moshpit is a video editor with a datamosher built in, running in the browser. Cut your clips, music and titles together on a multi-track timeline, then mosh the result: it edits the compressed frames directly (removing keyframes, repeating motion frames, borrowing motion from other shots, corrupting bytes) with an effect stack and mosh transitions to control all of it. Exports go up to 4K and 60 fps, sized for Reels, TikTok and Shorts.
Nothing is uploaded. Decoding and encoding happen locally with ffmpeg.wasm; the picture effects run on WebGL.
Open moshpit → Website · Docs
Getting started
Open the site and you're on the home screen: start a New project, import some clips, or start from a template (pick your clips and the mosh is set up for you) or an example (footage drawn on your device, nothing to import). Clips dropped into an empty project are melted straight away so there's something to see; cut them together on the timeline, change the mosh, and press Space.
Every project is saved on this device by itself and listed on the home screen with a picture of where you left off; the logo takes you back there.
To run it locally:
git clone https://github.com/furniture3k/Video-Datamosher.git
cd Video-Datamosher
npm install
npm run dev # http://localhost:5173
npm run build writes a static copy to dist/ that can be hosted anywhere: the website at the root (index.html, docs/) and the editor in app/. The ~30 MB video engine is bundled, so it works offline. The dev server serves both too: the website at http://localhost:5173 and the editor at http://localhost:5173/app/.
The quickest start: under Make a video like this, pick a look (Behind the subject, Kinetic lyrics, Pop-up collage, Tour poster or Red notes), choose your clips and a song, type your words, and the titles, cut-outs, tracked marks and timing are made for you. Templates in the editor does the same for clips already on the timeline, and one Undo takes it off.
A quick first video by hand:
- Import clips, photos and music. Drag them from the Media panel onto the timeline: footage on the video track, sound on an audio track.
- Edit like any editor. Drag clips to reorder, drag edges to trim, S splits at the playhead, right-click a clip for more (detach audio, reverse, duplicate).
- Click the + on a cut (or drag from the Transitions tab). Melt removes the keyframe at the cut, so the next clip's motion plays on top of the last picture. Classic dissolves, dips, wipes and slides are there too.
- Add titles with Text, fade music with the dots on its clip, and choose per track whether sound stays clean or stutters with the mosh.
- Layer mosh effects on the Mosh FX lanes, or start from Presets and Randomize.
- Export to MP4 or WebM at up to 4K, GIF, PNG frames, or the raw broken AVI.
Apps
Install from the browser (phones, tablets, laptops). moshpit is an installable web app. Open the site, then:
- iPhone / iPad: Safari → Share → Add to Home Screen.
- Android: Chrome → menu → Install app (or Add to Home screen).
- Desktop Chrome / Edge: the install icon in the address bar.
It opens in its own window with no browser bars, and the whole app, including the video engine, is kept on the device, so it starts and works offline. Updates arrive the next time it's opened online.
Installed, it also works with the rest of the system:
- Open with moshpit. In Chrome and Edge, videos, GIFs and sound files get moshpit in their Open with menu.
- Share to moshpit. On Android, share a video from the gallery or another app straight into moshpit. The export dialog has Share… on phones and tablets.
- Save dialog. In Chrome and Edge, Save project asks where to put the file and Ctrl S saves to the same file again.
Desktop app (Windows, macOS, Linux). The same editor in a native window, running a native FFmpeg instead of the browser one. Native FFmpeg uses every CPU core, so preparing and exporting are many times faster, 1440p and 4K are practical, and output can be 30 minutes long (10 minutes in the browser). Exports are saved with the normal Save dialog. Videos opened with the desktop app (Open with, or dropped on its icon) go into the open project. Download it from Releases:
| File |
|---|
| Windows 10/11 | moshpit_x.y.z_x64-setup.exe or .msi |
| macOS (Apple Silicon) | moshpit_x.y.z_aarch64.dmg |
| macOS (Intel) | moshpit_x.y.z_x64.dmg |
| Linux | .AppImage, .deb or .rpm |
The builds aren't code-signed yet. On macOS, right-click the app and choose Open the first time; on Windows, choose More info → Run anyway if SmartScreen asks. See DESKTOP.md for building it yourself.
Android app (experimental). Each release also has moshpit-android-arm64.apk: the editor as an Android app, with the browser's video engine, saving exports to Downloads. It hasn't been tried on many phones yet, so the installable web app (above) is still the safer choice on Android.
Effects
Bitstream effects change the compressed video itself. The decoder then reconstructs the picture from the damaged instructions, which is where the melting comes from.
This is the beginning of the README. Read the rest at the original. Read the full README ↗
