fix(fx-rt): burst 4-block input batch qua bridge — hết lag/giật/crackle master FX

- worklet gom 1024 mẫu (4 block) vào 1 frame interleaved, main thread tách 4 WS frame 512 floats
- bridge take=min(avail,4) xử lí 1 call process cho burst → overhead VST3 amortize 4 lần
- engine _pump_output pace theo deadline thay vì sleep cố định (outRead 131→187.5/s)
- FX_RT_ROUNDTRIP_SAMPLES 512→1792 (RTT batching ~7 block)

app/api/v1/plugins.py

@@ -1071,6 +1071,7 @@ async def ws_fx_realtime(websocket: WebSocket, session_id: str):
         # de bu delay dry-bypass path (app.jsx fxRtApplyPdc).
         _last_lat = None
         try:
+            _loop = asyncio.get_event_loop()
             while True:
                 try:
                     _lats = sess.get_latencies()
@@ -1088,9 +1089,17 @@ async def ws_fx_realtime(websocket: WebSocket, session_id: str):
                 if not blks:
                     await asyncio.sleep(0.002)
                     continue
-                for blk in blks:
+                # Pace theo deadline (không sleep cố định sau mỗi send): thời
+                # gian send_bytes (WS → browser) CỘNG sleep cố định làm chu kì
+                # mỗi block > block_sec → engine drain chậm hơn realtime
+                # (đo: outRead 131/s thay vì 187.5/s → worklet zero-fill crackle).
+                # Gửi mỗi block cách nhau đúng block_sec kể từ mốc t0.
+                _t0 = _loop.time()
+                for _i, blk in enumerate(blks):
                     await websocket.send_bytes(blk)
-                    await asyncio.sleep(block_sec)
+                    _dt = _t0 + (_i + 1) * block_sec - _loop.time()
+                    if _dt > 0:
+                        await asyncio.sleep(_dt)
         except Exception:
             pass
     pump_task = asyncio.create_task(_pump_output())

app/static/js/app.jsx

@@ -1711,7 +1711,7 @@ async function fxRtStart() {
   fxRt.sessionId = st.session_id;
   fxRtGuiPushShm();
   try {
-    await ctx.audioWorklet.addModule(`${API_BASE_URL}/static/js/sf-fx-realtime.js?v=202608212200`);
+    await ctx.audioWorklet.addModule(`${API_BASE_URL}/static/js/sf-fx-realtime.js?v=202608212300`);
     fxRt.node = new AudioWorkletNode(ctx, 'sf-fx-realtime', { numberOfInputs: 1, numberOfOutputs: 1, outputChannelCount: [2] });
     const u = new URL(API_BASE_URL);
     const wsProto = u.protocol === 'https:' ? 'wss://' : 'ws://';
@@ -1720,7 +1720,11 @@ async function fxRtStart() {
     const ws = new WebSocket(wsUrl);
     fxRt.ws = ws;
     ws.binaryType = 'arraybuffer';
-    ws.onopen = () => { fxRt.active = true; try { fxRtPushAllParams(); } catch (e) {} };
+    ws.onopen = () => {
+      fxRt.active = true;
+      fxRt.inQueue = [];  // bỏ audio stale sản xuất trước khi WS open (~4s load VST) — hết lag khởi đầu
+      try { fxRtPushAllParams(); } catch (e) {}
+    };
     ws.onmessage = (ev) => {
       // Gap 8 (PDC realtime): text frame {cmd:'latency', total} tu server ->
       // cap nhat delay dry-bypass path (bu latency chain VST3 realtime).
@@ -1752,20 +1756,25 @@ async function fxRtStart() {
         return;
       }
       if (d.type !== 'in') return;
-      if (fxRt.inQueue.length > 64) fxRt.inQueue.shift();
-      fxRt.inQueue.push(d.data);
+      // Worklet gom 4 block (1024 mẫu) vào 1 frame → tách 4 WS frame 512 floats
+      // ở đây. Bridge VST3 nhận input dồn → take=4 → batch 1 call process 1024
+      // mẫu (~3.5-4.75ms/block) → đủ 187.5/s (take=1: 5.5ms > budget 5.33ms →
+      // drop → crackle). KHÔNG dùng f.subarray().buffer — nó gửi cả backing
+      // buffer 8192B; slice() copy đúng 2048B.
+      if (ws.readyState === 1) {
+        try {
+          const f = new Float32Array(d.data);
+          if (f.length > 512) {
+            for (let i = 0; i < f.length; i += 512) ws.send(f.slice(i, i + 512).buffer);
+          } else {
+            ws.send(d.data);
+          }
+        } catch (e) {}
+      }
     };
     // Pace input: tối đa 1 block/kỳ (~5.8ms). Gửi dồn theo burst (main thread bị
     // rAF renderFrame block khi mở MASTERING PANEL) → SHM ring 4-slot tràn → mất
     // block → ngắt quãng.
-    const blockMs = Math.max(4, Math.round((256 / (ctx.sampleRate || 44100)) * 1000));
-    if (fxRt.pumpTimer) clearInterval(fxRt.pumpTimer);
-    fxRt.pumpTimer = setInterval(() => {
-      const ws = fxRt.ws;
-      if (!ws || ws.readyState !== 1 || !fxRt.inQueue.length) return;
-      const d = fxRt.inQueue.shift();
-      try { ws.send(d); } catch (e) { fxRt.inQueue.unshift(d); }
-    }, blockMs);
     // Phase 4.2: fader SAU worklet — worklet chèn giữa outputAnalyser (chain
     // output) và output (fader/destination). output → analyser/splitter giữ
     // nguyên (meter đo âm SAU fader).
@@ -1812,7 +1821,8 @@ function fxRtStop(silent) {
 // qua worklet → lệch pha với mastered. fxRtApplyPdc trễ dry path đúng lượng
 // để align. FX_RT_ROUNDTRIP_SAMPLES là ước lượng (~2 block 256 @44.1k) —
 // ponytail: đo RTT thật (tag seq trên block) khi cần sample-accurate.
-const FX_RT_ROUNDTRIP_SAMPLES = 512;
+// Batching 4 block làm RTT ~7 block (~40ms @48k) → 1792.
+const FX_RT_ROUNDTRIP_SAMPLES = 1792;
 function fxRtApplyPdc() {
   const ctx = getAudioContext();
   const bus = masterBus;
@@ -23652,7 +23662,7 @@ const App = () => {
     fxRtTracks[key] = entry;
     fxRtGuiPushShm();
     try {
-      await ctx.audioWorklet.addModule(`${API_BASE_URL}/static/js/sf-fx-realtime.js?v=202608212200`);
+      await ctx.audioWorklet.addModule(`${API_BASE_URL}/static/js/sf-fx-realtime.js?v=202608212300`);
       const node = new AudioWorkletNode(ctx, 'sf-fx-realtime', { numberOfInputs: 1, numberOfOutputs: 1, outputChannelCount: [2] });
       entry.node = node;
       const u = new URL(API_BASE_URL);
@@ -23663,6 +23673,7 @@ const App = () => {
       ws.binaryType = 'arraybuffer';
       ws.onopen = () => {
         entry.ready = true;
+        entry.inQueue = [];  // bỏ audio stale trước khi WS open — hết lag khởi đầu
         fxRtTrackSplice(trackId, path);
         try {
           (entry.paramsBySlot || []).forEach((pl, slot) => pl.forEach(p => ws.send(JSON.stringify({ cmd: 'set_param', slot, key: p.key, value: p.value }))));
@@ -23687,16 +23698,18 @@ const App = () => {
           return;
         }
         if (d.type !== 'in') return;
-        if (entry.inQueue.length > 64) entry.inQueue.shift();
-        entry.inQueue.push(d.data);
+        // Burst 4 block (1024 mẫu) → tách 4 WS frame 512 floats → bridge batch 4.
+        if (ws.readyState === 1) {
+          try {
+            const f = new Float32Array(d.data);
+            if (f.length > 512) {
+              for (let i = 0; i < f.length; i += 512) ws.send(f.slice(i, i + 512).buffer);
+            } else {
+              ws.send(d.data);
+            }
+          } catch (e) {}
+        }
       };
-      const blockMs = Math.max(4, Math.round((256 / (ctx.sampleRate || 44100)) * 1000));
-      entry.pumpTimer = setInterval(() => {
-        const ws = entry.ws;
-        if (!ws || ws.readyState !== 1 || !entry.inQueue.length) return;
-        const d = entry.inQueue.shift();
-        try { ws.send(d); } catch (e) { entry.inQueue.unshift(d); }
-      }, blockMs);
     } catch (e) {
       console.warn('[FX RT track] setup fail', trackId, path, e);
       fxRtTrackStop(trackId, path, true);

