Version 0.3.0

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,31 @@
+---
+name: Bug report
+about: Create a report to help us address broken functionality
+
+---
+
+**Describe the bug**
+A clear and concise description of what the bug is.
+
+**Steps to reproduce**
+Any special steps that are required for the bug to appear.
+
+**Screenshots**
+If applicable, add screenshots to help explain your problem. If the issue is related to video glitching or poor quality, please include screenshots.
+
+**Moonlight settings (please complete the following information)**
+- Have any settings been adjusted from defaults?
+- If so, which settings have been changed?
+- Does the problem still occur after reverting settings back to default?
+
+**Client PC details (please complete the following information)**
+ - OS: [e.g. Windows 10 1803]
+ - Moonlight Version: [e.g. v0.2.0]
+
+**Logs (please attach)**
+- On Windows, `Moonlight-###.log` files can be found in `%TEMP%`. Simply type that into the File Explorer path field to navigate there.
+- On macOS, `Moonlight-###.log` files can be found in `/tmp`. In Finder, press Cmd+Shift+G, then type `/tmp` to navigate there.
+- On Linux, logs print to the terminal when running via `flatpak run com.moonlight_stream.Moonlight`
+
+**Additional context**
+Add any other context about the problem here.

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,17 @@
+---
+name: Feature request
+about: Suggest an idea for this project
+
+---
+
+**Is your feature request related to a problem? Please describe.**
+A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
+
+**Describe the solution you'd like**
+A clear and concise description of what you want to happen.
+
+**Describe alternatives you've considered**
+A clear and concise description of any alternative solutions or features you've considered.
+
+**Additional context**
+Add any other context or screenshots about the feature request here.

app/Info.plist

@@ -23,9 +23,9 @@
 	<key>NSSupportsAutomaticGraphicsSwitching</key>
 	<true/>
 	<key>CFBundleVersion</key>
-	<string>0.2.0</string>
+	<string>0.3.0</string>
 	<key>CFBundleShortVersionString</key>
-	<string>0.2.0</string>
+	<string>0.3.0</string>
 	<key>CFBundleDisplayName</key>
 	<string>Moonlight</string>
 </dict>

app/Moonlight.exe.manifest

@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<assembly xmlns="urn:schemas-microsoft-com:asm.v1" xmlns:asmv3="urn:schemas-microsoft-com:asm.v3" manifestVersion="1.0">
+    <trustInfo xmlns="urn:schemas-microsoft-com:asm.v3">
+        <security>
+            <requestedPrivileges>
+                <requestedExecutionLevel level="asInvoker" uiAccess="false" />
+            </requestedPrivileges>
+        </security>
+    </trustInfo>
+    <description>Moonlight Game Streaming</description>
+    <asmv3:application>
+        <asmv3:windowsSettings>
+            <dpiAware xmlns="http://schemas.microsoft.com/SMI/2005/WindowsSettings">true/pm</dpiAware>
+            <dpiAwareness xmlns="http://schemas.microsoft.com/SMI/2016/WindowsSettings">permonitor</dpiAwareness>
+        </asmv3:windowsSettings>
+    </asmv3:application>
+    <compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
+        <application>
+            <!-- Windows 10 -->
+            <supportedOS Id="{8e0f7a12-bfb3-4fe8-b9a5-48fd50a15a9a}"/>
+            <!-- Windows 8.1 -->
+            <supportedOS Id="{1f676c76-80e1-4239-95bb-83d0f6d0da78}"/>
+            <!-- Windows 8 -->
+            <supportedOS Id="{4a2f28e3-53b9-4441-ba9c-d69d4a4a6e38}"/>
+            <!-- Windows 7 -->
+            <supportedOS Id="{35138b9a-5d96-4fbd-8e2d-a2440225f93a}"/>
+            <!-- Windows Vista -->
+            <supportedOS Id="{e2011457-1546-43c5-a5fe-008deee3d3f0}"/>
+        </application> 
+    </compatibility>
+</assembly>

app/app.pro

@@ -34,7 +34,7 @@ win32 {
         LIBS += -L$$PWD/../libs/windows/lib/x64
     }
 
-    LIBS += ws2_32.lib winmm.lib dxva2.lib ole32.lib
+    LIBS += ws2_32.lib winmm.lib dxva2.lib ole32.lib gdi32.lib user32.lib d3d9.lib dwmapi.lib
 }
 macx {
     INCLUDEPATH += $$PWD/../libs/mac/include $$PWD/../libs/mac/Frameworks/SDL2.framework/Versions/A/Headers
@@ -88,7 +88,8 @@ SOURCES += \
     gui/computermodel.cpp \
     gui/appmodel.cpp \
     streaming/streamutils.cpp \
-    backend/autoupdatechecker.cpp
+    backend/autoupdatechecker.cpp \
+    path.cpp
 
 HEADERS += \
     utils.h \
@@ -104,7 +105,8 @@ HEADERS += \
     gui/appmodel.h \
     streaming/video/decoder.h \
     streaming/streamutils.h \
-    backend/autoupdatechecker.h
+    backend/autoupdatechecker.h \
+    path.h
 
 # Platform-specific renderers and decoders
 ffmpeg {
@@ -113,10 +115,16 @@ ffmpeg {
     DEFINES += HAVE_FFMPEG
     SOURCES += \
         streaming/video/ffmpeg.cpp \
-        streaming/video/ffmpeg-renderers/sdl.cpp
+        streaming/video/ffmpeg-renderers/sdl.cpp \
+        streaming/video/ffmpeg-renderers/pacer/pacer.cpp \
+        streaming/video/ffmpeg-renderers/pacer/nullthreadedvsyncsource.cpp
+
+
     HEADERS += \
         streaming/video/ffmpeg.h \
-        streaming/video/ffmpeg-renderers/renderer.h
+        streaming/video/ffmpeg-renderers/renderer.h \
+        streaming/video/ffmpeg-renderers/pacer/pacer.h \
+        streaming/video/ffmpeg-renderers/pacer/nullthreadedvsyncsource.h
 }
 libva {
     message(VAAPI renderer selected)
@@ -156,14 +164,24 @@ config_SLVideo {
 win32 {
     message(DXVA2 renderer selected)
 
-    SOURCES += streaming/video/ffmpeg-renderers/dxva2.cpp
-    HEADERS += streaming/video/ffmpeg-renderers/dxva2.h
+    SOURCES += \
+        streaming/video/ffmpeg-renderers/dxva2.cpp \
+        streaming/video/ffmpeg-renderers/pacer/dxvsyncsource.cpp
+
+    HEADERS += \
+        streaming/video/ffmpeg-renderers/dxva2.h \
+        streaming/video/ffmpeg-renderers/pacer/dxvsyncsource.h
 }
 macx {
     message(VideoToolbox renderer selected)
 
-    SOURCES += streaming/video/ffmpeg-renderers/vt.mm
-    HEADERS += streaming/video/ffmpeg-renderers/vt.h
+    SOURCES += \
+        streaming/video/ffmpeg-renderers/vt.mm \
+        streaming/video/ffmpeg-renderers/pacer/displaylinkvsyncsource.cpp
+
+    HEADERS += \
+        streaming/video/ffmpeg-renderers/vt.h \
+        streaming/video/ffmpeg-renderers/pacer/displaylinkvsyncsource.h
 }
 
 RESOURCES += \
@@ -213,6 +231,8 @@ unix:!macx: {
 }
 win32 {
     RC_ICONS = moonlight.ico
+    CONFIG -= embed_manifest_exe
+    QMAKE_LFLAGS += /MANIFEST:embed /MANIFESTINPUT:$${PWD}/Moonlight.exe.manifest
 }
 macx {
     QMAKE_INFO_PLIST = $$PWD/Info.plist
@@ -222,5 +242,5 @@ macx {
     QMAKE_BUNDLE_DATA += APP_BUNDLE_RESOURCES
 }
 
-VERSION = 0.2.0
-DEFINES += VERSION_STR=\\\"0.2.0\\\"
+VERSION = 0.3.0
+DEFINES += VERSION_STR=\\\"0.3.0\\\"

app/backend/boxartmanager.cpp

@@ -1,13 +1,12 @@
 #include "boxartmanager.h"
+#include "../path.h"
 
-#include <QStandardPaths>
 #include <QImageReader>
 #include <QImageWriter>
 
 BoxArtManager::BoxArtManager(QObject *parent) :
     QObject(parent),
-    m_BoxArtDir(
-        QStandardPaths::writableLocation(QStandardPaths::CacheLocation) + "/boxart")
+    m_BoxArtDir(Path::getBoxArtCacheDir())
 {
     if (!m_BoxArtDir.exists()) {
         m_BoxArtDir.mkpath(".");

app/backend/nvhttp.cpp

@@ -16,6 +16,8 @@
 NvHTTP::NvHTTP(QString address) :
     m_Address(address)
 {
+    Q_ASSERT(!address.isEmpty());
+
     m_BaseUrlHttp.setScheme("http");
     m_BaseUrlHttps.setScheme("https");
     m_BaseUrlHttp.setHost(address);

app/deploy/linux/com.moonlight_stream.Moonlight.appdata.xml

@@ -33,6 +33,15 @@
 	</screenshots>
 
 	<releases>
+		<release version="0.3.0" date="2018-08-21">
+			<description>
+				<p>Bugfixes:</p>
+				<ul>
+					<li>Reduced power consumption when the app is minimized</li>
+					<li>Fixed malformed asset requests being sent when the first host in the grid is offline</li>
+				</ul>
+			</description>
+		</release>
 		<release version="0.2.0" date="2018-08-12">
 			<description>
 				<p>Bugfixes:</p>

app/gui/AppView.qml

@@ -36,15 +36,9 @@ GridView {
 
     onVisibleChanged: {
         if (visible) {
-            // Start polling when this view is shown
-            ComputerManager.startPolling()
-
             appModel.computerLost.connect(computerLost)
         }
         else {
-            // Stop polling when this view is not on top
-            ComputerManager.stopPollingAsync()
-
             appModel.computerLost.disconnect(computerLost)
         }
     }
@@ -106,9 +100,7 @@ GridView {
             }
 
             var component = Qt.createComponent("StreamSegue.qml")
-            var segue = component.createObject(stackView)
-            segue.appName = model.name
-            segue.session = appModel.createSessionForApp(index)
+            var segue = component.createObject(stackView, {"appName": model.name, "session": appModel.createSessionForApp(index)})
             stackView.push(segue)
         }
 
@@ -121,20 +113,19 @@ GridView {
             standardButtons: StandardButton.Yes | StandardButton.No
             onYes: {
                 var component = Qt.createComponent("QuitSegue.qml")
-                var segue = component.createObject(stackView)
-                segue.appName = appName
+                var params = {"appName": appName}
                 if (segueToStream) {
                     // Store the session and app name if we're going to stream after
                     // successfully quitting the old app.
-                    segue.nextAppName = model.name
-                    segue.nextSession = appModel.createSessionForApp(index)
+                    params.nextAppName = model.name
+                    params.nextSession = appModel.createSessionForApp(index)
                 }
                 else {
-                    segue.nextAppName = null
-                    segue.nextSession = null
+                    params.nextAppName = null
+                    params.nextSession = null
                 }
 
-                stackView.push(segue)
+                stackView.push(component.createObject(stackView, params))
 
                 // Trigger the quit after pushing the quit segue on screen
                 appModel.quitRunningApp()

app/gui/PcView.qml

@@ -2,6 +2,7 @@ import QtQuick 2.9
 import QtQuick.Controls 2.2
 import QtQuick.Dialogs 1.3
 import QtQuick.Layouts 1.3
+import QtQuick.Window 2.2
 
 import ComputerModel 1.0
 
@@ -42,25 +43,11 @@ GridView {
         }
     }
 
-    onVisibleChanged: {
-        if (visible) {
-            // Start polling when this view is shown
-            ComputerManager.startPolling()
-        }
-        else {
-            // Stop polling when this view is not top-most
-            ComputerManager.stopPollingAsync()
-        }
-    }
-
     function pairingComplete(error)
     {
         // Close the PIN dialog
         pairDialog.close()
 
-        // Start polling again
-        ComputerManager.startPolling()
-
         // Display a failed dialog if we got an error
         if (error !== null) {
             errorDialog.text = error
@@ -167,18 +154,13 @@ GridView {
                         if (model.paired) {
                             // go to game view
                             var component = Qt.createComponent("AppView.qml")
-                            var appView = component.createObject(stackView)
-                            appView.computerIndex = index
-                            appView.objectName = model.name
+                            var appView = component.createObject(stackView, {"computerIndex": index, "objectName": model.name})
                             stackView.push(appView)
                         }
                         else {
                             if (!model.busy) {
                                 var pin = ("0000" + Math.floor(Math.random() * 10000)).slice(-4)
 
