Feature Request: Dynamic display switching via Moonlight client

[wintrover]

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Feature Request

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Problem Summary

Currently, output_name in sunshine.conf is a static configuration loaded once at startup. When using the kms capture method on Linux (Wayland/X11), the Moonlight client's display selection buttons have no effect — only the statically configured monitor is streamed, regardless of which display the user selects in the Moonlight app.

Technical Analysis

After reviewing the source code (src/display_device.cpp, src/rtsp.h, src/nvhttp.cpp):

1. launch_session_t (the RTSP session struct) contains width, height, fps, appid, etc., but no display_index or monitor_id field.
2. parse_configuration() assigns config.m_device_id = video_config.output_name; — it only reads from the static config file, never from the client session.
3. kmsgrab.cpp initializes the DRM connector at startup. There is no runtime re-initialization logic to switch connectors on-the-fly.

Why This Matters

• Multi-monitor setups are extremely common (laptops with external displays, docking stations, etc.).
• Users expect to switch displays from the Moonlight client without SSHing into the host to edit sunshine.conf and restart the service.

Proposed Implementation (Theory)

1. Protocol: Add a display_index (or monitor_id) field to the GameStream launch/resume request parameters.
2. Moonlight client: Send the selected display index to the host.
3. Sunshine server:
   • Add display_index to launch_session_t.
   • In parse_configuration(), use the session's display_index to dynamically set config.m_device_id.
   • For kmsgrab: re-initialize the DRM framebuffer capture when the display changes.

Environment

• OS: Ubuntu 26.04 LTS (Wayland / GNOME)
• GPU: NVIDIA + AMD hybrid (laptop)
• Sunshine version: 2025.924.154138
• Capture methods tested: kms (works, static only), pipewire (fails to initialize on GNOME/Wayland), x11 (fails to initialize)

Current Workaround

Manually edit sunshine.conf to change output_name, then restart the Sunshine service:

systemctl --user restart sunshine

Request

Please consider implementing dynamic display switching so that multi-monitor users can select displays directly from the Moonlight client UI.

[ReenigneArcher]

I don't think any official moonlight clients tell sunshine what monitor to use.

You can use keyboard shortcuts to change the streamed monitor on the fly. I guess AI wouldn't know that though.

[semaseme4ka]

Can you tell me what keyboard shortcut I can use?

[ReenigneArcher]

https://docs.lizardbyte.dev/projects/sunshine/latest/md_docs_2getting__started.html#shortcuts