Video generation

Duration, first and last frames, task modes, reference video and audio, and upscaling.

Switch to video mode with the icons at the top of the form. Most of the form is the same; this page covers what is different.

Duration

A slider whose range comes from the model. Switching models applies that model’s default.

Seedance models offer auto duration. With it on, the slider disappears and the model decides how long the clip should be. The cost estimate then shows a per-second rate rather than a total, because the final charge depends on what the model produces.

First and last frames

First and last frame slots

If a model supports them, slots appear for a start image and an end image. You can upload a file, pick from your asset library, or take a frame from a history result. A swap button exchanges the two.

Filter the video model list by first frame or first and last frame to see only models that support this.

Task modes

Seedance models offer three:

Mode	What it does	Requires
Generate	Text to video, or multimodal reference	Nothing extra
Edit	Modify an existing clip	At least one reference video, and edit keywords in the prompt
Extend	Continue an existing clip	At least one reference video, and extend keywords in the prompt

Task mode and prompt wording must agree. Edit mode needs words like edit, add, remove, or replace in the prompt; extend mode needs extend or continue. A generate-mode prompt containing edit keywords will be rejected so it is not misclassified.

Edit and extend mode force the aspect ratio to adaptive and hide the ratio picker. Edit mode also forces MOV output.

Video upscaling

A separate capability with its own settings:

• Scenario — general, UGC short video, AIGC, short drama, or classic film restoration
• Enhancement level — fast, standard, or pro
• Resolution — original, 720p, 1080p, 2K, or 4K
• Bit depth — 8, 10, or 12-bit

Seedance results also offer HD upscaling directly from the history card, provided the original has a seed. The available resolutions depend on the model and the original resolution.

Text to audio

The fourth mode generates speech. Its settings come from the TTS model: speaker, speech rate, pitch, loudness, sample rate, and format.

What video editing is not

WJI has no timeline editor in this app, and no way to cancel a running generation. Selective regeneration of part of a clip exists, but only on the Infinite Canvas.