mirror of https://github.com/moonlight-stream/moonlight-qt.git synced 2026-10-11 19:13:59 +00:00

T

Cameron Gutman e3fd29e4d7 Fix a livelock that can occur between SDL, libdecor-gtk, and Qt

The Qt UI continuously redrawing prevents libdecor-gtk's glib dispatch loop
from ever returning since it constantly posts new messages to draw again.

The result is that Moonlight randomly hangs (with the spinner still animating)
at the "Starting app..." phase of connection establishment and never proceeds
until the livelock is broken by loss of focus, hiding the window, or similar.

For posterity, the hanging stack:

QtWaylandClient::QWaylandWindow::waitForFrameSync (this=this@entry=..., timeout=timeout@entry=...) at qwaylandwindow.cpp:891
QtWaylandClient::QWaylandGLContext::swapBuffers (this=..., surface=...) at qwaylandglcontext.cpp:494
QRhiGles2::endFrame (this=..., swapChain=..., flags=...) at qrhigles2.cpp:2390
QRhi::endFrame (this=..., swapChain=..., flags=...) at qrhi.cpp:11600
QSGGuiThreadRenderLoop::renderWindow (this=..., window=...) at qsgrenderloop.cpp:714
QQuickWindow::event (this=..., event=...) at qquickwindow.cpp:1663
QCoreApplication::notifyInternal2 (receiver=..., event=...) at qcoreapplication.cpp:1126
QCoreApplication::sendEvent (receiver=..., event=...) at qcoreapplication.cpp:1571
QPlatformWindow::deliverUpdateRequest (this=...) at qplatformwindow.cpp:831
QObject::event (this=..., e=...) at qobject.cpp:1480
QCoreApplication::notifyInternal2 (receiver=..., event=...) at qcoreapplication.cpp:1126
QCoreApplication::sendEvent (receiver=..., event=...) at qcoreapplication.cpp:1571
QCoreApplicationPrivate::sendPostedEvents (receiver=..., event_type=..., data=...) at qcoreapplication.cpp:1926
postEventSourceDispatch (s=...) at qeventdispatcher_glib.cpp:248
g_main_dispatch (context=...) at gmain.c:3591
g_main_context_dispatch_unlocked (context=...) at gmain.c:4451
g_main_context_iterate_unlocked (context=context@entry=..., block=block@entry=..., dispatch=dispatch@entry=..., self=...) at gmain.c:4516
g_main_context_iteration (context=..., context@entry=..., may_block=may_block@entry=...) at gmain.c:4582
libdecor_plugin_gtk_dispatch (plugin=..., timeout=...) at libdecor-gtk.c:509
Wayland_PumpEvents (_this=...) at SDL_waylandevents.c:610
Wayland_GLES_LoadLibrary (_this=..., path=...) at SDL_waylandopengles.c:51
SDL_GL_LoadLibrary_REAL (path=...) at SDL_video.c:4735
SDL_RecreateWindow (window=..., flags=...) at SDL_video.c:2796
GLES2_CreateRenderer (renderer=..., window=..., create_props=...) at SDL_render_gles2.c:2329
SDL_CreateRendererWithProperties_REAL (props=props@entry=...) at SDL_render.c:1126
SDL_CreateRenderer_REAL (window=..., name=...) at SDL_render.c:1287
SDL_CreateRenderer_REAL (window=..., idx=..., flags=...) at sdl2_compat.c:5986
EGLRenderer::initialize (this=..., params=...) at eglvid.cpp:445
FFmpegVideoDecoder::initializeRendererInternal (this=..., renderer=..., params=...) at ffmpeg.cpp:323
FFmpegVideoDecoder::createFrontendRenderer (this=..., params=..., useAlternateFrontend=...) at ffmpeg.cpp:426
FFmpegVideoDecoder::completeInitialization (this=..., decoder=..., requiredFormat=..., params=..., testMode=..., useAlternateFrontend=...) at ffmpeg.cpp:486
FFmpegVideoDecoder::tryInitializeRenderer(AVCodec const*, AVPixelFormat, _DECODER_PARAMETERS*, AVCodecHWConfig const*, IFFmpegRenderer::InitFailureReason*, std::function<IFFmpegRenderer* ()>)
    (this=..., decoder=..., requiredFormat=..., params=..., hwConfig=..., failureReason=..., createRendererFunc=...) at ffmpeg.cpp:1200
FFmpegVideoDecoder::tryInitializeHwAccelDecoder (this=..., params=..., pass=..., terminallyFailedHardwareDecoders=...) at ffmpeg.cpp:1544
FFmpegVideoDecoder::initialize (this=..., params=...) at ffmpeg.cpp:1701
Session::chooseDecoder (vds=..., renderer=..., window=..., videoFormat=..., width=..., height=..., frameRate=..., enableVsync=..., enableFramePacing=..., testOnly=..., chosenDecoder=...) at session.cpp:322
Session::getDecoderAvailability (window=..., vds=..., videoFormat=..., width=..., height=..., frameRate=...) at session.cpp:498
Session::initialize (this=..., qtWindow=...) at session.cpp:755

