Avoid serializing runtime timeline tensors

ltx_director.py

@@ -208,6 +208,27 @@ def _build_runtime_timeline_payload(external_timeline, frame_rate: float) -> tup
     return tdata, " | ".join(local_prompts), ",".join(segment_lengths), duration_seconds, duration_frames
 
 
+def _make_json_safe(value):
+    """Return a JSON-serializable copy of runtime data by stripping live tensor payloads."""
+    if isinstance(value, torch.Tensor):
+        return None
+    if isinstance(value, dict):
+        cleaned = {}
+        for key, item in value.items():
+            safe_item = _make_json_safe(item)
+            if safe_item is not None:
+                cleaned[key] = safe_item
+        return cleaned
+    if isinstance(value, (list, tuple)):
+        cleaned = []
+        for item in value:
+            safe_item = _make_json_safe(item)
+            if safe_item is not None:
+                cleaned.append(safe_item)
+        return cleaned
+    return value
+
+
 def _compute_signal_peaks(samples: np.ndarray, num_peaks: int = PEAK_BUCKETS) -> list[float]:
     if samples.size == 0:
         return [0.0] * num_peaks
@@ -2086,14 +2107,19 @@ class LTXDirector(io.ComfyNode):
             merged_tdata["segments"] = external_tdata["segments"]
             merged_tdata.setdefault("motionSegments", existing_tdata.get("motionSegments", []))
             merged_tdata.setdefault("audioSegments", existing_tdata.get("audioSegments", []))
-            timeline_data = json.dumps(merged_tdata)
+            timeline_data = json.dumps(_make_json_safe(merged_tdata))
             local_prompts = external_local_prompts
             segment_lengths = external_segment_lengths
             if duration is None:
                 duration_seconds = external_duration_seconds
                 duration_frames = external_duration_frames
+        else:
+            merged_tdata = None
 
         # Parse timeline data
+        if merged_tdata is not None:
+            tdata = merged_tdata
+        else:
             try:
                 tdata = _safe_json_loads(timeline_data)
             except Exception as e: