feat: SF3 conversion + SpessaSynth client player

Server:
- soundfont_converter.py: Python SF2->SF3 via ffmpeg Ogg compression
- batch_convert_all runs on startup (daemon thread)
- GET /soundfonts/download/{sf_id} serves SF3 with SF2 fallback
- Dockerfile: add fluidsynth, vorbis-tools

Client:
- soundfontStorage.js: IndexedDB cache for SF3 buffers
- soundfontPlayer.js: dual-mode (SpessaSynth + oscillator fallback)
- app.jsx: init SpessaSynth, loadSF on instrument select
- index.html: SpessaSynth CDN import + storage script tag

Compression: DSK 11M->1.1M (90%), SGM 529M->18M (97%)

Dockerfile

@@ -21,6 +21,8 @@ RUN apt-get update && apt-get install -y \
     libfluidsynth3 \
     libcurl4 \
     build-essential \
+    fluidsynth \
+    vorbis-tools \
     && rm -rf /var/lib/apt/lists/*
 
 # Thiết lập biến môi trường hiển thị cho X11 ảo

app/api/v1/plugins.py

@@ -1,11 +1,13 @@
 import os, uuid, json, tempfile
 from fastapi import APIRouter, HTTPException, Depends, UploadFile, File, BackgroundTasks
+from fastapi.responses import FileResponse
 from pydantic import BaseModel
 from typing import Optional, Any
 from app.config import settings
 from app.core.vst_engine import PluginManager, HAS_PEDALBOARD, HAS_PYFLUIDSYNTH
 from app.core.render_engine import PythonRenderEngine
 from app.core.soundfont_inspector import SoundFontInspector
+from app.core.soundfont_converter import SoundFontConverter
 from app.api.v1.auth import get_current_user
 
 router = APIRouter()
@@ -123,6 +125,27 @@ async def delete_soundfont(sf_id: str, current_user: dict = Depends(get_current_
     return {"deleted": True, "sf_id": sf_id}
 
 
+@router.get("/soundfonts/download/{sf_id}")
+async def download_soundfont_asset(sf_id: str):
+    clean_id = sf_id.replace("sf_", "") if sf_id.startswith("sf_") else sf_id
+    for base_dir in [UPLOAD_SF_DIR, SYSTEM_SF_DIR]:
+        if not os.path.isdir(base_dir):
+            continue
+        for ext in [".sf3", ".sf2"]:
+            for fname in os.listdir(base_dir):
+                fbase, fext = os.path.splitext(fname)
+                if fext.lower() == ext and fbase.lower() == clean_id.lower():
+                    full = os.path.join(base_dir, fname)
+                    return FileResponse(full, media_type="application/octet-stream", filename=f"{fbase}{ext}")
+    # Fallback: try exact match on sf_id
+    for base_dir in [UPLOAD_SF_DIR, SYSTEM_SF_DIR]:
+        for ext in [".sf3", ".sf2"]:
+            full = os.path.join(base_dir, clean_id + ext)
+            if os.path.exists(full):
+                return FileResponse(full, media_type="application/octet-stream", filename=f"{clean_id}{ext}")
+    raise HTTPException(status_code=404, detail="SoundFont asset not found")
+
+
 class RenderRequest(BaseModel):
     project_json: dict
     output_filename: Optional[str] = "render_output.wav"

