diff --git a/toonz/sources/include/toonzqt/flipconsole.h b/toonz/sources/include/toonzqt/flipconsole.h
index b9de6cf..91340e5 100644
--- a/toonz/sources/include/toonzqt/flipconsole.h
+++ b/toonz/sources/include/toonzqt/flipconsole.h
@@ -19,6 +19,7 @@
 #include "toonz/imagepainter.h"
 #include "tstopwatch.h"
 #include <QThread>
+#include <QElapsedTimer>
 
 #undef DVAPI
 #undef DVVAR
@@ -52,6 +53,7 @@ class PlaybackExecutor final : public QThread {
 
   int m_fps;
   bool m_abort;
+  QElapsedTimer m_timer;
 
 public:
   PlaybackExecutor();
@@ -60,12 +62,14 @@ public:
 
   void run() override;
   void abort() { m_abort = true; }
-
-  void emitNextFrame(int fps) { emit nextFrame(fps); }
+  bool isAborted() { return m_abort; }
+  void emitNextFrame(int fps) { emit nextFrame(fps, nullptr, 0); }
 
 signals:
-  void nextFrame(int fps);  // Must be connect with Qt::BlockingQueuedConnection
-                            // connection type.
+  void nextFrame(
+      int fps, QElapsedTimer *timer,
+      qint64 targetInstant);  // Must be connect with
+                              // Qt::BlockingQueuedConnection connection type.
 };
 
 //-----------------------------------------------------------------------------
@@ -298,7 +302,7 @@ public:
   }
 
   bool isLinkable() const { return m_isLinkable; }
-  void playNextFrame();
+  void playNextFrame(QElapsedTimer *timer = nullptr, qint64 targetInstant = 0);
   void updateCurrentFPS(int val);
 
   bool hasButton(std::vector<int> buttonMask, FlipConsole::EGadget buttonId) {
@@ -401,9 +405,9 @@ protected slots:
   }
   void onButtonPressed(int button);
   void incrementCurrentFrame(int delta);
-  void onNextFrame(int fps);
+  void onNextFrame(int fps, QElapsedTimer *timer, qint64 target);
   void onCustomizeButtonPressed(QAction *);
-  bool drawBlanks(int from, int to);
+  bool drawBlanks(int from, int to, QElapsedTimer *timer, qint64 target);
   void onSliderRelease();
 
   void onFPSEdited();
diff --git a/toonz/sources/include/toonzqt/flipconsoleowner.h b/toonz/sources/include/toonzqt/flipconsoleowner.h
index b3eec23..40a3560 100644
--- a/toonz/sources/include/toonzqt/flipconsoleowner.h
+++ b/toonz/sources/include/toonzqt/flipconsoleowner.h
@@ -16,7 +16,9 @@ class FlipConsole;
 class FlipConsoleOwner {
 public:
   virtual void onDrawFrame(int frame,
-                           const ImagePainter::VisualSettings &settings) = 0;
+                           const ImagePainter::VisualSettings& settings,
+                           QElapsedTimer* timer = nullptr,
+                           qint64 targetInstant = 0) = 0;
 
   virtual void swapBuffers(){};
   virtual void changeSwapBehavior(bool enable){};
diff --git a/toonz/sources/stopmotion/stopmotioncontroller.cpp b/toonz/sources/stopmotion/stopmotioncontroller.cpp
index 00d7b3c..4befa72 100644
--- a/toonz/sources/stopmotion/stopmotioncontroller.cpp
+++ b/toonz/sources/stopmotion/stopmotioncontroller.cpp
@@ -1933,8 +1933,8 @@ void StopMotionController::onNewCameraSelected(int index, bool useWebcam) {
     m_resolutionCombo->hide();
     m_resolutionLabel->hide();
     m_cameraStatusLabel->hide();
-    m_pickZoomButton->setStyleSheet("border:1px solid rgb(0, 0, 0, 0);");
-    m_zoomButton->setStyleSheet("border:1px solid rgb(0, 0, 0, 0);");
+    m_pickZoomButton->setStyleSheet("border:1px solid rgba(0, 0, 0, 0);");
+    m_zoomButton->setStyleSheet("border:1px solid rgba(0, 0, 0, 0);");
     m_pickZoomButton->setChecked(false);
     m_zoomButton->setChecked(false);
     m_dslrFrame->hide();
@@ -2382,9 +2382,9 @@ void StopMotionController::onPictureStyleChangedSignal(QString text) {
 void StopMotionController::onFocusCheckToggled(bool on) {
 #ifdef WITH_CANON
   if (on) {
-    m_zoomButton->setStyleSheet("border:1px solid rgb(0, 255, 0, 255);");
+    m_zoomButton->setStyleSheet("border:1px solid rgba(0, 255, 0, 255);");
   } else {
-    m_zoomButton->setStyleSheet("border:1px solid rgb(0, 0, 0, 0);");
+    m_zoomButton->setStyleSheet("border:1px solid rgba(0, 0, 0, 0);");
   }
   m_zoomButton->blockSignals(true);
   m_zoomButton->setChecked(on);
@@ -2397,10 +2397,10 @@ void StopMotionController::onFocusCheckToggled(bool on) {
 void StopMotionController::onPickFocusCheckToggled(bool on) {
 #ifdef WITH_CANON
   if (on) {
-    m_pickZoomButton->setStyleSheet("border:1px solid rgb(0, 255, 0, 255);");
+    m_pickZoomButton->setStyleSheet("border:1px solid rgba(0, 255, 0, 255);");
 
