vertical video safe areas: review the placement preview rather than the aspect ratio alone
Vertical video safe areas are a delivery-layout decision, not just an aspect-ratio choice. A generated 9:16 clip can still place its subject behind interface controls or leave no room for captions. Define the actual placement and inspect its overlays before approving the edit.
Genace exposes an aspect_ratio input for supported video models. That input does not automatically apply a publishing platform’s current interface masks, crop rules, or caption layout. Safe-area guides, subtitles, reframing, and final export are your post-production responsibilities.
Capture the destination view
Use the current publishing preview or a test placement to identify visible interface regions. Record the surface, device layout, capture date, and whether captions or action buttons occupy part of the frame. Avoid treating one remembered set of pixel margins as a permanent rule for every destination.
Make a guide layer in your editor. Mark areas for the subject, optional decorative content, and added text. Keep the guide separate from the delivered media so it cannot accidentally appear in the final video.
Review movement through the whole clip
| Element | Required review | Common failure |
|---|---|---|
| Main subject | Position across time | Subject exits the readable region |
| Product detail | Visibility during important beat | Interface covers the detail |
| Captions | Final line breaks and position | Last line touches controls |
| End card | Full destination preview | Action text is cropped |
| Alternate placement | Separate guide and export | Wide crop removes meaning |
A subject can begin inside the guide and move outside it later. Scrub the entire clip and watch it in real time. Frame samples are useful for navigation, but they do not establish that every motion segment remains readable.
Solve crop problems in the right stage
If the source has enough space, create a deliberate reframe in your editor. If the source cannot support the placement, select another shot or generate a new candidate under a revised brief. Do not stretch the frame to force the subject into the guide.
Add exact captions and campaign wording after generation. Inspect the flattened export with the same text size and line breaks that will be used at delivery. A clean working timeline can still produce poor small-screen readability after compression.
For multilingual versions, allow enough space for the longest reviewed copy. A text box that works in one language may become too tall in another. The relevant guide is the final rendered version, not an empty placeholder.
Preserve placement-specific approval
Link each export to its source clip, crop recipe, caption revision, and guide version. Approving one vertical derivative should not automatically approve every other crop. If a destination changes its interface, you should be able to find the affected exports without regenerating the source video.
Keep the unmodified source available so future safe-area changes can be handled as editing work rather than a new render.
Acceptance checklist
Preview the exact destination, watch the full motion, check captions and end cards, and inspect small-screen playback. Confirm that no guide layer is exported and that each placement has its own review record.
Related workflows cover thumbnail selection, responsive image derivatives, and asset lineage.
Continue with creative workflows
Where these facts come from
- codebase: src/app/api/v1/video/generations/route.ts
- codebase: src/ai/providers/types.ts
- Application-owned workflow recommendations; human review and post-processing are outside the generation gateway
- Editorial keyword hypothesis; search volume not measured