/physical-ai-video-data-augmentation

Trailer-dashcam VLM prompt.

Loaded at runtime from /workspace/configs/video_event_analysis_prompt_redid.md.

Submission format for this scene:

• Exactly two JSON objects.
• Object 1: metadata summary.
• Object 2: event list payload.
• No text before, between, or after the two objects.

Observation setup:

• Rear-facing wide-angle camera on a towing vehicle.
• Trailer body and hitch occupy central frame; trailing traffic appears around the trailer silhouette.

Task: Classify towing safety events and normal towing behavior over the segment.

Permitted event labels:

1. rear_collision
2. backing_contact
3. near_miss_following
4. near_miss_lane_change
5. obstacle_proximity
6. trailer_sway
7. hitch_issue
8. normal_towing
9. normal_backing

Metadata object contract:

• Must provide: version, video_id, format, rectified, scenario_info, scene_description, event_summary, fps, duration, height, width, camera_id
• scenario_info must be "TRAILER_DASHCAM"
• scene_description should mention trailer/hitch condition, roadway type, surroundings, weather, lighting, and whether motion is towing/backing/stationary
• event_summary should condense towing stability plus timestamped incidents

Event payload contract:

• Top level: version and events
• Event records must contain:
  • event_id
  • start_time
  • end_time
  • category (collision | near_miss | anomaly | normal_traffic)
  • sub_category (array)
  • instances (array)
  • event_caption

Category mapping for trailer footage:

• collision -> rear_collision, backing_contact
• near_miss -> near_miss_following, near_miss_lane_change, obstacle_proximity
• anomaly -> trailer_sway, hitch_issue
• normal_traffic -> normal_towing, normal_backing

Output correctness rules:

• sub_category must be an array, never a scalar
• event_caption includes severity (low/medium/high), involved actors, and time bounds
• Use tracker IDs when available, otherwise descriptive identities (following vehicle, cyclist, pedestrian, trailer)
• Use numeric seconds for timing

No-following-traffic case:

• If the rear scene is clear and towing remains stable, include metadata plus one normal_towing event.

Trailer-scene caveats:

• Wide-angle edge distortion alters apparent distance; evaluate sway using hitch-relative motion near frame center.
• The trailer occludes centerline view; side-channel visibility may be the only evidence of trailing vehicles.
• Vertical bounce on rough roads is expected; classify hitch_issue only when motion is excessive or coupling geometry shifts abnormally.
• Trailer angle changes during turns are normal; sway requires persistent lateral oscillation beyond steering dynamics.
• Backing clips naturally reduce clearance; call backing_contact only on contact, and obstacle_proximity on sub-meter near misses.
• Trailer shadows can mimic moving objects on pavement; verify motion source before labeling.

Required order: metadata object first, annotation object second.