   } else {
-    m_pickZoomButton->setStyleSheet("border:1px solid rgb(0, 0, 0, 0);");
+    m_pickZoomButton->setStyleSheet("border:1px solid rgba(0, 0, 0, 0);");
   }
   m_pickZoomButton->blockSignals(true);
   m_pickZoomButton->setChecked(on);
diff --git a/toonz/sources/toonz/comboviewerpane.cpp b/toonz/sources/toonz/comboviewerpane.cpp
index c342707..9e49841 100644
--- a/toonz/sources/toonz/comboviewerpane.cpp
+++ b/toonz/sources/toonz/comboviewerpane.cpp
@@ -286,10 +286,13 @@ void ComboViewerPanel::onShowHideActionTriggered(QAction *act) {
 
 //-----------------------------------------------------------------------------
 
-void ComboViewerPanel::onDrawFrame(
-    int frame, const ImagePainter::VisualSettings &settings) {
+void ComboViewerPanel::onDrawFrame(int frame,
+                                   const ImagePainter::VisualSettings &settings,
+                                   QElapsedTimer *timer, qint64 targetInstant) {
   TApp *app = TApp::instance();
   m_sceneViewer->setVisual(settings);
+  m_sceneViewer->setTimerAndTargetInstant(timer, targetInstant);
+
   TFrameHandle *frameHandle = app->getCurrentFrame();
 
   if (m_sceneViewer->isPreviewEnabled()) {
@@ -324,6 +327,12 @@ void ComboViewerPanel::onDrawFrame(
 
   else if (settings.m_blankColor != TPixel::Transparent)
     m_sceneViewer->update();
+
+  // make sure to redraw the frame here.
+  // repaint() does NOT immediately redraw the frame for QOpenGLWidget
+  if (frameHandle->isPlaying())
+    qApp->processEvents(QEventLoop::ExcludeUserInputEvents |
+                        QEventLoop::ExcludeSocketNotifiers);
 }
 
 //-----------------------------------------------------------------------------
@@ -644,10 +653,10 @@ void ComboViewerPanel::changeWindowTitle() {
     name = name + tr("   ::   Level: ") + imageName;
 
     if (!m_sceneViewer->is3DView()) {
-      TAffine aff                             = m_sceneViewer->getViewMatrix();
+      TAffine aff = m_sceneViewer->getViewMatrix();
       if (m_sceneViewer->getIsFlippedX()) aff = aff * TScale(-1, 1);
       if (m_sceneViewer->getIsFlippedY()) aff = aff * TScale(1, -1);
-      name                                    = name + "  ::  Zoom : " +
+      name = name + "  ::  Zoom : " +
              QString::number((int)(100.0 * sqrt(aff.det()) *
                                    m_sceneViewer->getDpiFactor())) +
              "%";
@@ -659,16 +668,15 @@ void ComboViewerPanel::changeWindowTitle() {
                  ->isActualPixelViewOnSceneEditingModeEnabled() &&
              TApp::instance()->getCurrentLevel()->getSimpleLevel() &&
              !CleanupPreviewCheck::instance()
-                  ->isEnabled()  // cleanup preview must be OFF
-             &&
-             !CameraTestCheck::instance()  // camera test mode must be OFF
-                                           // neither
-                  ->isEnabled() &&
+                  ->isEnabled()               // cleanup preview must be OFF
+             && !CameraTestCheck::instance()  // camera test mode must be OFF
+                                              // neither
+                     ->isEnabled() &&
              !m_sceneViewer->is3DView()) {
-      TAffine aff                             = m_sceneViewer->getViewMatrix();
+      TAffine aff = m_sceneViewer->getViewMatrix();
       if (m_sceneViewer->getIsFlippedX()) aff = aff * TScale(-1, 1);
       if (m_sceneViewer->getIsFlippedY()) aff = aff * TScale(1, -1);
-      name                                    = name + "  ::  Zoom : " +
+      name = name + "  ::  Zoom : " +
              QString::number((int)(100.0 * sqrt(aff.det()) *
                                    m_sceneViewer->getDpiFactor())) +
              "%";
@@ -688,7 +696,7 @@ void ComboViewerPanel::changeWindowTitle() {
         TAffine aff = m_sceneViewer->getViewMatrix();
         if (m_sceneViewer->getIsFlippedX()) aff = aff * TScale(-1, 1);
         if (m_sceneViewer->getIsFlippedY()) aff = aff * TScale(1, -1);
-        name                                    = name + "  ::  Zoom : " +
+        name = name + "  ::  Zoom : " +
                QString::number((int)(100.0 * sqrt(aff.det()) *
                                      m_sceneViewer->getDpiFactor())) +
                "%";
diff --git a/toonz/sources/toonz/comboviewerpane.h b/toonz/sources/toonz/comboviewerpane.h
index df778a3..cb6c4f8 100644
--- a/toonz/sources/toonz/comboviewerpane.h
+++ b/toonz/sources/toonz/comboviewerpane.h
@@ -86,8 +86,8 @@ public:
   void updateShowHide();
   void addShowHideContextMenu(QMenu *);
 