-                                // Stop polling, since pairing may make GFE unresponsive
-                                ComputerManager.stopPollingAsync()
-
                                 // Kick off pairing in the background
                                 computerModel.pairComputer(index, pin)
 

app/gui/QuitSegue.qml

@@ -33,9 +33,7 @@ Item {
         // If we're supposed to launch another game after this, do so now
         if (error === undefined && nextSession !== null) {
             var component = Qt.createComponent("StreamSegue.qml")
-            var segue = component.createObject(stackView)
-            segue.appName = nextAppName
-            segue.session = nextSession
+            var segue = component.createObject(stackView, {"appName": nextAppName, "session": nextSession})
             stackView.push(segue)
         }
     }
@@ -44,16 +42,10 @@ Item {
         if (visible) {
             // Connect the quit completion signal
             ComputerManager.quitAppCompleted.connect(quitAppCompleted)
-
-            // We must be polling or we won't get the quitAppCompleted() callback
-            ComputerManager.startPolling()
         }
         else {
             // Disconnect the signal
             ComputerManager.quitAppCompleted.disconnect(quitAppCompleted)
-
-            // Stop polling when this view is not on top
-            ComputerManager.stopPollingAsync()
         }
     }
 

app/gui/SettingsView.qml

@@ -230,13 +230,26 @@ ScrollView {
                     }
                 }
 
-                CheckBox {
-                    id: fullScreenCheck
-                    text: "<font color=\"white\">Full-screen</font>"
-                    font.pointSize:  12
-                    checked: prefs.fullScreen
-                    onCheckedChanged: {
-                        prefs.fullScreen = checked
+                Row {
+                    CheckBox {
+                        id: fullScreenCheck
+                        text: "<font color=\"white\">Full-screen</font>"
+                        font.pointSize:  12
+                        checked: prefs.fullScreen
+                        onCheckedChanged: {
+                            prefs.fullScreen = checked
+                        }
+                    }
+
+                    CheckBox {
+                        id: vsyncCheck
+                        text: "<font color=\"white\">Enable V-Sync</font>"
+                        font.pointSize:  12
+                        visible: fullScreenCheck.checked
+                        checked: prefs.enableVsync
+                        onCheckedChanged: {
+                            prefs.enableVsync = checked
+                        }
                     }
                 }
             }

app/gui/main.qml

@@ -1,12 +1,16 @@
 import QtQuick 2.9
 import QtQuick.Controls 2.2
 import QtQuick.Layouts 1.3
+import QtQuick.Window 2.2
 
 import QtQuick.Controls.Material 2.1
 
+import ComputerManager 1.0
 import AutoUpdateChecker 1.0
 
 ApplicationWindow {
+    property bool pollingActive: false
+
     id: window
     visible: true
     width: 1280
@@ -21,6 +25,24 @@ ApplicationWindow {
         anchors.fill: parent
     }
 
+    onVisibilityChanged: {
+        // We don't want to just use 'active' here because that will stop polling if
+        // we lose focus, which might be overzealous for users with multiple screens
+        // where we may be clearly visible on the other display. Ideally we'll poll
+        // only if the window is visible to the user (not if obscured by other windows),
+        // but it seems difficult to do this portably.
+        var shouldPoll = visibility !== Window.Minimized && visibility !== Window.Hidden
+
+        if (shouldPoll && !pollingActive) {
+            ComputerManager.startPolling()
+            pollingActive = true
+        }
+        else if (!shouldPoll && pollingActive) {
+            ComputerManager.stopPollingAsync()
+            pollingActive = false
+        }
+    }
+
     function navigateTo(url, objectName)
     {
         var existingItem = stackView.find(function(item, index) {

app/main.cpp

@@ -11,6 +11,7 @@
 #define SDL_MAIN_HANDLED
 #include <SDL.h>
 
+#include "path.h"
 #include "gui/computermodel.h"
 #include "gui/appmodel.h"
 #include "backend/autoupdatechecker.h"
@@ -130,15 +131,23 @@ void qtLogToDiskHandler(QtMsgType type, const QMessageLogContext&, const QString
 
 int main(int argc, char *argv[])
 {
+    if (QFile(QDir::currentPath() + "/portable.dat").exists()) {
+        qInfo() << "Running in portable mode from:" << QDir::currentPath();
+        QSettings::setDefaultFormat(QSettings::IniFormat);
+        QSettings::setPath(QSettings::IniFormat, QSettings::UserScope, QDir::currentPath());
+        QSettings::setPath(QSettings::IniFormat, QSettings::SystemScope, QDir::currentPath());
+
+        // Initialize paths for portable mode
+        Path::initialize(true);
+    }
+    else {
+        // Initialize paths for standard installation
+        Path::initialize(false);
+    }
+
 #ifdef USE_CUSTOM_LOGGER
 #ifdef LOG_TO_FILE
-#ifdef Q_OS_DARWIN
-    // On macOS, $TMPDIR is some random folder under /var/folders/ that nobody can
-    // easily find, so use the system's global tmp directory instead.
-    QDir tempDir("/tmp");
-#else
-    QDir tempDir(QDir::tempPath());
-#endif
+    QDir tempDir(Path::getLogDir());
     s_LoggerFile = new QFile(tempDir.filePath(QString("Moonlight-%1.log").arg(QDateTime::currentSecsSinceEpoch())));
     if (s_LoggerFile->open(QIODevice::WriteOnly)) {
         qInfo() << "Redirecting log output to " << s_LoggerFile->fileName();
@@ -200,6 +209,11 @@ int main(int argc, char *argv[])
                      SDL_GetError());
     }
 
+    // Avoid the default behavior of changing the timer resolution to 1 ms.
+    // We don't want this all the time that Moonlight is open. We will set
+    // it manually when we start streaming.
+    SDL_SetHint(SDL_HINT_TIMER_RESOLUTION, "0");
+
     int err = app.exec();
 
     SDL_Quit();

app/path.cpp

@@ -0,0 +1,39 @@
+#include "path.h"
+
+#include <QtDebug>
+#include <QDir>
+#include <QStandardPaths>
+#include <QSettings>
+
+QString Path::s_LogDir;
+QString Path::s_BoxArtCacheDir;
+
+QString Path::getLogDir()
+{
+    Q_ASSERT(!s_LogDir.isEmpty());
+    return s_LogDir;
+}
+
+QString Path::getBoxArtCacheDir()
+{
+    Q_ASSERT(!s_BoxArtCacheDir.isEmpty());
+    return s_BoxArtCacheDir;
+}
+
+void Path::initialize(bool portable)
+{
+    if (portable) {
+        s_LogDir = QDir::currentPath();
+        s_BoxArtCacheDir = QDir::currentPath() + "/boxart";
+    }
+    else {
+#ifdef Q_OS_DARWIN
+        // On macOS, $TMPDIR is some random folder under /var/folders/ that nobody can
+        // easily find, so use the system's global tmp directory instead.
+        s_LogDir = "/tmp";
+#else
+        s_LogDir = QDir::tempPath();
+#endif
+        s_BoxArtCacheDir = QStandardPaths::writableLocation(QStandardPaths::CacheLocation) + "/boxart";
+    }
+}

app/path.h

@@ -0,0 +1,17 @@
+#pragma once
+
+#include <QString>
+
+class Path
+{
+public:
+    static QString getLogDir();
+
+    static QString getBoxArtCacheDir();
+
+    static void initialize(bool portable);
+
+private:
+    static QString s_LogDir;
+    static QString s_BoxArtCacheDir;
+};

app/settings/streamingpreferences.cpp

@@ -9,6 +9,7 @@
 #define SER_FPS "fps"
 #define SER_BITRATE "bitrate"
 #define SER_FULLSCREEN "fullscreen"
+#define SER_VSYNC "vsync"
 #define SER_GAMEOPTS "gameopts"
 #define SER_HOSTAUDIO "hostaudio"
 #define SER_MULTICONT "multicontroller"
@@ -30,6 +31,7 @@ void StreamingPreferences::reload()
     fps = settings.value(SER_FPS, 60).toInt();
     bitrateKbps = settings.value(SER_BITRATE, getDefaultBitrate(width, height, fps)).toInt();
     fullScreen = settings.value(SER_FULLSCREEN, true).toBool();
+    enableVsync = settings.value(SER_VSYNC, true).toBool();
     gameOptimizations = settings.value(SER_GAMEOPTS, true).toBool();
     playAudioOnHost = settings.value(SER_HOSTAUDIO, false).toBool();
     multiController = settings.value(SER_MULTICONT, true).toBool();
@@ -50,6 +52,7 @@ void StreamingPreferences::save()
     settings.setValue(SER_FPS, fps);
     settings.setValue(SER_BITRATE, bitrateKbps);
     settings.setValue(SER_FULLSCREEN, fullScreen);
+    settings.setValue(SER_VSYNC, enableVsync);
     settings.setValue(SER_GAMEOPTS, gameOptimizations);
     settings.setValue(SER_HOSTAUDIO, playAudioOnHost);
     settings.setValue(SER_MULTICONT, multiController);

app/settings/streamingpreferences.h

@@ -55,6 +55,7 @@ public:
     Q_PROPERTY(int fps MEMBER fps NOTIFY displayModeChanged)
     Q_PROPERTY(int bitrateKbps MEMBER bitrateKbps NOTIFY bitrateChanged)
     Q_PROPERTY(bool fullScreen MEMBER fullScreen NOTIFY fullScreenChanged)
+    Q_PROPERTY(bool enableVsync MEMBER enableVsync NOTIFY enableVsyncChanged)
     Q_PROPERTY(bool gameOptimizations MEMBER gameOptimizations NOTIFY gameOptimizationsChanged)
     Q_PROPERTY(bool playAudioOnHost MEMBER playAudioOnHost NOTIFY playAudioOnHostChanged)
     Q_PROPERTY(bool multiController MEMBER multiController NOTIFY multiControllerChanged)
@@ -68,6 +69,7 @@ public:
     int fps;
     int bitrateKbps;
     bool fullScreen;
+    bool enableVsync;
     bool gameOptimizations;
     bool playAudioOnHost;
     bool multiController;
@@ -79,6 +81,7 @@ signals:
     void displayModeChanged();
     void bitrateChanged();
     void fullScreenChanged();
+    void enableVsyncChanged();
     void gameOptimizationsChanged();
     void playAudioOnHostChanged();
     void multiControllerChanged();

app/streaming/audio.cpp

@@ -182,8 +182,13 @@ void Session::sdlAudioDecodeAndPlaySample(char* sampleData, int sampleLength)
     Uint32 queuedAudio = qMax((int)SDL_GetQueuedAudioSize(s_AudioDevice) - (int)s_BaselinePendingData, 0);
     Uint32 framesQueued = queuedAudio / (SAMPLES_PER_FRAME * s_ChannelCount * sizeof(short));
 
+    // We must check this prior to the below checks to ensure we don't
+    // underflow if framesQueued - s_PendingHardDrops < 0.
+    if (framesQueued <= MIN_QUEUED_FRAMES) {
+        s_PendingDrops = s_PendingHardDrops = 0;
+    }
     // Pend enough drops to get us back to MIN_QUEUED_FRAMES
-    if (framesQueued - s_PendingHardDrops > STOP_THE_WORLD_LIMIT) {
+    else if (framesQueued - s_PendingHardDrops > STOP_THE_WORLD_LIMIT) {
         s_PendingHardDrops = framesQueued - MIN_QUEUED_FRAMES;
         SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
                     "Pending hard drop of %u audio frames",
@@ -194,10 +199,7 @@ void Session::sdlAudioDecodeAndPlaySample(char* sampleData, int sampleLength)
     }
 
     // Determine if this frame should be dropped
-    if (framesQueued <= MIN_QUEUED_FRAMES) {
-        s_PendingDrops = s_PendingHardDrops = 0;
-    }
-    else if (s_PendingHardDrops != 0) {
+    if (s_PendingHardDrops != 0) {
         // Hard drops happen all at once to forcefully
         // resync with the source.
         s_PendingHardDrops--;

app/streaming/session.cpp

@@ -5,6 +5,12 @@
 #include <SDL.h>
 #include "utils.h"
 
+// HACK: Need to call SetThreadExecutionState() because SDL doesn't
+#ifdef Q_OS_WIN32
+#define WIN32_LEAN_AND_MEAN
+#include <Windows.h>
+#endif
+
 #ifdef HAVE_FFMPEG
 #include "video/ffmpeg.h"
 #endif
@@ -13,10 +19,8 @@
 #include "video/sl.h"
 #endif
 
-#if defined(Q_OS_WIN32) || defined(Q_OS_DARWIN)
-// Using full-screen desktop allows us to avoid needing to enable V-sync on Windows
-// and it also avoids some strange flickering issues on my Win7 test machine
-// with Intel HD 5500 graphics. It also allows Spaces to work on macOS.
+#if defined(Q_OS_DARWIN)
+// Using full-screen desktop allows allows Spaces to work on macOS.
 #define SDL_OS_FULLSCREEN_FLAG SDL_WINDOW_FULLSCREEN_DESKTOP
 #else
 #define SDL_OS_FULLSCREEN_FLAG SDL_WINDOW_FULLSCREEN
@@ -106,7 +110,7 @@ void Session::clLogMessage(const char* format, ...)
 
 bool Session::chooseDecoder(StreamingPreferences::VideoDecoderSelection vds,
                             SDL_Window* window, int videoFormat, int width, int height,
-                            int frameRate, IVideoDecoder*& chosenDecoder)
+                            int frameRate, bool enableVsync, IVideoDecoder*& chosenDecoder)
 {
 #ifdef HAVE_SLVIDEO
     chosenDecoder = new SLVideoDecoder();
@@ -125,7 +129,7 @@ bool Session::chooseDecoder(StreamingPreferences::VideoDecoderSelection vds,
 
