Furnace

Batch video transcoder for home archival. Scans your movie collection, lets you pick tracks in a TUI, saves a JSON plan, then encodes everything with NVEncC (NVIDIA hardware encoder).

Why Furnace

• Plan, review, then run — choose tracks and preview in a TUI, save a JSON plan you can inspect or edit before hours of encoding
• Resumable — failed jobs retry on next run, plan updated atomically after each job
• Live progress on every long step — ffmpeg extraction, eac3to, qaac, mkvmerge, NVEncC all stream into one unified progress bar; no more silent multi-gigabyte waits
• Auto quality — CQ value interpolated by pixel area, no manual tuning across SD/720p/1080p/4K
• Disc demux — Blu-ray (BDMV) and DVD (VIDEO_TS) fed straight into the pipeline with playlist/title selection
• Anamorphic SAR fix — detects and corrects wrong sample aspect ratio on DVD sources
• Dolby Vision — Profile 7 FEL (converted to P8.1) and Profile 8 MEL with RPU passthrough via dovi_tool
• HDR10 passthrough — mastering display, content light level, BT.2020/PQ preserved through encode
• Auto deinterlace — detects interlaced content from the video stream and applies nnedi (neural network) automatically
• Smart crop — black bars detected automatically across the timeline
• mpv preview — audition audio tracks, check subtitles, or preview video right from the TUI before committing
• Per-track downmix — fold 7.1 or 5.1 into stereo or 5.1 from the track selector, useful when the multichannel mix is a fake upmix or the movie is dialogue-heavy
• Satellite files — external audio and subtitle files next to the video are picked up as extra tracks automatically

Workflow

furnace plan <source> -o <output> --audio-lang rus,eng --sub-lang rus,eng
# -> opens TUI for track selection -> saves furnace-plan.json

furnace run furnace-plan.json
# -> encodes all pending jobs with live progress TUI

Requirements

• Python 3.13+
• ffmpeg / ffprobe
• MKVToolNix (mkvmerge, mkvpropedit)
• eac3to
• qaac64
• mkclean
• mpv (track preview)
• MakeMKV (DVD demux)
• NVEncC (video encoder)
• dovi_tool (Dolby Vision RPU, optional)

Install

uv pip install .

Configuration

Copy furnace.toml.example to furnace.toml and set paths to your tools. Searched in order: --config flag, current directory, %APPDATA%\furnace\.

Usage

Plan with dry run (no TUI, just print what would happen):

furnace plan D:\Movies -o E:\Encoded --audio-lang jpn --sub-lang eng --dry-run

Plan and encode:

furnace plan D:\Movies -o E:\Encoded --audio-lang rus,eng --sub-lang rus,eng
furnace run E:\Encoded\furnace-plan.json

Enable VMAF + SSIM quality scoring (single pass):

furnace plan D:\Movies -o E:\Encoded --audio-lang eng --sub-lang eng --vmaf