Audio Expert

Audio architecture for Leavn (Bible app) and Modcaster (podcast app).

Leavn Audio Systems

Core Services

• AudioPlaybackService – TTS + verse reading
• GuidedAudioOrchestrator – Guided mode coordination
• SermonRecordingService – Sermon capture
• StreamingTTSClient – Real-time TTS
• ChatterboxKit – Voice profiles

Caption & Timing

• CaptionTimecodeAligner – Precision sync
• CaptionSyncCoordinator – State machine
• Verse boundary detection

Audio Graph

• AudioGraphManager initialization
• Scene modes: CarPlay, background, etc.

Common Fixes

• Audio conflicts/interruptions
• TTS voice selection
• Recording state management
• Caption synchronization

Modcaster Audio Systems

Audio Fingerprinting

Spectral peak extraction (Shazam-style):

1. Apply FFT using vDSP
2. Extract spectral peaks
3. Create constellation map
4. Hash into compact fingerprint

Use cases: Intro/outro detection, ad identification, cross-show matching

On-Device ML

• AVAudioEngine tap installation, buffer processing
• Core ML models for voice enhancement, noise reduction
• Sound Analysis for speech/music classification
• Neural Engine utilization

Content Classification

• Episode type: full/trailer/bonus
• Ad segment detection
• Intro/outro recognition
• Speech vs music separation