zebra-spaces: deploy 4s speaker buffer + HTTP lip-sync override

zebra-report/zebra-spaces.html

@@ -1976,6 +1976,7 @@ function resetListenerBufferReady(){
  * last applied value. */
 const lipSync = new Map(); /* pubHex → state */
 const sfuAudioReceivers = new Map(); /* pubHex → RTCRtpReceiver (SFU audio) — cached so we can restore as the lip-sync source after mesh fail */
+const httpLipSyncOverride = new Map(); /* pubHex → fixed delay (sec). When set, lip-sync uses this directly and skips worklet-derived measurement — for HTTP /stream toggle ON case where the audio source isn't the worklet anymore. */
 const LIP_SYNC_HISTORY = 5;
 const LIP_SYNC_THRESHOLD = 0.05;   /* 50ms — below this is within perception noise */
 
@@ -2009,7 +2010,26 @@ async function refreshLipSyncForUuid(uuid){
   for (const [ph, st] of lipSync){
     if (st.audioUuid === uuid){ pubHex = ph; e = st; break; }
   }
-  if (!e || !e.audioReceiver || e.videoReceivers.size === 0) return;
+  if (!e || e.videoReceivers.size === 0) return;
+  /* HTTP /stream override path: when the per-speaker stream toggle is
+   * ON for this publisher, the audio is coming from an <audio>
+   * element with its own deep buffer instead of the worklet. We don't
+   * have a clean way to read that element's effective delay, so we
+   * use a fixed HTTP_STREAM_DELAY_SEC estimate (set by startStream).
+   * Apply it directly with the same threshold/hysteresis as the
+   * worklet path. */
+  const override = httpLipSyncOverride.get(pubHex);
+  if (typeof override === 'number'){
+    if (Math.abs(override - e.lastApplied) < LIP_SYNC_THRESHOLD) return;
+    for (const [kind, rx] of e.videoReceivers){
+      try { rx.playoutDelayHint    = override; } catch(_){}
+      try { rx.jitterBufferTarget  = override * 1000; } catch(_){}
+    }
+    e.lastApplied = override;
+    logLine('', 'lip-sync pub='+pubHex.slice(0,4)+' delay='+override.toFixed(2)+'s (HTTP /stream override)');
+    return;
+  }
+  if (!e.audioReceiver) return;
   const node = listenerAudioNodes.get(uuid);
   if (!node) return;
   const workletBufferedSec = node.bufferedSeconds || 0;
@@ -2040,6 +2060,25 @@ async function refreshLipSyncForUuid(uuid){
   logLine('', 'lip-sync pub='+pubHex.slice(0,4)+' delay='+med.toFixed(2)+'s ('+e.videoReceivers.size+' video rx, history median of '+e.history.length+')');
 }
 
