# AV1 Batch Video Transcoder

A high-performance batch video transcoding tool using NVIDIA's **AV1 NVENC** codec with intelligent audio/subtitle handling and automatic quality optimization.

## ✨ Key Features

- **8-bit AV1 Encoding** - NVIDIA GPU acceleration (yuv420p, preset p7)
- **Smart Audio Processing** - Auto-detects bitrate, AAC for stereo, EAC3 for 5.1, downmixes, re-encodes only when needed
- **Audio Filtering** - Keep only best English audio + Commentary tracks (remove other languages)
- **Subtitle Embedding** - Auto-detects and embeds subtitles (.vtt, .srt, .ass, .ssa, .sub)
- **Smart Resolution** - Scales 4K→1080p, preserves lower resolutions
- **Two-Phase Encoding** - CQ mode first, automatic Bitrate fallback if size threshold exceeded
- **Automatic Cleanup** - Deletes originals + subtitles after successful encoding
- **Test Mode** - Encode one file, check compression ratio before batch processing
- **Optional Language Tagging** - Tag audio streams with language codes
- **CSV Tracking** - Detailed conversion logs with compression ratios

## 🚀 Quick Start

### Requirements

- **Python 3.8+**
- **FFmpeg** with libfdk-aac support
- **NVIDIA GPU** (GeForce RTX 2060+, Quadro, or newer)
- **NVIDIA CUDA Toolkit** (for av1_nvenc support)

### Installation

```bash
# Clone repository
git clone https://github.com/yourusername/conversion_project.git
cd conversion_project

# Install Python dependencies (if any needed in future)
# pip install -r requirements.txt
```

### Basic Usage

```bash
# Encode a TV folder (smart mode)
python main.py "P:\tv\Show Name"

# Test single file before batch processing
python main.py "P:\tv\Show Name" --test

# Force specific quality (CQ 30)
python main.py "P:\movies\Movie" --cq 30

# Force bitrate mode
python main.py "P:\tv\Show" --m bitrate

# Specific resolution
python main.py "P:\movies" --r 720

# Tag audio with language
python main.py "P:\tv\Show" --language eng
```

## 📖 Documentation

- **[Full Usage Guide](README_RESTRUCTURE.md)** - Detailed commands, features, troubleshooting
- **[Technical Architecture](PROJECT_STRUCTURE.md)** - Module breakdown, workflow, config reference

## ⚙️ Configuration

Edit `config.xml` to customize:

```xml
<!-- CQ quality per content type -->
<cq>
  <tv_1080>28</tv_1080>
  <tv_720>32</tv_720>
  <movie_1080>32</movie_1080>
  <movie_720>34</movie_720>
</cq>

<!-- Audio bitrate buckets -->
<audio>
  <stereo>
    <high>192000</high>
    <medium>160000</medium>
  </stereo>
  <multi_channel>
    <medium>448000</medium>
    <low>384000</low>
  </multi_channel>
</audio>

<!-- Subtitle auto-detection -->
<subtitles>
  <enabled>true</enabled>
  <extensions>.vtt,.srt,.ass,.ssa,.sub</extensions>
</subtitles>
```

## 📊 Example Output

**Input:**
```
Show.S01E01.mkv (1.5GB)
Show.S01E01.en.vtt (subtitle)
```

**Output:**
```
Show.S01E01 - [EHX].mkv (450MB, subtitle embedded, audio tagged)
```

**Compression:** 1.5GB → 450MB (30% ratio, 70% reduction)

## 🔧 Encoding Specs

| Setting | Value |
|---------|-------|
| Video Codec | AV1 (av1_nvenc) |
| Bit Depth | 8-bit (yuv420p) |
| GPU Preset | p1 (high quality) |
| Audio Codec | AAC |
| Audio Mode | Smart (copy or re-encode) |
| Container | MKV |
| Subtitles | Embedded SRT |

## 🎯 Workflow

1. **Scan** folder for video files
2. **Detect** subtitles, audio streams, resolution
3. **Encode** with AV1 codec (Phase 1: CQ)
4. **Check** size threshold (default 75%)
5. **Retry** with Bitrate mode if needed (Phase 2)
6. **Move** encoded file to original location
7. **Cleanup** original + subtitles + temp files
8. **Log** results to CSV tracker

## 📋 Requirements

- Windows 10/11 or Linux
- NVIDIA GPU with NVENC support
- NVIDIA CUDA Toolkit 11.0+
- FFmpeg compiled with av1_nvenc support
- Python 3.8+

## 🛠️ Troubleshooting

**Files not moving?**
- Check `reduction_ratio_threshold` in config.xml (default 0.75)
- Run with `--test` to see compression ratio

**Subtitles not embedding?**
- Verify filename: `video.en.vtt` or `video.vtt`
- Check config.xml `<subtitles><enabled>true</enabled>`

**Wrong audio quality?**
- Adjust CQ values in config.xml per content type
- Use `--cq` override: `python main.py folder --cq 30`

See [Full Guide](README_RESTRUCTURE.md) for more help.

## 📄 License

MIT

## 📞 Support

For detailed usage, see [README_RESTRUCTURE.md](README_RESTRUCTURE.md)

For technical architecture, see [PROJECT_STRUCTURE.md](PROJECT_STRUCTURE.md)