diff --git a/source/app/InputStream.cpp b/source/app/InputStream.cpp
index 60ccfd3..34dd57c 100755
--- a/source/app/InputStream.cpp
+++ b/source/app/InputStream.cpp
@@ -307,7 +307,7 @@ Void InputStream::readNextFrame()
   }
 #endif
 
-  UInt64 frame_bytes_input = m_ppcFrameBuffer[0]->getBytesPerFrame();
+  UInt64 frame_bytes_input = m_pcNextFrame->getBytesPerFrame();
   bytes_read = fread( m_pInputBuffer, sizeof(Pel), frame_bytes_input, m_pFile );
   if( bytes_read != frame_bytes_input )
   {
diff --git a/source/app/plaYUVerApp.cpp b/source/app/plaYUVerApp.cpp
index a554572..7312533 100644
--- a/source/app/plaYUVerApp.cpp
+++ b/source/app/plaYUVerApp.cpp
@@ -220,11 +220,14 @@ void plaYUVerApp::updateProperties()
 void plaYUVerApp::play()
 {
   playingTimer->stop();
-  if( activeSubWindow() )
+  m_uiAveragePlayInterval = 0;
+  if( m_pcCurrentSubWindow )
   {
     UInt frameRate = activeSubWindow()->getInputStream()->getFrameRate();
     UInt timeInterval = ( UInt )( 1000.0 / frameRate + 0.5 );
+    qDebug() << "Desired frame rate: " << QString::number( 1000 / timeInterval ) << " fps";
     playingTimer->start( timeInterval );
+    m_cTimer.start();
   }
 }
 
@@ -235,23 +238,33 @@ void plaYUVerApp::pause()
 
 void plaYUVerApp::stop()
 {
-  activeSubWindow()->stopEvent();
-  m_pcFrameSlider->setValue( activeSubWindow()->getInputStream()->getCurrFrameNum() );
-  playingTimer->stop();
+  if( m_pcCurrentSubWindow )
+  {
+    m_pcCurrentSubWindow->stopEvent();
+    m_pcFrameSlider->setValue( m_pcCurrentSubWindow->getInputStream()->getCurrFrameNum() );
+    playingTimer->stop();
+    if( m_uiAveragePlayInterval )
+      qDebug() << "Real display time: " << QString::number( 1000 / m_uiAveragePlayInterval ) << " fps";
+    m_uiAveragePlayInterval = 0;
+  }
 }
 
 void plaYUVerApp::playEvent()
 {
-  if( activeSubWindow() )
+  //m_cTimer.restart();
+  if( m_pcCurrentSubWindow )
   {
-    if( !activeSubWindow()->playEvent() )
+    UInt time = m_cTimer.elapsed();
+    m_cTimer.restart();
+    m_uiAveragePlayInterval = ( m_uiAveragePlayInterval + time) / 2;
+    if( !m_pcCurrentSubWindow->playEvent() )
     {
       if( !actionVideoLoop->isChecked() )
       {
         stop();
       }
     }
-    m_pcFrameSlider->setValue( activeSubWindow()->getInputStream()->getCurrFrameNum() );
+    m_pcFrameSlider->setValue( m_pcCurrentSubWindow->getInputStream()->getCurrFrameNum() );
   }
 }
 
diff --git a/source/app/plaYUVerApp.h b/source/app/plaYUVerApp.h
index 43ee08a..a1f95d2 100644
--- a/source/app/plaYUVerApp.h
+++ b/source/app/plaYUVerApp.h
@@ -103,6 +103,8 @@ private:
 
   QString m_cLastOpenPath;
   QTimer *playingTimer;
+  QTime m_cTimer;
+  UInt m_uiAveragePlayInterval;
 
   Void updateMenus();
   Void updateProperties();