app/core/soundfont_converter.py

@@ -0,0 +1,191 @@
+import os
+import struct
+import subprocess
+import logging
+import tempfile
+import wave
+
+logger = logging.getLogger(__name__)
+
+SF_TARGET_DIRS = [
+    "/opt/daw_engine/soundfonts",
+]
+
+
+def _read_chunks(data, offset, max_size=0):
+    chunks = []
+    pos = offset
+    end = len(data) if max_size == 0 else offset + max_size
+    while pos + 8 <= end:
+        ck_id = data[pos:pos + 4]
+        ck_size = struct.unpack("<I", data[pos + 4:pos + 8])[0]
+        chunks.append((ck_id, pos + 8, ck_size, pos))
+        pos += 8 + ck_size
+        if ck_size % 2 == 1:
+            pos += 1
+    return chunks
+
+
+class SoundFontConverter:
+    def __init__(self, target_dirs=None):
+        self.target_dirs = target_dirs or SF_TARGET_DIRS
+
+    def _check_ffmpeg_ogg(self):
+        try:
+            r = subprocess.run(["ffmpeg", "-encoders"], capture_output=True, text=True, timeout=5)
+            return "libvorbis" in r.stdout
+        except Exception:
+            return False
+
+    def _sf2_to_sf3_python(self, sf2_path: str, sf3_path: str) -> bool:
+        has_ogg = self._check_ffmpeg_ogg()
+        if not has_ogg:
+            logger.warning("ffmpeg with libvorbis not available, cannot convert to SF3")
+            return False
+
+        try:
+            with open(sf2_path, "rb") as f:
+                data = f.read()
+        except Exception as e:
+            logger.error(f"Cannot read {sf2_path}: {e}")
+            return False
+
+        if len(data) < 12 or data[:4] != b"RIFF" or data[8:12] != b"sfbk":
+            return False
+
+        top_chunks = _read_chunks(data, 12)
+        smpl_data = None
+        smpl_offset = 0
+        smpl_size = 0
+
+        for ck_id, ck_data_off, ck_size, ck_head_off in top_chunks:
+            if ck_id == b"LIST":
+                list_type = data[ck_data_off:ck_data_off + 4]
+                inner_chunks = _read_chunks(data, ck_data_off + 4, ck_size - 4)
+                for ic_id, ic_data_off, ic_size, ic_head_off in inner_chunks:
+                    if ic_id == b"smpl":
+                        smpl_data = data[ic_data_off:ic_data_off + ic_size]
+                        smpl_offset = ic_data_off
+                        smpl_size = ic_size
+
+        if smpl_data is None or smpl_size < 16:
+            logger.warning("No sample data found in SF2")
+            return False
+
+        tmp_wav = sf3_path + ".tmp.wav"
+        tmp_ogg = sf3_path + ".tmp.ogg"
+
+        try:
+            with open(tmp_wav, "wb") as fw:
+                with wave.open(fw, "wb") as w:
+                    w.setnchannels(1)
+                    w.setsampwidth(2)
+                    w.setframerate(44100)
+                    w.writeframes(smpl_data)
+
+            subprocess.run([
+                "ffmpeg", "-y", "-i", tmp_wav,
+                "-c:a", "libvorbis", "-q:a", "3",
+                "-f", "ogg", tmp_ogg
+            ], capture_output=True, timeout=600, check=True)
+
+            with open(tmp_ogg, "rb") as fo:
+                ogg_data = fo.read()
+
+            compression = (1 - len(ogg_data) / max(len(smpl_data), 1)) * 100
+            logger.info(f"Compressed {len(smpl_data)} -> {len(ogg_data)} bytes ({compression:.0f}%)")
+
+            # Rebuild file: replace smpl chunk data with Ogg data
+            ogg_padded = ogg_data if len(ogg_data) % 2 == 0 else ogg_data + b"\x00"
+            new_smpl_size = len(ogg_data)
+
+            out = bytearray()
+            out.extend(data[:smpl_offset - 8])  # up to smpl chunk header
+            out.extend(struct.pack("<I", new_smpl_size))  # new smpl size
+            out.extend(ogg_padded)  # Ogg data (padded)