app/static/js/app.precompiled.js

@@ -281,12 +281,18 @@ return(ms.chain||[]).filter(s=>s&&s.active!==false&&(s.type!=='vst3'||!ms.vstByp
 const FX_RT_PARAM_MAP={eq:[['g1','eqLowGain'],['g2','eqMid1Gain'],['g3','eqMid2Gain'],['g4','eqHighGain']],compressor:[['threshold','compThreshold'],['ratio','compRatio'],['makeup','compMakeup']],limiter:[['ceiling','limThreshold'],['mode','limMode'],['lookahead_ms','limLookahead']],exciter:[['drive','excDrive']],rebalance:[['mid','rebalMid'],['side','rebalSide']],imager:[['w1','w1'],['w2','w2'],['w3','w3'],['w4','w4']],maximizer:[['boost_db','maxGain'],['soft_clip','maxSoftClip'],['upward','maxUpward'],['ceiling_db','ceiling']]};function fxRtEntryParams(entry,ms){const out=[];if(!entry||entry.type==='vst3')return out;const src=ms||window.currentMasteringSettings||{};const push=(k,v)=>{const n=Number(v);if(isFinite(n))out.push({key:k,value:n});};const map=FX_RT_PARAM_MAP[entry.type]||[];map.forEach(([cppKey,jsKey])=>{if(entry.params&&entry.params[cppKey]!==undefined)push(cppKey,entry.params[cppKey]);else if(entry.params&&entry.params[jsKey]!==undefined)push(jsKey,entry.params[jsKey]);else if(src[jsKey]!==undefined)push(cppKey,src[jsKey]);});if(entry.type==='eqpro'){if(entry.params&&entry.params.amount!==undefined)push('amount',entry.params.amount);const bands=entry.params&&entry.params.bands||[];bands.forEach((b,i)=>{['freq','gain','q'].forEach(k=>{if(b&&b[k]!==undefined)push('band'+i+'_'+k,b[k]);});});}return out;}function fxRtPushAllParams(){if(!fxRt||!fxRt.ws||fxRt.ws.readyState!==1)return;const chain=fxRtChain();chain.forEach((s,i)=>{fxRtEntryParams(s,null).forEach(p=>{try{fxRt.ws.send(JSON.stringify({cmd:'set_param',slot:i,key:p.key,value:p.value}));}catch(e){}});});}async function fxRtStart(){const chain=fxRtChain();const ck=fxRtChainKey(chain);if(fxRt.active){// masterBus bị rebuild (recovery/export) → node thuộc graph cũ → restart.
 if(!fxRt.node||fxRt.node.context!==getAudioContext())fxRtStop(true);// Chain VST thay đổi (insert/remove/bypass/reorder trong MASTER FX CHAIN)
 // → stop + start lại để bridge load đúng chuỗi FX mới.
-else if(fxRt.chainKey!==ck)fxRtStop(true);else return;}if(!chain.length)return;const ctx=getAudioContext();if(!ctx||!ctx.audioWorklet||!masterBus||!masterBus.output||!masterBus.analyser)return;const chainPayload=chain.map(s=>s.type==='vst3'?{type:'vst3',path:s.path,name:s.name||s.path,preset_b64:s.preset_b64||'',bypass:false}:{type:'builtin',id:s.type,params:s.params&&Object.keys(s.params).length?s.params:{},bypass:false});let st;try{st=await window.SonicAPI.fxRealtimeStart({fx_chain:chainPayload,sample_rate:ctx.sampleRate||44100});}catch(e){console.warn('[FX RT] start fail:',e);showToast('Không khởi động VST FX realtime: '+(e.message||e),'warning');return;}fxRt.sessionId=st.session_id;fxRtGuiPushShm();try{await ctx.audioWorklet.addModule(`${API_BASE_URL}/static/js/sf-fx-realtime.js?v=202608212200`);fxRt.node=new AudioWorkletNode(ctx,'sf-fx-realtime',{numberOfInputs:1,numberOfOutputs:1,outputChannelCount:[2]});const u=new URL(API_BASE_URL);const wsProto=u.protocol==='https:'?'wss://':'ws://';const tok=localStorage.getItem('sonic_token')||'';const wsUrl=`${wsProto}${u.host}${st.ws_url}${tok?'?token='+encodeURIComponent(tok):''}`;const ws=new WebSocket(wsUrl);fxRt.ws=ws;ws.binaryType='arraybuffer';ws.onopen=()=>{fxRt.active=true;try{fxRtPushAllParams();}catch(e){}};ws.onmessage=ev=>{// Gap 8 (PDC realtime): text frame {cmd:'latency', total} tu server ->
+else if(fxRt.chainKey!==ck)fxRtStop(true);else return;}if(!chain.length)return;const ctx=getAudioContext();if(!ctx||!ctx.audioWorklet||!masterBus||!masterBus.output||!masterBus.analyser)return;const chainPayload=chain.map(s=>s.type==='vst3'?{type:'vst3',path:s.path,name:s.name||s.path,preset_b64:s.preset_b64||'',bypass:false}:{type:'builtin',id:s.type,params:s.params&&Object.keys(s.params).length?s.params:{},bypass:false});let st;try{st=await window.SonicAPI.fxRealtimeStart({fx_chain:chainPayload,sample_rate:ctx.sampleRate||44100});}catch(e){console.warn('[FX RT] start fail:',e);showToast('Không khởi động VST FX realtime: '+(e.message||e),'warning');return;}fxRt.sessionId=st.session_id;fxRtGuiPushShm();try{await ctx.audioWorklet.addModule(`${API_BASE_URL}/static/js/sf-fx-realtime.js?v=202608212300`);fxRt.node=new AudioWorkletNode(ctx,'sf-fx-realtime',{numberOfInputs:1,numberOfOutputs:1,outputChannelCount:[2]});const u=new URL(API_BASE_URL);const wsProto=u.protocol==='https:'?'wss://':'ws://';const tok=localStorage.getItem('sonic_token')||'';const wsUrl=`${wsProto}${u.host}${st.ws_url}${tok?'?token='+encodeURIComponent(tok):''}`;const ws=new WebSocket(wsUrl);fxRt.ws=ws;ws.binaryType='arraybuffer';ws.onopen=()=>{fxRt.active=true;fxRt.inQueue=[];// bỏ audio stale sản xuất trước khi WS open (~4s load VST) — hết lag khởi đầu
