Video Editor

A video in a tab: Clipkit's timeline editor, over a project file that is the edit. The project is JSON (CKP/1.0), and the media it names sits beside it, so an agent can read the cut, write a new one, and see it on the timeline the moment it is saved.

pumi plugin add pumi-dev/plugins/video-editor
pumi call pumi_dev.video_editor.open '{"path":"take.ckp.json"}'

The tab opens beside the one you are in ({"split":"down"} for below it). The page is drawn in a web view, so it is macOS only for now.

#The project

The project file is the edit: clips, tracks, their placement, and the media's paths relative to the project's folder. Everything it names — the video, the audio, the stills — is served from that folder, so a source of take.mp4 is the file beside the JSON.

• Saved on every edit, 300 ms after the last change, and the whole file at once: it is written beside the project and renamed over it, so a reader never sees half an edit.
• Written by someone else: when the file on disk becomes something the page did not write — an agent rewrote it, a script regenerated it — the tab opens the new version in place of the old.
• Agents write the JSON, not the UI: the timeline is a view of the file, and the file is the cut.

#What it needs

Nothing but pumi. The editor's page is bundled from the plugin's own dependencies into web/ the first time a project opens (a tenth of a second), and again when the page or Clipkit changes; its workers are built beside it. Nothing is fetched from the network at run time, and the page, the project and the media stay on 127.0.0.1.

#The tab

pumi_dev.video_editor.open takes path, and split (right, down, left, up); it answers the tab's id. A relative path is from the calling tab's folder.

Space and the arrows go to the editor (play, step a frame), as do cmd+z and cmd+shift+z: the window's own bindings do not take them while the tab has the keyboard.

#Working on it

bun install
bun run check                  # the worker and the window, then the page
bun run build                  # build web/ now, as the plugin does at first use
pumi plugin dev video-editor   # link it, reload on save

• src/main.ts runs in the plugin's worker: it opens tabs, starts a page server per project (src/serve.ts) and builds the page (src/page.ts).
• src/serve.ts is the project's server, and pure: bun src/serve.ts take.ckp.json prints the address, and a browser can open it.
• src/ui.tsx is the window's half: a <WebView> on that address, with the project and its media on the other side of it.
• page/ is the page itself, Clipkit's editor over the project the server serves beside it.