diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0602b8a..d1d0719 100755
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -8,6 +8,8 @@
 
 cmake_minimum_required( VERSION 2.8.9 )
 
+INCLUDE( cmake/CMakeMacros.cmake )
+
 PROJECT( playuver )
 
 SET( PROJECT_NAME playuver )
@@ -33,103 +35,6 @@ FILE( GLOB HEADERS_FILES   ${INC_DIR}/*.h   )
 FILE( GLOB FORMS_FILES     ${UI_DIR}/*.ui   )
 FILE( GLOB RESOURCES_FILES ${RSC_DIR}/*.qrc )
 
-######################################################################################
-# Macros
-######################################################################################
-macro(ADD_OPTION variable description value)
-  set(__value ${value})
-  set(__condition "")
-  set(__varname "__value")
-  foreach(arg ${ARGN})
-    if(arg STREQUAL "IF" OR arg STREQUAL "if")
-      set(__varname "__condition")
-    else()
-      list(APPEND ${__varname} ${arg})
-    endif()
-  endforeach()
-  unset(__varname)
-  if("${__condition}" STREQUAL "")
-    set(__condition 2 GREATER 1)
-  endif()
-
-  if(${__condition})
-    if("${__value}" MATCHES ";")
-      if(${__value})
-        option(${variable} "${description}" ON)
-      else()
-        option(${variable} "${description}" OFF)
-      endif()
-    elseif(DEFINED ${__value})
-      if(${__value})
-        option(${variable} "${description}" ON)
-      else()
-        option(${variable} "${description}" OFF)
-      endif()
-    else()
-      option(${variable} "${description}" ${__value})
-    endif()
-  else()
-    unset(${variable} CACHE)
-  endif()
-  unset(__condition)
-  unset(__value)
-endmacro()
-
-# Status report function.
-# Automatically align right column and selects text based on condition.
-# Usage:
-#   status(<text>)
-#   status(<heading> <value1> [<value2> ...])
-#   status(<heading> <condition> THEN <text for TRUE> ELSE <text for FALSE> )
-function(status text)
-  set(status_cond)
-  set(status_then)
-  set(status_else)
-
-  set(status_current_name "cond")
-  foreach(arg ${ARGN})
-    if(arg STREQUAL "THEN")
-      set(status_current_name "then")
-    elseif(arg STREQUAL "ELSE")
-      set(status_current_name "else")
-    else()
-      list(APPEND status_${status_current_name} ${arg})
-    endif()
-  endforeach()
-
-  if(DEFINED status_cond)
-    set(status_placeholder_length 32)
-    string(RANDOM LENGTH ${status_placeholder_length} ALPHABET " " status_placeholder)
-    string(LENGTH "${text}" status_text_length)
-    if(status_text_length LESS status_placeholder_length)
-      string(SUBSTRING "${text}${status_placeholder}" 0 ${status_placeholder_length} status_text)
-    elseif(DEFINED status_then OR DEFINED status_else)
-      message(STATUS ${text})
-      set(status_text "${status_placeholder}")
-    else()
-      set(status_text "${text}")
-    endif()
-
-    if(DEFINED status_then OR DEFINED status_else)
-      if(${status_cond})
-        string(REPLACE ";" " " status_then "${status_then}")
-        string(REGEX REPLACE "^[ \t]+" "" status_then "${status_then}")
-        message(STATUS "${status_text} ${status_then}")
-      else()
-        string(REPLACE ";" " " status_else "${status_else}")
-        string(REGEX REPLACE "^[ \t]+" "" status_else "${status_else}")
-        message(STATUS "${status_text} ${status_else}")
-      endif()
-    else()
-      string(REPLACE ";" " " status_cond "${status_cond}")
-      string(REGEX REPLACE "^[ \t]+" "" status_cond "${status_cond}")
-      message(STATUS "${status_text} ${status_cond}")
-    endif()
-  else()
-    message(STATUS "${text}")
-  endif()
-endfunction()
-
 
 ######################################################################################
 # Variables
@@ -139,45 +44,12 @@ ADD_OPTION(USE_QT4           "Build with QT4"           OFF )
 ADD_OPTION(USE_OPENCV        "Add OpenCV support"       OFF )
 ADD_OPTION(USE_FFMPEG        "Add FFMPEG support"       OFF )
 
-#####################################################################################
-# Qt library
-######################################################################################
-IF( USE_QT4 )
-    FIND_PACKAGE( Qt4 REQUIRED QtCore QtGui )
-    IF( NOT QT4_FOUND)
-        SET(USE_QT4 FALSE)
-    ENDIF()
-    INCLUDE( ${QT_USE_FILE} )
-    ADD_DEFINITIONS( ${QT_DEFINITIONS} )
-    
-    QT4_WRAP_UI( FORMS_HEADERS_FILES ${FORMS_FILES} )
-    QT4_ADD_RESOURCES( RESOURCES_RCC_FILES ${RESOURCES_FILES} )
-    
-    SET( LINKER_LIBS ${LINKER_LIBS} ${QT_LIBRARIES} )
-ENDIF()
-
-IF( NOT USE_QT4 )
-    FIND_PACKAGE( Qt5Core REQUIRED )
-    FIND_PACKAGE( Qt5Gui REQUIRED )
-    FIND_PACKAGE( Qt5Widgets REQUIRED )
-    
-    INCLUDE_DIRECTORIES( ${Qt5Widgets_INCLUDE_DIRS} ${Qt5Core_INCLUDE_DIRS} ${Qt5Gui_INCLUDE_DIRS} )
-    # QT5_WRAP_CPP( HEADERS_MOC_FILES ${HEADERS_FILES} )
-    QT5_WRAP_UI( FORMS_HEADERS_FILES ${FORMS_FILES} )
-    QT5_ADD_RESOURCES( RESOURCES_RCC_FILES ${RESOURCES_FILES} )
-    
-    # Add compiler flags for building executables (-fPIE)
-    SET( CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS} ${Qt5Core_EXECUTABLE_COMPILE_FLAGS} )
-    
-    SET( LINKER_LIBS ${LINKER_LIBS} ${Qt5Core_LIBRARIES} ${Qt5Gui_LIBRARIES} ${Qt5Widgets_LIBRARIES} )
-    
-    SET( CURR_QT_MODULES Core Gui Widgets )
-ENDIF()
-
 
