PocketMIDI: MIDI Keyboard

PocketMIDI is a free, low-latency MIDI synthesizer and piano app for Android, built for live performance. Whether you're connecting a USB MIDI keyboard on stage or playing the on-screen piano keyboard, PocketMIDI delivers studio-quality sound with a latency target of under 40 ms — fully offline, no ads, no tracking. ────────────────────────────────────── INSTRUMENTS ────────────────────────────────────── • Grand Piano — Salamander Grand Piano V3 (Alexander Holm), 30 root notes spanning the full 88-key range (A0–C8), OGG Vorbis samples. • Strings — rich, expressive orchestral strings with natural attack and release. • Dark Pad — lush, atmospheric pad for ambient and cinematic performance. • Synthesizer — built-in digital synthesizer with PolyBLEP waveforms (sine, saw, square, triangle), full ADSR envelope, and a state-variable filter. ────────────────────────────────────── USB MIDI KEYBOARD SUPPORT ────────────────────────────────────── Connect any class-compliant USB MIDI keyboard via OTG adapter. PocketMIDI automatically detects the device and routes MIDI note on/off and sustain pedal (CC64) events directly to the audio engine with minimal overhead. • Auto-launch when a keyboard is connected (optional) • Full polyphony: up to 96 simultaneous voices (64 sample + 32 synth) • Velocity sensitivity and sustain pedal support ────────────────────────────────────── ON-SCREEN KEYBOARD ────────────────────────────────────── • 2-octave multi-touch piano keyboard (C3–C5) • Up to 10 simultaneous touches for polyphonic playing • Velocity-sensitive: tap position affects note velocity • Amber highlight on pressed keys ────────────────────────────────────── ARPEGGIATOR ────────────────────────────────────── • Selectable patterns, rates (including triplets), octave span, gate, and latch • Auto-plays as you hold keys — tap Latch to keep it running hands-free • Tap-to-type BPM input, synced with the metronome • Chord mode: tap chord buttons while playing to trigger full chords and arpeggios in real time ────────────────────────────────────── SYNTH EDITOR ────────────────────────────────────── When the Synthesizer instrument is selected, a full synth editor is available: • Waveform selector: Sine, Saw, Square, Triangle • ADSR envelope: Attack (1 ms–4 s), Decay (1 ms–4 s), Sustain (0–100%), Release (1 ms–8 s) • Low-pass filter: Cutoff and Resonance ────────────────────────────────────── PRESETS ────────────────────────────────────── • Save your favourite instrument and synth settings as named presets • Load presets instantly during a performance • Export all presets to a JSON file and share via any app • Import presets from a JSON file ────────────────────────────────────── MIDI RECORDING ────────────────────────────────────── • Record everything you play and review it in a real-time piano roll • Fixed-timeline playback with moving playhead; pinch-to-zoom and pan ────────────────────────────────────── METRONOME ────────────────────────────────────── • Built-in click track: 20–300 BPM • Time signatures: 2/4, 3/4, 4/4, 6/8, 7/8, 5/4 • Visual pulse animation on the status bar ────────────────────────────────────── PERFORMANCE & SETTINGS ────────────────────────────────────── • Real-time performance monitor: active voices, buffer size, sample rate, estimated latency, buffer underruns • Fully offline — no internet connection required, no ads, no tracking ────────────────────────────────────── TECHNICAL ────────────────────────────────────── • Audio engine: Oboe 1.9.0 (AAudio with OpenSL ES fallback) • Audio buffer: ~4 ms @ 192 frames, 48 kHz • Automatic stream restart with exponential backoff • Minimum Android 8.0 (API 26) ────────────────────────────────────── ATTRIBUTIONS ────────────────────────────────────── Salamander Grand Piano V3 samples by Alexander Holm are used under the Creative Commons Attribution 3.0 license (CC BY 3.0). No modifications were made to the samples. https://creativecommons.org/licenses/by/3.0/