Alibaba Happyhorse 1.1 Video Extend

Alibaba Happyhorse 1.1 Video Extend

Playground

Alibaba HappyHorse 1.1 Video Extend extends existing videos with seamless AI-generated continuation, supporting 720P / 1080P output while preserving visual continuity and motion consistency. Ready-to-use REST inference API, best performance, no coldstarts, affordable pricing.

Features

Alibaba Happy Horse 1.1 Video Extend

Alibaba Happy Horse 1.1 Video Extend continues an existing video clip with new AI-generated footage, seamlessly extending the scene from where the original ends. Upload a source video, describe how the video should continue, and the model generates a coherent continuation in 720p or 1080p.

• Need to edit an existing clip instead of extending it? Try Alibaba Happy Horse 1.0 Video Edit.
• Need to generate a new video from text? Try Alibaba Happy Horse 1.1 Text-to-Video.

Why Choose This?

• Seamless video continuation Extend an existing clip with newly generated footage that picks up naturally from the original ending.

• Prompt-guided scene progression Describe how the action, camera movement, atmosphere, or story should continue using natural language.

• Cinematic motion Generate smooth, expressive motion while preserving the overall feel and flow of the source video.

• Flexible resolution options Choose 720p for lower-cost iteration or 1080p for higher-quality final output.

• Production-ready API Access the model through a REST inference API with no cold starts for scalable integration into creative workflows.

Parameters

How to Use

1. Upload your source video — provide the clip you want to continue.
2. Write your prompt — describe how the scene, subject, camera, or atmosphere should progress after the original ending.
3. Choose resolution — use 720p for lower-cost iteration or 1080p for higher-quality results.
4. Set duration — choose the total output duration between 3 and 15 seconds.
5. Set a seed (optional) — use a fixed seed if you want more reproducible results.
6. Submit — generate and download the extended video.

Example Prompt

Continue the scene with a slow forward camera movement, the subject walking deeper into the alley, soft rain beginning to fall, stronger reflections on the ground, and a cinematic moody nighttime atmosphere

Pricing

Per 5 Seconds

Example Costs

Billing Rules

• Base price: 720p costs $0.70 per 5 seconds
• 1080p surcharge: 1080p costs 2× the 720p rate
• Total price formula:
  total_price = 0.70 × (resolution == "1080p" ? 2 : 1) × duration / 5

Best Use Cases

• Scene continuation — Extend cinematic clips with natural motion and coherent progression.
• Storyboarding and concept work — Explore how a shot or sequence might continue without manual video production.
• Ad creative development — Expand short promo clips into longer variations for campaigns and testing.
• Social media content — Create longer edits from short source footage for platform-specific needs.
• Atmospheric scene building — Continue motion, lighting, and mood from an existing clip into a richer sequence.
• Creative prototyping — Quickly test alternate continuations before investing in full production.

Pro Tips

• Use a source video with a clear ending frame for smoother continuation.
• Be explicit about what should happen next, including subject action, camera motion, lighting, and atmosphere.
• Keep prompts visually concrete, such as “camera slowly pushes in,” “the subject turns and walks away,” or “fog begins to roll in.”
• Use 720p for quick testing, then switch to 1080p for final-quality output.
• Reuse the same seed when you want more reproducible generations.
• Start with shorter durations to validate continuity before generating longer clips.

Notes

• Both video and prompt are required.
• Ensure video URLs are publicly accessible.
• Supported resolutions are 720p and 1080p.
• Supported total output duration is 3–15 seconds.
• Pricing scales linearly with duration.
• 1080p pricing is exactly 2× the 720p rate.

Related Models

• Alibaba Happy Horse 1.0 Video Edit — Perform prompt-driven editing on existing videos.
• Alibaba Happy Horse 1.1 Text-to-Video — Generate cinematic videos directly from natural-language prompts.
• Alibaba Happy Horse 1.1 Image-to-Video — Animate a single reference image into a cinematic clip.

# Submit the task
curl --location --request POST "https://api.wavespeed.ai/api/v3/alibaba/happyhorse-1.1/video-extend" \
--header "Content-Type: application/json" \
--header "Authorization: Bearer ${WAVESPEED_API_KEY}" \
--data-raw '{
    "resolution": "720p",
    "duration": 5
}'

# Get the result
curl --location --request GET "https://api.wavespeed.ai/api/v3/predictions/${requestId}/result" \
--header "Authorization: Bearer ${WAVESPEED_API_KEY}"