> ## Documentation Index
> Fetch the complete documentation index at: https://docs.jiekou.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Seedance 1.5 Pro Image-to-Video

This is an asynchronous API that returns a task\_id. Use the task\_id with the task result query API to obtain the video generation result. Supports text-to-video, image-to-video (first frame), and image-to-video (first and last frames) generation.

<Tip>
  This is an **asynchronous** API and only returns the task\_id of the async task. You should use this task\_id to request the [Task Result Query API](/en/docs/models/reference-get-async-task-result) to retrieve the generation result.
</Tip>

## Request Headers

<ParamField header="Content-Type" type="string" required={true}>
  Enum value: `application/json`
</ParamField>

<ParamField header="Authorization" type="string" required={true}>
  Bearer authentication format: Bearer \{\{API Key}}.
</ParamField>

## Request Body

<ParamField body="fps" type="integer" default={24}>
  Frame rate (frames per second). Only 24 fps is supported.

  Optional value: `24`
</ParamField>

<ParamField body="seed" type="integer" default={-1}>
  Seed integer used to control randomness. Range: \[-1, 2^32-1]. -1 means using a random seed. The same seed and the same request will produce similar (but not exactly identical) results.

  Value range: \[-1, 4294967295]
</ParamField>

<ParamField body="image" type="string" required={true}>
  The first-frame image for image-to-video generation. It can be an image URL or a Base64-encoded image. The URL must be accessible. Base64 format: `data:image/<图像格式>;base64,<Base64 编码>`. Supported formats: jpeg, png, webp, bmp, tiff, gif. Aspect ratio: (0.4, 2.5), dimensions: (300, 6000) pixels, size: \< 30 MB.
</ParamField>

<ParamField body="ratio" type="string" default="adaptive">
  The aspect ratio of the generated video. 'adaptive': for text-to-video, the model intelligently selects the best ratio based on the prompt; for image-to-video, it is automatically selected based on the aspect ratio of the uploaded first-frame image.

  Optional values: `16:9`, `4:3`, `1:1`, `3:4`, `9:16`, `21:9`, `adaptive`
</ParamField>

<ParamField body="prompt" type="string" required={true}>
  A text prompt describing the expected video content. Chinese and English are supported. It is recommended to keep it under 500 characters. If you need to generate audio with dialogue, place the spoken content in double quotation marks for better audio generation results.
</ParamField>

<ParamField body="duration" type="integer" default={5}>
  Video duration, in seconds. Specified durations within the range \[4, 12] are supported. Note: duration affects billing.

  Value range: \[4, 12]
</ParamField>

<ParamField body="watermark" type="boolean" default={false}>
  Whether the generated video contains a watermark. true: with watermark. false: without watermark.
</ParamField>

<ParamField body="last_image" type="string">
  The last-frame image for first-and-last-frame image-to-video generation. It can be an image URL or a Base64-encoded image. The requirements are the same as those for the image field. When the aspect ratios differ, the last frame will be automatically cropped to match the first frame.
</ParamField>

<ParamField body="resolution" type="string" default="720p">
  Video resolution. Seedance 1.5 pro supports 480p, 720p, and 1080p.

  Optional values: `480p`, `720p`, `1080p`
</ParamField>

<ParamField body="camera_fixed" type="boolean" default={false}>
  Whether to fix the camera position. true: the platform appends fixed-camera instructions to the prompt (effect not guaranteed). false: the camera is not fixed.
</ParamField>

<ParamField body="service_tier" type="string" default="default">
  The service tier for processing the request. 'default': online inference mode, with lower RPM and concurrency quotas, suitable for latency-sensitive scenarios. 'flex': offline inference mode, with a higher TPD quota and priced at 50% of online mode, suitable for latency-insensitive scenarios.

  Optional values: `default`, `flex`
</ParamField>

<ParamField body="generate_audio" type="boolean" default={true}>
  Whether the generated video contains synchronized audio. true: the video includes speech, sound effects, and background music automatically generated based on the prompt and visual content. false: outputs a silent video.
</ParamField>

<ParamField body="execution_expires_after" type="integer" default={172800}>
  Task timeout threshold, in seconds, calculated from the created\_at timestamp. Default value: 172800 (48 hours). Range: \[3600, 259200]. Tasks exceeding this time will be automatically terminated and marked as 'expired'.

  Value range: \[3600, 259200]
</ParamField>

## Response Information

<ResponseField name="task_id" type="string" required={true}>
  The task\_id of the asynchronous task. You should use this task\_id to request the [Task Result Query API](/en/docs/models/reference-get-async-task-result) to obtain the generation result
</ResponseField>