2026-09-10 21:00:57 -05:00

.github

Update to SDL 3.4.16

2026-09-05 00:21:22 -05:00

AntiHooking

Block the Bandicam Vulkan layer from loading into Moonlight

2025-10-24 23:17:03 -05:00

app

Fix a livelock that can occur between SDL, libdecor-gtk, and Qt

2026-09-10 21:00:57 -05:00

config.tests

Attempt to fix build with SDL 2.26 on systems with old GL headers

2022-11-21 20:32:10 -06:00

h264bitstream

Fix C4146 warning on MSVC

2026-07-26 20:12:58 -05:00

moonlight-common-c

Update moonlight-common-c with frame loss fixes

2026-09-08 23:49:33 -05:00

qmdnsengine

Update qmdnsengine submodule with latest upstream changes

2026-08-26 01:31:31 -05:00

scripts

Don't try fallback driver paths with the host libva

2026-09-05 14:30:28 -05:00

wix

Update MSVC redistributable in the installer

2026-07-26 19:46:27 -05:00

.gitignore

Switch to downloading prebuilt release artifacts instead of a submodule

2026-05-03 21:04:06 -05:00

.gitmodules

Import minimal set of code from h264bitstream needed for SPS fixups

2026-07-26 19:23:34 -05:00

globaldefs.pri

Modernize ASAN flags for MSVC

2026-07-04 15:37:21 -04:00

LICENSE

Add license and readme

2018-07-07 14:59:48 -07:00

moonlight-qt.pro

Revert "Make h264bitstream dependency optional"

2026-07-26 19:23:34 -05:00

README.md

Update Windows and macOS build requirements

2026-08-05 00:56:04 -05:00

setup-deps.ps1

Update to SDL 3.4.16

2026-09-05 00:21:22 -05:00

setup-deps.py

Update to SDL 3.4.16

2026-09-05 00:21:22 -05:00

README.md

Moonlight PC

Moonlight PC is an open source PC client for NVIDIA GameStream and Sunshine.

Moonlight also has mobile versions for Android and iOS.

You can follow development on our Discord server and help translate Moonlight into your language on Weblate.

Features

Hardware accelerated video decoding on Windows, Mac, and Linux
H.264, HEVC, and AV1 codec support (AV1 requires Sunshine and a supported host GPU)
YUV 4:4:4 support (Sunshine only)
HDR streaming support
7.1 surround sound audio support
10-point multitouch support (Sunshine only)
Gamepad support with force feedback and motion controls for up to 16 players
Support for both pointer capture (for games) and direct mouse control (for remote desktop)
Support for passing system-wide keyboard shortcuts like Alt+Tab to the host

Downloads

Nightly Builds

Downloads

Special Thanks

Hosting for Moonlight's Debian and L4T package repositories is graciously provided for free by Cloudsmith.

Building

Windows Build Requirements

Qt 6.11 SDK or later (earlier versions may work but are not officially supported)
Visual Studio 2026 (Community edition is fine)
Select MSVC option during Qt installation. MinGW is not supported.
7-Zip (only if building installers for non-development PCs)
Graphics Tools (only if running debug builds)
- Install "Graphics Tools" in the Optional Features page of the Windows Settings app.
- Alternatively, run dism /online /add-capability /capabilityname:Tools.Graphics.DirectX~~~~0.0.1.0 and reboot.

macOS Build Requirements

Qt 6.11 SDK or later (earlier versions may work but are not officially supported)
Xcode 15 or later (earlier versions may work but are not officially supported)
create-dmg (only if building DMGs for use on non-development Macs)

