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Process, create, and transform videos with Video Api Hub

Actions21

Auto Caption Video → Add Stylish Captions

AI-generated

Summary

Add animated, stylish captions to a video by transcribing its audio and burning word-level captions with optional AI style prompting and b-roll clips.

Inputs

  • Video Source (required) — Provide the video to caption, either as a storage key from your upload step or a public HTTPS URL.
  • Style Preset (required) — Select the visual animation style for the captions from preset options like Neon Pop, Bold Yellow Karaoke, etc.
  • Prompt — Optional natural-language guidance to influence the AI's style and emphasis for the captions.
  • Add B-Roll Clips — Choose whether to auto-insert relevant b-roll clips around the captions.
  • B-Roll Image URLs — If adding b-roll, optionally provide comma-separated HTTPS image URLs to use as b-roll sources.
  • B-Roll Position — Set vertical position of b-roll cutaways: Top, Center, or Bottom.
  • Language Hint — Optional ISO language code to guide transcription.
  • Output Width (Pixels) — Set the output video width in pixels.
  • Output Height (Pixels) — Set the output video height in pixels.
  • Duration (Seconds) — Specify an optional clip duration; free plans typically limit this to 10 seconds.
  • Email — Optional email to associate with the job.
  • How to Get the Result (required) — Choose how to receive the finished captioned video: as a direct file download, public URL, temporary signed download link, or stored only.
  • Link Expires After (Seconds) — If receiving a temporary signed download link, specify its expiration time in seconds (60–86400).
  • Advanced Settings - Custom Save Path — Optionally specify a custom storage path for the output video; leave empty to auto-generate.

Output shape

A JSON object containing the job response with info about the captioning job and how to access the output video as per the selected output type.

The result includes a URL or file depending on the outputType chosen. If outputType is 'signed_url', the download link expires after the specified time. If 'stored', the output is saved in VideoApiHub storage for later access.

Examples

Example 1: Caption a video hosted at a public URL with neon-pop styled captions and receive a temporary download link that expires in one hour.

Set Video Source to the video URL, choose 'Neon Pop' style preset, leave prompt blank, set outputType to 'signed_url', and outputExpiry to 3600.

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