-  void onDrawFrame(int frame,
-                   const ImagePainter::VisualSettings &settings) override;
+  void onDrawFrame(int frame, const ImagePainter::VisualSettings &settings,
+                   QElapsedTimer *timer, qint64 targetInstant) override;
 
   void onEnterPanel() {
     m_sceneViewer->setFocus(Qt::OtherFocusReason);
diff --git a/toonz/sources/toonz/flipbook.cpp b/toonz/sources/toonz/flipbook.cpp
index ce2bf9c..ac550ac 100644
--- a/toonz/sources/toonz/flipbook.cpp
+++ b/toonz/sources/toonz/flipbook.cpp
@@ -1668,9 +1668,11 @@ else*/
 
 /*! Set current level frame to image viewer. Add the view image in cache.
  */
-void FlipBook::onDrawFrame(int frame, const ImagePainter::VisualSettings &vs) {
+void FlipBook::onDrawFrame(int frame, const ImagePainter::VisualSettings &vs,
+                           QElapsedTimer *timer, qint64 targetInstant) {
   try {
     m_imageViewer->setVisual(vs);
+    m_imageViewer->setTimerAndTargetInstant(timer, targetInstant);
 
     TImageP img = getCurrentImage(frame);
 
diff --git a/toonz/sources/toonz/flipbook.h b/toonz/sources/toonz/flipbook.h
index 474550f..5424f69 100644
--- a/toonz/sources/toonz/flipbook.h
+++ b/toonz/sources/toonz/flipbook.h
@@ -238,7 +238,8 @@ public:
 
   void reset();
 
-  void onDrawFrame(int frame, const ImagePainter::VisualSettings &vs) override;
+  void onDrawFrame(int frame, const ImagePainter::VisualSettings &vs,
+                   QElapsedTimer *timer, qint64 targetInstant) override;
 
   void minimize(bool doMinimize);
 
diff --git a/toonz/sources/toonz/imageviewer.cpp b/toonz/sources/toonz/imageviewer.cpp
index 768e1c7..96f74f8 100644
--- a/toonz/sources/toonz/imageviewer.cpp
+++ b/toonz/sources/toonz/imageviewer.cpp
@@ -225,7 +225,8 @@ ImageViewer::ImageViewer(QWidget *parent, FlipBook *flipbook,
     , m_histogramPopup(0)
     , m_isRemakingPreviewFx(false)
     , m_rectRGBPick(false)
-    , m_firstImage(true) {
+    , m_firstImage(true)
+    , m_timer(nullptr) {
   m_visualSettings.m_sceneProperties =
       TApp::instance()->getCurrentScene()->getScene()->getProperties();
   m_visualSettings.m_drawExternalBG = true;
@@ -415,10 +416,13 @@ void ImageViewer::setImage(TImageP image) {
 
   if (m_isHistogramEnable && m_histogramPopup->isVisible())
     m_histogramPopup->setImage(image);
+
+  // make sure to redraw the frame here.
+  // repaint() does NOT immediately redraw the frame for QOpenGLWidget
+  update();
   if (!isColorModel())
-    repaint();
-  else
-    update();
+    qApp->processEvents(QEventLoop::ExcludeUserInputEvents |
+                        QEventLoop::ExcludeSocketNotifiers);
 }
 
 //-------------------------------------------------------------------
@@ -563,6 +567,12 @@ void ImageViewer::paintGL() {
   if (!m_image) {
     if (m_lutCalibrator && m_lutCalibrator->isValid())
       m_lutCalibrator->onEndDraw(m_fbo);
+    if (m_timer && m_timer->isValid()) {
+      qint64 currentInstant = m_timer->nsecsElapsed();
+      while (currentInstant < m_targetInstant) {
+        currentInstant = m_timer->nsecsElapsed();
+      }
+    }
     return;
   }
 
@@ -642,6 +652,14 @@ void ImageViewer::paintGL() {
 
   if (m_lutCalibrator && m_lutCalibrator->isValid())
     m_lutCalibrator->onEndDraw(m_fbo);
+
+  // wait to achieve precise fps
+  if (m_timer && m_timer->isValid()) {
+    qint64 currentInstant = m_timer->nsecsElapsed();
+    while (currentInstant < m_targetInstant) {
+      currentInstant = m_timer->nsecsElapsed();
+    }
+  }
 }
 
 //------------------------------------------------------------------------------
diff --git a/toonz/sources/toonz/imageviewer.h b/toonz/sources/toonz/imageviewer.h
index 42700ad..55b9f94 100644
--- a/toonz/sources/toonz/imageviewer.h
+++ b/toonz/sources/toonz/imageviewer.h
@@ -17,6 +17,7 @@ class QOpenGLFramebufferObject;
 class LutCalibrator;
 class QTouchEvent;
 class QGestureEvent;
+class QElapsedTimer;
 //-----------------------------------------------------------------------------
 
 //====================
@@ -79,6 +80,10 @@ class ImageViewer final : public GLWidgetForHighDpi {
   bool m_stylusUsed       = false;
   bool m_firstInitialized = true;
 
+  // passed from PlaybackExecutor
+  QElapsedTimer *m_timer;
+  qint64 m_targetInstant;
+
   int getDragType(const TPoint &pos, const TRect &loadBox);
   void updateLoadbox(const TPoint &curPos);
   void updateCursor(const TPoint &curPos);
@@ -132,6 +137,11 @@ public:
   void changeSwapBehavior(bool enable);
   void invalidateCompHisto();
 
