Anime Upscaler

A CLI tool to batch upscale anime videos using Real-CUGAN with GPU acceleration. Designed for Mac M4 (Metal via Vulkan/MoltenVK) but works on any platform with Vulkan support.

Features

• Batch process MKV files from input directory
• Upscale using Real-CUGAN (optimized for anime)
• Preserve all audio tracks, subtitles, chapters, and font attachments
• Hardware-accelerated encoding (VideoToolbox on Mac)
• Resume interrupted jobs
• Progress reporting with ETA
• Optional Japanese-only audio filter

Requirements

Dependencies

# macOS
brew install ffmpeg mkvtoolnix

# Linux (Debian/Ubuntu)
sudo apt install ffmpeg mkvtoolnix

# Linux (Arch)
sudo pacman -S ffmpeg mkvtoolnix-cli

Real-CUGAN

Download the pre-built binary for your platform from: https://github.com/nihui/realcugan-ncnn-vulkan/releases

Extract and place the binary in one of these locations:

• ~/tools/realcugan-ncnn-vulkan (recommended)
• ~/.local/bin/realcugan-ncnn-vulkan
• /usr/local/bin/realcugan-ncnn-vulkan
• Or specify the path with --realcugan-path

Installation

# Clone the repository
git clone https://github.com/yourusername/anime-upscaler.git
cd anime-upscaler

# Build and install
cargo install --path .

Usage

# Basic usage
anime-upscaler -i ~/anime-input -o ~/anime-output

# With processed folder (moves originals after completion)
anime-upscaler -i ~/anime-input -o ~/anime-output -p ~/anime-processed

# 4x upscale with maximum denoise (slowest, best quality)
anime-upscaler -i ~/input -o ~/output -s 4 -n 3

# 2x upscale with no denoise (fastest)
anime-upscaler -i ~/input -o ~/output -s 2 -n -1

# Resume an interrupted job
anime-upscaler -i ~/input -o ~/output --resume

# Dry run (see what would be processed)
anime-upscaler -i ~/input -o ~/output --dry-run

# Verbose logging
anime-upscaler -i ~/input -o ~/output -v

Options

Option	Default	Description
-i, --input	required	Input directory containing MKV files
-o, --output	required	Output directory for upscaled files
-p, --processed	none	Directory to move originals after processing
-w, --work-dir	system cache	Working directory for temporary files
-s, --scale	2	Scale factor (2, 3, or 4)
-n, --denoise	1	Denoise level (-1=none, 0, 1, 2, 3=max)
-m, --model	pro	Model to use (pro=quality, se=fast)
-g, --gpu	0	GPU ID to use
-t, --tile-size	0 (auto)	Tile size (256/512/1024 if memory issues)
-b, --bitrate	20M	Video bitrate for output
--codec	hevc_videotoolbox	Video codec (use libx265 on Linux)
--japanese-only	true	Keep only Japanese audio tracks
--realcugan-path	auto-detect	Path to realcugan-ncnn-vulkan binary
--resume	false	Resume incomplete jobs
--dry-run	false	Show what would be done without processing
-v, --verbose	false	Enable verbose logging

Processing Pipeline

1. Extract - Frames (PNG), audio tracks, subtitles, chapters, and font attachments
2. Upscale - Process frames with Real-CUGAN using GPU
3. Reassemble - Encode upscaled frames to video with hardware acceleration
4. Mux - Combine video with preserved audio, subtitles, chapters, and fonts

Platform Notes

macOS (Apple Silicon)

Uses hevc_videotoolbox for hardware-accelerated H.265 encoding. Real-CUGAN uses Vulkan via MoltenVK for GPU acceleration.

Linux

Change the codec to libx265 for software encoding:

anime-upscaler -i ~/input -o ~/output --codec libx265

Or use VAAPI/NVENC if available:

# NVIDIA
anime-upscaler -i ~/input -o ~/output --codec hevc_nvenc

# AMD/Intel VAAPI
anime-upscaler -i ~/input -o ~/output --codec hevc_vaapi

Troubleshooting

Out of GPU memory

Reduce tile size:

anime-upscaler -i ~/input -o ~/output -t 256

Slow upscaling

Use the faster model (slightly lower quality):

anime-upscaler -i ~/input -o ~/output -m se

Resume not working

Ensure you use the same input/output directories and add --resume:

anime-upscaler -i ~/input -o ~/output --resume

License

MIT