GNOME Network Displays adds virtual screen casting, MICE, and VA-API encoding

GNOME Network Displays is a GPLv3 graphical application for wireless desktop casting to Miracast and Chromecast receivers, developed by Benjamin Berg and Christian Glombek. The software captures desktop output through the standard desktop screencast portal (with X11 fallback) and streams it live to external displays, including support for casting a virtual screen rather than mirroring physical monitors.

The application supports Miracast over both Wi-Fi Direct and Miracast over Infrastructure (MICE), discovers available receivers automatically, and encodes video using GStreamer's available H.264 encoders with VA-API hardware acceleration where supported. Audio is handled through a dedicated PulseAudio sink and encoded as AAC. The tool is written in C and hosted in the official GNOME GitLab repository.

Casting architecture and protocol support

• Display capture: Uses the desktop screencast portal as the primary capture mechanism, falling back to X11 frame-grabbing when the portal is unavailable.
• Virtual display output: Can cast a virtual screen instead of mirroring an existing physical monitor, enabling extended-desktop workflows without cable connections.
• Miracast connectivity: Supports both peer-to-peer Wi-Fi Direct and Miracast over Infrastructure (MICE), the latter allowing Miracast traffic to traverse standard Wi-Fi networks rather than requiring direct device-to-device links.
• Hardware encoding: Automatically selects H.264 encoders through GStreamer and supports VA-API-based hardware encoding on compatible Intel/AMD GPUs.
• Audio pipeline: Creates a dedicated Network-Displays PulseAudio sink for system audio capture and streams it as AAC alongside the video feed.

Why it matters

For Linux desktop users and presenters, GNOME Network Displays fills a functional gap that Windows and macOS have long addressed with built-in wireless casting, making Linux workstations more viable in conference rooms and living rooms with Miracast or Chromecast hardware. The MICE support is particularly significant for enterprise and educational networks where Wi-Fi Direct is often disabled, while the virtual display capability aligns with modern Wayland multi-monitor workflows and could benefit Steam Deck or other handheld users seeking larger displays without docking cables.