 ######################################################################################
 # Dependencies
 ######################################################################################
+INCLUDE( cmake/LibQT.cmake )
+
 INCLUDE_DIRECTORIES( ${EXTERNAL_SRC}/scode )
 ADD_LIBRARY( Scode ${EXTERNAL_SRC}/scode/viewarea.cpp ${EXTERNAL_SRC}/scode/gridmanager.cpp ${EXTERNAL_SRC}/scode/scosettings.cpp )
 SET( LINKER_LIBS ${LINKER_LIBS} Scode )
@@ -192,24 +64,7 @@ IF( USE_OPENCV )
     ENDIF()
 ENDIF()
 
-IF( USE_FFMPEG )
-    IF( NOT WIN32 )
-        FIND_PACKAGE( FFmpeg )
-        IF( NOT FFMPEG_FOUND )
-            SET( USE_FFMPEG FALSE )
-        ELSE()
-            INCLUDE_DIRECTORIES( ${LIB_DIR}/ffmpeg )
-            #SET( CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS} -D__STDC_CONSTANT_MACROS )
-            INCLUDE_DIRECTORIES(${FFMPEG_INCLUDE_DIR} ${FFMPEG_INCLUDE_DIRS})
-            ADD_LIBRARY( FFmpeg ${LIB_DIR}/ffmpeg/LibAvContextHandle.cpp )
-            TARGET_LINK_LIBRARIES( FFmpeg ${FFMPEG_LIBRARIES} )
-            SET( LINKER_LIBS ${LINKER_LIBS} FFmpeg )
-        ENDIF()
-    ELSE()
-        SET( USE_FFMPEG FALSE )
-    ENDIF()
-ENDIF()
-
+INCLUDE( cmake/LibFFmpeg.cmake )
 
