XZY Notes

Lecture notes for online courses: screenshots, timestamp jump-back, subtitle search, offline transcription, Markdown export.

XZY Notes —— lecture notes for online courses: screenshots, subtitle search, offline speech transcription, Markdown export WHAT IT IS FOR Taking notes on a video lecture usually means opening another app: pause the video, switch windows, grab a screenshot, try to remember where you were. This extension moves all of that into the side panel next to the video — capture and type notes against the exact moment, jump back to it later, then export the whole course to Markdown for your own knowledge base. WHAT YOU CAN DO - One-key screenshot notes. Alt+S grabs the current frame together with its timestamp, without pausing the video; Alt+A opens an annotator (rectangle, arrow, pen, text, mosaic) so you can mark up the slide. - Timestamp jump-back and A-B loop. Click a note's timestamp to seek straight back to that moment; set an A-B range to re-listen to a key passage. - Subtitle timeline. The whole course transcript in one searchable pane, with CJK-aware full-text search, follow-playback highlighting and click-to-seek — no more dragging the progress bar to find that one formula. - Local speech transcription (fallback when a course has no subtitles). A speech recognition model running entirely in your browser (sherpa-onnx WASM) turns the lecture audio into timestamped text: when the video's source file is reachable the whole file is transcribed fast-forward — far faster than real time, or streaming while it downloads — and otherwise the tab's audio is captured and transcribed live along with playback. The model is downloaded once on first use and then works fully offline. On Chrome the task runs in its own background document, so closing the side panel does not interrupt it. - Chapter outlines and summaries. For courses without a chapter list, generate one by rules, or connect your own model (OpenAI-compatible endpoint; the token is stored only on your device) to split the lecture into topics and write a summary for each. - Markdown export. Outline + timestamped notes + screenshots (embedded or as file references) + clickable seek links, ready for Obsidian, Notion or any Markdown tool. - Full local backup. Everything is stored in IndexedDB on your machine; the settings page shows how much space it uses and can pack or restore a complete zip backup. WHY INSTALL IT 1. No more window juggling. Notes and video share one interface: capturing a frame is a note, and every note carries its timestamp. 2. It works on courses without subtitles. The local model turns an unsubtitled lecture into searchable, seekable text — something most note-taking tools cannot do. 3. Transcription does not make you wait through the video. Once the video's source file is resolved the whole lecture is transcribed fast-forward, and it keeps running even if you close the side panel. 4. Your data never leaves your device. No account, no sign-in, no cloud sync, no server, no telemetry — your courses, notes and screenshots stay on your computer. (Transcript text is sent to an AI endpoint only if you configure one yourself and explicitly click to generate.) 5. Install once, keep it free. The transcription model runs locally at no cost — no API credits, no subscription. 6. No lock-in. Everything exports as standard Markdown plus image files, ready to take with you. 7. Chinese and English UI, following your system language automatically and switchable manually. SUPPORTED SITES Bilibili, icourse163 (China University MOOC), XuetangX, and Zhihuishu — plus any page with an HTML5 video element (generic mode; click the toolbar icon once on the page to activate it). GETTING STARTED Open the side panel on a video page → press Alt+S to capture, read or search the full transcript in the subtitle pane, or click "Start transcription" when a course has none → export the whole course to Markdown when you are done. Shortcuts can be customized at chrome://extensions/shortcuts.