# google-video (Google Video)

This example generates videos from text, images, and existing Veo videos.

You can run this example with:

```bash
npx promptfoo@latest init --example google-video
cd google-video
```

## Prerequisites

Choose one:

- Google AI Studio / Gemini API key
- Google Cloud project with Vertex AI API enabled and authentication via `gcloud auth application-default login`

## Setup

```bash
# Option 1: Google AI Studio / Gemini API
export GOOGLE_API_KEY=your-api-key

# Option 2: Vertex AI
gcloud services enable aiplatform.googleapis.com
gcloud auth application-default login
export GOOGLE_PROJECT_ID=your-project-id
```

## Environment Variables

- `GOOGLE_API_KEY` - Google AI Studio / Gemini API key
- `GOOGLE_PROJECT_ID` - Google Cloud project ID for Vertex AI

## Available Models

Google AI Studio / Gemini API:

| Model                           | Description                                          | Duration |
| ------------------------------- | ---------------------------------------------------- | -------- |
| `veo-3.1-generate-preview`      | Veo 3.1 with extension, references, and 4k           | 4, 6, 8s |
| `veo-3.1-fast-generate-preview` | Faster Veo 3.1 with extension, references, and 4k    | 4, 6, 8s |
| `veo-3.1-lite-generate-preview` | Veo 3.1 Lite Preview without extension or references | 4, 6, 8s |

Vertex AI:

| Provider ID                              | Description          | Generation duration |
| ---------------------------------------- | -------------------- | ------------------- |
| `vertex:video:veo-3.1-generate-001`      | Veo 3.1 GA           | 4, 6, 8s            |
| `vertex:video:veo-3.1-fast-generate-001` | Faster Veo 3.1 GA    | 4, 6, 8s            |
| `vertex:video:veo-3.1-lite-generate-001` | Lite Veo 3.1 Preview | 4, 6, 8s            |

## Running the Example

```bash
npx promptfoo@latest eval
```

## Configuration Options

| Option             | Type   | Description                                                                                                                     |
| ------------------ | ------ | ------------------------------------------------------------------------------------------------------------------------------- |
| `aspectRatio`      | string | `16:9` (default) or `9:16`                                                                                                      |
| `resolution`       | string | `720p` (default), `1080p`, or `4k`; 4k requires Veo 3.1 or 3.1 Fast                                                             |
| `durationSeconds`  | number | 4, 6, or 8 for generation; use 8 for references or Gemini API 1080p/4k output. See Video Extension for fixed extension duration |
| `personGeneration` | string | Veo 3.1: `allow_all` for text, `allow_adult` for image-based modes; EU, UK, Switzerland, and MENA support only `allow_adult`    |
| `negativePrompt`   | string | Concepts to avoid                                                                                                               |
| `image`            | string | Source image for image-to-video                                                                                                 |
| `lastImage`        | string | End frame for interpolation                                                                                                     |
| `extendVideoId`    | string | Deprecated alias for `sourceVideo`                                                                                              |
| `sourceVideo`      | string | Prior Veo video's Gemini URI, `file://` MP4 path, or raw base64 bytes; Vertex also accepts a `gs://` URI                        |
| `storageUri`       | string | Vertex-only output destination such as `gs://bucket/veo-output/`; the returned `gcsUri` is exposed as `metadata.sourceVideoUri` |
| `referenceImages`  | array  | Up to 3 asset reference images (file paths or objects)                                                                          |

## Features

### Text-to-Video

Generate videos from text prompts (see `promptfooconfig.yaml`).

### Image-to-Video

Generate videos from a starting image (see `promptfooconfig-image.yaml`).

### Video Extension (Veo 3.1)

Extend a previously generated Veo video by passing its original Gemini URI, a `file://` MP4
path, or raw base64 bytes as `sourceVideo` (see `promptfooconfig-extension.yaml`). This
configuration requires `GOOGLE_API_KEY` or `GEMINI_API_KEY`. Use the prior response's
`metadata.sourceVideoUri` for the URI input. Google supports extension only for videos
generated by Veo that were generated or referenced within the last two days; its
[Gemini API REST example](https://ai.google.dev/gemini-api/docs/veo?hl=en#extending_veo_videos)
also shows how to extend a saved video's base64 data.

For Vertex AI, configure `storageUri: gs://bucket/prefix/` on the source generation. Promptfoo
downloads the output to its blob store and preserves the returned `gs://` object URI in
`metadata.sourceVideoUri`; pass that value as `sourceVideo` in the next Vertex generation.
Vertex also accepts saved MP4 files through `file://` or raw base64 bytes. Operation IDs are not video inputs.

The response reports `metadata.extensionSeconds: 7` and omits `video.duration` for extension
because the total source duration is unknown. `metadata.videoUri` is a compatibility alias for
the same sanitized URI as `metadata.sourceVideoUri`. Native extension requires a 720p Veo
source no longer than 141 seconds; arbitrary videos are outside that documented contract.

Export an eval with `-o results.json` to inspect the response metadata.

## Notes

- Generated videos are stored in promptfoo's blob storage system
- Videos use content-addressable hashing for automatic deduplication
- Use `--no-cache` flag to force regeneration
- Videos are served via the local server for viewing in the UI
- Veo models use long-running operations with polling for completion
- `google:video:*` uses Google AI Studio by default and auto-detects Vertex AI when project-based auth is configured
- Existing project-based `google:video:*` configs remain compatible; use `vertex:video:*` for explicit Vertex AI routing
- Gemini API extensions use 720p output and an 8-second request setting, whether `durationSeconds` is omitted or configured. Vertex extension requests omit `durationSeconds`, including when configured. Both APIs add a fixed 7 seconds to the source video.
- Google AI Studio does not accept Vertex operation IDs for extension