 ######################################################################################
 # Create config.h
diff --git a/cmake/CMakeMacros.cmake b/cmake/CMakeMacros.cmake
new file mode 100644
index 0000000..3b381f6
--- /dev/null
+++ b/cmake/CMakeMacros.cmake
@@ -0,0 +1,97 @@
+######################################################################################
+# Macros definition
+######################################################################################
+
+macro(ADD_OPTION variable description value)
+  set(__value ${value})
+  set(__condition "")
+  set(__varname "__value")
+  foreach(arg ${ARGN})
+    if(arg STREQUAL "IF" OR arg STREQUAL "if")
+      set(__varname "__condition")
+    else()
+      list(APPEND ${__varname} ${arg})
+    endif()
+  endforeach()
+  unset(__varname)
+  if("${__condition}" STREQUAL "")
+    set(__condition 2 GREATER 1)
+  endif()
+
+  if(${__condition})
+    if("${__value}" MATCHES ";")
+      if(${__value})
+        option(${variable} "${description}" ON)
+      else()
+        option(${variable} "${description}" OFF)
+      endif()
+    elseif(DEFINED ${__value})
+      if(${__value})
+        option(${variable} "${description}" ON)
+      else()
+        option(${variable} "${description}" OFF)
+      endif()
+    else()
+      option(${variable} "${description}" ${__value})
+    endif()
+  else()
+    unset(${variable} CACHE)
+  endif()
+  unset(__condition)
+  unset(__value)
+endmacro()
+
+# Status report function.
+# Automatically align right column and selects text based on condition.
+# Usage:
+#   status(<text>)
+#   status(<heading> <value1> [<value2> ...])
+#   status(<heading> <condition> THEN <text for TRUE> ELSE <text for FALSE> )
+function(status text)
+  set(status_cond)
+  set(status_then)
+  set(status_else)
+
+  set(status_current_name "cond")
+  foreach(arg ${ARGN})
+    if(arg STREQUAL "THEN")
+      set(status_current_name "then")
+    elseif(arg STREQUAL "ELSE")
+      set(status_current_name "else")
+    else()
+      list(APPEND status_${status_current_name} ${arg})
+    endif()
+  endforeach()
+
+  if(DEFINED status_cond)
+    set(status_placeholder_length 32)
+    string(RANDOM LENGTH ${status_placeholder_length} ALPHABET " " status_placeholder)
+    string(LENGTH "${text}" status_text_length)
+    if(status_text_length LESS status_placeholder_length)
+      string(SUBSTRING "${text}${status_placeholder}" 0 ${status_placeholder_length} status_text)
+    elseif(DEFINED status_then OR DEFINED status_else)
+      message(STATUS ${text})
+      set(status_text "${status_placeholder}")
+    else()
+      set(status_text "${text}")
+    endif()
+
+    if(DEFINED status_then OR DEFINED status_else)
+      if(${status_cond})
+        string(REPLACE ";" " " status_then "${status_then}")
+        string(REGEX REPLACE "^[ \t]+" "" status_then "${status_then}")
+        message(STATUS "${status_text} ${status_then}")
+      else()
+        string(REPLACE ";" " " status_else "${status_else}")
+        string(REGEX REPLACE "^[ \t]+" "" status_else "${status_else}")
+        message(STATUS "${status_text} ${status_else}")
+      endif()
+    else()
+      string(REPLACE ";" " " status_cond "${status_cond}")
+      string(REGEX REPLACE "^[ \t]+" "" status_cond "${status_cond}")
+      message(STATUS "${status_text} ${status_cond}")
+    endif()
+  else()
+    message(STATUS "${text}")
+  endif()
+endfunction()
\ No newline at end of file
diff --git a/FindFFmpeg.cmake b/cmake/LibFFmpeg.cmake
similarity index 84%
rename from FindFFmpeg.cmake
rename to cmake/LibFFmpeg.cmake
index 6368206..2f6841c 100644
--- a/FindFFmpeg.cmake
+++ b/cmake/LibFFmpeg.cmake
@@ -96,3 +96,22 @@ IF ( ${INC_SUCCESS} EQUAL ${LIST_SIZE_} )
    SET( FFMPEG_FOUND TRUE )
    SET( FFMPEG_SWSCALE_FOUND ${SWSCALE_FOUND} )
 ENDIF ( ${INC_SUCCESS} EQUAL ${LIST_SIZE_} ) 
+
+
+IF( USE_FFMPEG )
+    IF( NOT WIN32 )
+        IF( NOT FFMPEG_FOUND )
+            SET( USE_FFMPEG FALSE )
+        ELSE()
+            INCLUDE_DIRECTORIES( ${LIB_DIR}/ffmpeg )
+            #SET( CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS} -D__STDC_CONSTANT_MACROS )
+            INCLUDE_DIRECTORIES(${FFMPEG_INCLUDE_DIR} ${FFMPEG_INCLUDE_DIRS})
+            ADD_LIBRARY( FFmpeg ${LIB_DIR}/ffmpeg/LibAvContextHandle.cpp )
+            TARGET_LINK_LIBRARIES( FFmpeg ${FFMPEG_LIBRARIES} )
+            SET( LINKER_LIBS ${LINKER_LIBS} FFmpeg )
+        ENDIF()
+    ELSE()
+        SET( USE_FFMPEG FALSE )
+    ENDIF()
+ENDIF()
+
diff --git a/cmake/LibQT.cmake b/cmake/LibQT.cmake
new file mode 100644
index 0000000..73b6c8d
--- /dev/null
+++ b/cmake/LibQT.cmake
@@ -0,0 +1,35 @@
+#####################################################################################
+# Qt library cmake file
+######################################################################################
+
+IF( USE_QT4 )
+    FIND_PACKAGE( Qt4 REQUIRED QtCore QtGui )
+    IF( NOT QT4_FOUND)
+        SET(USE_QT4 FALSE)
+    ENDIF()
+    INCLUDE( ${QT_USE_FILE} )
+    ADD_DEFINITIONS( ${QT_DEFINITIONS} )
+    
+    QT4_WRAP_UI( FORMS_HEADERS_FILES ${FORMS_FILES} )
+    QT4_ADD_RESOURCES( RESOURCES_RCC_FILES ${RESOURCES_FILES} )
+    
+    SET( LINKER_LIBS ${LINKER_LIBS} ${QT_LIBRARIES} )
+ENDIF()
+
+IF( NOT USE_QT4 )
+    FIND_PACKAGE( Qt5Core REQUIRED )
+    FIND_PACKAGE( Qt5Gui REQUIRED )
+    FIND_PACKAGE( Qt5Widgets REQUIRED )
+    
+    INCLUDE_DIRECTORIES( ${Qt5Widgets_INCLUDE_DIRS} ${Qt5Core_INCLUDE_DIRS} ${Qt5Gui_INCLUDE_DIRS} )
+    # QT5_WRAP_CPP( HEADERS_MOC_FILES ${HEADERS_FILES} )
+    QT5_WRAP_UI( FORMS_HEADERS_FILES ${FORMS_FILES} )
+    QT5_ADD_RESOURCES( RESOURCES_RCC_FILES ${RESOURCES_FILES} )
+    
+    # Add compiler flags for building executables (-fPIE)
+    SET( CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS} ${Qt5Core_EXECUTABLE_COMPILE_FLAGS} )
+    
+    SET( LINKER_LIBS ${LINKER_LIBS} ${Qt5Core_LIBRARIES} ${Qt5Gui_LIBRARIES} ${Qt5Widgets_LIBRARIES} )
+    
+    SET( CURR_QT_MODULES Core Gui Widgets )
+ENDIF()
diff --git a/source/InputStream.cpp b/source/InputStream.cpp
index e67064c..9e7c478 100755
--- a/source/InputStream.cpp
+++ b/source/InputStream.cpp
@@ -39,7 +39,7 @@ InputStream::InputStream()
   m_uiWidth = 0;
   m_uiHeight = 0;
   m_uiTotalFrameNum = 0;
-  m_uiCurrFrameNum = 0;
+  m_iCurrFrameNum = -1;
   m_iErrorStatus = 0;
   m_iPixelFormat = -1;
 
@@ -137,9 +137,12 @@ Void InputStream::init( QString filename, UInt width, UInt height, Int input_for
   m_cStreamInformationString = QString( "[" );
 
 #ifdef USE_FFMPEG
-  avStatus = m_cLibAvContext.initAvFormat( m_cFilename.toLocal8Bit().data(), m_uiWidth, m_uiHeight, m_iPixelFormat, m_uiFrameRate );
-  m_cStreamInformationString.append( QString::fromUtf8( m_cLibAvContext.getStreamInformation() ) );
-  m_uiTotalFrameNum = 100;
+  if( QFileInfo( filename ).completeSuffix().compare( QString( "yuv" ) ) )
+  {
+    avStatus = m_cLibAvContext.initAvFormat( m_cFilename.toLocal8Bit().data(), m_uiWidth, m_uiHeight, m_iPixelFormat, m_uiFrameRate );
+    m_cStreamInformationString.append( QString::fromUtf8( m_cLibAvContext.getStreamInformation() ) );
+    m_uiTotalFrameNum = 100;
+  }
 #endif
 
   if( m_uiWidth <= 0 || m_uiHeight <= 0 )
@@ -181,7 +184,7 @@ Void InputStream::init( QString filename, UInt width, UInt height, Int input_for
 
   m_cStreamInformationString.append( QFileInfo( m_cFilename ).fileName() );
 