+  void setTimerAndTargetInstant(QElapsedTimer *timer, qint64 target) {
+    m_timer         = timer;
+    m_targetInstant = target;
+  }
+
 protected:
   void contextMenuEvent(QContextMenuEvent *event) override;
   void initializeGL() override;
diff --git a/toonz/sources/toonz/sceneviewer.cpp b/toonz/sources/toonz/sceneviewer.cpp
index 01758ad..98be921 100644
--- a/toonz/sources/toonz/sceneviewer.cpp
+++ b/toonz/sources/toonz/sceneviewer.cpp
@@ -780,7 +780,8 @@ SceneViewer::SceneViewer(ImageUtils::FullScreenWidget *parent)
     , m_editPreviewSubCamera(false)
     , m_locator(NULL)
     , m_isLocator(false)
-    , m_isBusyOnTabletMove(false) {
+    , m_isBusyOnTabletMove(false)
+    , m_timer(nullptr) {
   m_visualSettings.m_sceneProperties =
       TApp::instance()->getCurrentScene()->getScene()->getProperties();
 #if defined(x64)
@@ -1936,6 +1937,14 @@ void SceneViewer::paintGL() {
 
   if (!m_isPicking && m_lutCalibrator && m_lutCalibrator->isValid())
     m_lutCalibrator->onEndDraw(m_fbo);
+
+  // wait to achieve precise fps
+  if (m_timer && m_timer->isValid()) {
+    qint64 currentInstant = m_timer->nsecsElapsed();
+    while (currentInstant < m_targetInstant) {
+      currentInstant = m_timer->nsecsElapsed();
+    }
+  }
 }
 
 //-----------------------------------------------------------------------------
diff --git a/toonz/sources/toonz/sceneviewer.h b/toonz/sources/toonz/sceneviewer.h
index f79fdbb..4ad3e4a 100644
--- a/toonz/sources/toonz/sceneviewer.h
+++ b/toonz/sources/toonz/sceneviewer.h
@@ -39,6 +39,7 @@ class QTouchEvent;
 class QOpenGLFramebufferObject;
 class LutCalibrator;
 class StopMotion;
+class QElapsedTimer;
 
 namespace ImageUtils {
 class FullScreenWidget;
@@ -189,6 +190,10 @@ class SceneViewer final : public GLWidgetForHighDpi,
 
   bool m_firstInitialized = true;
 
+  // passed from PlaybackExecutor
+  QElapsedTimer *m_timer;
+  qint64 m_targetInstant;
+
 public:
   enum ReferenceMode {
     NORMAL_REFERENCE   = 1,
@@ -290,6 +295,11 @@ public:
   void bindFBO() override;
   void releaseFBO() override;
 
+  void setTimerAndTargetInstant(QElapsedTimer *timer, qint64 target) {
+    m_timer         = timer;
+    m_targetInstant = target;
+  }
+
 public:
   // SceneViewer's gadget public functions
   TPointD winToWorld(const QPointF &pos) const;
diff --git a/toonz/sources/toonz/viewerpane.cpp b/toonz/sources/toonz/viewerpane.cpp
index 68f98fd..6923332 100644
--- a/toonz/sources/toonz/viewerpane.cpp
+++ b/toonz/sources/toonz/viewerpane.cpp
@@ -261,10 +261,13 @@ void SceneViewerPanel::onShowHideActionTriggered(QAction *act) {
   updateShowHide();
 }
 
-void SceneViewerPanel::onDrawFrame(
-    int frame, const ImagePainter::VisualSettings &settings) {
+void SceneViewerPanel::onDrawFrame(int frame,
+                                   const ImagePainter::VisualSettings &settings,
+                                   QElapsedTimer *timer, qint64 targetInstant) {
   TApp *app = TApp::instance();
   m_sceneViewer->setVisual(settings);
+  m_sceneViewer->setTimerAndTargetInstant(timer, targetInstant);
+
   TFrameHandle *frameHandle = app->getCurrentFrame();
 
   if (m_sceneViewer->isPreviewEnabled()) {
@@ -298,6 +301,12 @@ void SceneViewerPanel::onDrawFrame(
 
   else if (settings.m_blankColor != TPixel::Transparent)
     m_sceneViewer->update();
+
+  // make sure to redraw the frame here.
+  // repaint() does NOT immediately redraw the frame for QOpenGLWidget
+  if (frameHandle->isPlaying())
+    qApp->processEvents(QEventLoop::ExcludeUserInputEvents |
+                        QEventLoop::ExcludeSocketNotifiers);
 }
 
 //-----------------------------------------------------------------------------
diff --git a/toonz/sources/toonz/viewerpane.h b/toonz/sources/toonz/viewerpane.h
index 6197d74..c6a47d5 100644
--- a/toonz/sources/toonz/viewerpane.h
+++ b/toonz/sources/toonz/viewerpane.h
@@ -42,9 +42,9 @@ class SceneViewerPanel final : public QFrame,
   TPanelTitleBarButton *m_subcameraPreviewButton;
   bool m_onionSkinActive = false;
   UINT m_visiblePartsFlag;
-  bool m_playSound       = true;
-  bool m_hasSoundtrack   = false;
-  bool m_playing         = false;
+  bool m_playSound     = true;
+  bool m_hasSoundtrack = false;
+  bool m_playing       = false;
   double m_fps;
   int m_viewerFps;
   double m_samplesPerFrame;
@@ -62,23 +62,23 @@ public:
   // toggle show/hide of the widgets according to m_visiblePartsFlag
   void setVisiblePartsFlag(UINT flag);
   void updateShowHide();
-  void addShowHideContextMenu(QMenu*);
+  void addShowHideContextMenu(QMenu *);
 
