sermon-converter/README.md

# Sermon Converter

An event-driven Rust service that automatically detects and converts sermon video files for efficient storage and streaming. Uses the shared `video_processing` crate for optimal performance.

## Features

- **Event-driven file detection** - No polling, instant response to new files
- **AV1 video conversion** with Intel QSV hardware acceleration
- **Preserves original filenames** - Backend handles metadata parsing
- **File stability checking** - Ensures files are fully written before processing
- **Syncthing-aware** - Ignores temporary sync files
- **Efficient disk space usage** with modern compression
- **Configurable via environment variables**

## Prerequisites

- Rust (latest stable version)
- FFmpeg with AV1 support (or configure different codec)
- Intel Media SDK (for QSV acceleration, optional)
- Sufficient disk space for video processing

## Installation

1. Clone the repository:
```bash
git clone <repository-url>
cd sermon-converter
```

2. Build the project:
```bash
cargo build --release
```

## Configuration

Create a `.env` file based on `.env.example`:

```bash
cp .env.example .env
nano .env
```

### Required Environment Variables

```bash
# Directory paths (REQUIRED)
SERMON_WATCH_PATH=/path/to/watch/sermons
SERMON_OUTPUT_PATH=/path/to/output/sermons

# FFmpeg Configuration
FFMPEG_BINARY=ffmpeg
VIDEO_CODEC=av1_qsv              # or libx264, libx265, etc.
HW_ACCEL=qsv                     # hardware acceleration
HW_DEVICE=qsv=hw
FFMPEG_PRESET=4
VIDEO_BITRATE=6M
MAX_BITRATE=12M
BUFFER_SIZE=24M
AUDIO_CODEC=libopus              # or copy, aac, etc.
AUDIO_BITRATE=192k

# File Stability Settings
STABILITY_CHECK_INTERVAL=1       # seconds between stability checks
STABILITY_REQUIRED_CHECKS=30     # consecutive stable checks required
MAX_STABILITY_WAIT_HOURS=0.5     # maximum time to wait for stability

# Directory Settings
CREATE_YEAR_MONTH_DIRS=true      # organize by date (unused currently)
PRESERVE_ORIGINAL_FILES=false    # delete original after conversion
```

## Usage

Run the service:
```bash
cargo run --release
```

Or run the built binary:
```bash
./target/release/sermon_converter
```

The service will:
1. Process any existing MP4 files in the watch directory
2. Watch for new files using efficient event-driven detection
3. Wait for file stability before processing
4. Convert to optimized format with same filename
5. Output converted files for backend metadata handling

## Expected File Format

Sermon files should follow the naming convention:
```
Title - Speaker Month Day Year.mp4
```

Examples:
- `God's People in the Time of the End - Pastor John Smith December 28 2024.mp4`
- `The Great Hope - Elder Jane Doe January 15 2025.mp4`

The backend will parse this format automatically for metadata.

## Running as a System Service

Create a systemd service file at `/etc/systemd/system/sermon-converter.service`:

```ini
[Unit]
Description=Sermon Video Converter Service
After=network.target

[Service]
Type=simple
User=rockvilleav
Group=rockvilleav
ExecStart=/usr/local/bin/sermon_converter
WorkingDirectory=/home/rockvilleav/sermon-converter

# Load environment variables from .env file
EnvironmentFile=/home/rockvilleav/sermon-converter/.env

# System environment variables
Environment=HOME=/home/rockvilleav
Environment=USER=rockvilleav

# Intel Media Stack (if using QSV)
Environment=LIBVA_DRIVER_NAME=iHD
Environment=LIBVA_DRIVERS_PATH=/opt/intel/media/lib64
Environment=LD_LIBRARY_PATH=/opt/intel/media/lib64

Restart=always
RestartSec=10

[Install]
WantedBy=multi-user.target
```

Enable and start the service:
```bash
sudo systemctl enable sermon-converter
sudo systemctl start sermon-converter
sudo systemctl status sermon-converter
```

View logs:
```bash
sudo journalctl -u sermon-converter -f
```

## Architecture

This service uses a clean, event-driven architecture:

- **Event Detection**: Uses `inotify` for instant file detection (no polling)
- **File Stability**: Ensures files are completely written before processing
- **Shared Logic**: Uses `video_processing` crate for common functionality
- **Simple Processing**: Convert file, keep same name, let backend handle metadata
- **Resource Efficient**: Only uses CPU/disk when actually processing files

## Video Conversion Details

Default settings (configurable via .env):
- **Video Codec**: AV1 with Intel QSV acceleration
- **Audio Codec**: Opus (high efficiency)
- **Hardware Acceleration**: Intel Quick Sync Video
- **Video Bitrate**: 6Mbps (configurable)
- **Audio Bitrate**: 192kbps (configurable)

## Troubleshooting

### Common Issues

**Service fails to start:**
```bash
# Check if .env file exists and has correct paths
ls -la /home/rockvilleav/sermon-converter/.env

# Verify directories exist and are accessible
ls -la /path/to/watch/sermons
ls -la /path/to/output/sermons
```

**FFmpeg errors:**
```bash
# Test FFmpeg with your codec
ffmpeg -encoders | grep av1
ffmpeg -hwaccels | grep qsv

# Check Intel Media SDK installation
vainfo
```

**Files not being detected:**
```bash
# Check logs for file events
sudo journalctl -u sermon-converter -f

# Verify file permissions
ls -la /path/to/watch/sermons/
```

**Out of disk space:**
```bash
# Service checks for 5GB minimum free space
df -h /path/to/output/sermons
```

### Log Analysis

The service provides detailed logging:
- `INFO` level: Normal operation, file detection, conversion progress
- `WARN` level: Non-fatal issues (low disk space, sync failures)
- `ERROR` level: Conversion failures, configuration errors

## License

See LICENSE file for details.

## Contributing

Contributions are welcome! This service is part of a larger church media processing system.