v1.1.2 - Spatial Audio & UI Improvements

Changes in 1.1.2

• 4-Channel 8D Spatial Audio System:
  • Introduced discrete speaker role assignment (Front, Back, Left, Right) using StrictChannelMatrix and SpatialDspEngine.
  • Built low-latency UDP media transport with LeaderDomainClock presentation PTS timestamps.
  • Added interactive Devices Stage management UI and top-down 3D soundstage preview canvas.
  • Added Host-local dual-mono loopback rendering and atomic session teardown policies.
• High-Precision Acoustic Sync Trim:
  • Upgraded trim resolution to 0.125 ms increments with quick nudge buttons (-0.125ms / +0.125ms / Reset) and 3-decimal readout precision.
  • Made the trim card layout responsive with dynamic typography and compact button padding for small screens.
• Join Screen Clean-Up:
  • Removed the Devices tab from the Join Screen bottom navigation bar to keep channel setup exclusively on the Host.
• Network & Lifecycle Hardening:
  • Added per-packet error isolation in the TCP read loop to prevent socket drops on handler exceptions.
  • Fixed Android foreground service start-in-time race conditions during rapid playback stop/start cycles.

v1.0.2 - Reduced File size

Got rid of unnecessary permission it asked and reduced the file size

v1.0.0 - Initial Release

SyncItBaby (v1.0.0), a high-performance Android engine designed for real-time, sub-millisecond audio playback synchronization across multiple devices in a local Wi-Fi / Hotspot star topology. (that's what chatgpt wrote I don't claim sub-millisecond but hey it's usable atleast)

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Highlights

• Star-Topology Leader/Peer Sync: Seamless local hotspot audio streaming.
• RFC 5905 & 2-State Kalman Clock Discipline Engine: Continuous clock offset and drift rate tracking ($\theta, f$) with 8-slot minimum-RTT filtering and popcorn jitter rejection.
• Native Oboe C++ Audio Engine: Low-latency hardware DAC presentation using lock-free Single-Producer Single-Consumer (SPSC) ring buffers and AAudio MMAP Exclusive Mode.
• Snapcast Discrete Sample Manipulation: Artifact-free discrete sample insertion/duplication ($+1 / -1$ samples) eliminating DSP timestretch pitch warping.
• Real-Time Telemetry UI: Jetpack Compose live telemetry monitor displaying phase error ($\mu\text{s}$), frame delta, buffer depth, and drift velocity.

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Performance Benchmarks

• Lock-in Convergence Time: $< 250\text{ms}$ sub-millisecond synchronization.
• Steady-State Phase Error: $\pm 0.5\text{ms}$ sustained across multi-device playback.
• Audio Codec: Opus 48kHz stereo stream with dynamic jitter buffering.

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Key Fixes & Stability Hardening

• Compensated for hardware DAC and Android 10+ AudioPlaybackCapture HAL input latency anchors (~15.05ms).
• Added bounded rolling packet caching with NACK-based loss recovery and late-join handshake deduplication.

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Installation & Assets

Download the signed release APK below to test on physical devices:

• File: app-release.apk (18.06 MB)
• Supported Android Versions: Android 7.0+ (API 24 to 36)

v1.0.1 - bug fixes

• Added Acoustic Sync Trim manual slider to Host screen when streaming local files.
• Removed Test Metronome Tone button from Join Screen to prevent calibration loops.
• Updated Join Screen title header to show detailed real-time connection status (Buffering, Authenticating, Connected, Weak Connection, Reconnecting, Disconnected).
• Fixed Audio Capture Service persistence so stopping capture properly releases the media projection resources and clears the active notification.
• Fixed live capture routing bug that blocked audio playback on peers after playing a local file.