+try{fxRtPushAllParams();}catch(e){}};ws.onmessage=ev=>{// Gap 8 (PDC realtime): text frame {cmd:'latency', total} tu server ->
 // cap nhat delay dry-bypass path (bu latency chain VST3 realtime).
-if(typeof ev.data==='string'){try{const d=JSON.parse(ev.data);if(d&&d.cmd==='latency'&&typeof d.total==='number'){fxRt.latencyTotal=d.total;fxRtApplyPdc();}}catch(e){}return;}if(!(ev.data instanceof ArrayBuffer)||!fxRt.node)return;const f=new Float32Array(ev.data);const half=f.length/2;const l=new Float32Array(half);const r=new Float32Array(half);for(let i=0;i<half;i++){l[i]=f[i*2];r[i]=f[i*2+1];}fxRt.node.port.postMessage({type:'out',l,r});};ws.onclose=()=>fxRtStop(true);ws.onerror=()=>{try{ws.close();}catch(e){}};fxRt.node.port.onmessage=ev=>{const d=ev.data;if(!d||!fxRt.ws)return;if(d.type==='set_param'){try{fxRt.ws.send(JSON.stringify({cmd:'set_param',slot:d.slot,key:d.key,value:d.value}));}catch(e){}return;}if(d.type!=='in')return;if(fxRt.inQueue.length>64)fxRt.inQueue.shift();fxRt.inQueue.push(d.data);};// Pace input: tối đa 1 block/kỳ (~5.8ms). Gửi dồn theo burst (main thread bị
+if(typeof ev.data==='string'){try{const d=JSON.parse(ev.data);if(d&&d.cmd==='latency'&&typeof d.total==='number'){fxRt.latencyTotal=d.total;fxRtApplyPdc();}}catch(e){}return;}if(!(ev.data instanceof ArrayBuffer)||!fxRt.node)return;const f=new Float32Array(ev.data);const half=f.length/2;const l=new Float32Array(half);const r=new Float32Array(half);for(let i=0;i<half;i++){l[i]=f[i*2];r[i]=f[i*2+1];}fxRt.node.port.postMessage({type:'out',l,r});};ws.onclose=()=>fxRtStop(true);ws.onerror=()=>{try{ws.close();}catch(e){}};fxRt.node.port.onmessage=ev=>{const d=ev.data;if(!d||!fxRt.ws)return;if(d.type==='set_param'){try{fxRt.ws.send(JSON.stringify({cmd:'set_param',slot:d.slot,key:d.key,value:d.value}));}catch(e){}return;}if(d.type!=='in')return;// Worklet gom 4 block (1024 mẫu) vào 1 frame → tách 4 WS frame 512 floats
+// ở đây. Bridge VST3 nhận input dồn → take=4 → batch 1 call process 1024
+// mẫu (~3.5-4.75ms/block) → đủ 187.5/s (take=1: 5.5ms > budget 5.33ms →
+// drop → crackle). KHÔNG dùng f.subarray().buffer — nó gửi cả backing
+// buffer 8192B; slice() copy đúng 2048B.
+if(ws.readyState===1){try{const f=new Float32Array(d.data);if(f.length>512){for(let i=0;i<f.length;i+=512)ws.send(f.slice(i,i+512).buffer);}else{ws.send(d.data);}}catch(e){}}};// Pace input: tối đa 1 block/kỳ (~5.8ms). Gửi dồn theo burst (main thread bị
 // rAF renderFrame block khi mở MASTERING PANEL) → SHM ring 4-slot tràn → mất
 // block → ngắt quãng.
-const blockMs=Math.max(4,Math.round(256/(ctx.sampleRate||44100)*1000));if(fxRt.pumpTimer)clearInterval(fxRt.pumpTimer);fxRt.pumpTimer=setInterval(()=>{const ws=fxRt.ws;if(!ws||ws.readyState!==1||!fxRt.inQueue.length)return;const d=fxRt.inQueue.shift();try{ws.send(d);}catch(e){fxRt.inQueue.unshift(d);}},blockMs);// Phase 4.2: fader SAU worklet — worklet chèn giữa outputAnalyser (chain
+// Phase 4.2: fader SAU worklet — worklet chèn giữa outputAnalyser (chain
 // output) và output (fader/destination). output → analyser/splitter giữ
 // nguyên (meter đo âm SAU fader).
