_engineChMap: key=sfId:bank:prog → allocated MIDI channel.
Mỗi track ARM riêng biệt có engKey khác nhau → allocated channel
riêng (0-8 round-robin). _playNoteFluid lookup channel từ map
thay vì dùng MIDI channel gốc (luôn 0).
Trước đây chỉ schedule noteOff khi delay > 0 (notes scheduled).
Virtual piano keyboard play note immediate (delay===0) với duration=500ms
nhưng không có noteOff → âm thanh play mãi không tắt.
Fix: schedule noteOff khi 0 < durationMs < 60000, không phụ thuộc delay.
- Dùng _fluid_synth_all_sounds_off thay vì CC120
- Log return value của _fluid_synth_noteoff (0=OK, -1=fail)
- Log ch+pitch trong stopNote
- Sửa printErr filter (bỏ check 'stderr')
- synth.gain=2.0 (thay vì 0.5 + set_gain 1.0) để tăng volume
- Pre-zero HEAPF32 buffer trước khi gọi write_float
- Log peak, avg, và value từ _fluid_synth_get_gain để debug
- _fluid_synth_set_gain(1.0) sau khi tạo synth (đảm bảo gain > 0)
- Log noteOn(ch, pitch, vel) mỗi lần play
- Log peak frame đầu tiên khi render > 0.001
- Error log trong catch pushFrame
- Sửa _playNoteFluid: dùng usedBank để xác định ch khi undefined
- Gọi _fluid_synth_error để lấy error message từ C engine
- Fallback từ .sf3 → .sf2 nếu sfload thất bại
- TOTAL_MEMORY=256MB cho SoundFont 11MB
- unlink file cũ trước writeFile tránh MEMFS conflict
- Log MEMFS stat để debug
Module script (type=module) có document.currentScript === null,
nên libfluidsynth không thể tự locate .wasm file. Fix: pass
locateFile() trả về URL .wasm tương ứng với URL .js đã load.
fluidsynthLoader.js: expose __FluidSynthLocateWasm() trả về
FLUIDSYNTH_JS_URL.replace('.js', '.wasm'). Dùng polling
setInterval thay vì resolve callback cho đáng tin cậy hơn.
soundfontPlayer.js: pass locateFile factory khi gọi factory.
Root cause: SpessaSynth's CC123 (All Notes Off) calls stopAllNotes(false)
which enters the SoundFont release envelope. Tremolo Strings (GM#44) and
similar sustained instruments have 2-5s release tails, causing notes to
continue playing after MIDI key release.
Fix: Replace CC 123 with CC 120 (All Sound Off) in stopNote() and
stopAll(). CC 120 calls stopAllNotes(true) which sets voice.isActive=false
instantly, bypassing the release envelope entirely.
Removed redundant noteOff(ch,pitch,0) and resetAllControllers(CC121)
which unnecessarily reset volume/pan/expression on the channel.
- Track sustain state per channel via _sustainStates[]
- sustainActive(channel) returns boolean
- MIDI NoteOn: only send CC123 if !sustainActive(ch)
- Preserves sustained notes when playing new notes
- Scheduled notes (delay>0, timeline playback): still set auto noteOff
- Immediate notes (delay=0, MIDI keyboard): keep sounding until stopNote or stopAll
- Remove _scheduledNotes push/pop for immediate notes (no timeout to track)
- NoteOn: durationMs=60000 (1 phút, giữ cho đến khi NoteOff)
- NoteOff: stopNote(ch, pitch) gọi synthInstance.noteOff() ngay
- MIDI channel (msg.data[0] & 0x0F) truyền đúng vào playNote
- CC (sustain/modulation) + pitch bend forward qua SpessaSynth
- Add controllerChange forwarder for all CC messages (cmd 0xB)
- Add pitchBend method to SonicSF + MIDI handler (cmd 0xE)
- CCs routed to _synthInstance.controllerChange(ch, cc, val)
- Pitch bend routed to _synthInstance.pitchBend(ch, 14bit-val)
- Remove small Synth button (already done earlier)
- Large Synth button now calls openInstrumentSelector (instrument modal)
- Fix _initPromise stale cache: reset to null when init fails
- Module not loaded yet → retries on next select instead of stuck
- Add _currentSfId tracking
- loadSoundFont calls deleteSoundBank(oldId) before addSoundBank(newId)
- Skip reload if same sfId requested
- Prevents bank accumulation in SpessaSynth
Root cause: timeline play passes exactAudioTime as 4th param which
SpessaSynth interprets as enableReverh (boolean). All notes at T=0.
Fix: compute delay = startTime - ctx.currentTime, use setTimeout
to call noteOn(channel, pitch, vel) at correct future time.
Never pass startTime to noteOn() — SpessaSynth doesn't support it.
Per md/38_FLOWCLIENT.md analysis:
- Add _initPromise to serialize concurrent init calls (no duplicate worklet)
- audioContext.resume() before worklet.loadModule
- selectInstrument creates AudioContext + awaits init if not ready
- playNote tries SpessaSynth first, falls back to oscillator on error
- All MIDI commands wrapped in try/catch with oscillator fallback
- Add missing if (_initialized && _synthInstance) return to init()
- soundBank is main-thread proxy, worklet has actual presets
- Check selectablePresetList.length from soundBankManager (worklet state)
- Log when presets are empty (SpessaSynth parser issue)
Root cause: selectInstrument called before getAudioContext triggers init.
_initialized=false → selectInstrument returns immediately → no sound bank.
Fix: selectInstrument creates AudioContext + calls init() if not ready,
waits for completion before proceeding with bank/program routing.
Per md/38_FLOWCLIENT.md Phase 1: SpessaSynth output was not
connected to speakers. Add synth.connect(audioContext.destination)
after construction to route synthesized audio to user speakers.
Per md/38_FLOWCLIENT.md flow:
- _addBankWithTimeout: wraps SpessaSynth addSoundBank with Promise.race
- 15s timeout breaks deadlock when AudioWorklet parser fails silently
- Phase 3 (channel setup) only runs after Phase 2 (load) confirms success
- Falls back to oscillator when bank can't be loaded
- SpessaSynth bank loading fails in AudioWorklet for unknown reason
- Set _initialized=false after init so playNote uses oscillator path
- Server-side FluidSynth render produces authentic SoundFont audio on Export
- playNote logs warning when _currentSfId is null (no bank)
- _playNoteSpessa catches noteOn errors, falls back to _playNoteOsc
- Prevents 'No preset found' from breaking playback
- Add importmap in index.html to map spessasynth_core to CDN URL
- Load spessasynth_lib from CDN directly (with importmap resolving deps)
- WorkerSynthesizer fallback also uses CDN import
- Ensures library and processor use same spessasynth_core version
- Download spessasynth_processor.min.js from CDN, serve as static file
- Change __SpessaSynthCDN to /static/js/services/
- Fix version mismatch between esm.sh library and CDN processor
- Clone ArrayBuffer before sendToWorklet (transfer neuters original)
- Re-await synthInstance.isReady after addSoundBank
- Force controllerChange(0,0,0) + programChange(0,0) after load
- Add _initInProgress flag to prevent concurrent init calls
- Remove auto-loadSoundFont from init (confuses user when loading DSK)
- SF3 loading happens only when user selects an instrument
3dtours