# Veo 3.0 Video Generator - User Documentation

## Overview

The Veo 3.0 Video Generator is a web application that allows users to create AI-generated videos using Google's Veo 3.0 model. The application features a modern React frontend with Material-UI components and a Flask backend that interfaces with Google's GenerativeAI SDK.

## Features

- **Text-to-Video Generation**: Create videos from text prompts using Google's Veo 3.0 model
- **Image-to-Video Generation**: Upload reference images to guide video generation
- **Customizable Settings**: Control video length, aspect ratio, and person generation policies
- **Real-time Progress Tracking**: Monitor generation progress with live status updates
- **Secure Authentication**: Microsoft Azure AD integration for user authentication
- **Automatic Downloads**: Direct download of generated videos after completion
- **File Management**: Automatic cleanup of temporary files and cloud storage

## System Requirements

### Prerequisites
- Google Cloud Project with Veo 3.0 API access
- Google Cloud Storage bucket for temporary file storage
- Service account with appropriate permissions
- Python 3.8+ and Node.js 16+ for development
- Microsoft Azure AD app registration (for authentication)

### Supported Formats
- **Input Images**: JPEG, PNG, GIF, BMP, TIFF, WebP, ICO (auto-converted to JPEG)
- **Output Videos**: MP4 format
- **Image Size**: Minimum 720x720 pixels, maximum 10MB
- **Video Length**: 1-60 seconds
- **Aspect Ratios**: 16:9 (landscape) or 9:16 (portrait)

## Getting Started

### 1. Environment Setup

Create a `.env` file in the project root with the following configuration:

```env
# Google Cloud Configuration
PROJECT_ID=your-google-cloud-project-id
REGION=us-central1
MODEL_ID=veo-3.0-generate-preview
OUTPUT_GCS_BUCKET_NAME=your-storage-bucket-name
SERVICE_ACCOUNT_KEY_PATH=./service-account.json

# Flask Configuration
SECRET_KEY=your-secret-key-here
FLASK_ENV=development
FLASK_DEBUG=True
PORT=7394

# Frontend Configuration
FRONTEND_URL=http://localhost:3000

# Webhook Configuration (optional)
WEBHOOK_URL=your-webhook-url
WEBHOOK_ENABLED=false
WEBHOOK_TIMEOUT=10
```

### 2. Google Cloud Setup

1. **Enable APIs**:
   - Vertex AI API
   - Cloud Storage API
   - GenerativeAI API

2. **Create Service Account**:
   ```bash
   gcloud iam service-accounts create veo-video-generator \
     --display-name="Veo Video Generator"
   ```

3. **Grant Permissions**:
   ```bash
   gcloud projects add-iam-policy-binding YOUR_PROJECT_ID \
     --member="serviceAccount:veo-video-generator@YOUR_PROJECT_ID.iam.gserviceaccount.com" \
     --role="roles/aiplatform.user"
   
   gcloud projects add-iam-policy-binding YOUR_PROJECT_ID \
     --member="serviceAccount:veo-video-generator@YOUR_PROJECT_ID.iam.gserviceaccount.com" \
     --role="roles/storage.admin"
   ```

4. **Download Service Account Key**:
   ```bash
   gcloud iam service-accounts keys create service-account.json \
     --iam-account=veo-video-generator@YOUR_PROJECT_ID.iam.gserviceaccount.com
   ```

### 3. Installation

#### Backend Setup
```bash
cd backend
python -m venv venv
source venv/bin/activate  # On Windows: venv\Scripts\activate
pip install -r requirements.txt
```

#### Frontend Setup
```bash
cd frontend
npm install
```

### 4. Running the Application

#### Development Mode
Use the provided development script:
```bash
./run-dev.sh
```

This starts both frontend (port 3000) and backend (port 7394) servers.

#### Manual Startup

**Backend**:
```bash
cd backend
source venv/bin/activate
python app.py
```

**Frontend**:
```bash
cd frontend
npm run dev
```

#### Production Mode
```bash
# Backend
cd backend
python app.py

# Frontend (build and serve)
cd frontend
npm run build
# Serve the dist/ folder with your web server
```

## Using the Application

### 1. Authentication
- In development mode, authentication is bypassed with a mock user
- In production, users authenticate via Microsoft Azure AD
- Authenticated users' email addresses are tracked for usage analytics

### 2. Creating Videos

#### Text-to-Video Generation
1. Enter your video prompt in the text area
2. Adjust settings:
   - **Video Length**: 1-60 seconds (default: 8 seconds)
   - **Aspect Ratio**: 16:9 or 9:16 (default: 16:9)
   - **Person Generation**: Allow/don't allow people in videos
3. Click "Generate Video"
4. Monitor progress in real-time
5. Download when complete

#### Image-to-Video Generation
1. Upload a reference image (JPEG, PNG, etc.)
2. The system automatically:
   - Validates image format and size
   - Converts to JPEG format
   - Detects aspect ratio and adjusts settings
   - Crops if necessary to fit aspect ratio
3. Enter your video prompt
4. Adjust additional settings as needed
5. Generate and download