 try{masterBus.outputAnalyser.disconnect(masterBus.output);}catch(e){}masterBus.outputAnalyser.connect(fxRt.node);fxRt.node.connect(masterBus.output);fxRt.chainKey=ck;}catch(e){console.warn('[FX RT] setup fail:',e);fxRtStop(true);}}function fxRtStop(silent){if(fxRt.pumpTimer){clearInterval(fxRt.pumpTimer);fxRt.pumpTimer=null;}fxRt.inQueue=[];if(!fxRt.active&&!fxRt.ws&&!fxRt.node&&!fxRt.sessionId)return;try{if(fxRt.node){fxRt.node.disconnect();if(masterBus&&masterBus.outputAnalyser&&masterBus.output){try{masterBus.outputAnalyser.disconnect(masterBus.output);}catch(e){}try{masterBus.outputAnalyser.connect(masterBus.output);}catch(e){}}fxRt.node.port.onmessage=null;fxRt.node=null;}}catch(e){}try{if(fxRt.ws){fxRt.ws.onclose=null;fxRt.ws.onmessage=null;try{fxRt.ws.close();}catch(e){}fxRt.ws=null;}}catch(e){}const sid=fxRt.sessionId;fxRt.sessionId=null;fxRtGuiPushShm();fxRt.active=false;fxRt.chainKey=null;fxRt.latencyTotal=0;fxRtApplyPdc();if(sid){try{window.SonicAPI.fxRealtimeStop({session_id:sid}).catch(()=>{});}catch(e){}}}// ── Gap 8: PDC realtime — bù delay dry-bypass path (master chain) ──────────
@@ -295,7 +301,8 @@ try{masterBus.outputAnalyser.disconnect(masterBus.output);}catch(e){}masterBus.o
 // qua worklet → lệch pha với mastered. fxRtApplyPdc trễ dry path đúng lượng
 // để align. FX_RT_ROUNDTRIP_SAMPLES là ước lượng (~2 block 256 @44.1k) —
 // ponytail: đo RTT thật (tag seq trên block) khi cần sample-accurate.
-const FX_RT_ROUNDTRIP_SAMPLES=512;function fxRtApplyPdc(){const ctx=getAudioContext();const bus=masterBus;if(!ctx||!bus||!bus.pdcDelay)return;const l=fxRt&&fxRt.active?FX_RT_ROUNDTRIP_SAMPLES+(fxRt.latencyTotal||0):0;try{bus.pdcDelay.delayTime.setTargetAtTime(l/(ctx.sampleRate||44100),ctx.currentTime,0.05);}catch(e){}}// ── Realtime VST FX per-track (SHM bridge) — mọi luồng track qua bridge ─────
+// Batching 4 block làm RTT ~7 block (~40ms @48k) → 1792.
+const FX_RT_ROUNDTRIP_SAMPLES=1792;function fxRtApplyPdc(){const ctx=getAudioContext();const bus=masterBus;if(!ctx||!bus||!bus.pdcDelay)return;const l=fxRt&&fxRt.active?FX_RT_ROUNDTRIP_SAMPLES+(fxRt.latencyTotal||0):0;try{bus.pdcDelay.delayTime.setTargetAtTime(l/(ctx.sampleRate||44100),ctx.currentTime,0.05);}catch(e){}}// ── Realtime VST FX per-track (SHM bridge) — mọi luồng track qua bridge ─────
 // Mỗi track: session riêng (1 WS/SHM) cho TỪNG đường chain có âm — audio-clips
 // (path 'audio', splice fxEntry→mods→worklet→fxLegacyIn) và MIDI/SF (path 'sf',
 // splice sfEntry→mods→worklet→sfOut). Track vừa clips vừa MIDI → 2 session
@@ -1627,7 +1634,9 @@ fxRtTrackReconcile(trackId,node,track);}catch(e){console.warn('rebuildTrackFxGra
 // Cần activeTrackNodesRef/isPlayingRef. Session giống master (fxRtStart):
 // fetch start → AudioWorkletNode 'sf-fx-realtime' → WS; WS open → splice
 // worklet vào chain hiện tại (đọc mods MỚI NHẤT — an toàn với rebuild).
-const fxRtTrackStart=async(trackId,track,path)=>{const key=trackId+':'+path;const chain=fxRtTrackChain(track);if(!chain.length)return;if(fxRtTracks[key]){if(!fxRtTracks[key].node||fxRtTracks[key].node.context!==getAudioContext())fxRtTrackStop(trackId,path,true);else return;}const ctx=getAudioContext();if(!ctx||!ctx.audioWorklet)return;const chainPayload=chain.map(s=>s.type==='vst3'?{type:'vst3',path:s.path,name:s.name||s.path,preset_b64:s.preset_b64||'',bypass:false}:{type:'builtin',id:s.type,params:s.params&&Object.keys(s.params).length?s.params:{},bypass:false});let st;try{st=await window.SonicAPI.fxRealtimeStart({fx_chain:chainPayload,sample_rate:ctx.sampleRate||44100});}catch(e){console.warn('[FX RT track] start fail',trackId,path,e);return;}const entry={sessionId:st.session_id,ws:null,node:null,ready:false,path,spliced:null,chainKey:fxRtTrackChainKey(chain),paramsBySlot:chain.map(s=>fxRtEntryParams(s,null)),inQueue:[],pumpTimer:null};fxRtTracks[key]=entry;fxRtGuiPushShm();try{await ctx.audioWorklet.addModule(`${API_BASE_URL}/static/js/sf-fx-realtime.js?v=202608212200`);const node=new AudioWorkletNode(ctx,'sf-fx-realtime',{numberOfInputs:1,numberOfOutputs:1,outputChannelCount:[2]});entry.node=node;const u=new URL(API_BASE_URL);const wsProto=u.protocol==='https:'?'wss://':'ws://';const tok=localStorage.getItem('sonic_token')||'';const ws=new WebSocket(`${wsProto}${u.host}${st.ws_url}${tok?'?token='+encodeURIComponent(tok):''}`);entry.ws=ws;ws.binaryType='arraybuffer';ws.onopen=()=>{entry.ready=true;fxRtTrackSplice(trackId,path);try{(entry.paramsBySlot||[]).forEach((pl,slot)=>pl.forEach(p=>ws.send(JSON.stringify({cmd:'set_param',slot,key:p.key,value:p.value}))));}catch(e){}};ws.onmessage=ev=>{if(!