OpenRoto

OpenRoto is a local, open-source rotoscoping and object-removal workflow for DaVinci Resolve Free and Studio on Windows.

It can:

• export the clip under the playhead from Resolve;
• select and track a subject with SAM 2.1;
• render an alpha matte and apply it back through Fusion;
• remove a tracked object and reconstruct the covered background;
• run locally without uploading footage, prompts, masks or project data.

Status: developer preview. The Resolve Free round trip has been validated on real timelines. Studio support, installer/release packaging and the optional learned object-removal backends should still be treated as pre-1.0 software.

Rotoscope workflow

1. Put the playhead over the video clip you want to process.
2. Choose Workspace > Scripts > OpenRoto.
3. Resolve exports the visible clip range and OpenRoto opens automatically.
4. In Rotoscope, left-click the subject and right-click areas that must be excluded.
5. Scrub to difficult frames and add correction points where needed.
6. Choose Fast, Balanced or High, then track.
7. Adjust expand/contract, feather or invert.
8. Choose Render & Apply.

OpenRoto creates a non-destructive compound/Fusion setup. The original source remains available inside the compound.

Object removal

The Remove tab reuses the same SAM2 selection and tracking data, then reconstructs the masked region.

Available backends:

Backend	Availability	Intended use
Temporal Fill	Built in	Fast local fallback; best when the hidden background is visible in nearby frames
FGT++	Optional local sidecar	Classical learned video inpainting on consumer hardware
SVOR	Optional local sidecar	High-quality diffusion-based removal for high-VRAM systems

FGT++ and SVOR are not bundled with OpenRoto. Their code, environments and model weights remain separate and keep their upstream licenses. See docs/removal-backends.md and THIRD_PARTY_NOTICES.md.

SAM2 quality presets

Preset	SAM2.1 checkpoint	Intended use
Fast	Hiera Tiny	Quick previews and straightforward shots
Balanced	Hiera Base Plus	Default for most footage
High	Hiera Large	Difficult motion and fine boundaries

OpenRoto uses CUDA automatically when PyTorch detects a compatible NVIDIA GPU. CPU inference remains available but can be much slower. SAM2 checkpoints download only when first selected and are then available offline.

Requirements

• Windows 10 or Windows 11, 64-bit
• DaVinci Resolve 21.1 or newer, Free or Studio
• NVIDIA GPU strongly recommended
• roughly 6 GB VRAM for Balanced and 10 GB for High are comfortable SAM2 targets
• enough temporary disk space for the exported image sequence
• internet access when a model is downloaded for the first time

No system Python installation is required by the packaged application. OpenRoto ships a private official CPython 3.10.11 embeddable runtime for the Resolve Python bridge and packages the Qt application separately with PyInstaller.

Development

Create a Python 3.12 environment and install the application:

uv venv .venv --python 3.12
uv pip install --python .venv\Scripts\python.exe -e ".[inference,dev]"

For an NVIDIA release environment, install the pinned CUDA wheels first:

uv pip install --python .venv\Scripts\python.exe `
  torch==2.11.0+cu130 torchvision==0.26.0+cu130 `
  --index-url https://download.pytorch.org/whl/cu130

Run the main checks:

.venv\Scripts\python.exe -m unittest discover -s tests -v
.venv\Scripts\python.exe tests\run_ui_smoke.py
pyside6-qmllint app\openroto\ui\Main.qml

Build the application and installer:

.\scripts\build.ps1
.venv-build\Scripts\python.exe tests\run_packaged_smoke.py .\dist\OpenRoto\OpenRoto.exe
iscc .\installer\OpenRoto.iss

For local Resolve testing after a build:

.\scripts\install-dev.ps1 -AppExecutable .\dist\OpenRoto\OpenRoto.exe

Fully restart Resolve after installing or updating the Workspace script.

Resolve Free integration

Resolve Free uses a filesystem handoff because Workspace scripting restrictions can prevent the normal in-process Python bridge from running.

The Lua launcher:

• creates a DRT safety snapshot;
• renders the target clip to %LOCALAPPDATA%\OpenRoto\FreeExchange;
• waits for the OpenRoto Free agent to claim the session;
• waits for a local apply/cancel control signal;
• applies the generated Fusion composition and records an acknowledgement.

The installed Free agent is protected by a singleton mutex. Development installs verify the current agent with a free-v3 heartbeat so a stale executable cannot silently keep handling new exports.

Diagnostics

Runtime diagnostics are stored under %LOCALAPPDATA%\OpenRoto:

• free-agent.log — Resolve Free exchange/claim diagnostics;
• app.log — packaged application startup and uncaught errors;
• console.log — stdout/stderr from the packaged application;
• bridge logs — Studio/bootstrap diagnostics when that path is used.

Lua also exposes persistent stage information through Fusion application data, including OpenRoto.LauncherStage, OpenRoto.LauncherError and OpenRoto.Free.SessionId.

Architecture and safety

• resolve/OpenRoto.lua is the Resolve Workspace entry point.
• resolve/OpenRotoEntry.py and the bridge scripts implement Studio integration.
• app/openroto is the standalone Qt Quick application.
• Resolve communication is loopback-only or filesystem-local depending on edition.
• Session credentials are generated per run; no fixed API key is stored in the repository.
• The app keeps raw masks separate from final mattes so edge settings can be changed without rerunning tracking.
• The Resolve bridge validates the target timeline/clip before modifying the edit.
• If application fails after a timeline mutation begins, OpenRoto uses the DRT safety snapshot to recover where supported.

Session data lives under %LOCALAPPDATA%\OpenRoto\Sessions. Final matte/removal sequences can remain referenced by Fusion, so do not delete a session directory while a Resolve project still uses it.

Privacy

OpenRoto does not include telemetry and does not upload footage, points, masks or Resolve project data. Network access is used for explicit package/model downloads and build-time dependency downloads.

Security

Please do not publish security-sensitive reports as public issues. See SECURITY.md.

Contributing

Contributions are welcome. See CONTRIBUTING.md for the development and pull-request expectations.

License

OpenRoto is released under the MIT License. Runtime and optional model components retain their own licenses; see THIRD_PARTY_NOTICES.md.

OpenRoto is independent software and is not affiliated with, endorsed by or sponsored by Blackmagic Design, DaVinci Resolve, Meta, FGT++/Hitachi Research or Xiaomi Research.