 #ifdef HAVE_FFMPEG
     chosenDecoder = new FFmpegVideoDecoder();
-    if (chosenDecoder->initialize(vds, window, videoFormat, width, height, frameRate)) {
+    if (chosenDecoder->initialize(vds, window, videoFormat, width, height, frameRate, enableVsync)) {
         SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
                     "FFmpeg-based video decoder chosen");
         return true;
@@ -212,7 +216,7 @@ bool Session::isHardwareDecodeAvailable(StreamingPreferences::VideoDecoderSelect
         return false;
     }
 
-    if (!chooseDecoder(vds, window, videoFormat, width, height, frameRate, decoder)) {
+    if (!chooseDecoder(vds, window, videoFormat, width, height, frameRate, true, decoder)) {
         SDL_DestroyWindow(window);
         SDL_QuitSubSystem(SDL_INIT_VIDEO);
         return false;
@@ -471,10 +475,14 @@ void Session::getWindowDimensions(bool fullScreen,
 {
     int displayIndex = 0;
 
+    if (m_Window != nullptr) {
+        displayIndex = SDL_GetWindowDisplayIndex(m_Window);
+        SDL_assert(displayIndex >= 0);
+    }
     // If there's a display matching this exact resolution, pick that
     // one (for native full-screen streaming). Otherwise, assume
     // display 0 for now. TODO: Default to the screen that the Qt window is on
-    if (fullScreen) {
+    else if (fullScreen) {
         for (int i = 0; i < SDL_GetNumVideoDisplays(); i++) {
             SDL_DisplayMode mode;
             if (SDL_GetCurrentDisplayMode(i, &mode) == 0 &&
@@ -489,79 +497,44 @@ void Session::getWindowDimensions(bool fullScreen,
         }
     }
 
-    if (m_Window != nullptr) {
-        displayIndex = SDL_GetWindowDisplayIndex(m_Window);
-        if (displayIndex < 0) {
-            SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
-                         "SDL_GetWindowDisplayIndex() failed: %s",
-                         SDL_GetError());
+    SDL_Rect usableBounds;
+    if (SDL_GetDisplayUsableBounds(displayIndex, &usableBounds) == 0) {
+        width = usableBounds.w;
+        height = usableBounds.h;
+        x = usableBounds.x;
+        y = usableBounds.y;
 
-            // Assume display 0
-            displayIndex = 0;
-        }
-    }
+        if (m_Window != nullptr) {
+            int top, left, bottom, right;
 
-    if (fullScreen) {
-        SDL_DisplayMode currentMode;
+            if (SDL_GetWindowBordersSize(m_Window, &top, &left, &bottom, &right) < 0) {
+                SDL_LogWarn(SDL_LOG_CATEGORY_APPLICATION,
+                            "Unable to get window border size");
+                return;
+            }
 
-        if (SDL_GetCurrentDisplayMode(displayIndex, &currentMode) == 0) {
-            SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
-                        "Using current display mode: %dx%dx%d",
-                        currentMode.w, currentMode.h, currentMode.refresh_rate);
-            width = currentMode.w;
-            height = currentMode.h;
-        }
-        else {
-            SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
-                         "Unable to get current display mode: %s",
-                         SDL_GetError());
-            width = m_StreamConfig.width;
-            height = m_StreamConfig.height;
-        }
+            x += left;
+            y += top;
 
-        // Full-screen modes always start at the origin
-        x = y = SDL_WINDOWPOS_UNDEFINED_DISPLAY(displayIndex);
-    }
-    else {
-        SDL_Rect usableBounds;
-        if (SDL_GetDisplayUsableBounds(displayIndex, &usableBounds) == 0) {
-            width = usableBounds.w;
-            height = usableBounds.h;
-            x = usableBounds.x;
-            y = usableBounds.y;
+            width -= left + right;
+            height -= top + bottom;
 
-            if (m_Window != nullptr) {
-                int top, left, bottom, right;
-
-                if (SDL_GetWindowBordersSize(m_Window, &top, &left, &bottom, &right) < 0) {
-                    SDL_LogWarn(SDL_LOG_CATEGORY_APPLICATION,
-                                "Unable to get window border size");
-                    return;
-                }
-
-                x += left;
-                y += top;
-
-                width -= left + right;
-                height -= top + bottom;
-
-                // If the stream window can fit within the usable drawing area with 1:1
-                // scaling, do that rather than filling the screen.
-                if (m_StreamConfig.width < width && m_StreamConfig.height < height) {
-                    width = m_StreamConfig.width;
-                    height = m_StreamConfig.height;
-                }
+            // If the stream window can fit within the usable drawing area with 1:1
+            // scaling, do that rather than filling the screen.
+            if (m_StreamConfig.width < width && m_StreamConfig.height < height) {
+                width = m_StreamConfig.width;
+                height = m_StreamConfig.height;
             }
         }
-        else {
-            SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
-                         "SDL_GetDisplayUsableBounds() failed: %s",
-                         SDL_GetError());
+    }
+    else {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                     "SDL_GetDisplayUsableBounds() failed: %s",
+                     SDL_GetError());
 
-            width = m_StreamConfig.width;
-            height = m_StreamConfig.height;
-            x = y = SDL_WINDOWPOS_UNDEFINED_DISPLAY(displayIndex);
-        }
+        width = m_StreamConfig.width;
+        height = m_StreamConfig.height;
+        x = y = SDL_WINDOWPOS_UNDEFINED_DISPLAY(displayIndex);
     }
 }
 
@@ -676,8 +649,8 @@ void Session::exec()
     if (err != 0) {
         // We already displayed an error dialog in the stage failure
         // listener.
-        s_ActiveSessionSemaphore.release();
         SDL_QuitSubSystem(SDL_INIT_VIDEO);
+        s_ActiveSessionSemaphore.release();
         return;
     }
 
@@ -694,14 +667,13 @@ void Session::exec()
                                 y,
                                 width,
                                 height,
-                                m_Preferences.fullScreen ?
-                                    SDL_OS_FULLSCREEN_FLAG : 0);
+                                0);
     if (!m_Window) {
         SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                      "SDL_CreateWindow() failed: %s",
                      SDL_GetError());
-        s_ActiveSessionSemaphore.release();
         SDL_QuitSubSystem(SDL_INIT_VIDEO);
+        s_ActiveSessionSemaphore.release();
         return;
     }
 
@@ -718,6 +690,16 @@ void Session::exec()
         // creation causes our window to be full screen for some reason
         SDL_SetWindowResizable(m_Window, SDL_TRUE);
     }
+    else {
+        // Update the window display mode based on our current monitor
+        SDL_DisplayMode mode;
+        if (SDL_GetDesktopDisplayMode(SDL_GetWindowDisplayIndex(m_Window), &mode) == 0) {
+            SDL_SetWindowDisplayMode(m_Window, &mode);
+        }
+
+        // Enter full screen
+        SDL_SetWindowFullscreen(m_Window, SDL_OS_FULLSCREEN_FLAG);
+    }
 
     QSvgRenderer svgIconRenderer(QString(":/res/moonlight.svg"));
     QImage svgImage(ICON_SIZE, ICON_SIZE, QImage::Format_RGBA8888);
@@ -756,6 +738,17 @@ void Session::exec()
     // Disable the screen saver
     SDL_DisableScreenSaver();
 
+#ifdef Q_OS_WIN32
+    // HACK: SDL doesn't call this, so we must do so to disable the
+    // screensaver when we're in windowed mode. DirectX will disable
+    // it for us when we're in full-screen exclusive mode.
+    SetThreadExecutionState(ES_CONTINUOUS | ES_DISPLAY_REQUIRED);
+#endif
+
+    // Set timer resolution to 1 ms on Windows for greater
+    // sleep precision and more accurate callback timing.
+    SDL_SetHint(SDL_HINT_TIMER_RESOLUTION, "1");
+
     // Raise the priority of the main thread, since it handles
     // time-sensitive video rendering
     if (SDL_SetThreadPriority(SDL_THREAD_PRIORITY_HIGH) < 0) {
@@ -812,16 +805,36 @@ void Session::exec()
             // Fall through
         case SDL_RENDER_DEVICE_RESET:
         case SDL_RENDER_TARGETS_RESET:
+
             SDL_AtomicLock(&m_DecoderLock);
 
             // Destroy the old decoder
             delete m_VideoDecoder;
 
-            // Chose a new decoder (hopefully the same one, but possibly
+            // Flush any other pending window events that could
+            // send us back here immediately
+            SDL_PumpEvents();
+            SDL_FlushEvent(SDL_WINDOWEVENT);
+
+            // Update the window display mode based on our current monitor
+            SDL_DisplayMode mode;
+            if (SDL_GetDesktopDisplayMode(SDL_GetWindowDisplayIndex(m_Window), &mode) == 0) {
+                SDL_SetWindowDisplayMode(m_Window, &mode);
+            }
+
+            // Now that the old decoder is dead, flush any events it may
+            // have queued to reset itself (if this reset was the result
+            // of state loss).
+            SDL_PumpEvents();
+            SDL_FlushEvent(SDL_RENDER_DEVICE_RESET);
+            SDL_FlushEvent(SDL_RENDER_TARGETS_RESET);
+
+            // Choose a new decoder (hopefully the same one, but possibly
             // not if a GPU was removed or something).
             if (!chooseDecoder(m_Preferences.videoDecoderSelection,
                                m_Window, m_ActiveVideoFormat, m_ActiveVideoWidth,
                                m_ActiveVideoHeight, m_ActiveVideoFrameRate,
+                               m_Preferences.enableVsync,
                                s_ActiveSession->m_VideoDecoder)) {
                 SDL_AtomicUnlock(&m_DecoderLock);
                 SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
@@ -869,10 +882,16 @@ void Session::exec()
                  SDL_GetError());
 
 DispatchDeferredCleanup:
+#ifdef Q_OS_WIN32
+    // HACK: See comment above
+    SetThreadExecutionState(ES_CONTINUOUS);
+#endif
+
     // Uncapture the mouse and hide the window immediately,
     // so we can return to the Qt GUI ASAP.
     SDL_SetRelativeMouseMode(SDL_FALSE);
     SDL_EnableScreenSaver();
+    SDL_SetHint(SDL_HINT_TIMER_RESOLUTION, "0");
 
     // Destroy the decoder, since this must be done on the main thread
     SDL_AtomicLock(&m_DecoderLock);

app/streaming/session.hpp

@@ -54,7 +54,7 @@ private:
     static
     bool chooseDecoder(StreamingPreferences::VideoDecoderSelection vds,
                        SDL_Window* window, int videoFormat, int width, int height,
-                       int frameRate, IVideoDecoder*& chosenDecoder);
+                       int frameRate, bool enableVsync, IVideoDecoder*& chosenDecoder);
 
     static
     void clStageStarting(int stage);

app/streaming/video/decoder.h

@@ -16,7 +16,8 @@ public:
                             int videoFormat,
                             int width,
                             int height,
-                            int frameRate) = 0;
+                            int frameRate,
+                            bool enableVsync) = 0;
     virtual bool isHardwareAccelerated() = 0;
     virtual int submitDecodeUnit(PDECODE_UNIT du) = 0;
     virtual void renderFrame(SDL_UserEvent* event) = 0;

app/streaming/video/ffmpeg-renderers/dxva2.cpp

@@ -3,6 +3,13 @@
 #include "../ffmpeg.h"
 #include <streaming/streamutils.h>
 
+#include <SDL_syswm.h>
+
+#define WIN32_LEAN_AND_MEAN
+#include <Windows.h>
+#include <VersionHelpers.h>
+#include <dwmapi.h>
+
 #include <Limelight.h>
 
 DEFINE_GUID(DXVADDI_Intel_ModeH264_E, 0x604F8E68,0x4951,0x4C54,0x88,0xFE,0xAB,0xD2,0x5C,0x15,0xB3,0xD6);
@@ -10,7 +17,6 @@ DEFINE_GUID(DXVADDI_Intel_ModeH264_E, 0x604F8E68,0x4951,0x4C54,0x88,0xFE,0xAB,0x
 #define SAFE_COM_RELEASE(x) if (x) { (x)->Release(); }
 
 DXVA2Renderer::DXVA2Renderer() :
-    m_SdlRenderer(nullptr),
     m_DecService(nullptr),
     m_Decoder(nullptr),
     m_SurfacesUsed(0),
@@ -23,10 +29,15 @@ DXVA2Renderer::DXVA2Renderer() :
 {
     RtlZeroMemory(m_DecSurfaces, sizeof(m_DecSurfaces));
     RtlZeroMemory(&m_DXVAContext, sizeof(m_DXVAContext));
+
+    // Use MMCSS scheduling for lower scheduling latency while we're streaming
+    DwmEnableMMCSS(TRUE);
 }
 
 DXVA2Renderer::~DXVA2Renderer()
 {
+    DwmEnableMMCSS(FALSE);
+
     SAFE_COM_RELEASE(m_DecService);
     SAFE_COM_RELEASE(m_Decoder);
     SAFE_COM_RELEASE(m_Device);
@@ -41,10 +52,6 @@ DXVA2Renderer::~DXVA2Renderer()
     if (m_Pool != nullptr) {
         av_buffer_pool_uninit(&m_Pool);
     }
-
-    if (m_SdlRenderer != nullptr) {
-        SDL_DestroyRenderer(m_SdlRenderer);
-    }
 }
 
 void DXVA2Renderer::ffPoolDummyDelete(void*, uint8_t*)
@@ -430,34 +437,136 @@ bool DXVA2Renderer::isDecoderBlacklisted()
     return result;
 }
 