(ev.data instanceof ArrayBuffer)||!entry.node)return;const f=new Float32Array(ev.data);const half=f.length/2;const l=new Float32Array(half);const r=new Float32Array(half);for(let i=0;i<half;i++){l[i]=f[i*2];r[i]=f[i*2+1];}entry.node.port.postMessage({type:'out',l,r});};ws.onclose=()=>fxRtTrackStop(trackId,path,true);ws.onerror=()=>{try{ws.close();}catch(e){}};entry.node.port.onmessage=ev=>{const d=ev.data;if(!d||!entry.ws)return;if(d.type==='set_param'){try{entry.ws.send(JSON.stringify({cmd:'set_param',slot:d.slot,key:d.key,value:d.value}));}catch(e){}return;}if(d.type!=='in')return;if(entry.inQueue.length>64)entry.inQueue.shift();entry.inQueue.push(d.data);};const blockMs=Math.max(4,Math.round(256/(ctx.sampleRate||44100)*1000));entry.pumpTimer=setInterval(()=>{const ws=entry.ws;if(!ws||ws.readyState!==1||!entry.inQueue.length)return;const d=entry.inQueue.shift();try{ws.send(d);}catch(e){entry.inQueue.unshift(d);}},blockMs);}catch(e){console.warn('[FX RT track] setup fail',trackId,path,e);fxRtTrackStop(trackId,path,true);}};const fxRtTrackUnsplice=(trackId,path)=>{const entry=fxRtTracks[trackId+':'+path];if(!entry||!entry.spliced||!entry.node)return;try{entry.node.disconnect();try{entry.spliced.tail.connect(entry.spliced.dest);}catch(e){}entry.spliced=null;}catch(e){console.warn('[FX RT track] unsplice fail',trackId,path,e);}};const fxRtTrackSplice=(trackId,path)=>{const key=trackId+':'+path;const entry=fxRtTracks[key];const node=activeTrackNodesRef.current[trackId];if(!entry||!entry.ready||!entry.node||!node||entry.spliced)return;const tail=path==='audio'?node.fxEntry:node.sfEntry;const dest=path==='audio'?node.fxLegacyIn:node.sfOut;if(!tail||!dest)return;try{tail.disconnect(dest);entry.node.connect(dest);tail.connect(entry.node);entry.spliced={tail,dest};console.log('[FX RT track] spliced',trackId,path);}catch(e){console.warn('[FX RT track] splice fail',trackId,path,e);}};const fxRtTrackStop=(trackId,path,silent)=>{const key=trackId+':'+path;const entry=fxRtTracks[key];if(!entry)return;if(entry.pumpTimer){clearInterval(entry.pumpTimer);entry.pumpTimer=null;}entry.inQueue=[];try{fxRtTrackUnsplice(trackId,path);if(entry.node){entry.node.port.onmessage=null;try{entry.node.disconnect();}catch(e){}entry.node=null;}}catch(e){}try{if(entry.ws){entry.ws.onclose=null;entry.ws.onmessage=null;try{entry.ws.close();}catch(e){}entry.ws=null;}}catch(e){}const sid=entry.sessionId;delete fxRtTracks[key];fxRtGuiPushShm();if(sid){try{window.SonicAPI.fxRealtimeStop({session_id:sid}).catch(()=>{});}catch(e){}}};const fxRtTrackReconcile=(trackId,node,track)=>{try{const chain=fxRtTrackChain(track);const chainKey=fxRtTrackChainKey(chain);const wantPaths=chain.length?fxRtTrackPaths(track):[];const prefix=trackId+':';Object.keys(fxRtTracks).forEach(k=>{if(!k.startsWith(prefix))return;const p=k.slice(prefix.length);if(wantPaths.indexOf(p)<0)fxRtTrackStop(trackId,p,true);});if(!isPlayingRef.current)return;wantPaths.forEach(p=>{const key=trackId+':'+p;const entry=fxRtTracks[key];if(!entry)fxRtTrackStart(trackId,track,p);else if(entry.chainKey!==chainKey){fxRtTrackStop(trackId,p,true);fxRtTrackStart(trackId,track,p);}else if(entry.ready&&node){fxRtTrackUnsplice(trackId,p);// chain mới (sau rebuild) — splice lại đúng mods
+const fxRtTrackStart=async(trackId,track,path)=>{const key=trackId+':'+path;const chain=fxRtTrackChain(track);if(!chain.length)return;if(fxRtTracks[key]){if(!fxRtTracks[key].node||fxRtTracks[key].node.context!==getAudioContext())fxRtTrackStop(trackId,path,true);else return;}const ctx=getAudioContext();if(!ctx||!ctx.audioWorklet)return;const chainPayload=chain.map(s=>s.type==='vst3'?{type:'vst3',path:s.path,name:s.name||s.path,preset_b64:s.preset_b64||'',bypass:false}:{type:'builtin',id:s.type,params:s.params&&Object.keys(s.params).length?s.params:{},bypass:false});let st;try{st=await window.SonicAPI.fxRealtimeStart({fx_chain:chainPayload,sample_rate:ctx.sampleRate||44100});}catch(e){console.warn('[FX RT track] start fail',trackId,path,e);return;}const entry={sessionId:st.session_id,ws:null,node:null,ready:false,path,spliced:null,chainKey:fxRtTrackChainKey(chain),paramsBySlot:chain.map(s=>fxRtEntryParams(s,null)),inQueue:[],pumpTimer:null};fxRtTracks[key]=entry;fxRtGuiPushShm();try{await ctx.audioWorklet.addModule(`${API_BASE_URL}/static/js/sf-fx-realtime.js?v=202608212300`);const node=new AudioWorkletNode(ctx,'sf-fx-realtime',{numberOfInputs:1,numberOfOutputs:1,outputChannelCount:[2]});entry.node=node;const u=new URL(API_BASE_URL);const wsProto=u.protocol==='https:'?'wss://':'ws://';const tok=localStorage.getItem('sonic_token')||'';const ws=new WebSocket(`${wsProto}${u.host}${st.ws_url}${tok?'?token='+encodeURIComponent(tok):''}`);entry.ws=ws;ws.binaryType='arraybuffer';ws.onopen=()=>{entry.ready=true;entry.inQueue=[];// bỏ audio stale trước khi WS open — hết lag khởi đầu