-  m_uiCurrFrameNum = 0;
+  m_iCurrFrameNum = -1;
   m_iStatus = 1;
 
   return;
@@ -208,15 +211,12 @@ Void InputStream::readFrame()
     return;
   }
 
-  if( m_uiCurrFrameNum < m_uiTotalFrameNum )
-  {
-    m_uiCurrFrameNum++;
-  }
-  else
+  m_iCurrFrameNum++;
+  if( m_iCurrFrameNum >= m_uiTotalFrameNum )
   {
     m_iErrorStatus = END_OF_SEQ;
-    m_uiCurrFrameNum = 0;
-    seekInput( m_uiCurrFrameNum );
+    m_iCurrFrameNum = 0;
+    seekInput( m_iCurrFrameNum );
   }
 
 #ifdef USE_FFMPEG
@@ -243,14 +243,14 @@ Void InputStream::readFrame()
 
 Bool InputStream::writeFrame( const QString& filename )
 {
-  getFrameQImage().save( filename );
+  QImage img( m_uiWidth, m_uiHeight, QImage::Format_RGB888 );
+  getFrame( &img );
+  img.save( filename );
   return true;
 }
 
-QImage InputStream::getFrameQImage()
+Void InputStream::getFrame( QImage *qimage )
 {
-  // Create QImage
-  QImage img( m_uiWidth, m_uiHeight, QImage::Format_RGB888 );
   Pel*** bufferRGB = m_cCurrFrame->getPelBufferRGB();
 
   if( sizeof(Pel) == sizeof(unsigned char) )
@@ -259,7 +259,7 @@ QImage InputStream::getFrameQImage()
     {
       for( Int x = 0; x < m_uiWidth; x++ )
       {
-        img.setPixel( x, y, qRgb( bufferRGB[0][y][x], bufferRGB[1][y][x], bufferRGB[2][y][x] ) );
+        qimage->setPixel( x, y, qRgb( bufferRGB[0][y][x], bufferRGB[1][y][x], bufferRGB[2][y][x] ) );
       }
     }
   }
@@ -267,7 +267,6 @@ QImage InputStream::getFrameQImage()
   {
     Q_ASSERT( 0 );
   }
-  return img;
 }
 
 #ifdef USE_OPENCV
@@ -292,7 +291,7 @@ Void InputStream::seekInput( Int new_frame_num )
     UInt64 frame_bytes_input = m_uiWidth * m_uiHeight * 1.5;
     UInt64 nbytes_seek = frame_bytes_input * new_frame_num;
     fseek( m_pFile, nbytes_seek, SEEK_SET );
-    m_uiCurrFrameNum = new_frame_num;
+    m_iCurrFrameNum = new_frame_num - 1;
   }
 }
 
diff --git a/source/InputStream.h b/source/InputStream.h
index 9560171..7935d41 100755
--- a/source/InputStream.h
+++ b/source/InputStream.h
@@ -78,7 +78,7 @@ private:
   UInt m_uiHeight;
   UInt m_uiFrameRate;
   UInt m_uiTotalFrameNum;
-  UInt m_uiCurrFrameNum;
+  Int m_iCurrFrameNum;
 
 public:
   InputStream();
@@ -103,7 +103,7 @@ public:
 
   Bool writeFrame( const QString& filename );
 
-  QImage getFrameQImage();
+  Void getFrame( QImage *qimage );
 #ifdef USE_OPENCV
   cv::Mat getFrameCvMat();
 #endif
@@ -136,9 +136,9 @@ public:
   {
     return m_uiHeight;
   }
-  UInt getCurrFrameNum()
+  Int getCurrFrameNum()
   {
-    return m_uiCurrFrameNum;
+    return m_iCurrFrameNum;
   }
   UInt getFrameRate()
   {
diff --git a/source/PlaYUVerFrame.cpp b/source/PlaYUVerFrame.cpp
index e358111..7f93389 100755
--- a/source/PlaYUVerFrame.cpp
+++ b/source/PlaYUVerFrame.cpp
@@ -201,7 +201,10 @@ UInt64 PlaYUVerFrame::getBytesPerFrame()
   case RGB:
     return m_uiWidth * m_uiHeight * 3;
     break;
+  default:
+    return 0;
   }
+  return 0;
 }
 
 }  // NAMESPACE
diff --git a/source/SubWindowHandle.cpp b/source/SubWindowHandle.cpp
index fdb139a..009f43c 100644
--- a/source/SubWindowHandle.cpp
+++ b/source/SubWindowHandle.cpp
@@ -68,6 +68,7 @@ SubWindowHandle::SubWindowHandle( QWidget * parent ) :
   connect( m_pcFrameSlider, SIGNAL( valueChanged(int) ), this, SLOT( seekSliderEvent() ) );
 
   m_cWindowName = QString( " " );
+  m_bIsPlaying = true;
   m_dScaleFactor = 1;
 
 }
@@ -81,28 +82,32 @@ bool SubWindowHandle::loadFile( const QString &fileName )
 {
   ConfigureFormatDialog formatDialog( this );
 
-  if( m_currStream.needFormatDialog( fileName ) )
+  m_pCurrStream = new InputStream;
+
+  if( m_pCurrStream->needFormatDialog( fileName ) )
   {
     if( formatDialog.exec() == QDialog::Rejected )
     {
       return false;
     }
-    m_currStream.init( fileName, formatDialog.getResolution().width(), formatDialog.getResolution().height(), formatDialog.getPixelFormat(),
+    m_pCurrStream->init( fileName, formatDialog.getResolution().width(), formatDialog.getResolution().height(), formatDialog.getPixelFormat(),
         formatDialog.getFrameRate() );
   }
   else
   {
-    m_currStream.init( fileName, 0, 0, 0, 0 );
+    m_pCurrStream->init( fileName, 0, 0, 0, 0 );
   }
   QApplication::setOverrideCursor( Qt::WaitCursor );
   QApplication::restoreOverrideCursor();
-  if( m_currStream.getStatus() == 0 )
+  if( m_pCurrStream->getStatus() == 0 )
   {
     return false;
   }
 
