SonixPlayer

Unified audio player for playback with pitch shifting and tempo control.

What is SonixPlayer?

SonixPlayer plays audio files with real-time control over:

• Pitch: Shift up/down by semitones without affecting speed

• Tempo: Speed up/slow down without affecting pitch

• Volume: Control playback volume

• Looping: Repeat audio any number of times

Use it for:

• Karaoke apps: Play backing tracks with pitch/tempo adjustment

• Music practice: Slow down songs to learn parts

• Audio players: Standard playback with seek and loop

Quick Start

Kotlin

val player = SonixPlayer.create("song.mp3")
player.play()
// Later...
player.pause()
player.release()

Swift

let player = try await SonixPlayer.create(source: "song.mp3")
player.play()
// Later...
player.pause()
player.release()

Usage Tiers

Tier 1: Zero-Config (80% of users)

Kotlin

val player = SonixPlayer.create("song.mp3")
player.play()

Swift

let player = try await SonixPlayer.create(source: "song.mp3")
player.play()

Tier 2: With Config (15% of users)

Kotlin

val config = SonixPlayerConfig.Builder()
    .volume(0.8f)
    .pitch(-2f)        // Lower by 2 semitones
    .tempo(0.75f)      // 75% speed
    .loopCount(3)      // Repeat 3 times
    .onComplete { println("Done!") }
    .build()
val player = SonixPlayer.create("song.mp3", config)

Swift

let config = SonixPlayerConfig.Builder()
    .volume(0.8)
    .pitch(-2)
    .tempo(0.75)
    .loopCount(3)
    .onComplete { print("Done!") }
    .build()
let player = try await SonixPlayer.create(source: "song.mp3", config: config)

Tier 3: Runtime Control (5% of users)

Kotlin

player.pitch = -3f      // Change key at runtime
player.tempo = 0.5f     // Slow down to half speed
player.volume = 0.5f    // Reduce volume

Platform Notes

iOS

• Uses AVFoundation under the hood

• Supports M4A, MP3, WAV, and other system-supported formats

• Audio session automatically configured for playback

Android

• Uses ExoPlayer under the hood

• Supports M4A, MP3, WAV, OGG, and other ExoPlayer-supported formats

• Audio focus handled automatically

Common Pitfalls

1. Forgetting to release: Call player.release() to free resources

2. File not found: Ensure path is accessible (bundle/assets on iOS/Android)

3. Extreme tempo values: Keep between 0.25 and 4.0 for quality audio

4. Using after release: Create a new player if you need to play again

See also