dsh-quicktime-player

A sidebar video player for DeepSeek Harness — streaming playback with seek, wheel zoom and drag pan, plus frame capture and clip export.

Features

• Plays from anywhere. Registers its own right-sidebar tab type, so any video opened through DSH — Files tab, chat file reference, another sidebar plugin's tree, sidebar_open — lands in this player. Nothing else needs to be installed, and no other plugin needs adapting.
• Seekable. A Host route streams bytes with HTTP Range (206), so the progress bar scrubs instead of snapping back. Bytes stay on disk — a multi-GB video is never read into memory.
• Seek works on Desktop too. The Electron shell serves the page from dsh-app://, where Chromium cannot seek a <video> response; the player therefore streams from a tokenized 127.0.0.1 port and falls back to the same-origin route when that port is unavailable.
• Zoom and pan. Wheel zooms around the pointer (1× – 8×), drag pans while zoomed, and panning stops at the video's edge — the picture can never be dragged out of the frame. Double-click toggles fullscreen.
• Own controls. Play/pause, time ⇄ frame number, speed slider (0.2× – 5×, 0.2 steps), loop, vertical volume popup, mute, picture-in-picture, fullscreen. The chrome fades out while the mouse is idle.
• Frame stepping. ← / → step one frame; the frame rate is measured from delivered frames.
• Picks up where you left off. Each file's position, speed, loop, volume and mute are remembered by absolute path (the last 50 files, ignored after 30 days), so switching sessions and coming back resumes on the same frame. If the file was re-rendered (duration changed), the old record is dropped rather than seeking somewhere unrelated.
• Copy the current frame. The camera button next to ? writes the frame under the playhead to the clipboard as a PNG (falling back to a download), with a toast confirming it.
• Trim a range. The scissors button drops a marker at the playhead; two markers survive, linked by a dashed line, and hovering the scissors reveals save/clear. Saving runs the Host's ffmpeg with a stream copy, so the clip is byte-identical to the source — no re-encode, cut on the nearest keyframe. Without ffmpeg the button says so.
• Check for updates. The cloud button next to the camera asks the Host for this package's installed version and the registry's latest, then reports the answer in a small dialog. Manual only: no polling, no badge, no auto-install.
• Follows the harness theme. The chrome (header, guide card, dialogs, toasts) is painted with DSH's own --dsw-alias-* tokens, so a light theme gives a light player; the video stage stays dark because that is what sits under the picture. Without the tokens it falls back to the dark palette it has always used.
• Built-in guide. The ? in the corner lays a click-through guide card over the player: one row per feature, with the same control glyphs you see in the toolbar. It is plain text — no arrows to keep in sync.
• Keyboard is never stolen. While focus is inside the pane — even on a slider — Space and the arrows stay with the player.

Install

dsh plugin --profile <profile> add dsh-quicktime-player

Reopen the window once so the client bundle is picked up.

Requirements

• DSH with profile bundles (the package declares dsh.bundle.patch).
• ffmpeg on the Host, only for clip export. It is looked up at /opt/homebrew/bin/ffmpeg, /usr/local/bin/ffmpeg, then ffmpeg on PATH. Without it everything else still works; the save button says the Host has no ffmpeg instead of failing silently.

There is nothing to configure: the route prefix, the 4 GiB ceiling, the loopback media server and the working-directory confinement are fixed.

Controls

Input	Action
Space / K	play / pause
← →	one frame back / forward
Shift + ← →	±1 s
↑ ↓	volume
M	mute
F / Enter	fullscreen
0	reset zoom
+ / −	zoom in / out
click the clock	switch between time and frame numbers
the scissors button	drop a clip marker at the playhead (the last two are kept)
hover the scissors	reveal save / clear for the marked range
the camera button	copy the current frame to the clipboard as a PNG
the cloud button	check the registry for a newer version

How it works

• One tab type. ctx.sidebarRightTabs.register claims video addresses with per-suffix globs (dsh-resource://file/**/*.mp4, …). The registry ranks tab types by band, then by pattern length, then by registration order — a longer, video-only glob outranks a sidebar plugin's generic dsh-resource://file/**, so videos route here and every other file keeps its usual viewer.
• One Host route. ctx.webServer.register serves /quicktime/source, /quicktime/stream, /quicktime/clip, /quicktime/capabilities, /quicktime/version and the tokenized loopback port. Paths are confined to the session working directory.
• Clip export shells out to ffmpeg with -ss / -t -c copy: the streams are copied, not re-encoded, so the cut lands on the nearest keyframe and the frame data stays byte-identical. The temp file is deleted after it is sent.
• No dependency on any other plugin: the core is the tab type plus that route.

.mkv, .avi, .wmv and .flv are accepted but Chromium cannot decode them; the player reports that instead of pretending to play.

Troubleshooting

• ~/.dsh/quicktime-player.log — one JSON line per player event (source resolved, metadata, decode errors).
• "宿主上没有 ffmpeg" when saving a clip — install ffmpeg (brew install ffmpeg) and reopen the window.
• The update check says "检查失败" — the Host could not reach registry.npmjs.org (offline, proxy, or DNS).
• GET /quicktime/_graph — dev probe for whether the client bundle is in the module graph.

License

MIT. The icon is ours: a dark plate, a gradient ring and a play glyph, generated by scripts/make-icon.mjs (violet, teal, amber or rose). It contains no Apple artwork.