Pull dashcam footage off your comma device over your local network and stitch each drive into a single playable video — with audio — without uploading anything to the cloud. One native app for macOS, Linux, and Windows.
comma/openpilot store footage as one-minute segments of raw HEVC, split per camera,
in /data/media/0/realdata/ on the device. Getting a watchable video out normally means
SSH, scp, and manual ffmpeg work. Comma Sync does it all for you:
| Index Drives | Sync in progress |
|---|---|
 |
 |
| Browse every drive — on your computer and still on the comma — and download some or all. | Live progress bar and log while it pulls and stitches each drive. |
Follows your system's light or dark appearance. All screenshots use made-up example data — drive names, sizes, and paths are not real.
- 🔍 Auto-discovers the device on your WiFi (its IP usually changes every connect).
- ⬇️ Pulls only new drives — a ledger tracks what's done, so nothing re-downloads.
- 🎬 Stitches each drive into one MP4 per camera (road / wide / driver), named by the recording start time.
- 🎞️ Optional combined multi-angle video — 2 cameras side by side, or 3 with a main angle on top and the other two below. Re-render with a different layout anytime; it keeps each layout as its own file and skips one it has already made.
- 🔊 Adds the microphone audio when it was recorded.
- ♻️ Re-sync or re-stitch anything, even old drives you deleted locally — it pulls them back.
- 🖥️ Native app on macOS, Linux, and Windows — pick folders, watch a progress bar, browse/index every drive (on your computer and still on the comma), select some/all, and download — with the ability to close it and come back while it keeps working.
Tested on a comma 3X running sunnypilot. Should also work with stock openpilot and other forks that keep the standard layout.
Comma Sync is one native app for macOS, Linux, and Windows, all on the same engine.
The app shells out to ffmpeg/ffprobe to stitch the video — everything else (device
discovery, SSH, file transfer) is built in. Install it once:
- macOS:
brew install ffmpeg(get Homebrew first if you don't have it) - Linux:
sudo apt install ffmpeg(Debian/Ubuntu) ·sudo dnf install ffmpeg(Fedora) - Windows:
winget install Gyan.FFmpeg, then close and reopen your terminal so it's found
Grab the latest build for your system from the Releases page → Assets:
| Your computer | Download |
|---|---|
| macOS | Comma-Sync-macOS.zip |
| Linux | Comma.Sync_*_amd64.AppImage (simplest) — or .deb / .rpm |
| Windows | Comma.Sync_*_x64-setup.exe (installer) — or .msi |
(Each OS also has a SHA256SUMS-*.txt if you want to verify your download.)
- macOS: unzip to get
Comma Sync.appand drag it to Applications. It's a free open-source app (unsigned), so the first time right-click it → Open, then click Open in the dialog (after that, just double-click). - Linux (AppImage):
chmod +x Comma.Sync_*_amd64.AppImagethen run it — or install the.deb(sudo apt install ./Comma.Sync_*_amd64.deb) or.rpm(sudo dnf install ./*.rpm). - Windows: run the
*-setup.exe(or.msi). It isn't code-signed yet, so SmartScreen may warn — click More info → Run anyway.
The comma only allows computers whose SSH key is registered to it via a GitHub account.
- Make an SSH key (skip if you already have
~/.ssh/id_ed25519):- macOS / Linux:
ssh-keygen -t ed25519→ key at~/.ssh/id_ed25519.pub - Windows:
ssh-keygen -t ed25519in PowerShell (built into Windows 10/11) → key at%USERPROFILE%\.ssh\id_ed25519.pub
- macOS / Linux:
- Add the
.pubkey to a GitHub account at github.com/settings/keys → New SSH key. - On the comma: Settings → Developer → enable SSH, and enter that GitHub username. (On sunnypilot it's under the Developer section.)
- Make sure the comma is powered on and on the same WiFi as your computer.
- Open Comma Sync, pick where to save videos, and click Index Drives to see every drive and its size.
- Tick the ones you want (or Download All) and watch them transfer. Done!
Under the hood the app runs a single cross-platform Go core (core/) that you can
also run from a terminal (comma-sync sync / list / restitch <route> / discover). Its
behavior is tuned with environment variables:
| Variable | Default | Purpose |
|---|---|---|
ROOT |
./Comma Footage |
Where stitched videos go |
CHUNKS_DIR |
ROOT/Raw HEVC Chunks |
Where raw chunks are kept |
WITH_AUDIO |
1 |
Mux mic audio when present (0 = video only) |
WITH_COMBINED |
0 |
1 = also render the combined multi-angle video |
PRIMARY_CAM / SECONDARY_CAM / TERTIARY_CAM |
road / wide / driver |
Combined-video slots (labels road|wide|driver) |
CLEAN_RAW |
0 |
1 = delete a drive's chunks after stitching |
COMMA_IP |
(empty) | Pin a fixed IP instead of auto-discovering |
REMOTE_PORT |
22 |
SSH port (older devices used 8022) |
SSH_KEY |
~/.ssh/id_ed25519 |
Private key to authenticate with |
USE_USB |
0 |
1 = transfer over a USB-C/ADB link instead of WiFi (enable ADB on the comma; not faster than WiFi) |
BWLIMIT |
(none) | Cap the transfer rate (e.g. 3m = 3 MB/s) to lower the comma's power draw if it reboots mid-transfer |
Legacy: the original engine was a single bash script,
comma-sync.sh(rsync + ssh + ffmpeg, macOS/Linux only). It's retired in favor of the cross-platform app above, but it's kept in the repo for anyone who wants it — and the last script-based release, v1.0.6, stays downloadable.
Comma Sync runs on macOS, Linux, and Windows from one shared Go core — native SSH/SFTP
and device discovery are built in; only ffmpeg is external. The macOS UI is SwiftUI; Linux and
Windows use a Tauri front-end. Both drive the same core.
Found a bug or want to help? Open an issue, or fork the repo, work on a branch, and open a pull request.
The comma can reboot randomly during transfers, but the app picks back up where it left off and eventually gets the whole drive. If it's rebooting often:
- Best: transfer with the engine running (alternator → stable harness power), or power the device from a proper high-current USB-C supply (not a laptop port or a weak charger). Make sure the cable is fully seated.
- Mitigate: turn on "Limit speed for weak power sources" in the app (or set
BWLIMIT=3mfor the CLI) to lower the power draw.
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