MediaSession for Web

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About

A lightweight wrapper around the browser Media Session API. Provides unified media controls, metadata, and playback state management for audio/video apps with zero dependencies.

Empowers media experiences in NoMercyTV and other NoMercy projects.

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Features

• Zero Dependencies: No external packages required
• Media Metadata: Set title, artist, album, and artwork with automatic multi-size image generation
• Playback State: Control and reflect play, pause, stop, etc.
• Position State: Sync duration, position, and playback rate
• Action Handlers: Respond to play, pause, seek, next/previous, and more
• Chapter Support: Attach chapter markers to metadata for enhanced media navigation
• Skip Ad: Register a skip-ad action handler for ad-supported content
• Handler Cleanup: Unregister action handlers individually or all at once
• TypeScript Support: Full typings for safe integration
• Framework Agnostic: Use with any frontend framework
• Graceful Fallback: Silently no-ops when Media Session API is unavailable

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Quick Start

Installation

npm install @nomercy-entertainment/media-session

Basic Usage

import MediaSession from '@nomercy-entertainment/media-session';

const mediaSession = new MediaSession();

// Set metadata with chapters
mediaSession.setMetadata({
  title: 'Song Title',
  artist: 'Artist Name',
  album: 'Album Name',
  artwork: 'https://example.com/artwork.jpg',
  chapters: [
    { title: 'Intro', startTime: 0 },
    { title: 'Verse 1', startTime: 30 },
    { title: 'Chorus', startTime: 90, artwork: 'https://example.com/chorus.jpg' },
  ],
});

// Set playback state
mediaSession.setPlaybackState('playing');

const audioElement = document.createElement('audio');

// Set position state
mediaSession.setPositionState({
  duration: audioElement.duration,
  playbackRate: audioElement.playbackRate,
  position: audioElement.currentTime
});

// Set action handlers
mediaSession.setActionHandler({
  play: () => audioElement.play(),
  pause: () => audioElement.pause(),
  stop: () => {
    audioElement.pause();
    audioElement.currentTime = 0;
    audioElement.removeAttribute('src');
  },
  previous: () => {},
  next: () => {},
  seek: (time) => audioElement.currentTime = time,
  getPosition: () => audioElement.currentTime,
  skipAd: () => skipToContent(),
});

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Advanced Features

Media Session Integration

• Native OS media controls (lock screen, notification, hardware buttons)
• Customizable action handlers for all major media events
• Automatic artwork resizing for platform compatibility

Artwork Handling

When passing a string URL as artwork, the library automatically generates multiple image sizes (96x96 through 512x512) for optimal display across different platforms and devices.

You can also pass a MediaImage[] array directly for full control over artwork variants.

Chapters

Pass a chapters array in setMetadata to attach chapter markers to the current track. Each chapter object has:

• title (string) — display name for the chapter
• startTime (number) — start offset in seconds
• artwork (optional) — a string URL or MediaImage[] array; receives the same automatic multi-size generation as main artwork

Chapters are forwarded to the browser's MediaSession API as chapterInfo where supported.

mediaSession.setMetadata({
  title: 'My Video',
  chapters: [
    { title: 'Introduction', startTime: 0 },
    { title: 'Main Content', startTime: 120 },
    { title: 'Credits', startTime: 3540, artwork: 'https://example.com/credits.jpg' },
  ],
});

Handler Cleanup

Use clearActionHandler to unregister handlers when a component unmounts or media changes.

// Clear a specific handler
mediaSession.clearActionHandler('play');

// Clear multiple handlers
mediaSession.clearActionHandler(['play', 'pause', 'seekto']);

// Clear all handlers
mediaSession.clearActionHandler();

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Browser Support

Feature	Chrome	Firefox	Safari	Edge
Media Session API	73+	82+	15+	79+

When the Media Session API is not available, all methods silently no-op.

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Migration from v1.0.x

v1.1.0 is fully backwards compatible. No changes are required for existing code.

What's new:

• setMetadata now accepts an optional chapters array (see Chapters)
• setActionHandler now accepts an optional skipAd callback
• New clearActionHandler() method for cleanup (see Handler Cleanup)
• Fixed image/jpg MIME type typo — all generated artwork sizes now correctly use image/jpeg

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Migration from v0.x

v1.0.0 removes the Capacitor dependency. If you were relying on the Capacitor fallback for native mobile apps, you will need to handle that separately. For browser-only usage, the API is unchanged.

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Contributing

We welcome contributions! Please see our Contributing Guide for details.

Development Setup

# Clone the repository
git clone https://github.com/NoMercy-Entertainment/nomercy-media-session.git
cd nomercy-media-session

# Install dependencies
npm install

# Build and test
npm run build
npm run test

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License

This project is licensed under the Apache 2.0 License - see the LICENSE file for details.

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About NoMercy Entertainment

NoMercy Entertainment builds open-source media tools that give developers full control over their audio and video.

Our Ecosystem

• NoMercy MediaServer
• NoMercy VideoPlayer
• NoMercy MusicPlayer
• NoMercy FFmpeg

Links

• Website: nomercy.tv
• Contact: support@nomercy.tv
• GitHub: @NoMercy-Entertainment

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Built with care by the NoMercy Engineering Team