Add frame pacing toggle

app/cli/commandlineparser.cpp

@@ -287,6 +287,7 @@ void StreamCommandLineParser::parse(const QStringList &args, StreamingPreference
     parser.addToggleOption("mouse-acceleration", "mouse acceleration");
     parser.addToggleOption("game-optimization", "game optimizations");
     parser.addToggleOption("audio-on-host", "audio on host PC");
+    parser.addToggleOption("frame-pacing", "frame pacing");
     parser.addChoiceOption("video-codec", "video codec", m_VideoCodecMap.keys());
     parser.addChoiceOption("video-decoder", "video decoder", m_VideoDecoderMap.keys());
 
@@ -372,6 +373,9 @@ void StreamCommandLineParser::parse(const QStringList &args, StreamingPreference
     // Resolve --audio-on-host and --no-audio-on-host options
     preferences->playAudioOnHost = parser.getToggleOptionValue("audio-on-host", preferences->playAudioOnHost);
 
+    // Resolve --frame-pacing and --no-frame-pacing options
+    preferences->framePacing = parser.getToggleOptionValue("frame-pacing", preferences->framePacing);
+
     // Resolve --video-codec option
     if (parser.isSet("video-codec")) {
         preferences->videoCodecConfig = mapValue(m_VideoCodecMap, parser.getChoiceOptionValue("video-codec"));

app/gui/SettingsView.qml

@@ -383,7 +383,7 @@ Flickable {
                 CheckBox {
                     id: vsyncCheck
                     hoverEnabled: true
-                    text: "Enable V-Sync"
+                    text: "V-Sync"
                     font.pointSize:  12
                     checked: prefs.enableVsync
                     onCheckedChanged: {
@@ -395,6 +395,22 @@ Flickable {
                     ToolTip.visible: hovered
                     ToolTip.text: "Disabling V-Sync allows sub-frame rendering latency, but it can display visible tearing"
                 }
+
+                CheckBox {
+                    id: framePacingCheck
+                    hoverEnabled: true
+                    text: "Frame pacing"
+                    font.pointSize:  12
+                    enabled: prefs.enableVsync
+                    checked: prefs.enableVsync && prefs.framePacing
+                    onCheckedChanged: {
+                        prefs.framePacing = checked
+                    }
+                    ToolTip.delay: 1000
+                    ToolTip.timeout: 5000
+                    ToolTip.visible: hovered
+                    ToolTip.text: "Frame pacing reduces micro-stutter by delaying frames that come in too early"
+                }
             }
         }
 

app/settings/streamingpreferences.cpp

@@ -23,6 +23,7 @@
 #define SER_QUITAPPAFTER "quitAppAfter"
 #define SER_MOUSEACCELERATION "mouseacceleration"
 #define SER_STARTWINDOWED "startwindowed"
+#define SER_FRAMEPACING "framepacing"
 
 StreamingPreferences::StreamingPreferences(QObject *parent)
     : QObject(parent)
@@ -47,6 +48,7 @@ void StreamingPreferences::reload()
     quitAppAfter = settings.value(SER_QUITAPPAFTER, false).toBool();
     mouseAcceleration = settings.value(SER_MOUSEACCELERATION, false).toBool();
     startWindowed = settings.value(SER_STARTWINDOWED, false).toBool();
+    framePacing = settings.value(SER_FRAMEPACING, false).toBool();
     audioConfig = static_cast<AudioConfig>(settings.value(SER_AUDIOCFG,
                                                   static_cast<int>(AudioConfig::AC_STEREO)).toInt());
     videoCodecConfig = static_cast<VideoCodecConfig>(settings.value(SER_VIDEOCFG,
@@ -76,6 +78,7 @@ void StreamingPreferences::save()
     settings.setValue(SER_QUITAPPAFTER, quitAppAfter);
     settings.setValue(SER_MOUSEACCELERATION, mouseAcceleration);
     settings.setValue(SER_STARTWINDOWED, startWindowed);
+    settings.setValue(SER_FRAMEPACING, framePacing);
     settings.setValue(SER_AUDIOCFG, static_cast<int>(audioConfig));
     settings.setValue(SER_VIDEOCFG, static_cast<int>(videoCodecConfig));
     settings.setValue(SER_VIDEODEC, static_cast<int>(videoDecoderSelection));

