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happyhorse-1.1-i2v

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happyhorse-1.1-i2v

Turn a single first-frame image into the starting point for a dynamic short film with sound

happyhorse-1.1-i2v is the first-frame image-to-video model of HappyHorse 1.1. It uses one image to define the camera's starting point, then uses text to describe subject actions, environmental changes, and camera movement. It is suitable for turning product images, character design images, and scene illustrations into dynamic short films, supports 3–15-second creation, has native audio capabilities, and is especially suited for tasks with an already clear composition that need to further develop motion in the scene.

HappyHorseModel brand
VideoModel type
VideoTask capability

Specifications and API features

Clarify capacity, input/output, and invocation methods before selecting a model.

Creation method
Single first-frame image-to-video, with optional text action descriptions
Platform resolutions
720P、1080P
Video duration
3–15 seconds; the platform accepts whole seconds
Native video output
24 fps, MP4
Aspect ratio control
The output aspect ratio follows the first-frame image as closely as possible
Native audio
Supports audio-video generation
Task delivery
Supports asynchronous queries, completion callbacks, and video URL results

Native resolutions also include 480P; this platform provides 720P and 1080P options, and the aspect ratio for first-frame tasks is determined by the input image.

Core Capabilities

Learn what happyhorse-1.1-i2v can bring to your work.

Set the Frame First, Then Design the Motion

The first-frame image serves directly as the starting point of the video, providing a clear basis for product placement, character appearance, and scene composition. Compared with building a shot using text alone, this approach is better suited to creation with existing visual assets; prompts can focus on changes such as looking up, turning around, wind moving clothing, or a slow push-in, reducing repeated descriptions of the initial frame.

Develop Static Assets into Short Shots

This model is designed for first-frame animation and can create short clips around subject actions, environmental dynamics, and camera movement. In actual creation, it is recommended to first define one primary action, then add requirements for lighting, background, and camera movement, so that a few seconds of footage serve a clear purpose rather than cramming a complete story, multiple transitions, and complex interactions into the same clip.

Get Video Results by Task

Submit the first frame and creation description through POST /happyhorse/videos, explicitly selecting image_to_video and happyhorse-1.1-i2v. When background processing is needed, you can use async to obtain a task ID and check its status, or use callback_url to receive completed results, making it suitable for integration with asset creation tools and batch creation workflows.

Use Cases

Start with specific tasks to find where the model can be effective.

Animating Static Product Images

Input a product photo with a clear composition, describe a subtle camera push-in, changes in background light and shadow, or movement in the surrounding environment, and generate a short clip for marketing previews. When packaging and brand text need to stand out, restrained motion should be used to preserve visual focus, and labels, fine print, and outlines should be checked before delivery to prevent dynamic changes from affecting product information.

Character Shot Previsualization

Use a character design image as the first frame and pair it with action descriptions such as looking up, looking back, or clothing swaying to obtain dynamic storyboard drafts. The deliverables can be used to discuss performance direction and shot rhythm; if the task changes to having multiple character images jointly constrain a new scene, choose a reference-image-to-video model instead of continuing to add first-frame inputs.

Dynamic Previews for Scene Illustrations

Start with a landscape image or scene illustration, describe the movement of water, leaves, clouds, and the camera, and create short atmospheric shots. When producing vertical content, prepare a portrait-composition image first so the aspect ratio continues from the first frame; after completion, obtain the video URL, download the asset, and move it into the editing workflow to assemble longer content.

How to Choose This Model

Choose based on task complexity, input materials, and expected results.

Choose by Input Material for Model 1.1

If you already have an image that needs to serve as the opening frame, choose happyhorse-1.1-i2v; if you only have a text script, choose happyhorse-1.1-t2v; if you need multiple images to constrain characters, props, or style, choose happyhorse-1.1-r2v. The difference is whether the image must become the first frame, rather than merely serving as creative reference. Modifying an existing video belongs to the video-edit task.

Trade-offs with 1.0 and Other Video Tasks

The native duration, frame rate, and file format of the 1.1 and 1.0 first-frame models are the same; 1.1 adds a native 480P option. At this entry point, both use 720P or 1080P, so do not assume speed or image quality improvements based on the version number alone. For new first-frame tasks, you can choose 1.1; if you must specify the ending frame or connect long shots, choose a model that explicitly supports first- and last-frame control.

Get Started

From a small-scale task to formal integration.

01

Prepare the Task and Materials

Define the goal, required inputs, and output requirements, using real business examples as a starting point.

02

Try It in the API Testing Area

Open the trial page, confirm the parameters supported by this entry point, then submit a small-scale task to review the results.

03

Integrate According to the API Documentation

Keep the complete model ID, use the request format specified in the documentation, and confirm billing rules on the Pricing page.

Usage Boundaries

Before formal use, understand the output quality and capability scope.

  • This is a single-first-frame generation model, not a multi-image reference or existing-video editing tool. Do not use image_urls in place of image_url, and do not expect that passing video_url will allow you to modify a video; the task action and model must match, and you should explicitly specify image_to_video when submitting.
  • The aspect ratio should follow the first frame whenever possible; it is not suitable for forcibly changing composition through ratio. Materials must use publicly accessible image URLs; before uploading, complete landscape or portrait composition, subject spacing, and key content layout to avoid losing important visual elements through post-generation cropping.
  • The scope of a single creation is 3–15 seconds. The first frame defines the starting point, but does not mean every subsequent frame will retain unchanged details; complex occlusion, large turns, and fine text should be checked segment by segment. Audio capability also does not mean you can directly specify voice-over, reference audio tracks, or precise lip-sync.

Frequently Asked Questions

Answers to common questions about using happyhorse-1.1-i2v.

How must the first-frame image be submitted?

Use image_url to submit a publicly accessible image, and set action to image_to_video and model to happyhorse-1.1-i2v. The image will serve as the first frame of the video; use prompt to supplement subsequent actions, environmental changes, and camera movement, without needing to redescribe all static details.

Can I specify portrait or square videos?

The output aspect ratio for first-frame tasks will follow the image as closely as possible, so there is no need to pass an additional ratio. To create portrait or square content, first prepare a first-frame image with the corresponding composition; it is best to leave safe space around product labels, people's heads, and other important elements, then check the final video's actual frame.

Can it use multiple reference images to maintain character consistency?

This model starts generation from a single first-frame image and is not a multi-image reference mode. When you need to combine character, clothing, or prop references, choose happyhorse-1.1-r2v; if the main goal is to make an existing image start moving without reorganizing the scene, i2v better matches the task structure.

What resolutions, durations, and audio capabilities are supported?

This endpoint offers 720P or 1080P, with durations of whole-number 3–15 seconds; native video specifications are 24 fps, MP4, with audio support. Audio generation and precise dubbing control are different capabilities; retaining the original video audio or using reference audio input is not supported by this model.

How do I get the finished video after submission?

You can set async=true, save the returned task_id, and then query through /happyhorse/tasks; you can also provide callback_url and wait for a completion notification. Result statuses include pending, succeeded, and error, and successful results include video_url; do not assume the video has finished generating just because you have obtained a task ID.

Model information · Updated: 2026-10-01. For call parameters and billing rules, see the API and pricing sections.

Use happyhorse-1.1-i2v for your next task

Start with a clear goal and assess whether it fits your work based on actual results.