-bool DXVA2Renderer::initialize(SDL_Window* window, int videoFormat, int width, int height)
+bool DXVA2Renderer::initializeDevice(SDL_Window* window, bool enableVsync)
+{
+    SDL_SysWMinfo info;
+
+    SDL_VERSION(&info.version);
+    SDL_GetWindowWMInfo(window, &info);
+
+    IDirect3D9Ex* d3d9ex;
+    HRESULT hr = Direct3DCreate9Ex(D3D_SDK_VERSION, &d3d9ex);
+    if (FAILED(hr)) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                     "Direct3DCreate9Ex() failed: %x",
+                     hr);
+        return false;
+    }
+
+    int adapterIndex = SDL_Direct3D9GetAdapterIndex(SDL_GetWindowDisplayIndex(window));
+    Uint32 windowFlags = SDL_GetWindowFlags(window);
+
+    D3DCAPS9 deviceCaps;
+    d3d9ex->GetDeviceCaps(adapterIndex, D3DDEVTYPE_HAL, &deviceCaps);
+
+    D3DDISPLAYMODEEX currentMode;
+    currentMode.Size = sizeof(currentMode);
+    d3d9ex->GetAdapterDisplayModeEx(adapterIndex, &currentMode, nullptr);
+
+    D3DPRESENT_PARAMETERS d3dpp = {};
+    d3dpp.hDeviceWindow = info.info.win.window;
+    d3dpp.Flags = D3DPRESENTFLAG_VIDEO;
+    d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
+
+    if ((windowFlags & SDL_WINDOW_FULLSCREEN_DESKTOP) == SDL_WINDOW_FULLSCREEN) {
+        d3dpp.Windowed = false;
+        d3dpp.BackBufferWidth = currentMode.Width;
+        d3dpp.BackBufferHeight = currentMode.Height;
+        d3dpp.FullScreen_RefreshRateInHz = currentMode.RefreshRate;
+        d3dpp.BackBufferFormat = currentMode.Format;
+    }
+    else {
+        d3dpp.Windowed = true;
+        d3dpp.BackBufferFormat = D3DFMT_UNKNOWN;
+
+        SDL_GetWindowSize(window, (int*)&d3dpp.BackBufferWidth, (int*)&d3dpp.BackBufferHeight);
+    }
+
+    BOOL dwmEnabled;
+    DwmIsCompositionEnabled(&dwmEnabled);
+    if (d3dpp.Windowed && dwmEnabled) {
+        // If composition enabled, disable v-sync and let DWM manage things
+        // to reduce latency by avoiding double v-syncing.
+        d3dpp.PresentationInterval = D3DPRESENT_INTERVAL_IMMEDIATE;
+
+        // D3DSWAPEFFECT_FLIPEX requires at least 2 back buffers to allow us to
+        // continue while DWM is waiting to render the surface to the display.
+        d3dpp.SwapEffect = D3DSWAPEFFECT_FLIPEX;
+        d3dpp.BackBufferCount = 2;
+
+        SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
+                    "Windowed mode with DWM running");
+    }
+    else if (enableVsync) {
+        // Uncomposited desktop or full-screen exclusive mode with V-sync enabled
+        // We will enable V-sync in this scenario to avoid tearing.
+        d3dpp.PresentationInterval = D3DPRESENT_INTERVAL_ONE;
+        d3dpp.BackBufferCount = 1;
+
+        SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
+                    "V-Sync enabled");
+    }
+    else {
+        // Uncomposited desktop or full-screen exclusive mode with V-sync disabled
+        // We will allowing tearing for lowest latency.
+        d3dpp.PresentationInterval = D3DPRESENT_INTERVAL_IMMEDIATE;
+        d3dpp.BackBufferCount = 1;
+
+        SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
+                    "V-Sync disabled in tearing mode");
+    }
+
+    SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
+                "Windowed: %d | Present Interval: %x",
+                d3dpp.Windowed, d3dpp.PresentationInterval);
+
+    // FFmpeg requires this attribute for doing asynchronous decoding
+    // in a separate thread with this device.
+    int deviceFlags = D3DCREATE_MULTITHREADED;
+
+    if (deviceCaps.DevCaps & D3DDEVCAPS_HWTRANSFORMANDLIGHT) {
+        deviceFlags |= D3DCREATE_HARDWARE_VERTEXPROCESSING;
+    }
+    else {
+        SDL_LogWarn(SDL_LOG_CATEGORY_APPLICATION,
+                    "No hardware vertex processing support!");
+        deviceFlags |= D3DCREATE_SOFTWARE_VERTEXPROCESSING;
+    }
+
+    hr = d3d9ex->CreateDeviceEx(adapterIndex,
+                                D3DDEVTYPE_HAL,
+                                d3dpp.hDeviceWindow,
+                                deviceFlags,
+                                &d3dpp,
+                                d3dpp.Windowed ? nullptr : &currentMode,
+                                &m_Device);
+
+    d3d9ex->Release();
+
+    if (FAILED(hr)) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                     "CreateDeviceEx() failed: %x",
+                     hr);
+        return false;
+    }
+
+    hr = m_Device->SetMaximumFrameLatency(1);
+    if (FAILED(hr)) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                     "SetMaximumFrameLatency() failed: %x",
+                     hr);
+        return false;
+    }
+
+    return true;
+}
+
+bool DXVA2Renderer::initialize(SDL_Window* window, int videoFormat, int width, int height, int, bool enableVsync)
 {
     m_VideoFormat = videoFormat;
     m_VideoWidth = width;
     m_VideoHeight = height;
 
-    // FFmpeg will be decoding on different threads than the main thread that we're
-    // currently running on right now. We must set this hint so SDL will pass
-    // D3DCREATE_MULTITHREADED to IDirect3D9::CreateDevice().
-    SDL_SetHint(SDL_HINT_RENDER_DIRECT3D_THREADSAFE, "1");
-
-    // We require full-screen desktop mode to avoid having to enable V-sync
-    // to synchronize frame delivery (which has a much higher latency penalty).
-    m_SdlRenderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
-    if (!m_SdlRenderer) {
-        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
-                     "SDL_CreateRenderer() failed: %s",
-                     SDL_GetError());
-        return false;
-    }
-
-    m_Device = SDL_RenderGetD3D9Device(m_SdlRenderer);
-
-    // Draw a black frame until the video stream starts rendering
-    SDL_SetRenderDrawColor(m_SdlRenderer, 0, 0, 0, SDL_ALPHA_OPAQUE);
-    SDL_RenderClear(m_SdlRenderer);
-    SDL_RenderPresent(m_SdlRenderer);
-
     RtlZeroMemory(&m_Desc, sizeof(m_Desc));
 
     int alignment;
@@ -481,6 +590,10 @@ bool DXVA2Renderer::initialize(SDL_Window* window, int videoFormat, int width, i
     m_Desc.SampleFormat.SampleFormat = DXVA2_SampleProgressiveFrame;
     m_Desc.Format = (D3DFORMAT)MAKEFOURCC('N','V','1','2');
 
+    if (!initializeDevice(window, enableVsync)) {
+        return false;
+    }
+
     if (!initializeDecoder()) {
         return false;
     }
@@ -489,10 +602,24 @@ bool DXVA2Renderer::initialize(SDL_Window* window, int videoFormat, int width, i
         return false;
     }
 
+    // For some reason, using Direct3D9Ex breaks this with multi-monitor setups.
+    // When focus is lost, the window is minimized then immediately restored without
+    // input focus. This glitches out the renderer and a bunch of other stuff.
+    // Direct3D9Ex itself seems to have this minimize on focus loss behavior on its
+    // own, so just disable SDL's handling of the focus loss event.
+    SDL_SetHint(SDL_HINT_VIDEO_MINIMIZE_ON_FOCUS_LOSS, "0");
+
     return true;
 }
 
-void DXVA2Renderer::renderFrame(AVFrame* frame)
+bool DXVA2Renderer::needsTestFrame()
+{
+    // We validate the DXVA2 profiles are supported
+    // in initialize() so no test frame is required
+    return false;
+}
+
+void DXVA2Renderer::renderFrameAtVsync(AVFrame *frame)
 {
     IDirect3DSurface9* surface = reinterpret_cast<IDirect3DSurface9*>(frame->data[3]);
     HRESULT hr;
@@ -628,33 +755,27 @@ void DXVA2Renderer::renderFrame(AVFrame* frame)
 
     bltParams.Alpha = DXVA2_Fixed32OpaqueAlpha();
 
-    if (SDL_RenderClear(m_SdlRenderer) != 0) {
-        SDL_LogWarn(SDL_LOG_CATEGORY_APPLICATION,
-                    "SDL_RenderClear() failed: %s",
-                    SDL_GetError());
-        av_frame_free(&frame);
-
-        // We're going to cheat a little bit here. It seems SDL's
-        // renderer may flake out in scenarios like moving the window
-        // between monitors, so generate a synthetic reset event for
-        // the main loop to consume.
-        SDL_Event event;
-        event.type = SDL_RENDER_TARGETS_RESET;
-        SDL_PushEvent(&event);
-
-        return;
-    }
+    m_Device->Clear(0, nullptr, D3DCLEAR_TARGET, D3DCOLOR_ARGB(255, 0, 0, 0), 0.0f, 0);
 
     hr = m_Processor->VideoProcessBlt(m_RenderTarget, &bltParams, &sample, 1, nullptr);
-    av_frame_free(&frame);
-
     if (FAILED(hr)) {
         SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                      "VideoProcessBlt() failed: %x",
                      hr);
+        SDL_Event event;
+        event.type = SDL_RENDER_TARGETS_RESET;
+        SDL_PushEvent(&event);
+        return;
     }
 
-    // We must try to present to trigger SDL's logic to recover the render target,
-    // even if VideoProcessBlt() fails.
-    SDL_RenderPresent(m_SdlRenderer);
+    hr = m_Device->PresentEx(nullptr, nullptr, nullptr, nullptr, 0);
+    if (FAILED(hr)) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                     "PresentEx() failed: %x",
+                     hr);
+        SDL_Event event;
+        event.type = SDL_RENDER_TARGETS_RESET;
+        SDL_PushEvent(&event);
+        return;
+    }
 }

app/streaming/video/ffmpeg-renderers/dxva2.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include "renderer.h"
+#include "pacer/pacer.h"
 
 #include <d3d9.h>
 #include <dxva2api.h>
@@ -17,13 +18,17 @@ public:
     virtual bool initialize(SDL_Window* window,
                             int videoFormat,
                             int width,
-                            int height);
+                            int height,
+                            int maxFps,
+                            bool enableVsync);
     virtual bool prepareDecoderContext(AVCodecContext* context);
-    virtual void renderFrame(AVFrame* frame);
+    virtual void renderFrameAtVsync(AVFrame* frame);
+    virtual bool needsTestFrame();
 
 private:
     bool initializeDecoder();
     bool initializeRenderer();
+    bool initializeDevice(SDL_Window* window, bool enableVsync);
     bool isDecoderBlacklisted();
 
     static
@@ -42,8 +47,6 @@ private:
     int m_DisplayWidth;
     int m_DisplayHeight;
 
-    SDL_Renderer* m_SdlRenderer;
-
     struct dxva_context m_DXVAContext;
     IDirect3DSurface9* m_DecSurfaces[19];
     DXVA2_ConfigPictureDecode m_Config;
@@ -52,7 +55,7 @@ private:
     int m_SurfacesUsed;
     AVBufferPool* m_Pool;
 