app/settings/streamingpreferences.h

@@ -76,6 +76,7 @@ public:
     Q_PROPERTY(bool quitAppAfter MEMBER quitAppAfter NOTIFY quitAppAfterChanged)
     Q_PROPERTY(bool mouseAcceleration MEMBER mouseAcceleration NOTIFY mouseAccelerationChanged)
     Q_PROPERTY(bool startWindowed MEMBER startWindowed NOTIFY startWindowedChanged)
+    Q_PROPERTY(bool framePacing MEMBER framePacing NOTIFY framePacingChanged)
     Q_PROPERTY(AudioConfig audioConfig MEMBER audioConfig NOTIFY audioConfigChanged)
     Q_PROPERTY(VideoCodecConfig videoCodecConfig MEMBER videoCodecConfig NOTIFY videoCodecConfigChanged)
     Q_PROPERTY(VideoDecoderSelection videoDecoderSelection MEMBER videoDecoderSelection NOTIFY videoDecoderSelectionChanged)
@@ -95,6 +96,7 @@ public:
     bool quitAppAfter;
     bool mouseAcceleration;
     bool startWindowed;
+    bool framePacing;
     AudioConfig audioConfig;
     VideoCodecConfig videoCodecConfig;
     VideoDecoderSelection videoDecoderSelection;
@@ -116,5 +118,6 @@ signals:
     void videoDecoderSelectionChanged();
     void windowModeChanged();
     void startWindowedChanged();
+    void framePacingChanged();
 };
 

app/streaming/session.cpp

@@ -99,11 +99,11 @@ void Session::clLogMessage(const char* format, ...)
     va_end(ap);
 }
 
-#define CALL_INITIALIZE(dec) (dec)->initialize(vds, window, videoFormat, width, height, frameRate, enableVsync)
+#define CALL_INITIALIZE(dec) (dec)->initialize(vds, window, videoFormat, width, height, frameRate, enableVsync, enableFramePacing)
 
 bool Session::chooseDecoder(StreamingPreferences::VideoDecoderSelection vds,
                             SDL_Window* window, int videoFormat, int width, int height,
-                            int frameRate, bool enableVsync, IVideoDecoder*& chosenDecoder)
+                            int frameRate, bool enableVsync, bool enableFramePacing, IVideoDecoder*& chosenDecoder)
 {
 #ifdef HAVE_SLVIDEO
     chosenDecoder = new SLVideoDecoder();
@@ -217,7 +217,7 @@ bool Session::isHardwareDecodeAvailable(StreamingPreferences::VideoDecoderSelect
         return false;
     }
 
-    if (!chooseDecoder(vds, window, videoFormat, width, height, frameRate, true, decoder)) {
+    if (!chooseDecoder(vds, window, videoFormat, width, height, frameRate, true, false, decoder)) {
         SDL_DestroyWindow(window);
         SDL_QuitSubSystem(SDL_INIT_VIDEO);
         return false;
@@ -257,7 +257,7 @@ int Session::getDecoderCapabilities(StreamingPreferences::VideoDecoderSelection
         return false;
     }
 
-    if (!chooseDecoder(vds, window, videoFormat, width, height, frameRate, true, decoder)) {
+    if (!chooseDecoder(vds, window, videoFormat, width, height, frameRate, true, false, decoder)) {
         SDL_DestroyWindow(window);
         SDL_QuitSubSystem(SDL_INIT_VIDEO);
         return false;
@@ -1120,6 +1120,7 @@ void Session::exec(int displayOriginX, int displayOriginY)
                                    m_Window, m_ActiveVideoFormat, m_ActiveVideoWidth,
                                    m_ActiveVideoHeight, m_ActiveVideoFrameRate,
                                    enableVsync,
+                                   enableVsync && m_Preferences->framePacing,
                                    s_ActiveSession->m_VideoDecoder)) {
                     SDL_AtomicUnlock(&m_DecoderLock);
                     SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,

app/streaming/session.h

@@ -72,7 +72,8 @@ private:
     static
     bool chooseDecoder(StreamingPreferences::VideoDecoderSelection vds,
                        SDL_Window* window, int videoFormat, int width, int height,
-                       int frameRate, bool enableVsync, IVideoDecoder*& chosenDecoder);
+                       int frameRate, bool enableVsync, bool enableFramePacing,
+                       IVideoDecoder*& chosenDecoder);
 
     static
     void clStageStarting(int stage);

app/streaming/video/decoder.h

@@ -33,7 +33,8 @@ public:
                             int width,
                             int height,
                             int frameRate,
-                            bool enableVsync) = 0;
+                            bool enableVsync,
+                            bool enableFramePacing) = 0;
     virtual bool isHardwareAccelerated() = 0;
     virtual int getDecoderCapabilities() = 0;
     virtual int submitDecodeUnit(PDECODE_UNIT du) = 0;