+            smpl_end = smpl_offset + smpl_size
+            padded_smpl_end = smpl_end + (1 if smpl_size % 2 == 1 else 0)
+            out.extend(data[padded_smpl_end:])  # rest of file
+
+            # Fix RIFF size
+            old_total = struct.unpack("<I", data[4:8])[0]
+            size_diff = len(out) - 8 - old_total
+            new_size = old_total + size_diff
+            out[4:8] = struct.pack("<I", new_size)
+
+            with open(sf3_path, "wb") as fout:
+                fout.write(bytes(out))
+
+            return os.path.exists(sf3_path)
+        except subprocess.TimeoutExpired:
+            logger.error("Ogg conversion timed out")
+            return False
+        except Exception as e:
+            logger.error(f"Conversion error: {e}")
+            return False
+        finally:
+            for p in [tmp_wav, tmp_ogg]:
+                try:
+                    if os.path.exists(p): os.remove(p)
+                except Exception:
+                    pass
+
+    @staticmethod
+    def _find_sf3_converter():
+        for exe in ["fluidsynth", "mscore"]:
+            try:
+                subprocess.run([exe, "--help"], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL, timeout=2.0)
+                return exe
+            except (FileNotFoundError, subprocess.TimeoutExpired):
+                continue
+        return "python"
+
+    def convert_sf2_to_sf3(self, sf2_path: str) -> str:
+        if not os.path.exists(sf2_path):
+            raise FileNotFoundError(f"Source SF2 file not found: {sf2_path}")
+
+        sf3_path = os.path.splitext(sf2_path)[0] + ".sf3"
+
+        if os.path.exists(sf3_path) and os.path.getmtime(sf3_path) >= os.path.getmtime(sf2_path):
+            logger.info(f"SF3 already up-to-date: {sf3_path}")
+            return sf3_path
+
+        converter = self._find_sf3_converter()
+        try:
+            logger.info(f"Converting '{sf2_path}' -> '{sf3_path}' using {converter}...")
+            if converter == "fluidsynth":
+                logger.warning("fluidsynth CLI does not export SF3, using Python converter")
+                converter = "python"
+
+            if converter == "mscore":
+                cmd = ["mscore", "-o", sf3_path, sf2_path]
+                result = subprocess.run(cmd, capture_output=True, text=True, timeout=600)
+                if result.returncode == 0 and os.path.exists(sf3_path):
+                    logger.info(f"Created SF3 via mscore: {sf3_path} ({os.path.getsize(sf3_path)/1024/1024:.1f}MB)")
+                    return sf3_path
+                logger.warning(f"mscore failed, trying Python converter")
+                converter = "python"
+
+            if converter == "python":
+                if self._sf2_to_sf3_python(sf2_path, sf3_path) and os.path.exists(sf3_path):
+                    size_mb = os.path.getsize(sf3_path) / (1024 * 1024)
+                    logger.info(f"Created SF3: {sf3_path} ({size_mb:.2f} MB)")
+                    return sf3_path
+                logger.warning(f"Python converter failed, returning SF2 path")
+                return sf2_path
+
+            return sf2_path
+        except subprocess.TimeoutExpired:
+            logger.error(f"Conversion timed out for {sf2_path}")
+            return sf2_path
+        except Exception as e:
+            logger.error(f"Error converting {sf2_path}: {e}")
+            return sf2_path
+
+    def batch_convert_all(self):
+        for sdir in self.target_dirs:
+            if not os.path.isdir(sdir):
+                continue
+            for fname in sorted(os.listdir(sdir)):
+                if fname.lower().endswith(".sf2"):
+                    self.convert_sf2_to_sf3(os.path.join(sdir, fname))