-    IDirect3DDevice9* m_Device;
+    IDirect3DDevice9Ex* m_Device;
     IDirect3DSurface9* m_RenderTarget;
     IDirectXVideoProcessorService* m_ProcService;
     IDirectXVideoProcessor* m_Processor;

app/streaming/video/ffmpeg-renderers/pacer/displaylinkvsyncsource.cpp

@@ -0,0 +1,50 @@
+#include "displaylinkvsyncsource.h"
+
+DisplayLinkVsyncSource::DisplayLinkVsyncSource(Pacer* pacer)
+    : m_Pacer(pacer),
+      m_DisplayLink(nullptr)
+{
+
+}
+
+DisplayLinkVsyncSource::~DisplayLinkVsyncSource()
+{
+    if (m_DisplayLink != nullptr) {
+        CVDisplayLinkStop(m_DisplayLink);
+        CVDisplayLinkRelease(m_DisplayLink);
+    }
+}
+
+CVReturn
+DisplayLinkVsyncSource::displayLinkOutputCallback(
+    CVDisplayLinkRef,
+    const CVTimeStamp* /* now */,
+    const CVTimeStamp* /* vsyncTime */,
+    CVOptionFlags,
+    CVOptionFlags*,
+    void *displayLinkContext)
+{
+    auto me = reinterpret_cast<DisplayLinkVsyncSource*>(displayLinkContext);
+
+    // In my testing on macOS 10.13, this callback is invoked about 24 ms
+    // prior to the specified v-sync time (now - vsyncTime). Since this is
+    // greater than the standard v-sync interval (16 ms = 60 FPS), we will
+    // draw using the current host time, rather than the actual v-sync target
+    // time. Because the CVDisplayLink is in sync with the actual v-sync
+    // interval, even if many ms prior, we can safely use the current host time
+    // and get a consistent callback for each v-sync. This reduces video latency
+    // by at least 1 frame vs. rendering with the actual vsyncTime.
+    me->m_Pacer->vsyncCallback(500 / me->m_DisplayFps);
+
+    return kCVReturnSuccess;
+}
+
+bool DisplayLinkVsyncSource::initialize(SDL_Window*, int displayFps)
+{
+    m_DisplayFps = displayFps;
+
+    CVDisplayLinkCreateWithActiveCGDisplays(&m_DisplayLink);
+    CVDisplayLinkSetOutputCallback(m_DisplayLink, displayLinkOutputCallback, this);
+    CVDisplayLinkStart(m_DisplayLink);
+    return true;
+}

app/streaming/video/ffmpeg-renderers/pacer/displaylinkvsyncsource.h

@@ -0,0 +1,31 @@
+#pragma once
+
+#include <CoreVideo/CoreVideo.h>
+
+#include "pacer.h"
+
+class DisplayLinkVsyncSource : public IVsyncSource
+{
+public:
+    DisplayLinkVsyncSource(Pacer* pacer);
+
+    virtual ~DisplayLinkVsyncSource();
+
+    virtual bool initialize(SDL_Window* window, int displayFps);
+
+private:
+    static
+    CVReturn
+    displayLinkOutputCallback(
+        CVDisplayLinkRef,
+        const CVTimeStamp* now,
+        const CVTimeStamp* /* vsyncTime */,
+        CVOptionFlags,
+        CVOptionFlags*,
+        void *displayLinkContext);
+
+    Pacer* m_Pacer;
+    CVDisplayLinkRef m_DisplayLink;
+    int m_DisplayFps;
+};
+

app/streaming/video/ffmpeg-renderers/pacer/dxvsyncsource.cpp

@@ -0,0 +1,168 @@
+#include "dxvsyncsource.h"
+
+// Useful references:
+// https://bugs.chromium.org/p/chromium/issues/detail?id=467617
+// https://chromium.googlesource.com/chromium/src.git/+/c564f2fe339b2b2abb0c8773c90c83215670ea71/gpu/ipc/service/gpu_vsync_provider_win.cc
+
+DxVsyncSource::DxVsyncSource(Pacer* pacer) :
+    m_Pacer(pacer),
+    m_Thread(nullptr),
+    m_Gdi32Handle(nullptr)
+{
+    SDL_AtomicSet(&m_Stopping, 0);
+}
+
+DxVsyncSource::~DxVsyncSource()
+{
+    if (m_Thread != nullptr) {
+        SDL_AtomicSet(&m_Stopping, 1);
+        SDL_WaitThread(m_Thread, nullptr);
+    }
+
+    if (m_Gdi32Handle != nullptr) {
+        FreeLibrary(m_Gdi32Handle);
+    }
+}
+
+bool DxVsyncSource::initialize(SDL_Window* window, int displayFps)
+{
+    m_DisplayFps = displayFps;
+
+    m_Gdi32Handle = LoadLibraryA("gdi32.dll");
+    if (m_Gdi32Handle == nullptr) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                     "Failed to load gdi32.dll: %d",
+                     GetLastError());
+        return false;
+    }
+
+    m_D3DKMTOpenAdapterFromHdc = (PFND3DKMTOPENADAPTERFROMHDC)GetProcAddress(m_Gdi32Handle, "D3DKMTOpenAdapterFromHdc");
+    m_D3DKMTCloseAdapter = (PFND3DKMTCLOSEADAPTER)GetProcAddress(m_Gdi32Handle, "D3DKMTCloseAdapter");
+    m_D3DKMTWaitForVerticalBlankEvent = (PFND3DKMTWAITFORVERTICALBLANKEVENT)GetProcAddress(m_Gdi32Handle, "D3DKMTWaitForVerticalBlankEvent");
+
+    if (m_D3DKMTOpenAdapterFromHdc == nullptr ||
+            m_D3DKMTCloseAdapter == nullptr ||
+            m_D3DKMTWaitForVerticalBlankEvent == nullptr) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                     "Missing required function in gdi32.dll");
+        return false;
+    }
+
+    SDL_SysWMinfo info;
+
+    SDL_VERSION(&info.version);
+
+    if (!SDL_GetWindowWMInfo(window, &info)) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                     "SDL_GetWindowWMInfo() failed: %s",
+                     SDL_GetError());
+        return false;
+    }
+
+    m_Window = info.info.win.window;
+
+    m_Thread = SDL_CreateThread(vsyncThread, "DX Vsync Thread", this);
+    if (m_Thread == nullptr) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                     "Unable to create DX V-sync thread: %s",
+                     SDL_GetError());
+        return false;
+    }
+
+    return true;
+}
+
+int DxVsyncSource::vsyncThread(void* context)
+{
+    DxVsyncSource* me = reinterpret_cast<DxVsyncSource*>(context);
+
+    SDL_SetThreadPriority(SDL_THREAD_PRIORITY_HIGH);
+
+    D3DKMT_OPENADAPTERFROMHDC openAdapterParams = {};
+    HMONITOR lastMonitor = nullptr;
+    DEVMODEA monitorMode;
+    monitorMode.dmSize = sizeof(monitorMode);
+
+    while (SDL_AtomicGet(&me->m_Stopping) == 0) {
+        D3DKMT_WAITFORVERTICALBLANKEVENT waitForVblankEventParams;
+        NTSTATUS status;
+
+        // If the monitor has changed from last time, open the new adapter
+        HMONITOR currentMonitor = MonitorFromWindow(me->m_Window, MONITOR_DEFAULTTONEAREST);
+        if (currentMonitor != lastMonitor) {
+            MONITORINFOEXA monitorInfo = {};
+            monitorInfo.cbSize = sizeof(monitorInfo);
+            if (!GetMonitorInfoA(currentMonitor, &monitorInfo)) {
+                SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                             "GetMonitorInfo() failed: %d",
+                             GetLastError());
+                SDL_Delay(10);
+                continue;
+            }
+
+            if (!EnumDisplaySettingsA(monitorInfo.szDevice, ENUM_CURRENT_SETTINGS, &monitorMode)) {
+                SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                             "EnumDisplaySettings() failed: %d",
+                             GetLastError());
+                SDL_Delay(10);
+                continue;
+            }
+
+            SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
+                        "Monitor changed: %s %d Hz",
+                        monitorInfo.szDevice,
+                        monitorMode.dmDisplayFrequency);
+
+            if (openAdapterParams.hAdapter != 0) {
+                D3DKMT_CLOSEADAPTER closeAdapterParams = {};
+                closeAdapterParams.hAdapter = openAdapterParams.hAdapter;
+                me->m_D3DKMTCloseAdapter(&closeAdapterParams);
+            }
+
+            openAdapterParams.hDc = CreateDCA(nullptr, monitorInfo.szDevice, nullptr, nullptr);
+            if (!openAdapterParams.hDc) {
+                SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                             "CreateDC() failed: %d",
+                             GetLastError());
+                SDL_Delay(10);
+                continue;
+            }
+
+            status = me->m_D3DKMTOpenAdapterFromHdc(&openAdapterParams);
+            DeleteDC(openAdapterParams.hDc);
+
+            if (status != STATUS_SUCCESS) {
+                SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                             "D3DKMTOpenAdapterFromHdc() failed: %x",
+                             status);
+                SDL_Delay(10);
+                continue;
+            }
+
+            lastMonitor = currentMonitor;
+        }
+
+        waitForVblankEventParams.hAdapter = openAdapterParams.hAdapter;
+        waitForVblankEventParams.hDevice = 0;
+        waitForVblankEventParams.VidPnSourceId = openAdapterParams.VidPnSourceId;
+
+        status = me->m_D3DKMTWaitForVerticalBlankEvent(&waitForVblankEventParams);
+        if (status != STATUS_SUCCESS) {
+            SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                         "D3DKMTWaitForVerticalBlankEvent() failed: %x",
+                         status);
+            SDL_Delay(10);
+            continue;
+        }
+
+        me->m_Pacer->vsyncCallback(1000 / me->m_DisplayFps);
+    }
+
+    if (openAdapterParams.hAdapter != 0) {
+        D3DKMT_CLOSEADAPTER closeAdapterParams = {};
+        closeAdapterParams.hAdapter = openAdapterParams.hAdapter;
+        me->m_D3DKMTCloseAdapter(&closeAdapterParams);
+    }
+
+    return 0;
+}

app/streaming/video/ffmpeg-renderers/pacer/dxvsyncsource.h

@@ -0,0 +1,53 @@
+#pragma once
+
+#include "pacer.h"
+
+#include <SDL_syswm.h>
+
+// from <D3dkmthk.h>
+typedef LONG NTSTATUS;
+typedef UINT D3DKMT_HANDLE;
+typedef UINT D3DDDI_VIDEO_PRESENT_SOURCE_ID;
+#define STATUS_SUCCESS ((NTSTATUS)0x00000000L)
+#define STATUS_GRAPHICS_PRESENT_OCCLUDED ((NTSTATUS)0xC01E0006L)
+typedef struct _D3DKMT_OPENADAPTERFROMHDC {
+  HDC hDc;
+  D3DKMT_HANDLE hAdapter;
+  LUID AdapterLuid;
+  D3DDDI_VIDEO_PRESENT_SOURCE_ID VidPnSourceId;
+} D3DKMT_OPENADAPTERFROMHDC;
+typedef struct _D3DKMT_CLOSEADAPTER {
+  D3DKMT_HANDLE hAdapter;
+} D3DKMT_CLOSEADAPTER;
+typedef struct _D3DKMT_WAITFORVERTICALBLANKEVENT {
+  D3DKMT_HANDLE hAdapter;
+  D3DKMT_HANDLE hDevice;
+  D3DDDI_VIDEO_PRESENT_SOURCE_ID VidPnSourceId;
+} D3DKMT_WAITFORVERTICALBLANKEVENT;
+typedef NTSTATUS(APIENTRY* PFND3DKMTOPENADAPTERFROMHDC)(D3DKMT_OPENADAPTERFROMHDC*);
+typedef NTSTATUS(APIENTRY* PFND3DKMTCLOSEADAPTER)(D3DKMT_CLOSEADAPTER*);
+typedef NTSTATUS(APIENTRY* PFND3DKMTWAITFORVERTICALBLANKEVENT)(D3DKMT_WAITFORVERTICALBLANKEVENT*);
+
+class DxVsyncSource : public IVsyncSource
+{
+public:
+    DxVsyncSource(Pacer* pacer);
+
+    virtual ~DxVsyncSource();
+
+    virtual bool initialize(SDL_Window* window, int displayFps);
+
+private:
+    static int vsyncThread(void* context);
+
+    Pacer* m_Pacer;
+    SDL_Thread* m_Thread;
+    SDL_atomic_t m_Stopping;
+    HMODULE m_Gdi32Handle;
+    HWND m_Window;
+    int m_DisplayFps;
+
+    PFND3DKMTOPENADAPTERFROMHDC m_D3DKMTOpenAdapterFromHdc;
+    PFND3DKMTCLOSEADAPTER m_D3DKMTCloseAdapter;
+    PFND3DKMTWAITFORVERTICALBLANKEVENT m_D3DKMTWaitForVerticalBlankEvent;
+};

app/streaming/video/ffmpeg-renderers/pacer/nullthreadedvsyncsource.cpp

@@ -0,0 +1,43 @@
+#include "nullthreadedvsyncsource.h"
+
+NullThreadedVsyncSource::NullThreadedVsyncSource(Pacer* pacer) :
+    m_Pacer(pacer),
+    m_Thread(nullptr)
+{
+    SDL_AtomicSet(&m_Stopping, 0);
+}
+
+NullThreadedVsyncSource::~NullThreadedVsyncSource()
+{
+    if (m_Thread != nullptr) {
+        SDL_AtomicSet(&m_Stopping, 1);
+        SDL_WaitThread(m_Thread, nullptr);
+    }
+}
+
+bool NullThreadedVsyncSource::initialize(SDL_Window*, int displayFps)
+{
+    m_DisplayFps = displayFps;
+    m_Thread = SDL_CreateThread(vsyncThread, "Null Vsync Thread", this);
+    if (m_Thread == nullptr) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                     "Unable to create DX V-sync thread: %s",
+                     SDL_GetError());
+        return false;
+    }
+
+    return true;
+}
+
+int NullThreadedVsyncSource::vsyncThread(void* context)
+{
+    NullThreadedVsyncSource* me = reinterpret_cast<NullThreadedVsyncSource*>(context);
+
+    SDL_SetThreadPriority(SDL_THREAD_PRIORITY_HIGH);
+
+    while (SDL_AtomicGet(&me->m_Stopping) == 0) {
+        me->m_Pacer->vsyncCallback(1000 / me->m_DisplayFps);
+    }
+
+    return 0;
+}

app/streaming/video/ffmpeg-renderers/pacer/nullthreadedvsyncsource.h

@@ -0,0 +1,21 @@
+#pragma once
+
+#include "pacer.h"
+
+class NullThreadedVsyncSource : public IVsyncSource
+{
+public:
+    NullThreadedVsyncSource(Pacer* pacer);
+
+    virtual ~NullThreadedVsyncSource();
+
+    virtual bool initialize(SDL_Window* window, int displayFps);
+
+private:
+    static int vsyncThread(void* context);
+
+    Pacer* m_Pacer;
+    SDL_Thread* m_Thread;
+    SDL_atomic_t m_Stopping;
+    int m_DisplayFps;
+};