Linux/Unix Build Requirements

Qt 6 is recommended, but Qt 5.12 or later is also supported (replace qmake6 with qmake when using Qt 5).
GCC or Clang
FFmpeg 4.0 or later
Install the required packages:
- Debian/Ubuntu:
  - Base Requirements: libegl1-mesa-dev libgl1-mesa-dev libopus-dev libsdl2-dev libsdl2-ttf-dev libssl-dev libavcodec-dev libavformat-dev libswscale-dev libva-dev libvdpau-dev libxkbcommon-dev wayland-protocols libdrm-dev
  - Qt 6 (Recommended): qt6-base-dev qt6-declarative-dev libqt6svg6-dev qt6-wayland qml6-module-qtquick-controls qml6-module-qtquick-templates qml6-module-qtquick-layouts qml6-module-qtqml-workerscript qml6-module-qtquick-window qml6-module-qtquick
  - Qt 5: qtbase5-dev qt5-qmake qtdeclarative5-dev qtquickcontrols2-5-dev qml-module-qtquick-controls2 qml-module-qtquick-layouts qml-module-qtquick-window2 qml-module-qtquick2 qtwayland5
- RedHat/Fedora (RPM Fusion repo required):
  - Base Requirements: openssl-devel SDL2-devel SDL2_ttf-devel ffmpeg-devel libva-devel libvdpau-devel opus-devel pulseaudio-libs-devel alsa-lib-devel libdrm-devel
  - Qt 6 (Recommended): qt6-qtsvg-devel qt6-qtdeclarative-devel
  - Qt 5: qt5-qtsvg-devel qt5-qtquickcontrols2-devel
Building the Vulkan renderer requires a libplacebo-dev/libplacebo-devel version of at least v7.349.0 and FFmpeg 6.1 or later.

Steam Link Build Requirements

Steam Link SDK cloned on your build system
STEAMLINK_SDK_PATH environment variable set to the Steam Link SDK path

Steam Link Hardware Limitations
Moonlight builds for Steam Link are subject to hardware limitations of the Steam Link device:

Maximum resolution: 1080p (1920x1080)
Maximum framerate: 60 FPS
Maximum video bitrate: 40 Mbps
HDR streaming is not supported on the original hardware

Docker containers

If you want to use Docker for building, look at this repo containing canonical containers for different architectures, which handle building deps and extra linking for you.

Build Setup Steps

Install the latest Qt SDK (and optionally, the Qt Creator IDE) from https://www.qt.io/download
- You can install Qt via Homebrew on macOS, but you will need to use brew install qt --with-debug to be able to create debug builds of Moonlight.
- You may also use your Linux distro's package manager for the Qt SDK as long as the packages are Qt 5.12 or later.
- This step is not required for building on Steam Link, because the Steam Link SDK includes Qt 5.14.
Download submodules and dependencies
- Run git submodule update --init --recursive from within moonlight-qt/.
- On Windows and macOS, you must also run setup-deps.ps1 (Windows) or setup-deps.py (macOS).
- Perform these steps each time you pull new changes from the Git repository.
Open the project in Qt Creator or build from qmake on the command line.
- To build a binary for use on non-development machines, use the scripts in the scripts folder.
  - For Windows builds, use scripts\build-arch.bat and scripts\generate-bundle.bat. Execute these scripts from the root of the repository within a Qt command prompt. Ensure 7-Zip binary directory is on your %PATH%.
  - For macOS builds, use scripts/generate-dmg.sh. Execute this script from the root of the repository and ensure Qt's bin folder is in your $PATH.
  - For Steam Link builds, run scripts/build-steamlink-app.sh from the root of the repository.
- To build from the command line for development use on macOS or Linux, run qmake6 moonlight-qt.pro then make debug or make release.
  - The final binary will be placed in app/moonlight.
- To create an embedded build for a single-purpose device, use qmake6 "CONFIG+=embedded" moonlight-qt.pro and build normally.
  - This build will lack windowed mode, Discord/Help links, and other features that don't make sense on an embedded device.
  - For platforms with poor GPU performance, add "CONFIG+=gpuslow" to prefer direct KMSDRM rendering over GL/Vulkan renderers. Direct KMSDRM rendering can use dedicated YUV/RGB conversion and scaling hardware rather than slower GPU shaders for these operations.

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