+fxRtTrackSplice(trackId,path);try{(entry.paramsBySlot||[]).forEach((pl,slot)=>pl.forEach(p=>ws.send(JSON.stringify({cmd:'set_param',slot,key:p.key,value:p.value}))));}catch(e){}};ws.onmessage=ev=>{if(!(ev.data instanceof ArrayBuffer)||!entry.node)return;const f=new Float32Array(ev.data);const half=f.length/2;const l=new Float32Array(half);const r=new Float32Array(half);for(let i=0;i<half;i++){l[i]=f[i*2];r[i]=f[i*2+1];}entry.node.port.postMessage({type:'out',l,r});};ws.onclose=()=>fxRtTrackStop(trackId,path,true);ws.onerror=()=>{try{ws.close();}catch(e){}};entry.node.port.onmessage=ev=>{const d=ev.data;if(!d||!entry.ws)return;if(d.type==='set_param'){try{entry.ws.send(JSON.stringify({cmd:'set_param',slot:d.slot,key:d.key,value:d.value}));}catch(e){}return;}if(d.type!=='in')return;// Burst 4 block (1024 mẫu) → tách 4 WS frame 512 floats → bridge batch 4.
+if(ws.readyState===1){try{const f=new Float32Array(d.data);if(f.length>512){for(let i=0;i<f.length;i+=512)ws.send(f.slice(i,i+512).buffer);}else{ws.send(d.data);}}catch(e){}}};}catch(e){console.warn('[FX RT track] setup fail',trackId,path,e);fxRtTrackStop(trackId,path,true);}};const fxRtTrackUnsplice=(trackId,path)=>{const entry=fxRtTracks[trackId+':'+path];if(!entry||!entry.spliced||!entry.node)return;try{entry.node.disconnect();try{entry.spliced.tail.connect(entry.spliced.dest);}catch(e){}entry.spliced=null;}catch(e){console.warn('[FX RT track] unsplice fail',trackId,path,e);}};const fxRtTrackSplice=(trackId,path)=>{const key=trackId+':'+path;const entry=fxRtTracks[key];const node=activeTrackNodesRef.current[trackId];if(!entry||!entry.ready||!entry.node||!node||entry.spliced)return;const tail=path==='audio'?node.fxEntry:node.sfEntry;const dest=path==='audio'?node.fxLegacyIn:node.sfOut;if(!tail||!dest)return;try{tail.disconnect(dest);entry.node.connect(dest);tail.connect(entry.node);entry.spliced={tail,dest};console.log('[FX RT track] spliced',trackId,path);}catch(e){console.warn('[FX RT track] splice fail',trackId,path,e);}};const fxRtTrackStop=(trackId,path,silent)=>{const key=trackId+':'+path;const entry=fxRtTracks[key];if(!entry)return;if(entry.pumpTimer){clearInterval(entry.pumpTimer);entry.pumpTimer=null;}entry.inQueue=[];try{fxRtTrackUnsplice(trackId,path);if(entry.node){entry.node.port.onmessage=null;try{entry.node.disconnect();}catch(e){}entry.node=null;}}catch(e){}try{if(entry.ws){entry.ws.onclose=null;entry.ws.onmessage=null;try{entry.ws.close();}catch(e){}entry.ws=null;}}catch(e){}const sid=entry.sessionId;delete fxRtTracks[key];fxRtGuiPushShm();if(sid){try{window.SonicAPI.fxRealtimeStop({session_id:sid}).catch(()=>{});}catch(e){}}};const fxRtTrackReconcile=(trackId,node,track)=>{try{const chain=fxRtTrackChain(track);const chainKey=fxRtTrackChainKey(chain);const wantPaths=chain.length?fxRtTrackPaths(track):[];const prefix=trackId+':';Object.keys(fxRtTracks).forEach(k=>{if(!k.startsWith(prefix))return;const p=k.slice(prefix.length);if(wantPaths.indexOf(p)<0)fxRtTrackStop(trackId,p,true);});if(!isPlayingRef.current)return;wantPaths.forEach(p=>{const key=trackId+':'+p;const entry=fxRtTracks[key];if(!entry)fxRtTrackStart(trackId,track,p);else if(entry.chainKey!==chainKey){fxRtTrackStop(trackId,p,true);fxRtTrackStart(trackId,track,p);}else if(entry.ready&&node){fxRtTrackUnsplice(trackId,p);// chain mới (sau rebuild) — splice lại đúng mods
 fxRtTrackSplice(trackId,p);}});}catch(e){console.warn('fxRtTrackReconcile error:',e);}};const fxRtTrackStopAll=()=>{Object.keys(fxRtTracks).forEach(k=>{const i=k.lastIndexOf(':');fxRtTrackStop(k.slice(0,i),k.slice(i+1),true);});};// Route the SHARED FluidSynth output through the gainNode of the single
 // audible MIDI track so its FX Rack chain / fader / pan affect the soundfont
 // instrument (unified_fx_rack_panel.md + user request). With more than one