app/streaming/video/ffmpeg-renderers/pacer/pacer.cpp

@@ -0,0 +1,189 @@
+#include "pacer.h"
+
+#include "nullthreadedvsyncsource.h"
+
+#ifdef Q_OS_DARWIN
+#include "displaylinkvsyncsource.h"
+#endif
+
+#ifdef Q_OS_WIN32
+#include "dxvsyncsource.h"
+#endif
+
+#define FRAME_HISTORY_ENTRIES 8
+
+// We may be woken up slightly late so don't go all the way
+// up to the next V-sync since we may accidentally step into
+// the next V-sync period. It also takes some amount of time
+// to do the render itself, so we can't render right before
+// V-sync happens.
+#define TIMER_SLACK_MS 3
+
+Pacer::Pacer(IFFmpegRenderer* renderer) :
+    m_FrameQueueLock(0),
+    m_VsyncSource(nullptr),
+    m_VsyncRenderer(renderer),
+    m_MaxVideoFps(0),
+    m_DisplayFps(0)
+{
+
+}
+
+Pacer::~Pacer()
+{
+    // Stop V-sync callbacks
+    delete m_VsyncSource;
+    m_VsyncSource = nullptr;
+
+    while (!m_FrameQueue.isEmpty()) {
+        AVFrame* frame = m_FrameQueue.dequeue();
+        av_frame_free(&frame);
+    }
+}
+
+// Called in an arbitrary thread by the IVsyncSource on V-sync
+// or an event synchronized with V-sync
+void Pacer::vsyncCallback(int timeUntilNextVsyncMillis)
+{
+    // Make sure initialize() has been called
+    SDL_assert(m_MaxVideoFps != 0);
+
+    SDL_assert(timeUntilNextVsyncMillis >= TIMER_SLACK_MS);
+
+    Uint32 vsyncCallbackStartTime = SDL_GetTicks();
+
+    SDL_AtomicLock(&m_FrameQueueLock);
+
+    // If the queue length history entries are large, be strict
+    // about dropping excess frames.
+    int frameDropTarget = 1;
+
+    // If we may get more frames per second than we can display, use
+    // frame history to drop frames only if consistently above the
+    // one queued frame mark.
+    if (m_MaxVideoFps >= m_DisplayFps) {
+        for (int i = 0; i < m_FrameQueueHistory.count(); i++) {
+            if (m_FrameQueueHistory[i] <= 1) {
+                // Be lenient as long as the queue length
+                // resolves before the end of frame history
+                frameDropTarget = 3;
+                break;
+            }
+        }
+
+        if (m_FrameQueueHistory.count() == FRAME_HISTORY_ENTRIES) {
+            m_FrameQueueHistory.dequeue();
+        }
+
+        m_FrameQueueHistory.enqueue(m_FrameQueue.count());
+    }
+
+    // Catch up if we're several frames ahead
+    while (m_FrameQueue.count() > frameDropTarget) {
+        AVFrame* frame = m_FrameQueue.dequeue();
+        av_frame_free(&frame);
+    }
+
+
+    if (m_FrameQueue.isEmpty()) {
+        SDL_AtomicUnlock(&m_FrameQueueLock);
+
+        while (!SDL_TICKS_PASSED(SDL_GetTicks(),
+                                 vsyncCallbackStartTime + timeUntilNextVsyncMillis - TIMER_SLACK_MS)) {
+            SDL_Delay(1);
+
+            SDL_AtomicLock(&m_FrameQueueLock);
+            if (!m_FrameQueue.isEmpty()) {
+                // Don't release the lock
+                goto RenderNextFrame;
+            }
+            SDL_AtomicUnlock(&m_FrameQueueLock);
+        }
+
+        // Nothing to render at this time
+        return;
+    }
+
+RenderNextFrame:
+    // Grab the first frame
+    AVFrame* frame = m_FrameQueue.dequeue();
+    SDL_AtomicUnlock(&m_FrameQueueLock);
+
+    // Render it
+    m_VsyncRenderer->renderFrameAtVsync(frame);
+
+    // Free the frame
+    av_frame_free(&frame);
+}
+
+bool Pacer::initialize(SDL_Window* window, int maxVideoFps, bool enableVsync)
+{
+    m_MaxVideoFps = maxVideoFps;
+    m_EnableVsync = enableVsync;
+
+    int displayIndex = SDL_GetWindowDisplayIndex(window);
+    if (displayIndex < 0) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                     "Failed to get current display: %s",
+                     SDL_GetError());
+
+        // Assume display 0 if it fails
+        displayIndex = 0;
+    }
+
+    SDL_DisplayMode mode;
+    if (SDL_GetCurrentDisplayMode(displayIndex, &mode) == 0) {
+        // May be zero if undefined
+        m_DisplayFps = mode.refresh_rate;
+    }
+
+    if (m_EnableVsync) {
+        SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
+                    "Frame pacing in tear-free mode: target %d Hz with %d FPS stream",
+                    m_DisplayFps, m_MaxVideoFps);
+
+    #if defined(Q_OS_DARWIN)
+        m_VsyncSource = new DisplayLinkVsyncSource(this);
+    #elif defined(Q_OS_WIN32)
+        m_VsyncSource = new DxVsyncSource(this);
+    #else
+        // Platforms without a VsyncSource will just render frames
+        // immediately like they used to.
+    #endif
+
+        if (m_VsyncSource != nullptr && !m_VsyncSource->initialize(window, m_DisplayFps)) {
+            return false;
+        }
+    }
+    else {
+        SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
+                    "Minimal latency tearing mode: target %d Hz with %d FPS stream",
+                    m_DisplayFps, m_MaxVideoFps);
+    }
+
+    return true;
+}
+
+void Pacer::submitFrame(AVFrame* frame)
+{
+    // Make sure initialize() has been called
+    SDL_assert(m_MaxVideoFps != 0);
+
+    // Queue the frame until the V-sync callback if
+    // we have a V-sync source, otherwise deliver it
+    // immediately and hope for the best.
+    if (isUsingFrameQueue()) {
+        SDL_AtomicLock(&m_FrameQueueLock);
+        m_FrameQueue.enqueue(frame);
+        SDL_AtomicUnlock(&m_FrameQueueLock);
+    }
+    else {
+        m_VsyncRenderer->renderFrameAtVsync(frame);
+        av_frame_free(&frame);
+    }
+}
+
+bool Pacer::isUsingFrameQueue()
+{
+    return m_VsyncSource != nullptr;
+}

app/streaming/video/ffmpeg-renderers/pacer/pacer.h

@@ -0,0 +1,38 @@
+#pragma once
+
+#include "../renderer.h"
+
+#include <QQueue>
+
+class IVsyncSource {
+public:
+    virtual ~IVsyncSource() {}
+    virtual bool initialize(SDL_Window* window, int displayFps) = 0;
+};
+
+class Pacer
+{
+public:
+    Pacer(IFFmpegRenderer* renderer);
+
+    ~Pacer();
+
+    void submitFrame(AVFrame* frame);
+
+    bool initialize(SDL_Window* window, int maxVideoFps, bool enableVsync);
+
+    void vsyncCallback(int timeUntilNextVsyncMillis);
+
+    bool isUsingFrameQueue();
+
+private:
+    QQueue<AVFrame*> m_FrameQueue;
+    QQueue<int> m_FrameQueueHistory;
+    SDL_SpinLock m_FrameQueueLock;
+
+    IVsyncSource* m_VsyncSource;
+    IFFmpegRenderer* m_VsyncRenderer;
+    int m_MaxVideoFps;
+    int m_DisplayFps;
+    bool m_EnableVsync;
+};

app/streaming/video/ffmpeg-renderers/renderer.h

@@ -12,9 +12,12 @@ public:
     virtual bool initialize(SDL_Window* window,
                             int videoFormat,
                             int width,
-                            int height) = 0;
+                            int height,
+                            int maxFps,
+                            bool enableVsync) = 0;
     virtual bool prepareDecoderContext(AVCodecContext* context) = 0;
-    virtual void renderFrame(AVFrame* frame) = 0;
+    virtual void renderFrameAtVsync(AVFrame* frame) = 0;
+    virtual bool needsTestFrame() = 0;
 };
 
 class SdlRenderer : public IFFmpegRenderer {
@@ -24,9 +27,12 @@ public:
     virtual bool initialize(SDL_Window* window,
                             int videoFormat,
                             int width,
-                            int height);
+                            int height,
+                            int maxFps,
+                            bool enableVsync);
     virtual bool prepareDecoderContext(AVCodecContext* context);
-    virtual void renderFrame(AVFrame* frame);
+    virtual void renderFrameAtVsync(AVFrame* frame);
+    virtual bool needsTestFrame();
 
 private:
     SDL_Renderer* m_Renderer;

app/streaming/video/ffmpeg-renderers/sdl.cpp

@@ -30,12 +30,31 @@ bool SdlRenderer::prepareDecoderContext(AVCodecContext*)
     return true;
 }
 
+bool SdlRenderer::needsTestFrame()
+{
+    // This renderer should always work
+    return false;
+}
+
 bool SdlRenderer::initialize(SDL_Window* window,
                              int,
                              int width,
-                             int height)
+                             int height,
+                             int,
+                             bool enableVsync)
 {
-    m_Renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
+    Uint32 rendererFlags = SDL_RENDERER_ACCELERATED;
+
+    if ((SDL_GetWindowFlags(window) & SDL_WINDOW_FULLSCREEN_DESKTOP) == SDL_WINDOW_FULLSCREEN) {
+        // In full-screen exclusive mode, we enable V-sync if requested. For other modes, Windows and Mac
+        // have compositors that make rendering tear-free. Linux compositor varies by distro and user
+        // configuration but doesn't seem feasible to detect here.
+        if (enableVsync) {
+            rendererFlags |= SDL_RENDERER_PRESENTVSYNC;
+        }
+    }
+
+    m_Renderer = SDL_CreateRenderer(window, -1, rendererFlags);
     if (!m_Renderer) {
         SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                      "SDL_CreateRenderer() failed: %s",
@@ -67,7 +86,7 @@ bool SdlRenderer::initialize(SDL_Window* window,
     return true;
 }
 
-void SdlRenderer::renderFrame(AVFrame* frame)
+void SdlRenderer::renderFrameAtVsync(AVFrame* frame)
 {
     SDL_UpdateYUVTexture(m_Texture, nullptr,
                          frame->data[0],
@@ -77,9 +96,6 @@ void SdlRenderer::renderFrame(AVFrame* frame)
                          frame->data[2],
                          frame->linesize[2]);
 
-    // Done with the frame now
-    av_frame_free(&frame);
-
     SDL_RenderClear(m_Renderer);
     SDL_RenderCopy(m_Renderer, m_Texture, nullptr, nullptr);
     SDL_RenderPresent(m_Renderer);

app/streaming/video/ffmpeg-renderers/vaapi.cpp

@@ -27,7 +27,7 @@ VAAPIRenderer::~VAAPIRenderer()
 }
 
 bool
-VAAPIRenderer::initialize(SDL_Window* window, int, int width, int height)
+VAAPIRenderer::initialize(SDL_Window* window, int, int width, int height, int, bool)
 {
     int err;
     SDL_SysWMinfo info;
@@ -141,8 +141,16 @@ VAAPIRenderer::prepareDecoderContext(AVCodecContext* context)
     return true;
 }
 
+bool
+VAAPIRenderer::needsTestFrame()
+{
+    // We need a test frame to see if this VAAPI driver
+    // supports the profile used for streaming
+    return true;
+}
+
 void
-VAAPIRenderer::renderFrame(AVFrame* frame)
+VAAPIRenderer::renderFrameAtVsync(AVFrame* frame)
 {
     VASurfaceID surface = (VASurfaceID)(uintptr_t)frame->data[3];
     AVHWDeviceContext* deviceContext = (AVHWDeviceContext*)m_HwContext->data;
@@ -197,6 +205,4 @@ VAAPIRenderer::renderFrame(AVFrame* frame)
         // We don't accept anything else in initialize().
         SDL_assert(false);
     }
-
-    av_frame_free(&frame);
 }

app/streaming/video/ffmpeg-renderers/vaapi.h

@@ -33,9 +33,12 @@ public:
     virtual bool initialize(SDL_Window* window,
                             int videoFormat,
                             int width,
-                            int height);
+                            int height,
+                            int maxFps,
+                            bool enableVsync);
     virtual bool prepareDecoderContext(AVCodecContext* context);
-    virtual void renderFrame(AVFrame* frame);
+    virtual void renderFrameAtVsync(AVFrame* frame);
+    virtual bool needsTestFrame();
 
 private:
     int m_WindowSystem;

app/streaming/video/ffmpeg-renderers/vdpau.cpp

@@ -54,7 +54,7 @@ VDPAURenderer::~VDPAURenderer()
     }
 }
 
-bool VDPAURenderer::initialize(SDL_Window* window, int, int width, int height)
+bool VDPAURenderer::initialize(SDL_Window* window, int, int width, int height, int, bool)
 {
     int err;
     VdpStatus status;
@@ -223,7 +223,14 @@ bool VDPAURenderer::prepareDecoderContext(AVCodecContext* context)
     return true;
 }
 