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

@@ -644,9 +644,9 @@ int DXVA2Renderer::getDecoderCapabilities()
     return 0;
 }
 
-IFFmpegRenderer::VSyncConstraint DXVA2Renderer::getVsyncConstraint()
+IFFmpegRenderer::FramePacingConstraint DXVA2Renderer::getFramePacingConstraint()
 {
-    return VSYNC_ANY;
+    return PACING_ANY;
 }
 
 void DXVA2Renderer::renderFrameAtVsync(AVFrame *frame)

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

@@ -25,7 +25,7 @@ public:
     virtual void renderFrameAtVsync(AVFrame* frame);
     virtual bool needsTestFrame();
     virtual int getDecoderCapabilities();
-    virtual VSyncConstraint getVsyncConstraint();
+    virtual FramePacingConstraint getFramePacingConstraint();
 
 private:
     bool initializeDecoder();

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

@@ -124,15 +124,14 @@ RenderNextFrame:
     av_frame_free(&frame);
 }
 
-bool Pacer::initialize(SDL_Window* window, int maxVideoFps, bool enableVsync)
+bool Pacer::initialize(SDL_Window* window, int maxVideoFps, bool enablePacing)
 {
     m_MaxVideoFps = maxVideoFps;
-    m_EnableVsync = enableVsync;
     m_DisplayFps = StreamUtils::getDisplayRefreshRate(window);
 
-    if (m_EnableVsync) {
+    if (enablePacing) {
         SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
-                    "Frame pacing in tear-free mode: target %d Hz with %d FPS stream",
+                    "Frame pacing active: target %d Hz with %d FPS stream",
                     m_DisplayFps, m_MaxVideoFps);
 
     #if defined(Q_OS_DARWIN)
@@ -150,7 +149,7 @@ bool Pacer::initialize(SDL_Window* window, int maxVideoFps, bool enableVsync)
     }
     else {
         SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
-                    "Minimal latency tearing mode: target %d Hz with %d FPS stream",
+                    "Frame pacing disabled: target %d Hz with %d FPS stream",
                     m_DisplayFps, m_MaxVideoFps);
     }
 

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

@@ -20,7 +20,7 @@ public:
 
     void submitFrame(AVFrame* frame);
 
-    bool initialize(SDL_Window* window, int maxVideoFps, bool enableVsync);
+    bool initialize(SDL_Window* window, int maxVideoFps, bool enablePacing);
 
     void vsyncCallback(int timeUntilNextVsyncMillis);
 
@@ -35,6 +35,5 @@ private:
     IFFmpegRenderer* m_VsyncRenderer;
     int m_MaxVideoFps;
     int m_DisplayFps;
-    bool m_EnableVsync;
     PVIDEO_STATS m_VideoStats;
 };

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

@@ -8,10 +8,10 @@ extern "C" {
 
 class IFFmpegRenderer {
 public:
-    enum VSyncConstraint {
+    enum FramePacingConstraint {
-        VSYNC_FORCE_OFF,
+        PACING_FORCE_OFF,
-        VSYNC_FORCE_ON,
+        PACING_FORCE_ON,
-        VSYNC_ANY
+        PACING_ANY
     };
 
     virtual ~IFFmpegRenderer() {}
@@ -25,7 +25,7 @@ public:
     virtual void renderFrameAtVsync(AVFrame* frame) = 0;
     virtual bool needsTestFrame() = 0;
     virtual int getDecoderCapabilities() = 0;
-    virtual VSyncConstraint getVsyncConstraint() = 0;
+    virtual FramePacingConstraint getFramePacingConstraint() = 0;
 };
 
 class SdlRenderer : public IFFmpegRenderer {
@@ -42,7 +42,7 @@ public:
     virtual void renderFrameAtVsync(AVFrame* frame);
     virtual bool needsTestFrame();
     virtual int getDecoderCapabilities();
-    virtual VSyncConstraint getVsyncConstraint();
+    virtual FramePacingConstraint getFramePacingConstraint();
 
 private:
     SDL_Renderer* m_Renderer;

