DoubaoNativeContentItem
text：文本描述image_url：图片引用video_url：视频引用（会触发视频输入折扣）audio_url：音频引用{
"type": "text",
"text": "宇航员站起身，回望地球",
"image_url": {
"url": "https://example.com/reference-photo.jpg"
},
"video_url": {
"url": "https://example.com/input-video-clip.mp4"
},
"audio_url": {
"url": "https://example.com/background-music.mp3"
},
"role": "reference_image"
}