携带参考视频自动享受输入折扣

{
  "model": "doubao-seedance-2-0-260128",
  "content": [
    {"type": "text", "text": "参考视频1的运镜与节奏，生成同风格的城市夜景"},
    {"type": "video_url", "video_url": {"url": "https://example.com/ref.mp4"}, "role": "reference_video"}
  ],
  "resolution": "720p",
  "duration": 5
}