falVideo to videoComing soon

minimax/h3-max/extend-video

Name: minimax/h3-max/extend-video
Brand: fal

minimax/h3-max/extend-video is a video to video tool from fal that runs in the background and returns video. Coming soon: listed with its price, not yet open to runs.

This tool is listed but not yet available to run.

Priced by usage

Pricing

$0.065 per second. Billed on duration, default 5. The final charge comes from usage.

Limits

Runs: In the background
Returns: video
Longest queue wait: 3600s
Run deadline: 1800s
Largest inline input: 1024 KB
Largest input file: 500 MB
Largest output: 4768 MB
Outputs per run: 16

Input

Field	Kind	Default	Description
`video_url` required	URL or file	—	URL of the video to extend. Must be 1.625 s to 60 s long, up to 50 MB, aspect ratio between 0.4 and 2.5.
`prompt` required	text	—	What happens next. Describe the continuation, not the source.
`reference_audio_urls`	URLs or files	—	Optional audio references for the continuation (2–15 seconds each, 15 seconds combined). The full extended video retains its original source soundtrack, and its ending still conditions the transition. These clips guide the newly generated audio instead of using that soundtrack as an audio reference. Assign each clip a role in the prompt, such as 'Audio 1 for the voice' and 'Audio 2 for background music'.
`enable_prompt_expansion`	true or false	true	Automatically enhance the prompt using the source video to help keep the continuation consistent. May increase processing time.
`duration`	number 0.71 to 15	5	Seconds of new footage to add. The continuation clip also includes 1.625 seconds from the source's ending and may be longer because of frame rounding.
`resolution`	one of 480P, 768P, 1080P, 2K	768P	Output video resolution.
`aspect_ratio`	one of auto, 21:9, 16:9, 4:3, 1:1, 3:4, 9:16	auto	Output aspect ratio. 'auto' follows the source video. Other values crop the video to fit the selected ratio.
`seed`	number (whole)	—	Seed for the continuation. Random when omitted.
`output`	one of extended, continuation	extended	'extended' returns the source and new footage as one video. 'continuation' returns a clip that starts with a 1.625-second repeat of the source's ending, then shows the new footage.

Same request in code

curl https://api.spiral.ai/v1/runs \
  -H "Authorization: Bearer $SPIRAL_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{
    "provider": "fal",
    "model": "minimax/h3-max/extend-video",
    "input": {
      "video_url": "https://storage.googleapis.com/falserverless/example_inputs/flux-3-red-panda.mp4",
      "prompt": "The red panda keeps walking along the log, then looks up at a bird."
    }
  }'