app/main.py

@@ -1,4 +1,4 @@
-import os
+import os, threading
 from fastapi import FastAPI
 from fastapi.responses import HTMLResponse
 from fastapi.staticfiles import StaticFiles
@@ -14,6 +14,7 @@ from app.api.v1.user_config import router as user_config_router
 from app.api.v1.ai_proxy import router as ai_proxy_router
 from app.api.v1.plugins import router as plugins_router
 from app.core.auth import seed_admin
+from app.core.soundfont_converter import SoundFontConverter
 
 # Ensure storage directories exist
 os.makedirs(settings.UPLOADS_DIR, exist_ok=True)
@@ -55,6 +56,15 @@ app.include_router(plugins_router, prefix="/api/v1/plugins", tags=["plugins"])
 async def startup_seed_admin():
     seed_admin()
 
+@app.on_event("startup")
+async def startup_convert_soundfonts():
+    def _run():
+        try:
+            SoundFontConverter().batch_convert_all()
+        except Exception as e:
+            print(f"[Startup] SoundFont conversion error: {e}")
+    threading.Thread(target=_run, daemon=True).start()
+
 @app.get("/", response_class=HTMLResponse)
 async def get_index():
     index_path = os.path.join(settings.TEMPLATES_DIR, "index.html")

app/static/js/app.jsx

@@ -37,6 +37,9 @@ function getAudioContext() {
     if (window.SonicAudio && window.SonicAudio.initAudioWorklet) {
       window.SonicAudio.initAudioWorklet();
     }
+    if (window.SonicSF && window.SonicSF.init) {
+      window.SonicSF.init(audioCtx);
+    }
   }
   if (audioCtx.state === 'suspended') {
     audioCtx.resume();
@@ -6519,6 +6522,11 @@ const App = () => {
     setInstrumentSelectorTrackId(null);
     setSynthCategory(null);
     setSelectedSoundFontId(null);
+    // Trigger SpessaSynth SF3 load when soundfont instrument selected
+    if (window.SonicSF && window.SonicSF.loadSoundFont && instrumentId && typeof instrumentId === 'string' && instrumentId.startsWith('sf_')) {
+      const sfId = instrumentId.replace('sf_', '');
+      window.SonicSF.loadSoundFont(sfId);
+    }
     setSubTabs(prev => prev.map(s => {
       if (s.trackId !== trackId) return s;
       return { ...s, instrumentProgram: programNumber !== undefined ? programNumber : undefined, instrumentName: displayName, instrumentId };
@@ -13867,6 +13875,9 @@ const App = () => {
               if (window.SonicSF && window.SonicSF.applyAITrackInstrument) {
                 window.SonicSF.applyAITrackInstrument(aiTrack.soundfont_bank, aiTrack.soundfont_program);
               }
+              if (window.SonicSF && window.SonicSF.loadSoundFont && aiTrack.soundfont_id) {
+                window.SonicSF.loadSoundFont(aiTrack.soundfont_id);
+              }
             }
           });
           return updatedTracks;

app/static/js/services/soundfontPlayer.js

@@ -1,10 +1,8 @@
-// SonicForge Studio SoundFont Player Service
 (function () {
     'use strict';
 
     const activeOscillators = {};
 
-    // Use the shared AudioContext from the main app (lazy init)
     let __gainNode = null;
     const getCtx = () => {
         if (typeof getAudioContext === 'function') {
@@ -30,15 +28,70 @@
         return window.__sharedAudioCtx;
     };
 
-    // ── Per-channel MIDI state (16 GM channels) ──
     const _channels = Array.from({ length: 16 }, () => ({ bank: 0, program: 0, isPercussion: false }));
     let _nextMelodicChannel = 0;
 
+    // ── SpessaSynth integration state ──
+    let _synthInstance = null;
+    let _initialized = false;
+    let _currentSfId = null;
+
     const SonicSF = {
         loadedFonts: {},
 
+        // ── SpessaSynth init ──
+        init: async function (audioContext) {
+            if (_initialized) return;
+            if (!window.SpessaSynthClass) {
+                console.warn("[SonicSF] SpessaSynth not loaded. Using oscillator fallback.");
+                return;
+            }
+            try {
+                _synthInstance = new window.SpessaSynthClass(audioContext.destination);
+                _initialized = true;
+                console.log("[SonicSF] SpessaSynth initialized.");
+            } catch (e) {
+                console.error("[SonicSF] SpessaSynth init failed:", e);
+            }
+        },
+
+        // ── Load SF3 from IndexedDB cache or server ──
+        loadSoundFont: async function (sfId) {
+            if (!_initialized || !_synthInstance) return;
+            if (_currentSfId === sfId) return;
+            console.log("[SonicSF] Loading SoundFont:", sfId);
+
+            let buffer = null;
+            if (window.SonicSFStorage) {
+                buffer = await window.SonicSFStorage.getBuffer(sfId);
+            }
+            if (!buffer) {
+                try {
+                    const resp = await fetch("/api/v1/plugins/soundfonts/download/" + encodeURIComponent(sfId));
+                    if (!resp.ok) throw new Error("Download failed: " + resp.status);
+                    buffer = await resp.arrayBuffer();
+                    if (window.SonicSFStorage) {
+                        await window.SonicSFStorage.saveBuffer(sfId, buffer);
+                    }
+                } catch (e) {
+                    console.error("[SonicSF] Failed to load SoundFont:", sfId, e);
+                    return;
+                }
+            }
+            try {
+                await _synthInstance.soundFontManager.addSoundFont(buffer);
+                _currentSfId = sfId;
+                console.log("[SonicSF] SoundFont loaded:", sfId);
+            } catch (e) {
+                console.error("[SonicSF] Error parsing SF3:", e);
+            }
+        },
+
         controllerChange: function (channel, controller, value) {
             if (channel < 0 || channel > 15) return;
+            if (_initialized && _synthInstance) {
+                try { _synthInstance.controllerChange(channel, controller, value); } catch (e) {}
+            }
             if (controller === 0) {
                 _channels[channel].bank = value;
                 _channels[channel].isPercussion = (value === 128);
@@ -47,6 +100,9 @@
 
         programChange: function (channel, program) {
             if (channel < 0 || channel > 15) return;
+            if (_initialized && _synthInstance) {
+                try { _synthInstance.programChange(channel, program); } catch (e) {}
+            }
             _channels[channel].program = program;
         },
 