-  void onDrawFrame(int frame,
-                   const ImagePainter::VisualSettings &settings) override;
+  void onDrawFrame(int frame, const ImagePainter::VisualSettings &settings,
+                   QElapsedTimer *timer, qint64 targetInstant) override;
 
   void onEnterPanel() {
-      m_sceneViewer->setFocus(Qt::OtherFocusReason);
-      // activate shortcut key for this flipconsole
-      m_flipConsole->makeCurrent();
+    m_sceneViewer->setFocus(Qt::OtherFocusReason);
+    // activate shortcut key for this flipconsole
+    m_flipConsole->makeCurrent();
   }
   void onLeavePanel() { m_sceneViewer->clearFocus(); }
 
   // SaveLoadQSettings
-  virtual void save(QSettings& settings) const override;
-  virtual void load(QSettings& settings) override;
+  virtual void save(QSettings &settings) const override;
+  virtual void load(QSettings &settings) override;
 
-  void initializeTitleBar(TPanelTitleBar* titleBar);
+  void initializeTitleBar(TPanelTitleBar *titleBar);
 
 protected:
   void showEvent(QShowEvent *) override;
@@ -92,7 +92,7 @@ protected:
   void enableFlipConsoleForCamerastand(bool on);
   void playAudioFrame(int frame);
   bool hasSoundtrack();
-  void contextMenuEvent(QContextMenuEvent* event) override;
+  void contextMenuEvent(QContextMenuEvent *event) override;
 
 public slots:
 
@@ -112,7 +112,7 @@ protected slots:
   void onFrameTypeChanged();
   void onPlayingStatusChanged(bool playing);
   // for showing/hiding the parts
-  void onShowHideActionTriggered(QAction*);
+  void onShowHideActionTriggered(QAction *);
   void enableFullPreview(bool enabled);
   void enableSubCameraPreview(bool enabled);
 };
diff --git a/toonz/sources/toonzlib/imagepainter.cpp b/toonz/sources/toonzlib/imagepainter.cpp
index f76ceb2..f4cc3d4 100644
--- a/toonz/sources/toonzlib/imagepainter.cpp
+++ b/toonz/sources/toonzlib/imagepainter.cpp
@@ -355,8 +355,9 @@ void Painter::doFlushRasterImages(const TRasterP &rin, int bg,
   if (m_vSettings.m_useTexture)
     bbox = m_bbox;
   else {
-    double delta = sqrt(fabs(m_finalAff.det()));
-    bbox         = m_bbox.enlarge(delta) * viewRect;
+    // double delta = sqrt(fabs(m_finalAff.det()));
+    // bbox = m_bbox.enlarge(delta) * viewRect;
+    bbox = m_bbox * viewRect;
   }
 
   UCHAR chan = m_vSettings.m_colorMask;
@@ -367,13 +368,23 @@ void Painter::doFlushRasterImages(const TRasterP &rin, int bg,
   // TRaster32P ras;
   TRasterP _rin = rin;
   TAffine aff;
+  bool is16bpc = false;
   if (m_vSettings.m_useTexture) {
     ras = _rin;
     aff = m_aff;
     // ras->clear();
   } else {
     int lx = rect.getLx(), ly = rect.getLy();
+    // when the "30bit display" preference option is enabled,
+    // image previewed in 16bpc is not dithered & converted to 8bpc,
+    // but is kept the channel depth as 16bpc.
+    if (_rin->getPixelSize() == 8) {
+      ras     = TRaster64P(lx, ly);
+      is16bpc = true;
+    } else
+      ras = TRaster32P(lx, ly);
 
+    /*
     // Following lines are used to solve a problem that occurs with some
     // graphics cards!
     // It seems that the glReadPixels() function is very slow if the lx length
@@ -391,23 +402,22 @@ void Painter::doFlushRasterImages(const TRasterP &rin, int bg,
                  TGL_TYPE, backgroundRas->getRawData());
     TRect r = rect - rect.getP00();
     ras     = backgroundRas->extract(r);
-
+    */
     aff = TTranslation(-rect.x0, -rect.y0) * m_finalAff;
     aff *= TTranslation(TPointD(0.5, 0.5));  // very quick and very dirty fix:
                                              // in camerastand the images seems
                                              // shifted of an half pixel...it's
                                              // a quickput approximation?
-  }
-
-  // when the "30bit display" preference option is enabled,
-  // image previewed in 16bpc is not dithered & converted to 8bpc,
-  // but is kept the channel depth as 16bpc.
-  bool is16bpc = false;
-  if (_rin->getPixelSize() == 8) {
-    TRaster64P rasAux(ras->getLx(), ras->getLy());
-    TRop::convert(rasAux, ras);
-    ras     = rasAux;
-    is16bpc = true;
+    if (bg == 0x100000)
+      quickput(ras, buildCheckboard(bg, _rin->getSize()), m_palette, aff,
+               false);
+    else {
+      if (is16bpc)
+        ((TRaster64P)ras)
+            ->fill(bg == 0x40000 ? TPixel64::Black : TPixel64::White);
+      else
+        ((TRaster32P)ras)->fill(bg == 0x40000 ? TPixel::Black : TPixel::White);
+    }
   }
 
