Alibaba Happyhorse 1.0 Video Extend

Alibaba Happyhorse 1.0 Video Extend

Playground

Alibaba Happy Horse 1.0 (Video Extend) extends existing videos with seamless AI-generated continuation, supporting 720p/1080p output. Ready-to-use REST API, best performance, no coldstarts, affordable pricing.

Features

Alibaba Happy Horse 1.0 Video Extend

Alibaba Happy Horse 1.0 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 1.0 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 1.0 Text-to-Video — Generate cinematic videos directly from natural-language prompts.
• Alibaba Happy Horse 1.0 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-1.0/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}"