+/* Force a one-shot lip-sync application for a specific publisher.
+ * Bypasses the worklet-driven 'buffered' cadence — used when an
+ * external event (HTTP /stream toggle) changes the audio source and
+ * we want the video target to update immediately rather than wait
+ * for the next worklet message. */
+function applyLipSyncForPub(pubHex){
+  const e = lipSync.get(pubHex);
+  if (!e || e.videoReceivers.size === 0) return;
+  const override = httpLipSyncOverride.get(pubHex);
+  if (typeof override !== 'number') return;
+  for (const [kind, rx] of e.videoReceivers){
+    try { rx.playoutDelayHint    = override; } catch(_){}
+    try { rx.jitterBufferTarget  = override * 1000; } catch(_){}
+  }
+  e.lastApplied = override;
+  e.history = [];
+  logLine('', 'lip-sync pub='+pubHex.slice(0,4)+' forced delay='+override.toFixed(2)+'s (HTTP /stream toggle)');
+}
+
 /* Shared audio attach path. Every role routes through here now so the
  * worklet can apply role-appropriate buffer depth uniformly. Listener
  * gets a fat 4s cushion (lean-back, latency doesn't matter); speakers
@@ -2324,12 +2363,28 @@ const VIDEO_REMOVE_MUTE_WINDOW_SCREEN_MS = 120000;
  * out wiggle-stalls without a glitch. Big enough to survive any
  * realistic publisher-side hiccup. */
 const RECV_PLAYOUT_DELAY_SEC = 4.0;
-/* Speaker/cohost/host cushion — they're in active conversation, so
- * the buffer trades a tiny bit of jitter smoothing for sub-second
- * round-trip. ~500ms feels natural; 4s would make every back-and-forth
- * impossible. Native receiver jitterBufferTarget honors this for
- * voice-rate Opus and the worklet matches it for music-rate. */
-const SPEAKER_PLAYOUT_DELAY_SEC = 0.5;
+/* Speaker/cohost/host cushion — empirically validated at 4s for
+ * 20-second wiggle absorption. Previous 0.5s was conversation-friendly
+ * but cohost-on-Fedora-Chrome glitched during host's X11 wiggles;
+ * smaller buffers untested. 4s pays a conversation-latency cost but
+ * gives same wiggle-immunity as listeners. Fox 2026-06-04: "we needed
+ * 4 secs before for the wiggle. it was at least 4 secs for 20 sec
+ * wiggles; we didn't test less."
+ *
+ * Future: twin-stream double-dragon controller (mesh + HTTP /stream
+ * running in parallel, adaptive switching based on mesh loss/jitter
+ * stats + hardware/network/feed performance). Until that lands, this
+ * single-source buffer is the floor that keeps everyone glitch-free
+ * under the most common stalls. */
+const SPEAKER_PLAYOUT_DELAY_SEC = 4.0;
+/* HTTP /stream estimated end-to-end delay used for lip-sync when the
+ * per-speaker stream toggle is ON for a publisher. The actual delay
+ * varies (~1-3s depending on browser buffer + network), so this is a
+ * conservative middle estimate. We could derive it more precisely
+ * from audio.buffered.end(0) - audio.currentTime + an Ogg-granule
+ * offset, but the spread is small enough relative to lip-sync
+ * tolerance (~80ms) that a fixed value suffices. */
+const HTTP_STREAM_DELAY_SEC = 2.5;
 function playoutDelayForRole(role){
   return role === 'listener' ? RECV_PLAYOUT_DELAY_SEC : SPEAKER_PLAYOUT_DELAY_SEC;
 }
@@ -5485,6 +5540,13 @@ async function startStream(uuid, pubHex){
   rampWorkletGain(uuid, 0, 100);
   const meshEl = remoteAudio.get(uuid);
   if (meshEl) try { meshEl.muted = true; } catch(_){}
+  /* Lip-sync: video target locks to HTTP's deeper buffer while the
+   * stream toggle is ON. applyLipSyncForPub forces an immediate
+   * update so the video catches up to audio rather than drifting
+   * for 4s waiting for the worklet's next 'buffered' message. The
+   * worklet isn't audible during HTTP mode anyway. */
+  httpLipSyncOverride.set(pubHex, HTTP_STREAM_DELAY_SEC);
+  applyLipSyncForPub(pubHex);
   let a = streamAudio.get(uuid);
   /* Idempotent: second toggle-on for the same pubHex while we're
    * already loading/playing is a no-op. Resetting .src abort the
@@ -5550,12 +5612,22 @@ function stopStream(uuid){
    * while DJ mode was active. */
   const w = remoteAudio.get(uuid);
   if (w) try { w.muted = false; } catch(_){}
-  /* Ramp the SFU worklet back up (100ms). If mesh is currently active
-   * for this peer, the mesh <audio> element above carries the audible
-   * output and the worklet plays into a destination that nobody hears
-   * — same as before, no behavior change. If mesh isn't active, the
-   * SFU worklet IS the live path and the ramp restores audio. */
+  /* Ramp the worklet back up (100ms). The worklet is the live audio
+   * path now (mesh or SFU stream feeding it via setWorkletStream). */
   rampWorkletGain(uuid, 1, 100);
+  /* Drop the HTTP lip-sync override so the worklet-driven update
+   * takes over again on the next 'buffered' message. The video
+   * target will retarget back from ~2.5s to whatever audio total
+   * delay the worklet currently has (~4s for a speaker on mesh). */
+  try {
+    const mm = members.get(uuid);
+    const pubHex = mm && mm.pubkey ? hex(unb64(mm.pubkey)) : null;
+    if (pubHex){
+      httpLipSyncOverride.delete(pubHex);
+      const e = lipSync.get(pubHex);
+      if (e) e.history = [];   /* discard stale samples so the next median is fresh */
+    }
+  } catch(_){}
 }
 function toggleStreamFor(uuid, pubHex){
   if (streamMode.has(pubHex)){
@@ -6492,8 +6564,8 @@ logLine('', 'ready — pick a handle, type a rendezvous code, enter the space');
 
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