-void VDPAURenderer::renderFrame(AVFrame* frame)
+bool VDPAURenderer::needsTestFrame()
+{
+    // We need a test frame to see if this VDPAU driver
+    // supports the profile used for streaming
+    return true;
+}
+
+void VDPAURenderer::renderFrameAtVsync(AVFrame* frame)
 {
     VdpStatus status;
     VdpVideoSurface videoSurface = (VdpVideoSurface)(uintptr_t)frame->data[3];
@@ -235,14 +242,14 @@ void VDPAURenderer::renderFrame(AVFrame* frame)
     // We need to create the mixer on the fly, because we don't know the dimensions
     // of our video surfaces in advance of decoding
     if (m_VideoMixer == 0) {
-        VdpChromaType chroma;
+        VdpChromaType videoSurfaceChroma;
         uint32_t videoSurfaceWidth, videoSurfaceHeight;
-        status = m_VdpVideoSurfaceGetParameters(videoSurface, &chroma, &videoSurfaceWidth, &videoSurfaceHeight);
+        status = m_VdpVideoSurfaceGetParameters(videoSurface, &videoSurfaceChroma,
+                                                &videoSurfaceWidth, &videoSurfaceHeight);
         if (status != VDP_STATUS_OK) {
             SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                          "VdpVideoSurfaceGetParameters() failed: %s",
                          m_VdpGetErrorString(status));
-            av_frame_free(&frame);
             return;
         }
 
@@ -250,14 +257,16 @@ void VDPAURenderer::renderFrame(AVFrame* frame)
                     "VDPAU surface size: %dx%d",
                     videoSurfaceWidth, videoSurfaceHeight);
 
-    #define PARAM_COUNT 2
+    #define PARAM_COUNT 3
         const VdpVideoMixerParameter params[PARAM_COUNT] = {
             VDP_VIDEO_MIXER_PARAMETER_VIDEO_SURFACE_WIDTH,
             VDP_VIDEO_MIXER_PARAMETER_VIDEO_SURFACE_HEIGHT,
+            VDP_VIDEO_MIXER_PARAMETER_CHROMA_TYPE,
         };
         const void* const paramValues[PARAM_COUNT] = {
             &videoSurfaceWidth,
             &videoSurfaceHeight,
+            &videoSurfaceChroma,
         };
 
         status = m_VdpVideoMixerCreate(m_Device, 0, nullptr,
@@ -267,7 +276,6 @@ void VDPAURenderer::renderFrame(AVFrame* frame)
             SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                          "VdpVideoMixerCreate() failed: %s",
                          m_VdpGetErrorString(status));
-            av_frame_free(&frame);
             return;
         }
     }
@@ -310,10 +318,6 @@ void VDPAURenderer::renderFrame(AVFrame* frame)
                                    nullptr,
                                    0,
                                    nullptr);
-
-    // The decoder can have this surface back now
-    av_frame_free(&frame);
-
     if (status != VDP_STATUS_OK) {
         SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                      "VdpVideoMixerRender() failed: %s",

app/streaming/video/ffmpeg-renderers/vdpau.h

@@ -16,9 +16,12 @@ public:
     virtual bool initialize(SDL_Window* window,
                             int videoFormat,
                             int width,
-                            int height);
+                            int height,
+                            int maxFps,
+                            bool enableVsync);
     virtual bool prepareDecoderContext(AVCodecContext* context);
-    virtual void renderFrame(AVFrame* frame);
+    virtual void renderFrameAtVsync(AVFrame* frame);
+    virtual bool needsTestFrame();
 
 private:
     uint32_t m_VideoWidth, m_VideoHeight;

app/streaming/video/ffmpeg-renderers/vt.mm

@@ -2,19 +2,16 @@
 // libavutil both defining AVMediaType
 #define AVMediaType AVMediaType_FFmpeg
 #include "vt.h"
+#include "pacer/pacer.h"
 #undef AVMediaType
 
 #include <SDL_syswm.h>
 #include <Limelight.h>
 
-#include <QQueue>
-
+#include <mach/mach_time.h>
 #import <Cocoa/Cocoa.h>
 #import <VideoToolbox/VideoToolbox.h>
 #import <AVFoundation/AVFoundation.h>
-#import <CoreVideo/CoreVideo.h>
-
-#define FRAME_HISTORY_ENTRIES 8
 
 class VTRenderer : public IFFmpegRenderer
 {
@@ -23,9 +20,7 @@ public:
         : m_HwContext(nullptr),
           m_DisplayLayer(nullptr),
           m_FormatDesc(nullptr),
-          m_View(nullptr),
-          m_DisplayLink(nullptr),
-          m_FrameQueueLock(0)
+          m_View(nullptr)
     {
     }
 
@@ -39,63 +34,28 @@ public:
             CFRelease(m_FormatDesc);
         }
 
-        if (m_DisplayLink != nullptr) {
-            CVDisplayLinkStop(m_DisplayLink);
-            CVDisplayLinkRelease(m_DisplayLink);
-        }
-
-        while (!m_FrameQueue.isEmpty()) {
-            AVFrame* frame = m_FrameQueue.dequeue();
-            av_frame_free(&frame);
-        }
-
         if (m_View != nullptr) {
             [m_View removeFromSuperview];
         }
     }
 
-    void drawFrame(uint64_t vsyncTime)
+    // Caller frees frame after we return
+    virtual void renderFrameAtVsync(AVFrame* frame) override
     {
         OSStatus status;
+        CVPixelBufferRef pixBuf = reinterpret_cast<CVPixelBufferRef>(frame->data[3]);
 
-        SDL_AtomicLock(&m_FrameQueueLock);
+        if (m_DisplayLayer.status == AVQueuedSampleBufferRenderingStatusFailed) {
+            SDL_LogWarn(SDL_LOG_CATEGORY_APPLICATION,
+                        "Resetting failed AVSampleBufferDisplay layer");
 
-        int frameDropTarget;
-
-        // If the queue length history entries are large, be strict
-        // about dropping excess frames.
-        frameDropTarget = 1;
-        for (int i = 0; i < m_FrameQueueHistory.count(); i++) {
-            if (m_FrameQueueHistory[i] <= 1) {
-                // Be lenient as long as the queue length
-                // resolves before the end of frame history
-                frameDropTarget = 3;
-            }
-        }
-
-        if (m_FrameQueueHistory.count() == FRAME_HISTORY_ENTRIES) {
-            m_FrameQueueHistory.dequeue();
-        }
-
-        m_FrameQueueHistory.enqueue(m_FrameQueue.count());
-
-        // Catch up if we're several frames ahead
-        while (m_FrameQueue.count() > frameDropTarget) {
-            AVFrame* frame = m_FrameQueue.dequeue();
-            av_frame_free(&frame);
-        }
-
-        if (m_FrameQueue.isEmpty()) {
-            SDL_AtomicUnlock(&m_FrameQueueLock);
+            // Trigger the main thread to recreate the decoder
+            SDL_Event event;
+            event.type = SDL_RENDER_TARGETS_RESET;
+            SDL_PushEvent(&event);
             return;
         }
 
-        // Grab the first frame
-        AVFrame* frame = m_FrameQueue.dequeue();
-        SDL_AtomicUnlock(&m_FrameQueueLock);
-
-        CVPixelBufferRef pixBuf = reinterpret_cast<CVPixelBufferRef>(frame->data[3]);
-
         // If the format has changed or doesn't exist yet, construct it with the
         // pixel buffer data
         if (!m_FormatDesc || !CMVideoFormatDescriptionMatchesImageBuffer(m_FormatDesc, pixBuf)) {
@@ -108,7 +68,6 @@ public:
                 SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                              "CMVideoFormatDescriptionCreateForImageBuffer() failed: %d",
                              status);
-                av_frame_free(&frame);
                 return;
             }
         }
@@ -117,7 +76,7 @@ public:
         CMSampleTimingInfo timingInfo = {
             .duration = kCMTimeInvalid,
             .decodeTimeStamp = kCMTimeInvalid,
-            .presentationTimeStamp = CMTimeMake(vsyncTime, 1000 * 1000 * 1000)
+            .presentationTimeStamp = CMTimeMake(mach_absolute_time(), 1000 * 1000 * 1000)
         };
 
         CMSampleBufferRef sampleBuffer;
@@ -130,45 +89,20 @@ public:
             SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
                          "CMSampleBufferCreateReadyWithImageBuffer() failed: %d",
                          status);
-            av_frame_free(&frame);
             return;
         }
 
         [m_DisplayLayer enqueueSampleBuffer:sampleBuffer];
 
         CFRelease(sampleBuffer);
-        av_frame_free(&frame);
-    }
-
-    static
-    CVReturn
-    displayLinkOutputCallback(
-        CVDisplayLinkRef,
-        const CVTimeStamp* now,
-        const CVTimeStamp* /* vsyncTime */,
-        CVOptionFlags,
-        CVOptionFlags*,
-        void *displayLinkContext)
-    {
-        VTRenderer* me = reinterpret_cast<VTRenderer*>(displayLinkContext);
-
-        // In my testing on macOS 10.13, this callback is invoked about 24 ms
-        // prior to the specified v-sync time (now - vsyncTime). Since this is
-        // greater than the standard v-sync interval (16 ms = 60 FPS), we will
-        // draw using the current host time, rather than the actual v-sync target
-        // time. Because the CVDisplayLink is in sync with the actual v-sync
-        // interval, even if many ms prior, we can safely use the current host time
-        // and get a consistent callback for each v-sync. This reduces video latency
-        // by at least 1 frame vs. rendering with the actual vsyncTime.
-        me->drawFrame(now->hostTime);
-
-        return kCVReturnSuccess;
     }
 
     virtual bool initialize(SDL_Window* window,
                             int videoFormat,
                             int,
-                            int) override
+                            int,
+                            int,
+                            bool) override
     {
         int err;
 
@@ -243,10 +177,6 @@ public:
             return false;
         }
 
-        CVDisplayLinkCreateWithActiveCGDisplays(&m_DisplayLink);
-        CVDisplayLinkSetOutputCallback(m_DisplayLink, displayLinkOutputCallback, this);
-        CVDisplayLinkStart(m_DisplayLink);
-
         return true;
     }
 
@@ -260,17 +190,10 @@ public:
         return true;
     }
 
-    virtual void renderFrame(AVFrame* frame) override
+    virtual bool needsTestFrame() override
     {
-        if (m_DisplayLayer.status == AVQueuedSampleBufferRenderingStatusFailed) {
-            SDL_LogWarn(SDL_LOG_CATEGORY_APPLICATION,
-                        "Resetting failed AVSampleBufferDisplay layer");
-            setupDisplayLayer();
-        }
-
-        SDL_AtomicLock(&m_FrameQueueLock);
-        m_FrameQueue.enqueue(frame);
-        SDL_AtomicUnlock(&m_FrameQueueLock);
+        // We query VT to determine whether the codec is supported
+        return false;
     }
 
 private:
@@ -296,10 +219,6 @@ private:
     AVSampleBufferDisplayLayer* m_DisplayLayer;
     CMVideoFormatDescriptionRef m_FormatDesc;
     NSView* m_View;
-    CVDisplayLinkRef m_DisplayLink;
-    QQueue<AVFrame*> m_FrameQueue;
-    QQueue<int> m_FrameQueueHistory;
-    SDL_SpinLock m_FrameQueueLock;
 };
 
 IFFmpegRenderer* VTRendererFactory::createRenderer() {

app/streaming/video/ffmpeg.cpp

@@ -53,7 +53,8 @@ FFmpegVideoDecoder::FFmpegVideoDecoder()
       m_DecodeBuffer(1024 * 1024, 0),
       m_HwDecodeCfg(nullptr),
       m_Renderer(nullptr),
-      m_ConsecutiveFailedDecodes(0)
+      m_ConsecutiveFailedDecodes(0),
+      m_Pacer(nullptr)
 {
     av_init_packet(&m_Pkt);
     SDL_AtomicSet(&m_QueuedFrames, 0);
@@ -91,19 +92,29 @@ void FFmpegVideoDecoder::reset()
             dropFrame(&event.user);
         }
         else {
-            SDL_Delay(100);
+            SDL_Delay(10);
             SDL_PumpEvents();
         }
     }
 
-    avcodec_free_context(&m_VideoDecoderCtx);
+    delete m_Pacer;
+    m_Pacer = nullptr;
 
     delete m_Renderer;
     m_Renderer = nullptr;
+
+    avcodec_free_context(&m_VideoDecoderCtx);
 }
 
-bool FFmpegVideoDecoder::completeInitialization(AVCodec* decoder, int videoFormat, int width, int height, bool testOnly)
+bool FFmpegVideoDecoder::completeInitialization(AVCodec* decoder, SDL_Window* window,
+                                                int videoFormat, int width, int height,
+                                                int maxFps, bool enableVsync, bool testOnly)
 {
+    m_Pacer = new Pacer(m_Renderer);
+    if (!m_Pacer->initialize(window, maxFps, enableVsync)) {
+        return false;
+    }
+
     m_VideoDecoderCtx = avcodec_alloc_context3(decoder);
     if (!m_VideoDecoderCtx) {
         SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
@@ -218,7 +229,8 @@ bool FFmpegVideoDecoder::initialize(
         int videoFormat,
         int width,
         int height,
-        int)
+        int maxFps,
+        bool enableVsync)
 {
     AVCodec* decoder;
 