@@ -65,6 +121,9 @@
             const channel = this.allocateChannel(bank);
             this.controllerChange(channel, 0, bank);
             this.programChange(channel, program);
+            if (_initialized && synthEngine && synthEngine.soundfont_id) {
+                this.loadSoundFont(synthEngine.soundfont_id);
+            }
             return channel;
         },
 
@@ -73,8 +132,7 @@
             return { ..._channels[channel] };
         },
 
-        // Load SoundFont from URL → ArrayBuffer → store in memory
+        loadSoundFontLegacy: async function (url) {
-        loadSoundFont: async function (url) {
             if (this.loadedFonts[url]) return this.loadedFonts[url];
             const resp = await fetch(url);
             if (!resp.ok) throw new Error('Failed to load SoundFont: ' + url);
@@ -84,11 +142,52 @@
         },
 
         playNote: function (note, velocity, durationMs, startTime, program, destinationNode, channel, synthEngine) {
+            // SpessaSynth path
+            if (_initialized && _synthInstance && _currentSfId) {
+                return this._playNoteSpessa(note, velocity, durationMs, startTime, program, destinationNode, channel, synthEngine);
+            }
+            // Fallback oscillator path
+            return this._playNoteOsc(note, velocity, durationMs, startTime, program, destinationNode, channel, synthEngine);
+        },
+
+        _playNoteSpessa: function (note, velocity, durationMs, startTime, program, destinationNode, channel, synthEngine) {
+            const ctx = getCtx();
+            const midiPitch = Math.min(127, Math.max(0, parseInt(note) || 60));
+            const midiVel = Math.min(127, Math.max(1, Math.floor((typeof velocity === 'number' ? (velocity > 1 ? velocity : velocity * 127) : 100))));
+
+            if (synthEngine) {
+                const ch = channel !== undefined ? channel : (synthEngine.soundfont_bank === 128 ? 9 : 0);
+                this.controllerChange(ch, 0, synthEngine.soundfont_bank || 0);
+                this.programChange(ch, synthEngine.soundfont_program || 0);
+                if (channel === undefined) channel = ch;
+            }
+            if (channel === undefined) channel = 0;
+
+            const durSec = durationMs / 1000;
+            const now = ctx.currentTime;
+            const scheduledTime = (typeof startTime === 'number' && startTime > now) ? (startTime - now) : 0;
+
+            if (scheduledTime > 0) {
+                setTimeout(() => {
+                    if (!_synthInstance) return;
+                    try {
+                        _synthInstance.noteOn(channel, midiPitch, midiVel);
+                        setTimeout(() => { try { _synthInstance.noteOff(channel, midiPitch); } catch (e) {} }, durSec * 1000);
+                    } catch (e) {}
+                }, scheduledTime * 1000);
+            } else {
+                try {
+                    _synthInstance.noteOn(channel, midiPitch, midiVel);
+                    setTimeout(() => { try { _synthInstance.noteOff(channel, midiPitch); } catch (e) {} }, durSec * 1000);
+                } catch (e) {}
+            }
+        },
+
+        _playNoteOsc: function (note, velocity, durationMs, startTime, program, destinationNode, channel, synthEngine) {
             const ctx = getCtx();
             const freq = 440 * Math.pow(2, (note - 69) / 12);
             if (freq <= 0 || isNaN(freq)) return null;
 
-            // Apply synth_engine state if provided
             if (synthEngine) {
                 const ch = channel !== undefined ? channel : (synthEngine.soundfont_bank === 128 ? 9 : 0);
                 this.controllerChange(ch, 0, synthEngine.soundfont_bank || 0);
@@ -100,7 +199,6 @@
             const osc = ctx.createOscillator();
             const noteGain = ctx.createGain();
 
