How do I control video duration and aspect ratio?

Gemini Omni Video requires both to be specified in the prompt. Use the Prompt Constructor subgraph to inject them, e.g., "duration: 4s, aspect_ratio: 16:9" followed by your motion description.

Do I need two images, and in what order?

Yes—this workflow is designed for two inputs: the first LoadImage is the start frame and the second is the end frame. For subtle motion from a single still, you can reuse the same image in both inputs.

Do I need an API key or special setup?

If your GeminiVideoOmni node/extension requires credentials, configure a valid Google Gemini API key in the node settings or environment as documented by the ComfyUI extension you installed.

Why is there no audio in the output?

Gemini’s video generation returns a silent clip. Use a video editor to add music or sound effects after exporting from SaveVideo.

Gemini Omni Flash: Image to Video

This ComfyUI workflow turns two still images into a short video using Google’s Gemini Omni Flash via the GeminiVideoOmni node. You provide a start image and an end image (two LoadImage nodes), then guide the motion, duration, and framing with a natural-language prompt. A built-in Prompt Constructor subgraph (custom node: b83478ba-1f3e-4e62-9869-c8a0c8e9a5f5) helps you explicitly include the required duration and aspect ratio in the final prompt string—both are mandatory for Gemini Omni Video. The GeminiVideoOmni node then generates a single video clip that you can preview with PreviewAny and export with SaveVideo.

Technically, the workflow wires your two image tensors and the constructed text prompt into GeminiVideoOmni, which requests a video from the Gemini Omni Flash model. Duration and aspect ratio are parsed from the prompt (for example: "duration: 4s, aspect_ratio: 16:9"), while the rest of your text describes the motion (e.g., zooms, pans, morphs, reveals). The MarkdownNote nodes embedded in the graph provide quick reminders and tips as you work. The result is a fast, conversational way to iterate on short brand clips, vertical social posts, and before/after reveals—without manual keyframing.

API

Use this workflow from code

Every Comfy workflow is a JSON graph. The payload below is this workflow, exactly as ComfyUI runs it — fetch it from the URL, keep it in version control, or load it in ComfyUI and run it node by node.

7b973ace62af.json

Fetching workflow JSON…

Run it from TypeScript or Python with the Comfy SDK. The same code targets Comfy Cloud or a ComfyUI you host yourself — only the base URL changes.

// Install (beta)
npm i @comfyorg/sdk

// Run this workflow (TypeScript)
import { Comfy } from "@comfyorg/sdk";

const client = new Comfy({ apiKey: "comfyui-..." });
const wf = await client.workflows.fromFile("workflow_api.json");
const job = await client.run(wf);
await job.getOutputs("<output-node-id>")[0].toFile("output.png");

The SDK takes a workflow in API format: open this workflow in ComfyUI and use File → Export Workflow (API).

Comfy Cloud API access requires a plan with an API key.

SDK docs Get an API key

FAQ

Frequently Asked Questions