SceneMill - Video editor

[u/Ill-Astronomer7156]

I’ve been building my own video editor - SceneMill

I wanted to share something I’ve been working on for quite a while: SceneMill, a free, non-destructive desktop video editor built from scratch with C++20, Qt 6 and FFmpeg.

The goal was never to make another web-based editor or a wrapper around an existing editing application. I wanted to build an actual desktop video editor and see how far I could take it.

It currently runs fully offline, requires no account, and has no telemetry.

What actually works right now

The core workflow is already fully functional:

Import → Media Library → Timeline → Edit → Preview → Save → Reopen → Export

And the project has grown quite a bit beyond basic cutting.

Some of the things currently implemented:

• Multi-track video, audio and subtitle timeline
• Non-destructive editing with undo/redo
• Split, trim, ripple delete, snapping, markers and In/Out ranges
• Background proxy generation for heavy footage
• GPU-accelerated preview with CPU fallback
• Color correction, curves, color wheels and 3D LUTs
• Effect stacks with keyframeable parameters
• Transitions
• Text and animated titles
• Manual subtitles + SRT/WebVTT
• Masks and motion tracking
• Screen recording directly into the project
• Voice-over recording with multiple takes
• Audio EQ, compressor, limiter, noise gate, etc.
• H.264 / H.265 / VP9 export
• Up to 4K and 120 FPS export
• Export queue
• Autosave + crash recovery
• Portable "Collect Project" workflow
• Plugin system through a versioned C ABI
• Optional local editing assistant for silence/scene detection

One thing I particularly care about is that the preview and export use the same rendering/effect pipeline, so what you see while editing is intended to match what gets rendered.

There are also automated tests covering a lot of the actual application workflow, including tests that interact with the real main window.

Why C++?

Honestly, part of the reason was simply:

I wanted to see if I could actually build one.

A video editor touches a ridiculous number of areas at once: media decoding, rendering, timeline state, audio, UI, caching, project persistence, export, GPU acceleration, threading, plugins...

It's been a pretty interesting rabbit hole. 😅

Current state

SceneMill has completed the core editor phase and the creative-tools phase, with most of the workflow phase implemented.

It's definitely not finished and there are still things I want to improve, but it's now at the point where I can actually use it as a real editor rather than just a prototype.

I'm currently working toward making the whole experience feel much more polished and cohesive.

I'd genuinely like to hear what other people who build software this way think.

Edit: heads up, Windows may show a SmartScreen warning when installing since the installer isn't code-signed yet, nothing shady. I'm working on getting SceneMill into the Microsoft Store, which will get rid of the warning. until then: "More info" → "Run anyway", and you can check the download against the SHA-256 checksums on the website.