-  m_currStream.readFrame();
-  if( m_currStream.checkErrors( READING ) )
+  m_pCurrFrameQImage = new QImage( m_pCurrStream->getWidth(), m_pCurrStream->getHeight(), QImage::Format_RGB888 );
+
+  m_pCurrStream->readFrame();
+  if( m_pCurrStream->checkErrors( READING ) )
   {
     QMessageBox::warning( this, tr( "plaYUVer" ), tr( "Cannot read %1." ).arg( fileName ) );
     return false;
@@ -110,12 +115,13 @@ bool SubWindowHandle::loadFile( const QString &fileName )
 
   QApplication::restoreOverrideCursor();
 
-  m_cViewArea->setImage( QPixmap::fromImage( m_currStream.getFrameQImage() ) );
+  m_pCurrStream->getFrame( m_pCurrFrameQImage );
+  m_cViewArea->setImage( QPixmap::fromImage( *m_pCurrFrameQImage ) );
 
   normalSize();
 
-  m_pcFrameSlider->setRange( 0, m_currStream.getFrameNum() );
-  m_cWindowName = m_currStream.getStreamInformationString();
+  m_cWindowName = QString( " " );
+  m_cWindowName = m_pCurrStream->getStreamInformationString();
   m_cCurrFileName = fileName;
 
   setWindowTitle( m_cWindowName );
@@ -141,7 +147,7 @@ bool SubWindowHandle::save()
 
   QApplication::setOverrideCursor( Qt::WaitCursor );
 
-  if( !m_currStream.writeFrame( fileName ) )
+  if( !m_pCurrStream->writeFrame( fileName ) )
   {
     QApplication::restoreOverrideCursor();
     QMessageBox::warning( this, tr( "SCode" ), tr( "Cannot save file %1" ).arg( fileName ) );
@@ -162,22 +168,44 @@ void SubWindowHandle::seekSliderEvent()
 
 bool SubWindowHandle::playEvent()
 {
-  m_currStream.readFrame();
-  if( m_currStream.checkErrors( READING ) )
+  bool iRet = true;
+  if( m_bIsPlaying )
   {
-    QMessageBox::warning( this, tr( "plaYUVer" ), tr( "Cannot read %1." ).arg( m_cCurrFileName ) );
-    return false;
+    m_pCurrStream->readFrame();
+    if( m_pCurrStream->checkErrors( READING ) )
+    {
+      QMessageBox::warning( this, tr( "plaYUVer" ), tr( "Cannot read %1." ).arg( m_cCurrFileName ) );
+      return false;
+    }
+    else if( m_pCurrStream->checkErrors( END_OF_SEQ ) )
+    {
+      iRet = false;
+    }
+    m_pCurrStream->getFrame( m_pCurrFrameQImage );
+    m_cViewArea->setImage( QPixmap::fromImage( *m_pCurrFrameQImage ) );
+    return iRet;
   }
-  else if( m_currStream.checkErrors( END_OF_SEQ ) )
-  {
-    m_cViewArea->setImage( QPixmap::fromImage( m_currStream.getFrameQImage() ) );
-    return false;
-  }
-  m_cViewArea->setImage( QPixmap::fromImage( m_currStream.getFrameQImage() ) );
- m_pcFrameSlider->setSliderPosition( m_currStream.getCurrFrameNum() );
-  return true;
+  return false;
 }
 
+Void SubWindowHandle::seekEvent( UInt new_frame_num )
+{
+  m_pCurrStream->seekInput( new_frame_num );
+  m_pCurrStream->readFrame();
+  m_pCurrStream->getFrame( m_pCurrFrameQImage );
+  m_cViewArea->setImage( QPixmap::fromImage( *m_pCurrFrameQImage ) );
+}
+
+Void SubWindowHandle::stopEvent()
+{
+  m_pCurrStream->seekInput( 0 );
+  m_pCurrStream->readFrame();
+  m_pCurrStream->getFrame( m_pCurrFrameQImage );
+  m_cViewArea->setImage( QPixmap::fromImage( *m_pCurrFrameQImage ) );
+  return;
+}
+
+
 Void SubWindowHandle::normalSize()
 {
   m_dScaleFactor = 1.0;
@@ -188,7 +216,7 @@ Void SubWindowHandle::zoomToFit()
 {
   // Scale to a smaller size that the real to a nicer look
   QSize niceFit( m_cScrollArea->viewport()->size().width() - 10, m_cScrollArea->viewport()->size().height() - 10 );
-  if( m_currStream.getWidth() <= niceFit.width() && m_currStream.getHeight() <= niceFit.height() )
+  if( m_pCurrStream->getWidth() <= niceFit.width() && m_pCurrStream->getHeight() <= niceFit.height() )
   {
     normalSize();
     return;
@@ -211,7 +239,7 @@ Void SubWindowHandle::scaleView( Int width, Int height )
 
 Void SubWindowHandle::scaleView( const QSize & size )
 {
-  QSize imgViewSize( m_currStream.getWidth(), m_currStream.getHeight() );
+  QSize imgViewSize( m_pCurrStream->getWidth(), m_pCurrStream->getHeight() );
   QSize newSize = imgViewSize;
   newSize.scale( size, Qt::KeepAspectRatio );
 
@@ -248,7 +276,7 @@ QSize SubWindowHandle::sizeHint() const
     maxSize = p->size();
   }
 