app/static/js/sf-fx-realtime.js

@@ -4,6 +4,13 @@
 // nhận block đã xử lý từ main thread → queue → phát ra output. Queue rỗng →
 // zero fill (WS chưa kịp round-trip).
 //
+// BURST (fix lag/giật/crackle): gom 4 block (1024 mẫu) vào 1 frame rồi post.
+// Bridge VST3 (fx_vst_bridge) chạy chậm hơn realtime khi take=1 (256 mẫu:
+// ~5.5ms/call > budget 5.33ms → 179/s < 187.5/s → engine drop input →
+// crackle). Gửi burst 4 block → bridge take=4 → 1 call process 1024 mẫu
+// (amortize overhead: 14-19ms/4 block ≈ 3.5-4.75ms/block) → đủ 187.5/s.
+// Latency thêm ~4 block (~21ms) — worklet outQueue 32 block hấp thụ.
+//
 // Latency ~2 block; backlog > 32 block (~190ms) → drop block cũ nhất. Cap cao
 // hấp thụ jitter main thread (rAF renderFrame nặng khi mở MASTERING PANEL) mà
 // không drop. ponytail: thay drop bằng adaptive stretch khi cần chất lượng cao.
@@ -11,8 +18,10 @@ class SfFxRealtimeProcessor extends AudioWorkletProcessor {
   constructor() {
     super();
     this.BLOCK = 256;          // FXRT_BLOCK
-    this.inL = new Float32Array(this.BLOCK);
-    this.inR = new Float32Array(this.BLOCK);
+    this.BURST = 4;            // số block gom 1 frame (bridge batch)
+    this.bufLen = this.BLOCK * this.BURST;
+    this.inL = new Float32Array(this.bufLen);
+    this.inR = new Float32Array(this.bufLen);
     this.inCount = 0;
     this.outQueue = [];        // [{l: Float32Array, r: Float32Array}]
     this.outPos = 0;
@@ -31,19 +40,20 @@ class SfFxRealtimeProcessor extends AudioWorkletProcessor {
     const outL = output[0];
     const outR = output[1];
 
