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Seedance 2.0 Fast First and Last Frame to Video

Authorizations

Authorization
string
header
required

Pass Authorization: Bearer <token> in the request header.

Body

application/json
model
enum<string>
required

The ID of the model you need to call (Model ID)

Available options:
dreamina-seedance-2-0-fast-260128
media
object[]
required

Multimodal input array. 2.0 Fast supports text, first_frame, last_frame, reference_image, reference_video, and reference_audio.

Minimum array length: 3
seconds
enum<string>
default:5

Video duration, integer only, in seconds.

  • Seedance 1.0 pro, Seedance 1.0 pro fast: [2, 12] s.
  • Seedance 1.5 pro: [4, 12] or set to -1
  • Seedance 2.0 series: [4, 15] or set to -1

Note

Seedance 2.0 series and Seedance 1.5 pro support two configuration methods:

  • Specify exact duration: Any integer within the valid range.
  • Smart mode: Set to -1 to let the model choose the appropriate video length (in whole seconds) within the valid range. The actual generated video duration can be obtained from the duration field returned by the query video generation task API. Note that video duration is related to billing, so set it carefully.
Available options:
4,
5,
6,
7,
8,
9,
10,
11,
12,
15,
-1
Example:

"5"

size
enum<string>
default:720p

Seedance 2.0 series and Seedance 1.5 pro default: 720p Seedance 1.0 pro & pro-fast default: 1080p

Video resolution. Enum values:

  • 480p
  • 720p
  • 1080p: Not supported by Seedance 2.0 Fast and Seedance 2.0 Mini.
  • 4k: Only supported by Seedance 2.0
Available options:
480p,
720p
ratio
enum<string>
default:adaptive

Seedance 2.0 series and Seedance 1.5 pro default: adaptive Other models: Text-to-Video default 16:9, Image-to-Video default adaptive

The aspect ratio of the generated video. See the table below for pixel dimensions for different aspect ratios.

  • 16:9
  • 4:3
  • 1:1
  • 3:4
  • 9:16
  • 21:9
  • adaptive: Automatically selects the most suitable aspect ratio based on input (see details below)

adaptive Rules

When ratio is set to adaptive, the model automatically adjusts the aspect ratio based on the generation scenario. The actual video aspect ratio can be obtained from the ratio field returned by the query video generation task API.

****Supported models:

  • Seedance 2.0 series, Seedance 1.5 Pro supported
  • Other models only supported in Image-to-Video scenarios

****Rules:

  • Text-to-Video:Based on the input prompt, intelligently selects the most suitable aspect ratio.
  • First Frame / First & Last Frame: Automatically selects the closest aspect ratio based on the uploaded first frame image ratio.
  • Multimodal Reference-to-Video: Determines based on user prompt intent. If it is first-frame video/editing video/extending video, selects the closest aspect ratio based on that image/video; otherwise, selects the closest aspect ratio based on the first media file (priority: video > image).

Pixel dimensions corresponding to different aspect ratios

Note: For Image-to-Video, if the selected aspect ratio does not match the uploaded image ratio, the platform will crop your image from the center.

Available options:
16:9,
4:3,
1:1,
3:4,
9:16,
21:9,
adaptive
seed
integer
default:-1

Temporarily not supported by Seedance 2.0 series

Seed integer for controlling the randomness of generated content. Range: integer in [-1, 2^32-1].

Notes:

  • With the same request, if the model receives different seed values (e.g., not specifying a seed, setting seed to -1 which uses a random number, or manually changing the seed value), different results will be generated.
  • With the same request, if the model receives the same seed value, similar results will be generated, but exact consistency is not guaranteed.
Required range: -1 <= x <= 4294967295
watermark
boolean
default:false

Whether the generated video contains a watermark.

  • false: The generated video does not contain a watermark.
  • true: The generated video displays an "AI Generated" watermark in the bottom-right corner.
generate_audio
boolean
default:true

Only supported by Seedance 2.0 series and Seedance 1.5 pro

Controls whether the generated video contains synchronized audio.

  • true: The model outputs video with synchronized audio. The model automatically generates matching voice, sound effects, and background music based on the text prompt and visual content. It is recommended to place dialogue in double quotes for better audio generation. For example: The man stops the woman and says, "Remember, never point your finger at the moon."
  • false: The model outputs video without audio.

Note: Generated audio videos are all mono, regardless of the input audio channel count.

return_last_frame
boolean
default:false

true: Return the last frame image of the generated video. When set to true, you can obtain the last frame image through the query video generation task API. The last frame image is in PNG format with the same pixel dimensions as the generated video, without watermarks.

Use this parameter to generate multiple consecutive videos: use the last frame of one video as the first frame of the next video task to quickly generate a sequence of consecutive videos.

false: Do not return the last frame image of the generated video.

safety_identifier
string

Unique identifier of end users, used to help the platform detect users in your application who may violate the ModelArk usage policy. This identifier is an English string, which must be fixed and unique for a single user, and the length cannot exceed 64 characters. It is recommended to pass in a string generated by hashing the username, user ID or email address to avoid leaking user privacy information.

Response

Submission successful, returns video task object.

id
string

Video generation task ID. Only stored for 7 days (from the created_at timestamp), then automatically deleted.

  • When draft: true, this is the Draft video task ID.
  • When draft: false, this is the normal video task ID.

Video generation is asynchronous. After obtaining the ID, use the query video generation task API to check the status. When successful, the API returns the generated video URL.