PolyStream ⚡

Stream multiple videos simultaneously across browser tabs without auto-pausing or "streaming on another device" lockouts.

---

📖 Overview

Many online learning platforms, course portals (e.g. PhysicsWallah, Coursera, Udemy, Panopto), and streaming websites intentionally restrict playback to only one tab at a time. When you open a second lecture or switch tabs, they:

• Automatically pause the video.
• Show intrusive lockout popups: "Playback Interrupted. Your account is already streaming on another device."
• Freeze or mute background tabs.

PolyStream eliminates these restrictions using a client-side API interception engine available as both a Firefox / Chrome Extension (Manifest V3) and a 1-click Userscript.

---

✨ Features

• 👁️ Visibility & Focus Lock: Spoofs document.hidden = false and document.visibilityState = 'visible'. Suppresses visibilitychange and window blur listeners so background tabs remain active.
• 📡 BroadcastChannel Tab Isolator: Scopes BroadcastChannel instances per tab (__mte_${TAB_ID}__...), preventing tabs from transmitting pause/stop commands to each other.
• 💾 Per-Tab Storage Virtualization: Isolates player heartbeat keys in localStorage so concurrent tabs never detect each other claiming active playback.
• 🔒 Web Locks API Shim: Bypasses navigator.locks exclusivity, granting playback locks concurrently to all tabs.
• 🛑 WebSocket Concurrency Shield: Intercepts server-sent WebSocket interrupt signals and silently drops concurrency kick notices before the frontend UI can react.
• 🎯 Modal Annihilator (MutationObserver): Instantly detects and deletes "Playback Interrupted / streaming on another device" dialogs within 0 milliseconds, cleans up backdrops, and restores unhindered mouse clicks.
• 🛡️ Anti-Pause Shield: Blocks programmatic background video.pause() calls while preserving genuine user clicks and spacebar controls.

---

🚀 Installation

Option 1: Userscript (Recommended for Firefox & Mobile)

Works with Violentmonkey, Tampermonkey, Greasemonkey, and mobile browsers like Kiwi / Orion.

1. Install Violentmonkey or Tampermonkey in your browser.
2. Open the userscript dashboard and click "Create a new script".
3. Copy the raw contents of multi-tab-enabler.user.js.
4. Paste it into the editor and press Ctrl + S to save.
5. Open your streaming portal (e.g. PhysicsWallah) in multiple tabs—they will now stream side-by-side without interruptions!

---

Option 2: Browser Extension (Chrome / Edge / Brave / Opera)

1. Clone or download this repository:

   git clone https://github.com/pdev-labs/polystream.git

2. Open chrome://extensions (or edge://extensions).
3. Turn on Developer mode (top-right toggle).
4. Click Load unpacked and select the polystream directory.
5. Pin PolyStream to your browser toolbar to access the dark-mode popup dashboard and live telemetry counters!

---

Option 3: Firefox Temporary Add-on

1. Open Firefox and navigate to about:debugging#/runtime/this-firefox.
2. Click "Load Temporary Add-on...".
3. Select manifest.json from this folder.
4. The extension with full popup UI is now active in Firefox!

---

Option 4: Firefox Multi-Account Containers (Native Firefox Trick)

For a zero-extension solution:

1. Install Mozilla's Firefox Multi-Account Containers.
2. Open your first video in your default container.
3. Open your second video in a different container (e.g. "Work" or "Personal").
4. Firefox isolates cookies, localStorage, and BroadcastChannel at the browser engine level, completely hiding each tab from the other!

---

🛠️ Interactive Test Lab

PolyStream includes a built-in test laboratory simulating the 4 most common stream restrictions:

1. Open test/test-page.html in your browser.
2. Duplicate the tab into a second window.
3. Test procedural canvas video playback, visibility changes, and cross-tab pause broadcasting.

---

🧪 Automated Testing

Run the automated interception test suite:

# Validate JavaScript syntax
npm run lint

# Run interception unit tests
npm test

Expected output:

--- Loading inject.js ---
Test 1: Visibility Spoofing
✓ Test 1 passed: Document appears always visible and focused
Test 2: BroadcastChannel Tab Isolation
✓ Test 2 passed: BroadcastChannel name is safely scoped
Test 3: Anti-Pause Shield
✓ Test 3 passed: Background script pause attempt was prevented!
Test 4: Web Locks Concurrent Shim
✓ Test 4 passed: Web Lock request was successfully scoped and acquired
Test 5: Storage Virtualization (PW active-tab bypass)
✓ Test 5 passed: Player key virtualization functional
Test 6: WebSocket Concurrency Interruption Dropping
✓ Test 6 passed: WebSocket interruption event was intercepted and dropped!

======================================
ALL INTERCEPTION TESTS PASSED CLEANLY!
======================================

---

🏗️ Architecture

┌─────────────────────────────────────────────────────────────┐
│                       WEBPAGE TAB                           │
│                                                             │
│   ┌─────────────────────────────────────────────────────┐   │
│   │                 Target Video Player                 │   │
│   │               <video> / MediaSession                │   │
│   └──────────────────────────┬──────────────────────────┘   │
│                              │                              │
│   ┌──────────────────────────▼──────────────────────────┐   │
│   │             PolyStream Injected Engine              │   │
│   │                                                     │   │
│   │   • document.hidden = false                         │   │
│   │   • document.visibilityState = 'visible'            │   │
│   │   • BroadcastChannel Scoped Namespace               │   │
│   │   • localStorage Player Key Virtualization          │   │
│   │   • WebSocket Concurrency Message Dropper           │   │
│   │   • MutationObserver Modal Annihilator              │   │
│   │   • HTMLMediaElement.prototype.pause Shield         │   │
│   └──────────────────────────┬──────────────────────────┘   │
│                              │ postMessage                  │
│   ┌──────────────────────────▼──────────────────────────┐   │
│   │          Content Script Bridge (ISOLATED)           │   │
│   └──────────────────────────┬──────────────────────────┘   │
│                              │ chrome.runtime               │
│   ┌──────────────────────────▼──────────────────────────┐   │
│   │             Extension Popup Dashboard               │   │
│   │            Live telemetry & module toggles          │   │
│   └─────────────────────────────────────────────────────┘   │
└─────────────────────────────────────────────────────────────┘

---

📄 License

This project is licensed under the MIT License © 2026 pdev-labs.