From 5349ed88e7adab0387bc6924f9abbca3e6f3360e Mon Sep 17 00:00:00 2001
From: Xin Wang <wx44wx@XindeMac-mini.local>
Date: Mon, 9 Feb 2026 13:39:55 +0800
Subject: [PATCH] Improve tts stream

---
 engine/core/duplex_pipeline.py |  1 -
 web/pages/Assistants.tsx       | 75 +++++++++++++++++++++++++---------
 2 files changed, 56 insertions(+), 20 deletions(-)

diff --git a/engine/core/duplex_pipeline.py b/engine/core/duplex_pipeline.py
index be31239..f01dd63 100644
--- a/engine/core/duplex_pipeline.py
+++ b/engine/core/duplex_pipeline.py
@@ -634,7 +634,6 @@ class DuplexPipeline:
                     break
                 
                 await self.transport.send_audio(chunk.audio)
-                await asyncio.sleep(0.005)  # Small delay to prevent flooding
         except asyncio.CancelledError:
             logger.debug("TTS sentence cancelled")
         except Exception as e:
diff --git a/web/pages/Assistants.tsx b/web/pages/Assistants.tsx
index d5d048d..f273c1b 100644
--- a/web/pages/Assistants.tsx
+++ b/web/pages/Assistants.tsx
@@ -1087,6 +1087,12 @@ export const DebugDrawer: React.FC<{
   const audioCtxRef = useRef<AudioContext | null>(null);
   const playbackTimeRef = useRef<number>(0);
   const activeAudioSourcesRef = useRef<Set<AudioBufferSourceNode>>(new Set());
+  const queuedAudioBuffersRef = useRef<AudioBuffer[]>([]);
+  const queuedAudioDurationRef = useRef<number>(0);
+
+  const PLAYBACK_INITIAL_BUFFER_SECONDS = 0.25;
+  const PLAYBACK_MAX_AHEAD_SECONDS = 0.8;
+  const PLAYBACK_SCHEDULE_LEAD_SECONDS = 0.04;
 
   const [devices, setDevices] = useState<MediaDeviceInfo[]>([]);
   const [selectedCamera, setSelectedCamera] = useState<string>('');
@@ -1169,8 +1175,10 @@ export const DebugDrawer: React.FC<{
 
   const clearPlaybackQueue = () => {
     const ctx = audioCtxRef.current;
-    if (!ctx) return;
-    playbackTimeRef.current = ctx.currentTime;
+    const now = ctx ? ctx.currentTime : 0;
+    playbackTimeRef.current = now;
+    queuedAudioBuffersRef.current = [];
+    queuedAudioDurationRef.current = 0;
   };
 
   const stopPlaybackImmediately = () => {
@@ -1186,6 +1194,49 @@ export const DebugDrawer: React.FC<{
     clearPlaybackQueue();
   };
 
+  const scheduleQueuedPlayback = (ctx: AudioContext) => {
+    const queue = queuedAudioBuffersRef.current;
+    if (queue.length === 0) return;
+
+    const now = ctx.currentTime;
+    if (playbackTimeRef.current < now) {
+      playbackTimeRef.current = now;
+    }
+
+    const hasActivePlayback = activeAudioSourcesRef.current.size > 0;
+    const minBufferSeconds = hasActivePlayback
+      ? 0
+      : PLAYBACK_INITIAL_BUFFER_SECONDS;
+
+    if (queuedAudioDurationRef.current < minBufferSeconds) {
+      return;
+    }
+
+    while (queue.length > 0 && (playbackTimeRef.current - now) < PLAYBACK_MAX_AHEAD_SECONDS) {
+      const audioBuffer = queue.shift();
+      if (!audioBuffer) break;
+      queuedAudioDurationRef.current = Math.max(0, queuedAudioDurationRef.current - audioBuffer.duration);
+
+      const source = ctx.createBufferSource();
+      source.buffer = audioBuffer;
+      source.connect(ctx.destination);
+      activeAudioSourcesRef.current.add(source);
+      source.onended = () => {
+        activeAudioSourcesRef.current.delete(source);
+        try {
+          source.disconnect();
+        } catch {
+          // no-op
+        }
+        scheduleQueuedPlayback(ctx);
+      };
+
+      const startAt = Math.max(ctx.currentTime + PLAYBACK_SCHEDULE_LEAD_SECONDS, playbackTimeRef.current);
+      source.start(startAt);
+      playbackTimeRef.current = startAt + audioBuffer.duration;
+    }
+  };
+
   const playPcm16Chunk = async (pcmBuffer: ArrayBuffer) => {
     if (!textTtsEnabled) return;
     if (mode !== 'text') return;
@@ -1201,23 +1252,9 @@ export const DebugDrawer: React.FC<{
     const sampleRate = 16000;
     const audioBuffer = ctx.createBuffer(1, float32.length, sampleRate);
     audioBuffer.copyToChannel(float32, 0);
-
-    const source = ctx.createBufferSource();
-    source.buffer = audioBuffer;
-    source.connect(ctx.destination);
-    activeAudioSourcesRef.current.add(source);
-    source.onended = () => {
-      activeAudioSourcesRef.current.delete(source);
-      try {
-        source.disconnect();
-      } catch {
-        // no-op
-      }
-    };
-
-    const startAt = Math.max(ctx.currentTime + 0.02, playbackTimeRef.current);
-    source.start(startAt);
-    playbackTimeRef.current = startAt + audioBuffer.duration;
+    queuedAudioBuffersRef.current.push(audioBuffer);
+    queuedAudioDurationRef.current += audioBuffer.duration;
+    scheduleQueuedPlayback(ctx);
   };
 
   useEffect(() => {