-  QSize isize = QSize( m_currStream.getWidth() + 500, m_currStream.getHeight() + 500 );
+  QSize isize = QSize( m_pCurrStream->getWidth() + 500, m_pCurrStream->getHeight() + 500 );
 
   // If the SubWindowHandle needs more space that the avaiable, we'll give
   // to the subwindow a reasonable size preserving the image aspect ratio.
diff --git a/source/SubWindowHandle.h b/source/SubWindowHandle.h
index d791922..e92233b 100644
--- a/source/SubWindowHandle.h
+++ b/source/SubWindowHandle.h
@@ -50,15 +50,16 @@ private:
   QScrollArea* m_cScrollArea;
   ViewArea* m_cViewArea;
 
-  QSlider* m_pcFrameSlider;
-
-  InputStream m_currStream;
+  InputStream* m_pCurrStream;
+  QImage* m_pCurrFrameQImage;
 
   QString m_cWindowName;
   QString m_cCurrFileName;
 
   Double m_dScaleFactor;
 
+  Bool m_bIsPlaying;
+
 public:
   SubWindowHandle( QWidget * parent = 0 );
   ~SubWindowHandle();
@@ -66,11 +67,12 @@ public:
   bool loadFile( const QString &fileName );
   bool save();
 
-  bool playEvent();
+  Void stopEvent();
+  Void seekEvent( UInt new_frame_num );
 
   InputStream* getInputStream()
   {
-    return &m_currStream;
+    return m_pCurrStream;
   }
 
   /**
@@ -126,8 +128,8 @@ public:
 protected:
   Void closeEvent( QCloseEvent *event );
 
-private slots:
-  void seekSliderEvent();
+public Q_SLOTS:
+  bool playEvent();
 };
 
 }  // NAMESPACE
diff --git a/source/lib/ffmpeg/LibAvContextHandle.h b/source/lib/ffmpeg/LibAvContextHandle.h
index 96e7460..4a35751 100755
--- a/source/lib/ffmpeg/LibAvContextHandle.h
+++ b/source/lib/ffmpeg/LibAvContextHandle.h
@@ -43,8 +43,6 @@ extern "C"
 #include <libavformat/avformat.h>
 }
 
-
-
 #include "TypeDef.h"
 
 namespace plaYUVer
@@ -53,6 +51,10 @@ namespace plaYUVer
 class LibAvContextHandle
 {
 public:
+  LibAvContextHandle() :
+      m_bHasStream( false )
+  {
+  }
   Bool initAvFormat( char* filename, UInt& width, UInt& height, Int& pixel_format, UInt& frame_rate );
   Void closeAvFormat();
   Bool decodeAvFormat();
diff --git a/source/plaYUVerApp.cpp b/source/plaYUVerApp.cpp
index e0b6e0c..53580c5 100644
--- a/source/plaYUVerApp.cpp
+++ b/source/plaYUVerApp.cpp
@@ -21,6 +21,10 @@
  * \brief    Main definition of the plaYUVerApp app
  */
 
+#include "plaYUVerApp.h"
+#include "SubWindowHandle.h"
+#include "InputStream.h"
+
 #if( QT_VERSION_PLAYUVER == 5 )
 #include <QtWidgets>
 #elif( QT_VERSION_PLAYUVER == 4 )
@@ -28,11 +32,6 @@
 #endif
 #include <QtDebug>
 
-#include "TypeDef.h"
-#include "plaYUVerApp.h"
-#include "SubWindowHandle.h"
-#include "InputStream.h"
-
 namespace plaYUVer
 {
 
@@ -46,9 +45,11 @@ plaYUVerApp::plaYUVerApp()
   //mdiArea->setHorizontalScrollBarPolicy( Qt::ScrollBarAsNeeded );
   //mdiArea->setVerticalScrollBarPolicy( Qt::ScrollBarAsNeeded );
 
-  connect( mdiArea, SIGNAL( subWindowActivated(QMdiSubWindow*) ), this, SLOT( updateMenus() ) );
-  windowMapper = new QSignalMapper( this );
-  connect( windowMapper, SIGNAL( mapped(QWidget*) ), this, SLOT( setActiveImageInterface(QWidget*) ) );
+  connect( mdiArea, SIGNAL( subWindowActivated(QMdiSubWindow*) ), this, SLOT( chageSubWindowSelection() ) );
+  //connect( mdiArea, SIGNAL( subWindowActivated(QMdiSubWindow*) ), this, SLOT( updateMenus() ) );
+
+  mapperWindow = new QSignalMapper( this );
+  connect( mapperWindow, SIGNAL( mapped(QWidget*) ), this, SLOT( setActiveSubWindow(QWidget*) ) );
 
   createActions();
   createMenus();
@@ -62,13 +63,12 @@ plaYUVerApp::plaYUVerApp()
   setWindowIcon( QIcon( ":/images/playuver.png" ) );
   setUnifiedTitleAndToolBarOnMac( true );
 
-  playingTimer = new QTimer( this );
+  playingTimer = new QTimer;
+  playingTimer->setTimerType( Qt::CoarseTimer );
+  connect( playingTimer, SIGNAL( timeout() ), this, SLOT( playEvent() ) );
 
   setAcceptDrops( true );
   mdiArea->setAcceptDrops( true );
-
-  connect( playingTimer, SIGNAL( timeout() ), this, SLOT( playEvent() ) );
-
 }
 
 Void plaYUVerApp::closeEvent( QCloseEvent *event )
@@ -104,17 +104,17 @@ void plaYUVerApp::open()
   {
     m_cLastOpenPath = QFileInfo( fileName ).path();
 
-    QMdiSubWindow *existing = findImageInterface( fileName );
+    QMdiSubWindow *existing = findSubWindow( fileName );
     if( existing )
     {
       mdiArea->setActiveSubWindow( existing );
       return;
     }
 