-    // Góp input thành block 256 → gửi main thread (transferable buffer).
+    // Góp input thành burst 4 block (1024 mẫu) → gửi main thread
+    // (transferable buffer). Main thread tách 4 WS frame → bridge batch 4.
     if (input && input[0]) {
       const inL = input[0];
       const inR = input[1] || input[0];
       for (let i = 0; i < n; i++) {
-        if (this.inCount < this.BLOCK) {
+        if (this.inCount < this.bufLen) {
           this.inL[this.inCount] = inL[i];
           this.inR[this.inCount] = inR[i];
         }
         this.inCount++;
-        if (this.inCount >= this.BLOCK) {
-          const inter = new Float32Array(this.BLOCK * 2);
-          for (let j = 0; j < this.BLOCK; j++) {
+        if (this.inCount >= this.bufLen) {
+          const inter = new Float32Array(this.bufLen * 2);
+          for (let j = 0; j < this.bufLen; j++) {
             inter[j * 2] = this.inL[j];
             inter[j * 2 + 1] = this.inR[j];
           }

app/templates/index.html

@@ -51,7 +51,7 @@
     <script src="/static/js/services/promptTemplateManager.js?v=202607281039"></script>
     <script src="/static/js/services/undoRedoEngine.js?v=202607290941"></script>
     <script src="/static/js/services/chordTheory.js?v=202608211300"></script>
-    <script src="/static/js/app.precompiled.js?v=202608212359" defer></script>
+    <script src="/static/js/app.precompiled.js?v=202608212300" defer></script>
     <link rel="stylesheet" href="/static/css/styles.css?v=202607271016">
     <style>
         :root {

native_bridge/src/RealtimeFxLoop.cpp

@@ -127,8 +127,14 @@ int run_realtime_fx_loop(const std::string& jobPath, const std::string& shmName,
         std::cerr << "[RealtimeFxLoop] no fx_chain in job (empty chain = passthrough)" << std::endl;
     }
 
+    // Batching (fix lag/giật/crackle): gom tối đa FXRT_IN_SLOTS block input
+    // (256 mẫu) → 1 call chain.process(L,R,batchN). Overhead VST3 (memcpy,
+    // lock param, setup processData, memset output) amortize 4 lần → engine
+    // theo kịp 187.5 block/s. setChain với batchN để plugin buffer đủ cho
+    // process n lớn (không overflow khi xử lí burst).
+    const uint32_t batchN = block * FXRT_IN_SLOTS;
     RealtimeFxChain chain;
-    chain.setChain(chainJson, sampleRate, block);
+    chain.setChain(chainJson, sampleRate, (int32_t)batchN);
 
     ShmView* v = openShm(shmName, sizeof(FxRealtimeIPC));
     if (!v) {
@@ -163,6 +169,7 @@ int run_realtime_fx_loop(const std::string& jobPath, const std::string& shmName,
     });
 
     const uint32_t n = block;
+    float L[FXRT_BLOCK * FXRT_IN_SLOTS], R[FXRT_BLOCK * FXRT_IN_SLOTS];
     uint32_t inMask = ipc->h.inSlots - 1;
     uint32_t outMask = ipc->h.outSlots - 1;
     uint64_t processed = 0;
@@ -201,20 +208,28 @@ int run_realtime_fx_loop(const std::string& jobPath, const std::string& shmName,
             std::cerr << "[RealtimeFxLoop] latency reported: " << lats.size()
                       << " slot(s)" << std::endl;
         }
-        const uint32_t avail = ipc->h.inWrite - ipc->h.inRead;
+        uint32_t avail = ipc->h.inWrite - ipc->h.inRead;
         if (avail == 0) { sleepMs(1); continue; }
-        const uint32_t slot = ipc->h.inRead & inMask;
-        float L[FXRT_BLOCK], R[FXRT_BLOCK];
-        std::memcpy(L, ipc->inL[slot], n * sizeof(float));
-        std::memcpy(R, ipc->inR[slot], n * sizeof(float));
-        ipc->h.inRead++;  // consume
-        chain.process(L, R, n);  // SEH-guarded; chain rỗng = passthrough
-        const uint32_t oslot = ipc->h.outWrite & outMask;
-        std::memcpy(ipc->outL[oslot], L, n * sizeof(float));
-        std::memcpy(ipc->outR[oslot], R, n * sizeof(float));
-        MemoryBarrier();  // dữ liệu trước index (đúng thứ tự trên ARM64)
-        ipc->h.outWrite++;  // publish
-        ++processed;
+        // Batch: tiêu thụ tối đa FXRT_IN_SLOTS block, xử lí 1 call. Input về
+        // đều → take=1 (latency thấp nhất); dồn burst → take>1 gom lại.
+        const uint32_t take = std::min<uint32_t>(avail, FXRT_IN_SLOTS);
+        uint32_t off = 0;
+        for (uint32_t i = 0; i < take; ++i) {
+            const uint32_t slot = ipc->h.inRead & inMask;
+            std::memcpy(L + off, ipc->inL[slot], n * sizeof(float));
+            std::memcpy(R + off, ipc->inR[slot], n * sizeof(float));
+            ipc->h.inRead++;  // consume
+            off += n;
+        }
+        chain.process(L, R, off);  // SEH-guarded; chain rỗng = passthrough
+        for (uint32_t i = 0, o = 0; i < take; ++i, o += n) {
+            const uint32_t oslot = ipc->h.outWrite & outMask;
+            std::memcpy(ipc->outL[oslot], L + o, n * sizeof(float));
+            std::memcpy(ipc->outR[oslot], R + o, n * sizeof(float));
+            MemoryBarrier();  // dữ liệu trước index (đúng thứ tự trên ARM64)
+            ipc->h.outWrite++;  // publish
+            ++processed;
+        }
     }
     ipc->h.state = FXRT_STATE_STARTING;  // đã dừng
     hb.join();