   ras->lock();
@@ -434,26 +444,6 @@ void Painter::doFlushRasterImages(const TRasterP &rin, int bg,
                                 ras->getSize(), true);
     ras->unlock();
   } else {
-    if (bg == 0x100000)
-      quickput(ras, buildCheckboard(bg, _rin->getSize()), m_palette, aff,
-               false);
-    else {
-      int lx = (m_imageSize.lx == 0 ? _rin->getLx() : m_imageSize.lx);
-      int ly = (m_imageSize.ly == 0 ? _rin->getLy() : m_imageSize.ly);
-
-      TRect rect = convert(aff * TRectD(0, 0, lx - 1, ly - 1));
-      // Image size is a 0 point.  Do nothing
-      if (rect.x0 == rect.x1 && rect.y0 == rect.y1) return;
-
-      if (is16bpc) {
-        TRaster64P raux = ras->extract(rect);
-        raux->fill(bg == 0x40000 ? TPixel64::Black : TPixel64::White);
-      } else {
-        TRaster32P raux = ras->extract(rect);
-        raux->fill(bg == 0x40000 ? TPixel::Black : TPixel::White);
-      }
-    }
-
     if (showChannelsOnMatte)
       quickput(ras, keepChannels(_rin, m_palette, chan), m_palette,
                m_vSettings.m_useTexture ? TAffine() : aff * TTranslation(offs),
diff --git a/toonz/sources/toonzqt/flipconsole.cpp b/toonz/sources/toonzqt/flipconsole.cpp
index f4b5bfa..6b15593 100644
--- a/toonz/sources/toonzqt/flipconsole.cpp
+++ b/toonz/sources/toonzqt/flipconsole.cpp
@@ -22,6 +22,8 @@
 
 #include "../toonz/tapp.h"
 
+#include <time.h>
+
 // Qt includes
 #include <QVBoxLayout>
 #include <QHBoxLayout>
@@ -153,110 +155,98 @@ void PlaybackExecutor::resetFps(int fps) { m_fps = fps; }
 void PlaybackExecutor::run() {
   // (Daniele)
   // We'll build the fps considering an interval of roughly 1 second (the last
-  // one).
-  // However, the fps should be sampled at a faster rate. Each sample is taken
-  // at
-  // 1/4 second, and the last 4 samples data are stored to keep trace of the
-  // last
-  // second of playback.
-
-  TStopWatch timer;
-  timer.start();
+  // one). However, the fps should be sampled at a faster rate. Each sample is
+  // taken at 1/4 second, and the last 4 samples data are stored to keep trace
+  // of the last second of playback.
+  m_timer.start();
 
-  TUINT32 timeResolution =
-      250;  // Use a sufficient sampling resolution (currently 1/4 sec).
-            // Fps calculation is made once per sample.
+  qint64 timeResolution =
+      250 * 1000000;  // Use a sufficient sampling resolution (currently 1/4
+                      // sec). Fps calculation is made once per sample.
 
   int fps = m_fps, currSample = 0;
-  TUINT32 playedFramesCount = 0;
-  TUINT32 loadedInstant, nextSampleInstant = timeResolution;
-  TUINT32 sampleTotalLoadingTime = 0;
-
-  TUINT32 lastFrameCounts[4]    = {0, 0, 0,
-                                0};  // Keep the last 4 'played frames' counts.
-  TUINT32 lastSampleInstants[4] = {0, 0, 0,
-                                   0};  // Same for the last sampling instants
-  TUINT32 lastLoadingTimes[4]   = {0, 0, 0,
-                                 0};  // Same for total sample loading times
+  qint64 playedFramesCount = 0;
+  qint64 nextSampleInstant = timeResolution;
 
-  double targetFrameTime =
-      1000.0 / abs(m_fps);  // User-required time between frames
+  qint64 lastFrameCounts[4]    = {0, 0, 0,
+                               0};  // Keep the last 4 'played frames' counts.
+  qint64 lastSampleInstants[4] = {0, 0, 0,
+                                  0};  // Same for the last sampling instants
 
-  TUINT32 emissionInstant = 0;  // Effective instant in which loading is invoked
-  double emissionInstantD = 0.0;  // Double precision version of the above
+  qint64 targetFrameTime =
+      1000000000 / (qint64)abs(m_fps);  // User-required time between frames
 
-  double lastLoadingTime = 0.0;  // Mean frame loading time in the last sample
+  qint64 emissionInstant = 0;  // starting instant in which rendering is invoked
+  qint64 avgSwapTime     = 0;  // average time for swapping bufers
+  qint64 shortTermDelayAdjuster =
+      0;  // accumurate recent errors and adjust in short term
 