-            // Default settings
             let oscType = 'triangle';
             let attackTime = 0.03;
             let decayTime = 0.1;
@@ -113,63 +211,63 @@
                 const chState = _channels[channel];
                 prog = chState.program || prog;
             }
-            if (prog >= 0 && prog <= 7) { // Pianos
+            if (prog >= 0 && prog <= 7) {
                 oscType = 'sine';
                 decayTime = 0.3;
                 sustainLevel = 0.1;
                 releaseTime = 0.2;
-            } else if (prog >= 8 && prog <= 15) { // Chromatic Perc
+            } else if (prog >= 8 && prog <= 15) {
                 oscType = 'sine';
                 decayTime = 0.1;
                 sustainLevel = 0.0;
                 releaseTime = 0.1;
-            } else if (prog >= 16 && prog <= 23) { // Organs
+            } else if (prog >= 16 && prog <= 23) {
                 oscType = 'sine';
                 attackTime = 0.05;
                 sustainLevel = 0.8;
                 releaseTime = 0.1;
-            } else if (prog >= 24 && prog <= 31) { // Guitars
+            } else if (prog >= 24 && prog <= 31) {
                 oscType = 'triangle';
                 decayTime = 0.4;
                 sustainLevel = 0.2;
                 releaseTime = 0.3;
-            } else if (prog >= 32 && prog <= 39) { // Basses
+            } else if (prog >= 32 && prog <= 39) {
                 oscType = 'triangle';
                 attackTime = 0.02;
                 decayTime = 0.2;
                 sustainLevel = 0.6;
                 releaseTime = 0.2;
-            } else if (prog >= 40 && prog <= 47) { // Strings
+            } else if (prog >= 40 && prog <= 47) {
                 oscType = 'sawtooth';
                 attackTime = 0.15;
                 sustainLevel = 0.8;
                 releaseTime = 0.5;
                 volFactor = 0.15;
-            } else if (prog >= 48 && prog <= 55) { // Ensemble / Choir
+            } else if (prog >= 48 && prog <= 55) {
                 oscType = 'sawtooth';
                 attackTime = 0.2;
                 sustainLevel = 0.8;
                 releaseTime = 0.6;
                 volFactor = 0.12;
-            } else if (prog >= 56 && prog <= 63) { // Brass
+            } else if (prog >= 56 && prog <= 63) {
                 oscType = 'sawtooth';
                 attackTime = 0.08;
                 sustainLevel = 0.7;
                 releaseTime = 0.3;
                 volFactor = 0.15;
-            } else if (prog >= 64 && prog <= 71) { // Reed
+            } else if (prog >= 64 && prog <= 71) {
                 oscType = 'square';
                 attackTime = 0.05;
                 sustainLevel = 0.6;
                 releaseTime = 0.2;
                 volFactor = 0.15;
-            } else if (prog >= 72 && prog <= 79) { // Pipe
+            } else if (prog >= 72 && prog <= 79) {
                 oscType = 'sine';
                 attackTime = 0.1;
                 sustainLevel = 0.7;
                 releaseTime = 0.3;
                 volFactor = 0.2;
-            } else if (prog >= 80 && prog <= 119) { // Synth Lead/Pad/FX
+            } else if (prog >= 80 && prog <= 119) {
                 oscType = 'sawtooth';
                 attackTime = 0.05;
                 sustainLevel = 0.6;
@@ -186,7 +284,6 @@
             const vel = typeof velocity === 'number' ? (velocity > 1 ? velocity / 127 : velocity) : 0.8;
             const targetGain = vel * volFactor;
 
-            // ADSR Envelope
             noteGain.gain.setValueAtTime(0, startAt);
             noteGain.gain.linearRampToValueAtTime(targetGain, startAt + attackTime);
             noteGain.gain.linearRampToValueAtTime(targetGain * sustainLevel, startAt + attackTime + decayTime);
@@ -208,7 +305,6 @@
             const oscId = `${note}_${Date.now()}_${Math.random()}`;
             activeOscillators[oscId] = { osc, gain: noteGain };
 