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

@@ -43,9 +43,9 @@ int SdlRenderer::getDecoderCapabilities()
     return CAPABILITY_REFERENCE_FRAME_INVALIDATION_AVC;
 }
 
-IFFmpegRenderer::VSyncConstraint SdlRenderer::getVsyncConstraint()
+IFFmpegRenderer::FramePacingConstraint SdlRenderer::getFramePacingConstraint()
 {
-    return VSYNC_ANY;
+    return PACING_ANY;
 }
 
 bool SdlRenderer::initialize(SDL_Window* window,

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

@@ -177,9 +177,9 @@ VAAPIRenderer::getDecoderCapabilities()
     return 0;
 }
 
-IFFmpegRenderer::VSyncConstraint VAAPIRenderer::getVsyncConstraint()
+IFFmpegRenderer::FramePacingConstraint VAAPIRenderer::getFramePacingConstraint()
 {
-    return VSYNC_ANY;
+    return PACING_ANY;
 }
 
 void

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

@@ -40,7 +40,7 @@ public:
     virtual void renderFrameAtVsync(AVFrame* frame);
     virtual bool needsTestFrame();
     virtual int getDecoderCapabilities();
-    virtual VSyncConstraint getVsyncConstraint();
+    virtual FramePacingConstraint getFramePacingConstraint();
 
 private:
     int m_WindowSystem;

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

@@ -246,9 +246,9 @@ int VDPAURenderer::getDecoderCapabilities()
     return 0;
 }
 
-IFFmpegRenderer::VSyncConstraint VDPAURenderer::getVsyncConstraint()
+IFFmpegRenderer::FramePacingConstraint VDPAURenderer::getFramePacingConstraint()
 {
-    return VSYNC_ANY;
+    return PACING_ANY;
 }
 
 void VDPAURenderer::renderFrameAtVsync(AVFrame* frame)

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

@@ -23,7 +23,7 @@ public:
     virtual void renderFrameAtVsync(AVFrame* frame);
     virtual bool needsTestFrame();
     virtual int getDecoderCapabilities();
-    virtual VSyncConstraint getVsyncConstraint();
+    virtual FramePacingConstraint getFramePacingConstraint();
 
 private:
     uint32_t m_VideoWidth, m_VideoHeight;

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

@@ -211,12 +211,12 @@ public:
         return 0;
     }
 
-    virtual IFFmpegRenderer::VSyncConstraint getVsyncConstraint() override
+    virtual IFFmpegRenderer::FramePacingConstraint getFramePacingConstraint() override
     {
         // This renderer is inherently tied to V-sync due how we're
         // rendering with AVSampleBufferDisplay layer. Running without
         // the V-Sync source leads to massive stuttering.
-        return VSYNC_FORCE_ON;
+        return PACING_FORCE_ON;
     }
 
 private:

app/streaming/video/ffmpeg.cpp

@@ -131,27 +131,27 @@ void FFmpegVideoDecoder::reset()
 
 bool FFmpegVideoDecoder::completeInitialization(AVCodec* decoder, SDL_Window* window,
                                                 int videoFormat, int width, int height,
-                                                int maxFps, bool enableVsync, bool testOnly)
+                                                int maxFps, bool enableFramePacing, bool testOnly)
 {
-    auto vsyncConstraint = m_Renderer->getVsyncConstraint();
+    auto vsyncConstraint = m_Renderer->getFramePacingConstraint();
-    if (vsyncConstraint == IFFmpegRenderer::VSYNC_FORCE_OFF && enableVsync) {
+    if (vsyncConstraint == IFFmpegRenderer::PACING_FORCE_OFF && enableFramePacing) {
         SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
-                    "V-sync is forcefully disabled by the active renderer");
+                    "Frame pacing is forcefully disabled by the active renderer");
-        enableVsync = false;
+        enableFramePacing = false;
     }
-    else if (vsyncConstraint == IFFmpegRenderer::VSYNC_FORCE_ON && !enableVsync) {
+    else if (vsyncConstraint == IFFmpegRenderer::PACING_FORCE_ON && !enableFramePacing) {
         // FIXME: This duplicates logic in Session.cpp
         int displayHz = StreamUtils::getDisplayRefreshRate(window);
         if (displayHz + 5 >= maxFps) {
             SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
-                        "V-sync is forcefully enabled by the active renderer");
+                        "Frame pacing is forcefully enabled by the active renderer");
-            enableVsync = true;
+            enableFramePacing = true;
         }
     }
 