@@ -253,8 +265,8 @@ bool FFmpegVideoDecoder::initialize(
             m_HwDecodeCfg = nullptr;
             m_Renderer = new SdlRenderer();
             if (vds != StreamingPreferences::VDS_FORCE_HARDWARE &&
-                    m_Renderer->initialize(window, videoFormat, width, height) &&
-                    completeInitialization(decoder, videoFormat, width, height, false)) {
+                    m_Renderer->initialize(window, videoFormat, width, height, maxFps, enableVsync) &&
+                    completeInitialization(decoder, window, videoFormat, width, height, maxFps, enableVsync, false)) {
                 return true;
             }
             else {
@@ -269,20 +281,26 @@ bool FFmpegVideoDecoder::initialize(
         }
 
         m_HwDecodeCfg = config;
-        // Submit test frame to ensure this codec really works
-        if (m_Renderer->initialize(window, videoFormat, width, height) &&
-                completeInitialization(decoder, videoFormat, width, height, true)) {
-            // OK, it worked, so now let's initialize it for real
-            reset();
-            if ((m_Renderer = createAcceleratedRenderer(config)) != nullptr &&
-                    m_Renderer->initialize(window, videoFormat, width, height) &&
-                    completeInitialization(decoder, videoFormat, width, height, false)) {
-                return true;
+        // Initialize the hardware codec and submit a test frame if the renderer needs it
+        if (m_Renderer->initialize(window, videoFormat, width, height, maxFps, enableVsync) &&
+                completeInitialization(decoder, window, videoFormat, width, height, maxFps, enableVsync, m_Renderer->needsTestFrame())) {
+            if (m_Renderer->needsTestFrame()) {
+                // The test worked, so now let's initialize it for real
+                reset();
+                if ((m_Renderer = createAcceleratedRenderer(config)) != nullptr &&
+                        m_Renderer->initialize(window, videoFormat, width, height, maxFps, enableVsync) &&
+                        completeInitialization(decoder, window, videoFormat, width, height, maxFps, enableVsync, false)) {
+                    return true;
+                }
+                else {
+                    SDL_LogCritical(SDL_LOG_CATEGORY_APPLICATION,
+                                    "Decoder failed to initialize after successful test");
+                    reset();
+                }
             }
             else {
-                SDL_LogCritical(SDL_LOG_CATEGORY_APPLICATION,
-                                "Decoder failed to initialize after successful test");
-                reset();
+                // No test required. Good to go now.
+                return true;
             }
         }
         else {
@@ -380,7 +398,7 @@ int FFmpegVideoDecoder::submitDecodeUnit(PDECODE_UNIT du)
 void FFmpegVideoDecoder::renderFrame(SDL_UserEvent* event)
 {
     AVFrame* frame = reinterpret_cast<AVFrame*>(event->data1);
-    m_Renderer->renderFrame(frame);
+    m_Pacer->submitFrame(frame);
     SDL_AtomicDecRef(&m_QueuedFrames);
 }
 
@@ -388,6 +406,15 @@ void FFmpegVideoDecoder::renderFrame(SDL_UserEvent* event)
 void FFmpegVideoDecoder::dropFrame(SDL_UserEvent* event)
 {
     AVFrame* frame = reinterpret_cast<AVFrame*>(event->data1);
-    av_frame_free(&frame);
+    // If Pacer is using a frame queue, we can just queue the
+    // frame and let it decide whether to drop or not. If Pacer
+    // is submitting directly for rendering, we drop the frame
+    // ourselves.
+    if (m_Pacer->isUsingFrameQueue()) {
+        m_Pacer->submitFrame(frame);
+    }
+    else {
+        av_frame_free(&frame);
+    }
     SDL_AtomicDecRef(&m_QueuedFrames);
 }

app/streaming/video/ffmpeg.h

@@ -2,6 +2,7 @@
 
 #include "decoder.h"
 #include "ffmpeg-renderers/renderer.h"
+#include "ffmpeg-renderers/pacer/pacer.h"
 
 extern "C" {
 #include <libavcodec/avcodec.h>
@@ -16,7 +17,8 @@ public:
                             int videoFormat,
                             int width,
                             int height,
-                            int frameRate) override;
+                            int maxFps,
+                            bool enableVsync) override;
     virtual bool isHardwareAccelerated() override;
     virtual int submitDecodeUnit(PDECODE_UNIT du) override;
     virtual void renderFrame(SDL_UserEvent* event) override;
@@ -25,8 +27,9 @@ public:
     virtual IFFmpegRenderer* getRenderer();
 
 private:
-    bool completeInitialization(AVCodec* decoder, int videoFormat,
-                                int width, int height, bool testOnly);
+    bool completeInitialization(AVCodec* decoder, SDL_Window* window,
+                                int videoFormat, int width, int height,
+                                int maxFps, bool enableVsync, bool testOnly);
 
     IFFmpegRenderer* createAcceleratedRenderer(const AVCodecHWConfig* hwDecodeCfg);
 
@@ -43,6 +46,7 @@ private:
     IFFmpegRenderer* m_Renderer;
     SDL_atomic_t m_QueuedFrames;
     int m_ConsecutiveFailedDecodes;
+    Pacer* m_Pacer;
 
     static const uint8_t k_H264TestFrame[];
     static const uint8_t k_HEVCTestFrame[];

app/streaming/video/sl.cpp

@@ -28,7 +28,7 @@ SLVideoDecoder::isHardwareAccelerated()
 bool
 SLVideoDecoder::initialize(StreamingPreferences::VideoDecoderSelection vds,
                            SDL_Window*,
-                           int videoFormat, int, int, int frameRate)
+                           int videoFormat, int, int, int frameRate, bool)
 {
     // SLVideo only supports hardware decoding
     if (vds == StreamingPreferences::VDS_FORCE_SOFTWARE) {

app/streaming/video/sl.h

@@ -14,7 +14,8 @@ public:
                             int videoFormat,
                             int width,
                             int height,
-                            int frameRate);
+                            int frameRate,
+                            bool enableVsync);
     virtual bool isHardwareAccelerated();
     virtual int submitDecodeUnit(PDECODE_UNIT du);
 

moonlight-qt.pro

@@ -4,7 +4,8 @@ SUBDIRS = \
     qmdnsengine \
     app
 
-CONFIG += ordered
+# Build the dependencies in parallel before the final app
+app.depends = qmdnsengine moonlight-common-c
 
 # Support debug and release builds from command line for CI
 CONFIG += debug_and_release

scripts/generate-installers.bat

@@ -88,21 +88,24 @@ if "%SIGN%"=="1" (
     )
 )
 
-echo Building installer
-set VCREDIST_INSTALLER=%VCREDIST_PATH%\vcredist_%ARCH%.exe
-msbuild %SOURCE_ROOT%\wix\Moonlight.sln /p:Configuration=%BUILD_CONFIG% /p:Platform=%ARCH%
-if !ERRORLEVEL! NEQ 0 goto Error
-
-echo Building portable package
-rem This must be done after WiX harvesting and signing, since the VCRT dlls are MS signed
-rem and should not be harvested for inclusion in the full installer
-copy "%VCREDIST_PATH%\%ARCH%\Microsoft.VC141.CRT\*.dll" %DEPLOY_FOLDER%
-if !ERRORLEVEL! NEQ 0 goto Error
-7z a %INSTALLER_FOLDER%\MoonlightPortable.zip %DEPLOY_FOLDER%\*
+echo Building MSI
+msbuild %SOURCE_ROOT%\wix\Moonlight\Moonlight.wixproj /p:Configuration=%BUILD_CONFIG% /p:Platform=%ARCH%
 if !ERRORLEVEL! NEQ 0 goto Error
 
 if "%SIGN%"=="1" (
-    echo Signing installer binary
+    echo Signing MSI
+    signtool %SIGNTOOL_PARAMS% %BUILD_FOLDER%\Moonlight.msi
+    if !ERRORLEVEL! NEQ 0 goto Error
+)
+
+echo Building bundle
+set VCREDIST_INSTALLER=%VCREDIST_PATH%\vcredist_%ARCH%.exe
+rem Bundles are always x86 binaries
+msbuild %SOURCE_ROOT%\wix\MoonlightSetup\MoonlightSetup.wixproj /p:Configuration=%BUILD_CONFIG% /p:Platform=x86
+if !ERRORLEVEL! NEQ 0 goto Error
+
+if "%SIGN%"=="1" (
+    echo Signing bundle
     "%WIX%\bin\insignia" -ib %INSTALLER_FOLDER%\MoonlightSetup.exe -o %BUILD_FOLDER%\engine.exe
     if !ERRORLEVEL! NEQ 0 goto Error
     signtool %SIGNTOOL_PARAMS% %BUILD_FOLDER%\engine.exe
@@ -113,6 +116,16 @@ if "%SIGN%"=="1" (
     if !ERRORLEVEL! NEQ 0 goto Error
 )
 
+echo Building portable package
+rem This must be done after WiX harvesting and signing, since the VCRT dlls are MS signed
+rem and should not be harvested for inclusion in the full installer
+copy "%VCREDIST_PATH%\%ARCH%\Microsoft.VC141.CRT\*.dll" %DEPLOY_FOLDER%
+rem This file tells Moonlight that it's a portable installation
+echo. > %DEPLOY_FOLDER%\portable.dat
+if !ERRORLEVEL! NEQ 0 goto Error
+7z a %INSTALLER_FOLDER%\MoonlightPortable.zip %DEPLOY_FOLDER%\*
+if !ERRORLEVEL! NEQ 0 goto Error
+
 if /i "%APPVEYOR%"=="true" (
     echo Pushing artifacts
     appveyor PushArtifact %INSTALLER_FOLDER%\MoonlightSetup.exe -FileName MoonlightSetup-%ARCH%-%BUILD_CONFIG%.exe

wix/Moonlight/Moonlight.wixproj

@@ -6,6 +6,7 @@
     <SchemaVersion>2.0</SchemaVersion>
     <OutputName>Moonlight</OutputName>
     <OutputType>Package</OutputType>
+    <DefineSolutionProperties>false</DefineSolutionProperties>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)' == 'Debug' ">
     <DefineConstants>Debug</DefineConstants>
@@ -26,6 +27,10 @@
       <HintPath>$(WixExtDir)\WixFirewallExtension.dll</HintPath>
       <Name>WixFirewallExtension</Name>
     </WixExtension>
+    <WixExtension Include="WixUtilExtension">
+      <HintPath>$(WixExtDir)\WixUtilExtension.dll</HintPath>
+      <Name>WixUtilExtension</Name>
+    </WixExtension>
   </ItemGroup>
   <Import Project="$(WixTargetsPath)" Condition=" '$(WixTargetsPath)' != '' " />
   <Import Project="$(MSBuildExtensionsPath32)\Microsoft\WiX\v3.x\Wix.targets" Condition=" '$(WixTargetsPath)' == '' AND Exists('$(MSBuildExtensionsPath32)\Microsoft\WiX\v3.x\Wix.targets') " />

wix/Moonlight/Product.wxs

@@ -8,7 +8,8 @@
 <?define InstallFolder = "Moonlight Game Streaming" ?>
 
 <Wix xmlns="http://schemas.microsoft.com/wix/2006/wi"
-     xmlns:fire="http://schemas.microsoft.com/wix/FirewallExtension">
+     xmlns:fire="http://schemas.microsoft.com/wix/FirewallExtension"
+     xmlns:util="http://schemas.microsoft.com/wix/UtilExtension">
 
   <Product Id="*"
            Name="$(var.FullName)"
@@ -20,7 +21,7 @@
     <Package InstallerVersion="500" Compressed="yes" InstallScope="perMachine" />
 
     <MajorUpgrade DowngradeErrorMessage="A newer version of [ProductName] is already installed." Schedule="afterInstallInitialize" />
-    <MediaTemplate CompressionLevel="high" />
+    <MediaTemplate CompressionLevel="high" EmbedCab="yes" />
 
     <?if $(var.Platform) = x64 ?>
       <?define PlatformProgramFilesFolder = "ProgramFiles64Folder" ?>
@@ -38,6 +39,8 @@
       </Directory>
     </Directory>
 
+    <Property Id="APPDATAFOLDER">%LOCALAPPDATA%\Moonlight Game Streaming</Property>
+
     <!-- There's no way to delete a registry key on uninstall but not major upgrade, so
         we have to roll our own deletion via custom action -->
     <CustomAction Id="DeleteRegistryKey"
@@ -65,6 +68,7 @@
                 WorkingDirectory="INSTALLFOLDER" />
       <RemoveFolder Id="CleanupStartMenuShortcut" Directory="ApplicationProgramsFolder" On="uninstall" />
       <RemoveFolder Id="CleanupDesktopShortcut" Directory="DesktopFolder" On="uninstall" />
+      <util:RemoveFolderEx Id="CleanupAppDataFolder" On="uninstall" Property="APPDATAFOLDER" />
       <RegistryValue Root="HKCU" Key="Software\Moonlight Game Streaming Project" Name="Installed" Type="integer" Value="1" KeyPath="yes" />
     </Component>
 

wix/MoonlightSetup/MoonlightSetup.wixproj

@@ -6,6 +6,7 @@
     <SchemaVersion>2.0</SchemaVersion>
     <OutputName>MoonlightSetup</OutputName>
     <OutputType>Bundle</OutputType>
+    <DefineSolutionProperties>false</DefineSolutionProperties>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)' == 'Debug' ">
     <DefineConstants>Debug</DefineConstants>