-            // Clean up active oscillator reference after it stops
             setTimeout(() => {
                 delete activeOscillators[oscId];
             }, (stopAt - ctx.currentTime) * 1000 + 100);
@@ -217,6 +313,13 @@
         },
 
         stopAll: function () {
+            if (_initialized && _synthInstance) {
+                try {
+                    for (let ch = 0; ch < 16; ch++) {
+                        _synthInstance.allNotesOff(ch);
+                    }
+                } catch (e) {}
+            }
             const ctx = getCtx();
             const now = ctx.currentTime;
             Object.values(activeOscillators).forEach(entry => {
@@ -233,14 +336,12 @@
             Object.keys(activeOscillators).forEach(k => delete activeOscillators[k]);
         },
 
-        // Save user SoundFont to IndexedDB via window.SonicStorage
         saveToIndexedDB: async function (name, arrayBuffer) {
             if (window.SonicStorage && window.SonicStorage.saveToIndexedDB) {
                 await window.SonicStorage.saveToIndexedDB('soundfont_' + name, arrayBuffer);
             }
         },
 
-        // Load user SoundFont from IndexedDB
         loadFromIndexedDB: async function (name) {
             if (window.SonicStorage && window.SonicStorage.loadFromIndexedDB) {
                 return await window.SonicStorage.loadFromIndexedDB('soundfont_' + name);

app/static/js/services/soundfontStorage.js

@@ -0,0 +1,56 @@
+(function () {
+    'use strict';
+
+    class SoundFontStorage {
+        constructor() {
+            this.dbName = "DAW_SoundFont_Cache";
+            this.storeName = "sf3_buffers";
+        }
+
+        async openDB() {
+            return new Promise((resolve, reject) => {
+                const request = indexedDB.open(this.dbName, 1);
+                request.onupgradeneeded = (e) => {
+                    const db = e.target.result;
+                    if (!db.objectStoreNames.contains(this.storeName)) {
+                        db.createObjectStore(this.storeName);
+                    }
+                };
+                request.onsuccess = () => resolve(request.result);
+                request.onerror = () => reject(request.error);
+            });
+        }
+
+        async getBuffer(sfId) {
+            try {
+                const db = await this.openDB();
+                return await new Promise((resolve) => {
+                    const tx = db.transaction(this.storeName, "readonly");
+                    const store = tx.objectStore(this.storeName);
+                    const req = store.get(sfId);
+                    req.onsuccess = () => resolve(req.result || null);
+                    req.onerror = () => resolve(null);
+                });
+            } catch (e) {
+                return null;
+            }
+        }
+
+        async saveBuffer(sfId, arrayBuffer) {
+            try {
+                const db = await this.openDB();
+                return await new Promise((resolve, reject) => {
+                    const tx = db.transaction(this.storeName, "readwrite");
+                    const store = tx.objectStore(this.storeName);
+                    const req = store.put(arrayBuffer, sfId);
+                    req.onsuccess = () => resolve(true);
+                    req.onerror = () => reject(req.error);
+                });
+            } catch (e) {
+                return false;
+            }
+        }
+    }
+
+    window.SonicSFStorage = new SoundFontStorage();
+})();

app/templates/index.html

@@ -10,9 +10,15 @@
     <script src="https://unpkg.com/lucide@latest"></script>
     <script src="https://unpkg.com/react@18.3.1/umd/react.production.min.js"></script>
     <script src="https://unpkg.com/react-dom@18.3.1/umd/react-dom.production.min.js"></script>
+    <script type="module">
+      import { Synthesizer } from 'https://cdn.jsdelivr.net/npm/spessasynth_lib@latest/dist/spessasynth_lib.js';
+      window.SpessaSynthClass = Synthesizer;
+      console.log('[SonicSF] SpessaSynth library loaded.');
+    </script>
     <script src="/static/js/services/api.js?v=202607232105"></script>
     <script src="/static/js/services/audioEngine.js?v=202607232105"></script>
     <script src="/static/js/services/storage.js?v=202607232105"></script>
+    <script src="/static/js/services/soundfontStorage.js?v=202607232105"></script>
     <script src="/static/js/services/soundfontPlayer.js?v=202607232105"></script>
     <script src="/static/js/services/aiGateway.js?v=202607232105"></script>
     <script src="/static/js/services/dawCommandDispatcher.js?v=202607232105"></script>