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

# 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

# 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 - Detailed commands, features, troubleshooting
• Technical Architecture - Module breakdown, workflow, config reference

⚙️ Configuration

Edit config.xml to customize:

<!-- 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 for more help.

📄 License

MIT

📞 Support

For detailed usage, see README_RESTRUCTURE.md

For technical architecture, see PROJECT_STRUCTURE.md