-    SubWindowHandle *interfaceChild = new SubWindowHandle( this );  //createImageInterface();
+    SubWindowHandle *interfaceChild = new SubWindowHandle( this );  //createSubWindow();
     if( interfaceChild->loadFile( fileName ) )
     {
-      addImageInterface( interfaceChild );
+      addSubWindow( interfaceChild );
       statusBar()->showMessage( tr( "File loaded" ), 2000 );
       interfaceChild->show();
     }
@@ -127,22 +127,21 @@ void plaYUVerApp::open()
 
 void plaYUVerApp::save()
 {
-  if( activeImageInterface() )
-    activeImageInterface()->save();
+  if( activeSubWindow() )
+    activeSubWindow()->save();
 }
 
 // -----------------------  Playing Functions  --------------------
 
 void plaYUVerApp::play()
 {
-  UInt frameRate;
-  UInt timeInterval;
-
-  frameRate = activeImageInterface()->getInputStream()->getFrameRate();
-  timeInterval = ( UInt )( 1000.0 / frameRate + 0.5 );
-
-  playingTimer->start( timeInterval );
-
+  playingTimer->stop();
+  if( activeSubWindow() )
+  {
+    UInt frameRate = activeSubWindow()->getInputStream()->getFrameRate();
+    UInt timeInterval = ( UInt )( 1000.0 / frameRate + 0.5 );
+    playingTimer->start( timeInterval );
+  }
 }
 
 void plaYUVerApp::pause()
@@ -152,55 +151,53 @@ void plaYUVerApp::pause()
 
 void plaYUVerApp::stop()
 {
+  activeSubWindow()->stopEvent();
+  m_pcFrameSlider->setValue( activeSubWindow()->getInputStream()->getCurrFrameNum() );
   playingTimer->stop();
-  //disconnect( playingTimer, SIGNAL( timeout() ), 0, 0 );
 }
 
 void plaYUVerApp::playEvent()
 {
-  if( activeImageInterface() )
+  if( activeSubWindow() )
   {
-    if( !activeImageInterface()->playEvent() )
+    if( !activeSubWindow()->playEvent() )
     {
-      playingTimer->stop();
+      stop();
     }
+    m_pcFrameSlider->setValue( activeSubWindow()->getInputStream()->getCurrFrameNum() );
   }
+}
 
+void plaYUVerApp::seekSliderEvent( int new_frame_num )
+{
+  if( activeSubWindow() )
+  {
+    activeSubWindow()->seekEvent( new_frame_num );
+  }
 }
 
 // -----------------------  Zoom Functions  -----------------------
 
-void plaYUVerApp::zoomIn()
-{
-  scaleImage( 1.25 );
-}
-
-void plaYUVerApp::zoomOut()
-{
-  scaleImage( 0.8 );
-}
-
 void plaYUVerApp::normalSize()
 {
-  if( activeImageInterface() )
-    activeImageInterface()->normalSize();
+  if( activeSubWindow() )
+    activeSubWindow()->normalSize();
 }
 
 void plaYUVerApp::zoomToFit()
 {
-  if( activeImageInterface() )
-    activeImageInterface()->zoomToFit();
+  if( activeSubWindow() )
+    activeSubWindow()->zoomToFit();
 }
 
-Void plaYUVerApp::scaleImage( Double factor )
+void plaYUVerApp::scaleFrame( int ratio )
 {
-
-  if( activeImageInterface() )
+  if( activeSubWindow() )
   {
-    activeImageInterface()->scaleView( factor );
+    activeSubWindow()->scaleView( ( Double )( ratio ) / 100.0 );
 
-    zoomInAct->setEnabled( activeImageInterface()->getScaleFactor() < 3.0 );
-    zoomOutAct->setEnabled( activeImageInterface()->getScaleFactor() > 0.333 );
+    actionZoomIn->setEnabled( activeSubWindow()->getScaleFactor() < 3.0 );
+    actionZoomOut->setEnabled( activeSubWindow()->getScaleFactor() > 0.333 );
   }
 }
 
@@ -211,49 +208,72 @@ void plaYUVerApp::about()
   QMessageBox::about( this, tr( "About plaYUVerApp" ), tr( "The <b>plaYUVerApp</b> is an open-source raw video player " ) );
 }
 
-void plaYUVerApp::updateMenus()
+void plaYUVerApp::chageSubWindowSelection()
 {
-  Bool hasImageInterface = ( activeImageInterface() != 0 );
-  saveAct->setEnabled( hasImageInterface );
-  closeAct->setEnabled( hasImageInterface );
-  closeAllAct->setEnabled( hasImageInterface );
-  tileAct->setEnabled( hasImageInterface );
-  cascadeAct->setEnabled( hasImageInterface );
-  nextAct->setEnabled( hasImageInterface );
-  previousAct->setEnabled( hasImageInterface );
-  separatorAct->setVisible( hasImageInterface );
+  playingTimer->stop();
+  if( activeSubWindow() )
+  {
+    m_pcFrameSlider->setMaximum( activeSubWindow()->getInputStream()->getFrameNum() - 1 );
+    m_pcFrameSlider->setValue( activeSubWindow()->getInputStream()->getCurrFrameNum() );
+  }
+  updateMenus();
+  //updateWindowMenu();
+}
 
-  zoomInAct->setEnabled( hasImageInterface );
-  zoomOutAct->setEnabled( hasImageInterface );
-  normalSizeAct->setEnabled( hasImageInterface );
-  zoomToFitAct->setEnabled( hasImageInterface );
+Void plaYUVerApp::updateMenus()
+{
+  Bool hasSubWindow = ( activeSubWindow() != 0 );
+  actionSave->setEnabled( hasSubWindow );
+  actionClose->setEnabled( hasSubWindow );
+  actionCloseAll->setEnabled( hasSubWindow );
+  actionTile->setEnabled( hasSubWindow );
+  actionCascade->setEnabled( hasSubWindow );
+  actionSeparator->setVisible( hasSubWindow );
 
