = 2, end = 2)
    .sampleRate(44100)
    .onError { error -> println("Error: $error") }
    .build()