   while (!m_abort) {
-    emissionInstant = timer.getTotalTime();
-
-    // Draw the next frame
-    if (playedFramesCount)
-      emit nextFrame(fps);  // Show the next frame, telling
-                            // currently measured fps
-
-    if (FlipConsole::m_areLinked) {
-      // In case there are linked consoles, update them too.
-      // Their load time must be included in the fps calculation.
-      int i, consolesCount = FlipConsole::m_visibleConsoles.size();
-      for (i = 0; i < consolesCount; ++i) {
-        FlipConsole *console = FlipConsole::m_visibleConsoles.at(i);
-        if (console->isLinkable() && console != FlipConsole::m_currentConsole)
-          console->playbackExecutor().emitNextFrame(m_fps < 0 ? -fps : fps);
-      }
-    }
-
-    //-------- Each nextFrame() blocks until the frame has been shown ---------
-
-    ++playedFramesCount;
-    loadedInstant = timer.getTotalTime();
-    sampleTotalLoadingTime += (loadedInstant - emissionInstant);
-
-    // Recalculate data only after the specified time resolution has passed.
-    if (loadedInstant > nextSampleInstant) {
-      // Sampling instant. Perform calculations.
-
-      // Store values
-      TUINT32 framesCount = playedFramesCount - lastFrameCounts[currSample];
-      TUINT32 elapsedTime = loadedInstant - lastSampleInstants[currSample];
-      double loadingTime =
-          (sampleTotalLoadingTime - lastLoadingTimes[currSample]) /
-          (double)framesCount;
+    emissionInstant = m_timer.nsecsElapsed();
+
+    if (emissionInstant > nextSampleInstant) {
+      // Fps calculation
+      qint64 framesCount = playedFramesCount - lastFrameCounts[currSample];
+      qint64 elapsedTime = emissionInstant - lastSampleInstants[currSample];
+      fps                = troundp((long double)(1000000000 * framesCount) /
+                    (long double)elapsedTime);
+
+      targetFrameTime =
+          1000000000 / (qint64)abs(m_fps);  // m_fps could have changed...
+
+      // estimate time for swapping buffers
+      qint64 avgSwapTimeD = (elapsedTime / framesCount) - targetFrameTime;
+      if (avgSwapTime - avgSwapTimeD >
+          20000000)  // Reset beyond, say, 20 msecs tolerance.
+        avgSwapTime = avgSwapTimeD;
+      else
+        avgSwapTime += avgSwapTimeD;
+      avgSwapTime = std::min(targetFrameTime, std::max(avgSwapTime, (qint64)0));
 
+      // preapre for the next sampling
       lastFrameCounts[currSample]    = playedFramesCount;
-      lastSampleInstants[currSample] = loadedInstant;
-      lastLoadingTimes[currSample]   = sampleTotalLoadingTime;
-
-      currSample        = (currSample + 1) % 4;
-      nextSampleInstant = loadedInstant + timeResolution;
-
-      // Rebuild current fps
-      fps             = troundp((1000 * framesCount) / (double)elapsedTime);
-      targetFrameTime = 1000.0 / abs(m_fps);  // m_fps could have changed...
-
-      // In case the playback is too slow to keep the required pace, reset the
-      // emission timeline.
-      // Otherwise, it should be kept as the difference needs to be compensated
-      // to get the required fps.
-      if ((int)emissionInstant - (int)emissionInstantD >
-          20)  // Reset beyond, say, 20 msecs tolerance.
-        emissionInstantD = (double)loadedInstant - loadingTime;
-      else
-        emissionInstantD +=
-            lastLoadingTime -
-            loadingTime;  // Otherwise, just adapt to the new loading time
+      lastSampleInstants[currSample] = emissionInstant;
+      currSample                     = (currSample + 1) % 4;
+      nextSampleInstant              = emissionInstant + timeResolution;
+    }
 
-      lastLoadingTime = loadingTime;
+    // draw the next frame
+    if (playedFramesCount) {
+      qint64 delayAdjust = shortTermDelayAdjuster / 4;
+      qint64 targetInstant =
+          emissionInstant + targetFrameTime - avgSwapTime - delayAdjust;
+      targetInstant = std::max(targetInstant, emissionInstant);
+      shortTermDelayAdjuster -= delayAdjust;
+
+      // Show the next frame, telling currently measured fps
+      // The wait time will be inserted at the end of paintGL in order to
+      // achieve precise playback
+      emit nextFrame(fps, &m_timer, targetInstant);
+
+      if (FlipConsole::m_areLinked) {
+        // In case there are linked consoles, update them too.
+        // Their load time must be included in the fps calculation.
+        int i, consolesCount = FlipConsole::m_visibleConsoles.size();
+        for (i = 0; i < consolesCount; ++i) {
+          FlipConsole *console = FlipConsole::m_visibleConsoles.at(i);
+          if (console->isLinkable() && console != FlipConsole::m_currentConsole)
+            console->playbackExecutor().emitNextFrame(m_fps < 0 ? -fps : fps);
+        }
+      }
     }
 
-    // Calculate the new emission instant
-    emissionInstant = std::max((int)(emissionInstantD += targetFrameTime), 0);
+    //-------- Each nextFrame() blocks until the frame has been shown ---------
+
+    // accumurate error and slightly adjust waiting time for subsequent frames
+    qint64 delay = m_timer.nsecsElapsed() - emissionInstant - targetFrameTime;
+    // just ignore a large error
+    if (delay < targetFrameTime) shortTermDelayAdjuster += delay;
 
-    // Sleep until the next emission instant has been reached
-    while (timer.getTotalTime() < emissionInstant) msleep(1);
+    ++playedFramesCount;
   }
 
   m_abort = false;
+  m_timer.invalidate();
 }
 
 //==========================================================================================
@@ -530,8 +520,10 @@ FlipConsole::FlipConsole(QVBoxLayout *mainLayout, std::vector<int> gadgetsMask,
 
   applyCustomizeMask();
 
