Precision Tuner

A precision all-in-one tuner for Android: instrument tuner, chromatic tuner with historical temperaments, a metronome, and an ear-training quiz module — with AI-assisted pitch detection (pYIN-lite + Tiny CREPE), a full multi-level settings system with preset themes, and in-app updates.

Features

• 乐器调音 (Instrument tuner) — guitar, bass, ukulele, violin, viola, cello, double bass, 中阮, 琵琶, 二胡, 大阮 with automatic string detection, manual string selection, per-string piano reference tones, and persistent custom tuning presets.
• 半音阶调音 (Chromatic tuner) — three temperaments: 十二平均律 (12-TET), 五度相生律 (Pythagorean), 纯律 (just intonation); a global A4 reference (415–466 Hz) that applies to every tuning mode, the piano reference tone, and survives restarts.
• AI-assisted detection — hybrid pipeline: FFT coarse localization + pYIN-lite refinement, arbitrated against a bundled Tiny CREPE neural model (LiteRT) to reject subharmonic errors. Configurable noise gate, sensitivity threshold, smoothing window and low-pass filter. The neural model is built-time selectable (tiny / small / full).
• 节拍器 (Metronome) — BPM presets, tap tempo, time signatures, subdivisions (eighths / triplets / sixteenths), downbeat accent, circular progress ring, and an instant first-click start (no priming delay).
• 视听练耳 (Ear training) — a game-like quiz module: 单音识别 (note), 音程听辨 (interval), 和弦听辨 (chord), 音阶听辨 (scale), 五线谱识谱 (staff reading) and 节奏听写 (rhythm dictation). Each recognition exercise offers 无尽 (endless), 挑战 (challenge, five lives) and 测试 (fixed-length test) modes with 简单/中等/困难 difficulty presets, played on bundled piano samples with game-style feedback (accuracy ring, lives, sound cues).
• 设置 (Settings) — multi-level sections: 主题 (themes), 调音选项 (tuning), 调弦预设 (presets), 版本信息 (about). Eight system theme presets (午夜蓝 / 森林 / 专业 / 石墨玫瑰 / 暖纸 / 海洋 / 黑金 / 樱花粉) plus custom dark/light mode with six accent colors. 图片主题 can derive three accessible color schemes from a locally imported photo, provides a fixed-screen-ratio crop and zoom editor, and keeps the three most recent backgrounds with independent palette, overlay and adjustable background-blur settings. Imported images stay in app-private storage and are never uploaded. Includes 恢复默认设置 one-tap reset and 检查更新 with in-app APK download and auto-install.
• Adaptive layouts — responsive phone, tablet, portrait and landscape arrangements with stable bottom-bar or navigation-rail shells.
• Visualizations — live spectrum (power-ratio scale with display ceiling, always visible even below the noise gate) and time-domain waveform; three gauge styles (precision rail / dial / scrolling pitch waterfall); dark/light themes with smooth transitions.

Build

The repo pins a writable Gradle home into the workspace (see build.sh for the read-only-~/.gradle workaround) and uses Android Studio's bundled JDK:

./build.sh ./gradlew assembleDebug                     # normal build (DSP-only)
./build.sh ./gradlew -PtinyCrepeEnabled=true assembleDebug            # + CREPE (arm64)
./build.sh ./gradlew -PtinyCrepeEnabled=true -PcrepeModel=small assembleDebug
./build.sh ./gradlew testDebugUnitTest                 # unit tests

Install to a connected device (CREPE enabled by default; pass --no-crepe to install a DSP-only build):

./install-device.sh DEVICE_SERIAL
./install-device.sh DEVICE_SERIAL --no-crepe

The CREPE build is arm64-only; the --no-crepe build keeps all ABIs. See tools/crepe/README.md for the reproducible model conversion pipeline (weights are kept out of Git; hashes are recorded).

Requirements

• Android 7.0+ (minSdk 24), 64-bit arm for the CREPE build.
• Microphone permission for tuning.

联系作者

• QQ: 1005028266 (app 内"版本信息"页可点击复制)

License

MIT — see LICENSE.

Third-party notices

• Tiny CREPE (neural pitch model) — MIT, © 2018 Jong Wook Kim (app/src/main/assets/licenses/CREPE_LICENSE.txt); pretrained weights from marl/crepe, conversion recorded in tools/crepe/convert_crepe.py.
• Kenney Interface Sounds (in-tune cue) — CC0, kenney.nl (app/src/main/assets/licenses/KENNEY_INTERFACE_SOUNDS_LICENSE.txt).
• Piano reference-tone samples — Splendid Grand Piano (Steinway), Public Domain samples by AKAI, conversion by kinwie (app/src/main/assets/licenses/REFERENCE_PIANO_LICENSE.txt).