ohms.js

This is the 3DH Lab development fork. See fork maintenance and contribution notes, including the focused upstream proposal and planned work.

ohms.js is a Javascript-based viewer for Oral History Metadata Synchronizer (OHMS) XML files.

Usage

ohms.html is the viewer, and it takes the URL of the OHMS XML file to display as the cachefile query string parameter, so ohms.html?cachefile=example.xml where example.xml is the XML file's URL. Relative and absolute URLs are both accepted.

Customization

Additional query string parameters can be used to customize the viewer interface.

• link_color: sets the color used for links; pass a six-character hex color code without the leading #
• metadata: pass none to disable displaying the title and repository on the top of the viewer

Timed transcript navigation

For WebVTT transcripts played through native audio or video (Other media host), the viewer highlights the passage at the current playback time and follows it inside the transcript pane. Following starts enabled.

• Click passage text or press Enter on a focused passage to seek there. Paused playback stays paused; playing media continues. Timestamp links retain their existing seek-and-play behavior, including fractional cue times.
• Press Space on a focused passage to play or pause. Links and player controls keep their own keyboard behavior.
• Scroll, use reading-navigation keys, or hold/select text to browse independently. Playback continues. Following resumes four seconds after the last interaction, once any held pointer or text selection is released.
• Follow playback turns automatic following on or off. Return to playback enables following and locates the current passage; it does not start paused media.
• Automatic movement stays within the transcript pane, preserves keyboard focus, and respects reduced-motion preferences. Silence between cues has no active row.

The new controls require valid WebVTT start/end times and a native media player. Legacy OHMS sync transcripts and hosted player integrations retain existing navigation. Speaker labeling and transcript editing are outside this feature.

Development checks

With Node.js installed:

npm install
npx playwright install chromium firefox webkit
npm test

The browser tests use generated tones and text plus a small synthetic video, and block remote requests. To try the audio example locally, run npm run demo and open the printed localhost URL. The example contains no recorded speech. See fixture provenance.

Cross-origin files and CORS

Loading OHMS XML files for display is subject to the same-origin policy. This isn't an issue if your files are on the same domain as the ohms.js viewer, but if they're on a different domain, you'll need to make sure CORS headers (i.e., Access-Control-Allow-Origin) are set by the server that hosts the XML files.