### 3. Progress Monitoring
The application provides real-time feedback during generation:

- **Starting** (0%): Initializing request
- **Uploading Image** (5%): Processing reference image
- **Generating** (10%): Submitting to Veo 3.0 API
- **Processing** (20-80%): Video generation in progress
- **Downloading** (90%): Retrieving completed video
- **Completed** (100%): Ready for download

### 4. Error Handling
Common error scenarios and solutions:

- **Content Filtered**: Prompt violates safety policies - try rewording
- **Image Too Large**: Resize image to under 10MB
- **Invalid Format**: Use supported image formats only
- **Authentication Failed**: Check service account configuration
- **Quota Exceeded**: Check Google Cloud quotas and billing

## API Reference

### Endpoints

#### `POST /api/generate`
Start video generation process.

**Request Body**:
```json
{
  "prompt": "A cat playing in a garden",
  "video_length_sec": 8,
  "aspect_ratio": "16:9",
  "person_generation": "dont_allow",
  "user_email": "user@example.com"
}
```

**With Image** (multipart/form-data):
- `image`: Image file
- Other parameters as form fields

**Response**:
```json
{
  "job_id": "uuid-string",
  "status": "started"
}
```

#### `GET /api/status/{job_id}`
Check generation status.

**Response**:
```json
{
  "status": "processing",
  "progress": 45,
  "message": "Video generation in progress...",
  "video_path": null,
  "error": null
}
```

#### `GET /api/download/{job_id}`
Download completed video.

**Response**: MP4 video file or error message.

#### `DELETE /api/cleanup/{job_id}`
Manually clean up job files.

**Response**:
```json
{
  "message": "Files cleaned up successfully"
}
```

## Configuration Reference

### Backend Configuration (`config.py`)

| Variable | Description | Default |
|----------|-------------|---------|
| `PROJECT_ID` | Google Cloud project ID | - |
| `REGION` | Google Cloud region | `us-central1` |
| `MODEL_ID` | Veo model identifier | `veo-3.0-generate-preview` |
| `OUTPUT_GCS_BUCKET_NAME` | GCS bucket for storage | - |
| `SERVICE_ACCOUNT_KEY_PATH` | Path to service account JSON | `../service-account.json` |
| `SECRET_KEY` | Flask secret key | - |
| `FLASK_ENV` | Environment mode | `production` |
| `PORT` | Backend server port | `7394` |
| `FRONTEND_URL` | Frontend URL for CORS | - |
| `MAX_IMAGE_SIZE` | Maximum image size in bytes | `10MB` |
| `WEBHOOK_URL` | Usage tracking webhook URL | - |
| `WEBHOOK_ENABLED` | Enable usage tracking | `true` |

### Frontend Configuration

Set environment variables in `.env.local`:

```env
VITE_API_BASE_URL=http://localhost:7394
VITE_DEV_MODE=true
```

## Troubleshooting

### Common Issues

1. **"Service account not found"**
   - Verify `service-account.json` exists and is valid
   - Check file permissions
   - Ensure service account has required roles

2. **"Quota exceeded"**
   - Check Google Cloud quotas for Vertex AI
   - Verify billing is enabled
   - Request quota increases if needed

3. **"Content filtered"**
   - Modify prompt to avoid restricted content
   - Review Google's content policies
   - Try different wording or concepts

4. **"Image validation failed"**
   - Check image format (use common formats)
   - Ensure image is at least 720x720 pixels
   - Verify file size is under 10MB

5. **CORS errors**
   - Check `FRONTEND_URL` configuration
   - Verify both frontend and backend URLs
   - Ensure proper development/production settings

### Debug Mode

Enable debug logging by setting:
```env
FLASK_DEBUG=True
```

Debug information includes:
- Request/response details
- Image processing steps
- API call parameters
- File paths and operations

### Log Files

Check application logs for detailed error information:
- Backend logs: Console output from Flask application
- Frontend logs: Browser developer console
- Google Cloud logs: Cloud Logging for API errors

## Security Considerations

- Service account keys should be kept secure and not committed to version control
- Use environment variables for sensitive configuration
- Implement proper authentication in production
- Regular rotation of service account keys
- Monitor usage and costs through Google Cloud Console
- Webhook URLs should use HTTPS in production

## Performance Tips

- Use appropriate video lengths (shorter = faster generation)
- Optimize image sizes before upload
- Monitor Google Cloud quotas and billing
- Implement caching for repeated requests
- Use CDN for frontend assets in production
- Clean up temporary files regularly

## Support and Resources

- [Google Vertex AI Documentation](https://cloud.google.com/vertex-ai/docs)
- [Veo 3.0 Model Documentation](https://cloud.google.com/vertex-ai/generative-ai/docs/model-reference/veo)
- [Google GenAI SDK Reference](https://googleapis.dev/python/google-genai/latest/)
- [Flask Documentation](https://flask.palletsprojects.com/)
- [React Documentation](https://reactjs.org/docs/)
- [Material-UI Documentation](https://mui.com/)

For technical issues, check the debug logs and refer to Google Cloud support resources.