{
  "video": "5.mp4",
  "task": "5",
  "instruction_index": 1,
  "total_instructions_for_video": 2,
  "instruction": {
    "category_label": "joint",
    "category": "J1",
    "operation": "J1.2 VFX Sync",
    "prompt_en": "Add a small, visible spark effect at the point of impact for each hammer strike; synchronize the visual spark with the sharp transient of each hammering sound.",
    "audio_label": {
      "audio_op": "add",
      "sound_type": "event_sfx",
      "edit_aspect": "content"
    },
    "difficulty": {
      "d1_object_localization": "hard",
      "d1_reason": "The model needs to precisely locate the point of impact for each hammer strike on the wall to add the spark effect.",
      "d2_audio_complexity": "simple",
      "d3_cross_modal_linkage": "explicit",
      "d3_reason": "The instruction explicitly describes both a visual effect (spark) and its synchronization with an audio event (hammering sound)."
    }
  }
}