| name | video |
| description | Generate videos using Veo 3.1 — text-to-video, image-to-video, frame interpolation, and video extension |
| argument-hint | [description or instruction] |
| allowed-tools | ["Read","Write","Edit","Bash"] |
| disable-model-invocation | true |
Nano Banana - Video Generation
Overview
Generate videos using Google's Veo 3.1 models via the google-genai SDK. Supports four generation modes: text-to-video, image-to-video, frame interpolation, and video extension.
Key Features:
- Four generation modes from a single script
- Fast (default) and standard quality models
- Aspect ratio control (16:9, 9:16)
- Resolution up to 1080p
- Configurable duration (4, 6, or 8 seconds)
- Automatic audio stripping (opt-in to keep)
- Reference images for style guidance
When to Use This Skill
Use this skill when you need:
- Animated content from a text description
- Image animation — bring a still photo or illustration to life
- Smooth transitions between two frames (interpolation)
- Extending an existing video clip
- Short-form video for reels, demos, or presentations
Not for: Static images (use image skill), technical diagrams (use diagram skill), or diagram source rendering (use kroki skill).
Quick Start
Text-to-Video (default)
python3 ${CLAUDE_SKILL_DIR}/scripts/generate_video.py "A drone flyover of a coastal city at golden hour" -o flyover.mp4
Image-to-Video
Animate a still image with a motion prompt:
python3 ${CLAUDE_SKILL_DIR}/scripts/generate_video.py "Camera slowly zooms in while clouds drift" \
--input photo.png -o animated.mp4
Frame Interpolation
Generate a smooth transition between two frames:
python3 ${CLAUDE_SKILL_DIR}/scripts/generate_video.py "Smooth morph between scenes" \
--input start.png --last-frame end.png -o transition.mp4
Video Extension
Continue an existing video clip:
python3 ${CLAUDE_SKILL_DIR}/scripts/generate_video.py "The camera keeps panning right revealing more of the landscape" \
--extend clip.mp4 -o extended.mp4
With Reference Images
Guide the visual style with up to 3 reference images:
python3 ${CLAUDE_SKILL_DIR}/scripts/generate_video.py "A cat walking through a garden" \
-o styled.mp4 --reference style1.png --reference style2.png
Models
| Model | ID | Speed | Best For |
|---|
| Veo 3.1 Fast | veo-3.1-fast-generate-preview | Fast | Default — quick iterations, drafts |
| Veo 3.1 | veo-3.1-generate-preview | Standard | Final output, higher quality |
Use -m to select a model:
python3 ${CLAUDE_SKILL_DIR}/scripts/generate_video.py "A sunset timelapse" -o sunset.mp4 -m veo-3.1-generate-preview
Resolution and Duration Constraints
| Resolution | Supported Durations | Notes |
|---|
| 720p (default) | 4, 6, 8 seconds | All durations, required for extension |
| 1080p | 8 seconds only | Higher quality, duration locked |
python3 ${CLAUDE_SKILL_DIR}/scripts/generate_video.py "Quick test" -o test.mp4 --resolution 720p --duration 4
python3 ${CLAUDE_SKILL_DIR}/scripts/generate_video.py "Cinematic landscape" -o landscape.mp4 --resolution 1080p --duration 8
Constraint rules:
--resolution 1080p requires --duration 8--extend requires --resolution 720p- Maximum 3
--reference images
Aspect Ratio
| Ratio | Use Case |
|---|
| 16:9 (default) | Landscape, presentations, YouTube |
| 9:16 | Portrait, mobile reels, TikTok, Stories |
python3 ${CLAUDE_SKILL_DIR}/scripts/generate_video.py "A vertical reel of a coffee being poured" \
-o reel.mp4 --aspect-ratio 9:16
Audio Handling
By default, audio is stripped from generated videos using ffmpeg. This avoids unexpected AI-generated audio.
python3 ${CLAUDE_SKILL_DIR}/scripts/generate_video.py "A beach scene" -o beach.mp4
python3 ${CLAUDE_SKILL_DIR}/scripts/generate_video.py "A concert crowd cheering" -o concert.mp4 --audio
Requirements for audio stripping:
ffmpeg must be installed (brew install ffmpeg on macOS)- If ffmpeg is not found, the video is saved with audio intact and a warning is printed
All CLI Flags
| Flag | Default | Description |
|---|
prompt (positional) | required | Text description of the video |
-o / --output | required | Output .mp4 file path |
-m / --model | veo-3.1-fast-generate-preview | Model ID |
-i / --input | — | Input image (image-to-video / interpolation) |
--last-frame | — | Last frame image (interpolation, requires --input) |
--extend | — | Video .mp4 to extend |
--reference | — | Reference image (repeatable, max 3) |
--aspect-ratio | 16:9 | 16:9 or 9:16 |
--resolution | 720p | 720p or 1080p |
--duration | 8 | 4, 6, or 8 seconds |
--audio | off | Keep generated audio |
--timeout | 360 | Max wait in seconds |
--api-key | — | Override GEMINI_API_KEY |
Configuration
API Key Setup
export GEMINI_API_KEY='your-key-here'
Get a key at https://aistudio.google.com/apikey.
Or add to a .env file in your project:
GEMINI_API_KEY=your-key-here
Run /nano-banana:setup for guided configuration.
Tips for Better Videos
Be Descriptive About Motion
"A mountain"
"A slow aerial drone shot pulling back from a snowy mountain peak, revealing the valley below, golden hour lighting"
Specify Camera Movement
Use terms like: pan left/right, zoom in/out, dolly, orbit, tracking shot, crane shot, steady cam, timelapse.
For Image-to-Video, Describe the Animation
python3 ${CLAUDE_SKILL_DIR}/scripts/generate_video.py "The clouds slowly drift across the sky while the water gently ripples" \
--input landscape.png -o animated.mp4
Troubleshooting
"No Gemini API key found"
Set the GEMINI_API_KEY environment variable or create a .env file. Run /nano-banana:setup for help.
"Constraint validation failed"
Check the resolution/duration constraint table above. Common issue: using --resolution 1080p with --duration 4.
Generation Timeout
Default timeout is 360 seconds (6 minutes). Video generation typically takes 1-4 minutes. Increase with --timeout 600 for complex prompts.
"ffmpeg not found" Warning
Install ffmpeg for automatic audio stripping: brew install ffmpeg. Without it, videos are saved with AI-generated audio.
Video Appears Black or Corrupted
Try a simpler prompt, or switch to the standard quality model (-m veo-3.1-generate-preview). Some complex scenes may not render well at lower quality settings.
Comparison: video vs image vs diagram
| Aspect | video | image | diagram |
|---|
| Output | .mp4 video | .png image | .png diagram |
| Models | Veo 3.1 | Gemini Flash/Pro | Gemini Pro |
| Duration | 4-8 seconds | Instant | 1-2 passes |
| Editing | Extend existing | Edit existing | Edit existing |
| Best For | Animation, motion | Photos, art | Architecture, flowcharts |
