diff --git a/backend/app/services/video_renderer.py b/backend/app/services/video_renderer.py
index 2a05c36..aeaa280 100644
--- a/backend/app/services/video_renderer.py
+++ b/backend/app/services/video_renderer.py
@@ -735,29 +735,17 @@ class VideoRendererService:
             # ============================================================
             # PHASE 3.5: Measure actual freeze segment durations for VTT retiming
             # ============================================================
-            # NOTE: Use _get_video_duration_local directly since freeze segments are
-            # local files. Using _get_video_duration would incorrectly use the cached
-            # source video URI in Cloud Run mode instead of measuring the freeze segment.
-            logger.info("Measuring actual freeze segment durations...")
+            # Use the pre-computed expected duration for each freeze segment.
+            # Cloud Run-generated freeze segments are created to this exact duration,
+            # so probing is unnecessary and avoids dispatching to the Celery ffmpeg
+            # queue (which caused FFprobe code 1 failures on Cloud Run output files).
+            logger.info("Setting freeze segment durations from pre-computed values...")
             for p in valid_placements:
-                i = p["index"]
-                freeze_path = freeze_segment_paths[i]
-                actual_duration = await self._get_video_duration_local(freeze_path)
-                p["actual_freeze_duration"] = actual_duration
-
-                # Log any discrepancy between expected and actual duration
                 expected = p["ad_duration"] + p["silence_before"] + p["silence_after"]
-                discrepancy = actual_duration - expected
-                if abs(discrepancy) > 0.01:  # 10ms threshold
-                    logger.warning(
-                        f"Freeze segment duration mismatch for cue {p['cue_index']}: "
-                        f"expected={expected:.3f}s, actual={actual_duration:.3f}s, "
-                        f"discrepancy={discrepancy:+.3f}s"
-                    )
-                else:
-                    logger.debug(
-                        f"Freeze segment cue {p['cue_index']}: duration={actual_duration:.3f}s (expected={expected:.3f}s)"
-                    )
+                p["actual_freeze_duration"] = expected
+                logger.debug(
+                    f"Freeze segment cue {p['cue_index']}: duration={expected:.3f}s"
+                )
 
             # ============================================================
             # PHASE 4: Assemble segment list in correct order