-  bool ret = connect(&m_playbackExecutor, SIGNAL(nextFrame(int)), this,
-                     SLOT(onNextFrame(int)), Qt::BlockingQueuedConnection);
+  bool ret = connect(&m_playbackExecutor,
+                     SIGNAL(nextFrame(int, QElapsedTimer *, qint64)), this,
+                     SLOT(onNextFrame(int, QElapsedTimer *, qint64)),
+                     Qt::BlockingQueuedConnection);
 
   assert(ret);
 
@@ -765,7 +757,8 @@ void FlipConsole::toggleLinked() {
 
 //----------------------------------------------------------------------------
 
-bool FlipConsole::drawBlanks(int from, int to) {
+bool FlipConsole::drawBlanks(int from, int to, QElapsedTimer *timer,
+                             qint64 target) {
   if (m_blanksCount == 0 || m_isPlay || m_framesCount <= 1) return false;
 
   // enable blanks only when the blank button is pressed
@@ -781,7 +774,7 @@ bool FlipConsole::drawBlanks(int from, int to) {
     m_blanksToDraw = (m_blanksToDraw == 0 ? m_blanksCount : m_blanksToDraw - 1);
     m_settings.m_blankColor     = m_blankColor;
     m_settings.m_drawBlankFrame = true;
-    m_consoleOwner->onDrawFrame(from, m_settings);
+    m_consoleOwner->onDrawFrame(from, m_settings, timer, target);
     m_settings.m_drawBlankFrame = false;
     return true;
   }
@@ -792,17 +785,19 @@ bool FlipConsole::drawBlanks(int from, int to) {
 
 //----------------------------------------------------------------------------
 
-void FlipConsole::onNextFrame(int fps) {
+void FlipConsole::onNextFrame(int fps, QElapsedTimer *timer,
+                              qint64 targetInstant) {
+  if (playbackExecutor().isAborted()) return;
   if (fps < 0)  // can be negative only if is a linked console; it means that
                 // the master console is playing backward
   {
     bool reverse = m_reverse;
     m_reverse    = true;
     fps          = -fps;
-    playNextFrame();
+    playNextFrame(timer, targetInstant);
     m_reverse = reverse;
   } else
-    playNextFrame();
+    playNextFrame(timer, targetInstant);
 
   if (fps == -1) return;
   if (m_fpsLabel)
@@ -818,7 +813,7 @@ void FlipConsole::onNextFrame(int fps) {
 
 //----------------------------------------------------------------------------
 
-void FlipConsole::playNextFrame() {
+void FlipConsole::playNextFrame(QElapsedTimer *timer, qint64 targetInstant) {
   int from = m_from, to = m_to;
   if (m_markerFrom <= m_markerTo) from = m_markerFrom, to = m_markerTo;
 
@@ -831,7 +826,7 @@ void FlipConsole::playNextFrame() {
       m_currentFrame = (m_reverse ? to : from);
     emit playStateChanged(false);
   } else {
-    if (drawBlanks(from, to)) return;
+    if (drawBlanks(from, to, timer, targetInstant)) return;
 
     if (m_reverse)
       m_currentFrame =
@@ -845,7 +840,7 @@ void FlipConsole::playNextFrame() {
   m_editCurrFrame->setText(QString::number(m_currentFrame));
   m_settings.m_blankColor        = TPixel::Transparent;
   m_settings.m_recomputeIfNeeded = true;
-  m_consoleOwner->onDrawFrame(m_currentFrame, m_settings);
+  m_consoleOwner->onDrawFrame(m_currentFrame, m_settings, timer, targetInstant);
 }
 
 //-----------------------------------------------------------------------------
diff --git a/toonz/sources/toonzqt/intfield.cpp b/toonz/sources/toonzqt/intfield.cpp
index 3ca87f5..16432a4 100644
--- a/toonz/sources/toonzqt/intfield.cpp
+++ b/toonz/sources/toonzqt/intfield.cpp
@@ -213,7 +213,7 @@ void IntLineEdit::setLineEditBackgroundColor(QColor color) {
     value = 255;  // white
 
   QString sheet =
-      QString("background-color: rgb(") + QString::number(color.red()) +
+      QString("background-color: rgba(") + QString::number(color.red()) +
       QString(",") + QString::number(color.green()) + QString(",") +
       QString::number(color.blue()) + QString(",") +
       QString::number(color.alpha()) +
@@ -298,7 +298,7 @@ IntField::IntField(QWidget *parent, bool isMaxRangeLimited, bool isRollerHide)
   m_slider = new QSlider(Qt::Horizontal, this);
   ret      = ret && connect(m_slider, SIGNAL(valueChanged(int)), this,
                        SLOT(onSliderChanged(int)));
-  ret = ret && connect(m_slider, SIGNAL(sliderReleased()), this,
+  ret      = ret && connect(m_slider, SIGNAL(sliderReleased()), this,
                        SLOT(onSliderReleased()));
 
   ret = ret && connect(m_lineEdit, SIGNAL(editingFinished()), this,
@@ -406,7 +406,7 @@ int IntField::pos2value(int x) const {
   else if (posRatio <= 0.9)
     t = -0.26 + 0.4 * posRatio;
   else
-    t              = -8.0 + 9.0 * posRatio;
+    t = -8.0 + 9.0 * posRatio;
   double sliderVal = (double)m_slider->minimum() + rangeSize * t;
   return (int)round(sliderVal * pow(0.1, NonLinearSliderPrecision));
 }