Sonance Player

Sonance Player is an audiophile-grade iOS music player combining a React Native/Expo UI with a high-performance, custom Swift AVAudioEngine backend. It features a dual-node audio graph for gapless playback and equal-power crossfades, a 10-band hardware equalizer, ReplayGain loudness normalization, and native iOS Lock Screen / Control Center integration.

Architecture & Core Audio Engineering

Engineered a high-fidelity iOS music player utilizing a hybrid architecture of React Native/Expo (TypeScript) and a custom native Swift audio engine. By bridging Expo Modules with Apple’s low-level Core Audio APIs, Sonance delivers audiophile-grade digital signal processing (DSP), zero-latency track transitions, and seamless background lock screen controls.

1. Dual-Node AVAudioEngine Audio Graph (Swift)

Employs dual AVAudioPlayerNode instances (playerNodeA & playerNodeB) connected through an AVAudioMixerNode to achieve true gapless playback and smooth equal-power crossfading between consecutive tracks with zero buffer hitching.

2. 10-Band Parametric Hardware Equalizer (AVAudioUnitEQ)

Directly interfaces with Apple’s digital signal processing (DSP) units for real-time frequency shaping (32Hz to 16kHz) and custom preamp gain adjustments, with a bit-perfect bypass mode for purist listening.

3. ReplayGain Loudness Normalization

Reads track and album peak/gain metadata (ITU-R BS.1770 / EBU R128) in Swift to dynamically adjust volume curves and prevent abrupt volume jumps across mixed-source playlists.

4. Native iOS Lock Screen & Remote Command Center (MediaPlayer)

Integrates MPNowPlayingInfoCenter and MPRemoteCommandCenter for lock screen timeline scrubbing, high-resolution album artwork rendering, play/pause/skip commands, and physical headphone/CarPlay controls.

5. System Audio Session & Interruption Management (AVAudioSession)

Robustly manages audio routing changes (Bluetooth, AirPods, CarPlay disconnects) and handles automatic pause/resume cycles during incoming cellular calls and Siri interruptions.

6. Offline-First SQLite Library & Cloud Sync

Built an offline-first SQLite library engine capable of indexing and querying thousands of local and Google Drive cloud-synced tracks in sub-milliseconds with OAuth 2.0 authentication.

7. Automated CI/CD & OTA Updates

Automated macOS-based CI/CD workflows via GitHub Actions for Swift 6 build patching, Xcode archive compilation, and instant EAS Over-The-Air (OTA) deployment.