     m_StreamFps = maxFps;
     m_Pacer = new Pacer(m_Renderer, &m_ActiveWndVideoStats);
-    if (!m_Pacer->initialize(window, maxFps, enableVsync)) {
+    if (!m_Pacer->initialize(window, maxFps, enableFramePacing)) {
         return false;
     }
 
@@ -363,7 +363,8 @@ bool FFmpegVideoDecoder::initialize(
         int width,
         int height,
         int maxFps,
-        bool enableVsync)
+        bool enableVsync,
+        bool enableFramePacing)
 {
     AVCodec* decoder;
 
@@ -399,7 +400,7 @@ bool FFmpegVideoDecoder::initialize(
             m_Renderer = new SdlRenderer();
             if (vds != StreamingPreferences::VDS_FORCE_HARDWARE &&
                     m_Renderer->initialize(window, videoFormat, width, height, maxFps, enableVsync) &&
-                    completeInitialization(decoder, window, videoFormat, width, height, maxFps, enableVsync, false)) {
+                    completeInitialization(decoder, window, videoFormat, width, height, maxFps, enableFramePacing, false)) {
                 return true;
             }
             else {
@@ -416,13 +417,13 @@ bool FFmpegVideoDecoder::initialize(
         m_HwDecodeCfg = config;
         // 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())) {
+                completeInitialization(decoder, window, videoFormat, width, height, maxFps, enableFramePacing, 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)) {
+                        completeInitialization(decoder, window, videoFormat, width, height, maxFps, enableFramePacing, false)) {
                     return true;
                 }
                 else {
@@ -493,7 +494,7 @@ int FFmpegVideoDecoder::submitDecodeUnit(PDECODE_UNIT du)
 
     // Flip stats windows roughly every second
     if (m_ActiveWndVideoStats.receivedFrames == m_StreamFps) {
-#if 0
+#if 1
         VIDEO_STATS lastTwoWndStats = {};
         addVideoStats(m_LastWndVideoStats, lastTwoWndStats);
         addVideoStats(m_ActiveWndVideoStats, lastTwoWndStats);

app/streaming/video/ffmpeg.h

@@ -18,7 +18,8 @@ public:
                             int width,
                             int height,
                             int maxFps,
-                            bool enableVsync) override;
+                            bool enableVsync,
+                            bool enableFramePacing) override;
     virtual bool isHardwareAccelerated() override;
     virtual int getDecoderCapabilities() override;
     virtual int submitDecodeUnit(PDECODE_UNIT du) override;
@@ -30,7 +31,7 @@ public:
 private:
     bool completeInitialization(AVCodec* decoder, SDL_Window* window,
                                 int videoFormat, int width, int height,
-                                int maxFps, bool enableVsync, bool testOnly);
+                                int maxFps, bool enableFramePacing, bool testOnly);
 
     void logVideoStats(VIDEO_STATS& stats, const char* title);
 

app/streaming/video/sl.cpp

@@ -34,7 +34,7 @@ SLVideoDecoder::getDecoderCapabilities()
 bool
 SLVideoDecoder::initialize(StreamingPreferences::VideoDecoderSelection vds,
                            SDL_Window*,
-                           int videoFormat, int, int, int frameRate, bool)
+                           int videoFormat, int, int, int frameRate, bool, bool)
 {
     // SLVideo only supports hardware decoding
     if (vds == StreamingPreferences::VDS_FORCE_SOFTWARE) {

app/streaming/video/sl.h

@@ -15,7 +15,8 @@ public:
                             int width,
                             int height,
                             int frameRate,
-                            bool enableVsync);
+                            bool enableVsync,
+                            bool enableFramePacing);
     virtual bool isHardwareAccelerated();
     virtual int getDecoderCapabilities();
     virtual int submitDecodeUnit(PDECODE_UNIT du);