Firefox Per-Tab MPRIS

Exposes every active media tab in Firefox as a separate MPRIS D-Bus player. Tools like playerctl and Waybar can see and control each tab individually.

Firefox's built-in MPRIS support only exposes a single player regardless of how many tabs have media. This project gives you per-tab control.

$ playerctl -l
firefox_tab_13
firefox_tab_18
firefox_tab_19

$ playerctl -a metadata --format '{{playerName}}: {{artist}} - {{title}} [{{status}}]'
firefox_tab_13: Ali Sethi - Gulon Main Rang [Playing]
firefox_tab_18: Humera Channa - Mujh Se Pehli Si Muhabbat [Paused]
firefox_tab_19: www.instagram.com - Instagram [Playing]

How it works

┌─────────────────────────────────────────────────────────┐
│ Firefox                                                 │
│  ┌──────────┐  runtime.sendMessage  ┌────────────────┐  │
│  │content.js├──────────────────────►│ background.js  │  │
│  │(per tab) │◄──────────────────────┤                │  │
│  └──────────┘  runtime.onMessage    └───────┬────────┘  │
│   Detects <video>/<audio>                   │           │
│   Extracts metadata                  Native Messaging   │
│   Executes play/pause/seek                  │           │
└─────────────────────────────────────────────┼───────────┘
                                              │
                          ┌───────────────────▼──────────┐
                          │  media_host.py (Python)      │
                          │                              │
                          │  Tab 13 → MPRIS Player 13    │
                          │  Tab 18 → MPRIS Player 18    │
                          │  Tab 19 → MPRIS Player 19    │
                          │                              │
                          │  Each on its own D-Bus       │
                          │  session bus connection       │
                          └──────────────┬───────────────┘
                                         │
                    D-Bus Session Bus (org.mpris.MediaPlayer2.firefox_tab_*)
                                         │
                          ┌──────────────▼───────────────┐
                          │  playerctl / Waybar / etc.   │
                          └──────────────────────────────┘

1. Content script is injected into every page. Detects <video> and <audio> elements, extracts metadata (with YouTube-specific handling for title/channel/thumbnail), and reports state to the background script.

2. Background script aggregates media state from all tabs and relays it to the native messaging host. Routes commands back to the correct tab.

3. Python native host creates a separate MPRIS D-Bus player for each active media tab. Each player gets its own bus connection to avoid conflicts. Implements the full org.mpris.MediaPlayer2.Player interface (Play, Pause, Stop, Next, Previous, Seek, SetPosition, Volume). Cleans up when tabs close.

Requirements

• Linux with D-Bus session bus
• Firefox
• Python 3.10+
• dbus-next (pip install dbus-next or yay -S python-dbus-next on Arch)
• playerctl (optional, for CLI control — sudo pacman -S playerctl)

Installation

git clone https://github.com/HRmemon/firefox-per-tab-mpris.git
cd firefox-per-tab-mpris
./install.sh

The install script will:

• Check and help install dependencies
• Create a launcher wrapper with the correct Python path
• Install the native messaging manifest to ~/.mozilla/native-messaging-hosts/
• Print instructions for loading the WebExtension

Then load the extension in Firefox:

1. Go to about:debugging#/runtime/this-firefox
2. Click Load Temporary Add-on...
3. Select extension/manifest.json

Usage

# List all per-tab MPRIS players
playerctl -l

# Show metadata for all players
playerctl -a metadata --format '{{playerName}}: {{artist}} - {{title}} [{{status}}]'

# Control a specific tab
playerctl -p firefox_tab_13 play-pause
playerctl -p firefox_tab_13 next
playerctl -p firefox_tab_13 volume 0.5

# View native host log
tail -f /tmp/firefox-mpris-host.log

Waybar integration

Add to your Waybar config (~/.config/waybar/config.jsonc):

"custom/mpris": {
    "exec": "playerctl -a metadata --format '{\"text\": \"{{playerName}}: {{markup_escape(title)}}\", \"tooltip\": \"{{playerName}}\\n{{markup_escape(title)}} - {{markup_escape(artist)}}\\n{{status}}\", \"class\": \"{{lc(status)}}\"}' -F",
    "return-type": "json",
    "max-length": 50,
    "on-click": "playerctl play-pause",
    "on-click-right": "playerctl next",
    "on-click-middle": "playerctl previous",
    "on-scroll-up": "playerctl volume 0.05+",
    "on-scroll-down": "playerctl volume 0.05-",
    "escape": true
}

See waybar/config-snippet.jsonc for CSS styling suggestions.

Disabling Firefox's built-in MPRIS

To avoid the duplicate built-in Firefox player, set media.hardwaremediakeys.enabled to false in about:config.

Project structure

extension/
  manifest.json     WebExtension manifest (Manifest V2)
  background.js     Background script — bridges content scripts and native host
  content.js        Content script — media detection and control per tab
native-host/
  media_host.py     Python native messaging host — per-tab MPRIS via dbus-next
waybar/
  config-snippet.jsonc          Waybar module config and CSS
install.sh                      Setup script

License

MIT