V44: fix crackle - uu tien audio thread bridge (HIGHEST) + FILL 24 (cushion ~90ms) PDC 7936

app/static/js/app.jsx

@@ -2165,7 +2165,7 @@ function fxRtStop(silent) {
 // ≈ 1792) + FILL buffer 16 block (4096) = 23 block ≈ 5888 (~123ms @48k). Giữ
 // đồng bộ với sf-fx-realtime.js. FX_RT_START_EST_MS: ước lượng khởi đầu khi
 // chưa có phép đo (fx_play_first) — dùng cho freeze playhead thay V39 0.31s.
-const FX_RT_ROUNDTRIP_SAMPLES = 5888;
+const FX_RT_ROUNDTRIP_SAMPLES = 7936;
 const FX_RT_START_EST_MS = 450;
 // G3: anchor processed — playhead = startOffset + (processed - anchor - latency)/sr
 // (da tru latency -> bam vi tri mau NGHE DUOC; pre-roll tu giu tai startOffset —

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

@@ -29,8 +29,8 @@ class SfFxRealtimeProcessor extends AudioWorkletProcessor {
     super();
     this.BLOCK = 256;          // FXRT_BLOCK
     this.BURST = 4;            // số block gom 1 frame (bridge batch)
-    this.FILL = 16;             // V43: 16 block ~85ms @48k: buffer khởi đầu — hấp thụ jitter main-thread (GUI decode, rAF, VST panel). PDC 5888 = (7+16)*256 (fxRtApplyPdc). V40 giam 24->8 -> cushion = FILL - d ~3-8; pump/WS gap 42ms + queue 3 -> underrun (fx_stats u=1 q=0 trong log). V43 len 16 -> cushion ~11-16, ngang muc q=10-15 sau flush/resume (het underrun trong log).
-    this.RESUME_FILL = 16;     // V26: re-buffer khi resume SAU STOP (flush_for_stop) — 16 block ~85ms (V43: = FILL) → play kế tiếp bắt đầu nhanh; underrun-stall vẫn dùng FILL (crackle/wobble).
+    this.FILL = 24;             // V44: 24 block ~128ms @48k: buffer khởi đầu — hấp thụ jitter main-thread + stall deschedule bridge 68-138ms. PDC 7936 = (7+24)*256 (fxRtApplyPdc). V43 16 -> cushion ~9 (q 3-9) chua du: stall 68-82ms van gay underrun. V44 len 24 -> cushion ~17 (~90ms).
+    this.RESUME_FILL = 24;     // V26: re-buffer khi resume SAU STOP (flush_for_stop) — 16 block ~85ms (V43: = FILL) → play kế tiếp bắt đầu nhanh; underrun-stall vẫn dùng FILL (crackle/wobble).
     this.resumeFill = this.FILL; // mức re-buffer khi resume sau flush — stop: RESUME_FILL, underrun-stall: FILL
     this.CAP = 32;             // V40: cap queue chặn overflow (~170ms)
     this.HOLD_FADE = 4;        // 4 block ~21ms: fade 1→0 sau HOLD hết (hết click cắt cứng)