Video Modes, Assets, and Prompt Optimization

Open Video Generation

The Video page displays model-specific parameters and hides or disables unsupported modes. After switching models, review the mode, media, and estimated credits again.

Creative mode

Uses the video description as the primary input and is suitable for starting from an idea. You can add reference images, videos, audio, and person assets when supported by the current model.

Some models call this Reference Generation. Follow the current field labels and controls to check whether a description is required, whether audio references are accepted, and whether sound can be generated.

First/Last Frame mode

Uses a first-frame image as the start of the new video. The last frame and video description are optional. Available inputs may include local images, assets, or uploading a video and extracting a frame at a chosen time. Use the inputs shown for the current model.

The aspect ratio may be locked to the first frame, so choose the first frame before reviewing the remaining settings.

Edit and Extend

Edit or Extend only appears when supported by the current model. Upload a source video, wait for its metadata and compatibility checks to succeed, then describe the changes or continuing action.

The page locks duration or aspect ratio values that the current mode derives from the source. Extend also lets you extend before or after the source. Edit and Extend each submit one task at a time.

Review the settings again after replacing the source. Do not treat a compatibility preview as proof of original quality. When Download Original is available, use that result as the source of truth.

Reference media

• Reference images, videos, and audio: add them through the local upload or asset inputs shown on the page. Follow that section's format, size, dimension, individual-duration, and total-duration guidance.
• Person assets: when supported, select digital characters, registered real-person assets, or virtual portraits. Prepare new assets through the available registration/upload controls or the Assets page.
• Seedance and Doubao assets: availability depends on the current service and team. After switching, select assets available for that service.

Some models count person assets together with ordinary references and impose a combined count and total video/audio duration limit. A source video used for Edit or Extend may also count as a video reference. Check more than the ordinary image count. Audio-only input support also depends on the model.

Mention media with @

1. Add or select media and confirm it appears in the media section.
2. Type @ in Video Description and find the candidate by type or name.
3. Select the candidate to insert its card, then describe its role. For example, insert a person and image card, then describe the person walking through the image's setting.
4. After removing or replacing media or switching models, check that every card still matches the intended media.

Mention numbers follow the selected media order. Typing @person1 manually or copying an old prompt does not ensure that it refers to the original asset. Out-of-range mentions, unavailable assets, and mentions retained in frame mode can block submission.

Switching models or providers may remove incompatible assets. Before submitting, review thumbnails, names, and mention markers again.

Prompt optimization

Supported models display Optimize Prompt in Creative generation mode. Select a valid project and enter a description first. The button freezes the original prompt, media, and parameters for this attempt, then obtains a quote showing the reserved amount, maximum charge, and available balance. Optimization starts after you confirm the cost; the final charge follows server settlement.

The optimized text is shown as a candidate and does not automatically replace the main prompt. Before applying it, check that:

1. person and asset mentions remain complete;
2. structural markers remain intact;
3. the main prompt, model, and assets did not change during optimization.

If the context changed, the page blocks the old candidate. Start a new optimization against the latest content instead of carrying old asset relationships into a new task.

After settlement, apply the candidate, keep it for later, or view the previous result. The application notice offers Undo; further edits to the main prompt prevent Undo from replacing the new content.

Drafts and devices

The Video form stores its main settings in the current browser. Drafts do not automatically sync to another device or browser and are lost when local browser data is cleared.

Drafts mainly include the description, model, standard parameters, references, person selections, and project/episode. First/last-frame images, Edit/Extend mode, and source videos are not fully restored; prepare those inputs again when reopening the page.

Next steps

View Video Results and History

Manage Person and Project Assets

Back to the user guide