-  actionVideoPlay->setEnabled( hasImageInterface );
-  actionVideoPause->setEnabled( hasImageInterface );
-  actionVideoStop->setEnabled( hasImageInterface );
-  actionVideoBackward->setEnabled( hasImageInterface );
-  actionVideoForward->setEnabled( hasImageInterface );
+  actionZoomIn->setEnabled( hasSubWindow );
+  actionZoomOut->setEnabled( hasSubWindow );
+  actionNormalSize->setEnabled( hasSubWindow );
+  actionZoomToFit->setEnabled( hasSubWindow );
+
+  actionVideoPlay->setEnabled( hasSubWindow );
+  actionVideoPause->setEnabled( hasSubWindow );
+  actionVideoStop->setEnabled( hasSubWindow );
+  actionVideoBackward->setEnabled( hasSubWindow );
+  actionVideoForward->setEnabled( hasSubWindow );
+  m_pcFrameSlider->setEnabled( hasSubWindow );
 }
 
 void plaYUVerApp::updateWindowMenu()
 {
-  windowMenu->clear();
-  windowMenu->addAction( closeAct );
-  windowMenu->addAction( closeAllAct );
-  windowMenu->addSeparator();
-  windowMenu->addAction( tileAct );
-  windowMenu->addAction( cascadeAct );
-  windowMenu->addSeparator();
-  windowMenu->addAction( nextAct );
-  windowMenu->addAction( previousAct );
-  windowMenu->addAction( separatorAct );
+  menuWindow->clear();
+  menuWindow->addAction( actionClose );
+  menuWindow->addAction( actionCloseAll );
+  menuWindow->addSeparator();
+  menuWindow->addAction( actionTile );
+  menuWindow->addAction( actionCascade );
+  menuWindow->addSeparator();
+  menuWindow->addAction( actionNext );
+  menuWindow->addAction( actionPrevious );
+  menuWindow->addAction( actionSeparator );
 
   updateMenus();
 
   QList<QMdiSubWindow *> windows = mdiArea->subWindowList();
-  separatorAct->setVisible( !windows.isEmpty() );
+  actionSeparator->setVisible( !windows.isEmpty() );
+  Int number_windows = windows.size();
 
-  for( Int i = 0; i < windows.size(); ++i )
+  if( number_windows > 1 )
+  {
+    actionNext->setEnabled( true );
+    actionPrevious->setEnabled( true );
+  }
+  else
+  {
+    actionNext->setEnabled( false );
+    actionPrevious->setEnabled( false );
+  }
+
+  for( Int i = 0; i < number_windows; ++i )
   {
     SubWindowHandle *child = qobject_cast<SubWindowHandle *>( windows.at( i ) );
 
@@ -266,15 +286,15 @@ void plaYUVerApp::updateWindowMenu()
     {
       text = tr( "%1 %2" ).arg( i + 1 ).arg( child->userFriendlyCurrentFile() );
     }
-    QAction *action = windowMenu->addAction( text );
+    QAction *action = menuWindow->addAction( text );
     action->setCheckable( true );
-    action->setChecked( child == activeImageInterface() );
-    connect( action, SIGNAL( triggered() ), windowMapper, SLOT( map() ) );
-    windowMapper->setMapping( action, windows.at( i ) );
+    action->setChecked( child == activeSubWindow() );
+    connect( action, SIGNAL( triggered() ), mapperWindow, SLOT( map() ) );
+    mapperWindow->setMapping( action, windows.at( i ) );
   }
 }
 
-SubWindowHandle *plaYUVerApp::createImageInterface()
+SubWindowHandle *plaYUVerApp::createSubWindow()
 {
   SubWindowHandle *child = new SubWindowHandle;
   mdiArea->addSubWindow( child );
@@ -282,7 +302,7 @@ SubWindowHandle *plaYUVerApp::createImageInterface()
   return child;
 }
 
-void plaYUVerApp::addImageInterface( SubWindowHandle *child )
+void plaYUVerApp::addSubWindow( SubWindowHandle *child )
 {
   //connect( child, SIGNAL( areaSelected( QRect ) ), this, SLOT( setSelection( QRect ) ) );
 
@@ -295,73 +315,84 @@ Void plaYUVerApp::createActions()
 {
   // ------------ File ------------
 
-  openAct = new QAction( QIcon( ":/images/open.png" ), tr( "&Open..." ), this );
-  openAct->setShortcuts( QKeySequence::Open );
-  openAct->setStatusTip( tr( "Open an existing file" ) );
-  connect( openAct, SIGNAL( triggered() ), this, SLOT( open() ) );
+  actionOpen = new QAction( QIcon( ":/images/open.png" ), tr( "&Open..." ), this );
+  actionOpen->setShortcuts( QKeySequence::Open );
+  actionOpen->setStatusTip( tr( "Open an existing file" ) );
+  connect( actionOpen, SIGNAL( triggered() ), this, SLOT( open() ) );
 
-  saveAct = new QAction( QIcon( ":/images/save.png" ), tr( "&Save..." ), this );
-  saveAct->setShortcuts( QKeySequence::SaveAs );
-  saveAct->setStatusTip( tr( "Save the document under a new name" ) );
-  connect( saveAct, SIGNAL( triggered() ), this, SLOT( save() ) );
+  actionSave = new QAction( QIcon( ":/images/save.png" ), tr( "&Save..." ), this );
+  actionSave->setShortcuts( QKeySequence::SaveAs );
+  actionSave->setStatusTip( tr( "Save the document under a new name" ) );
+  connect( actionSave, SIGNAL( triggered() ), this, SLOT( save() ) );
 
-  exitAct = new QAction( tr( "E&xit" ), this );
-  exitAct->setShortcuts( QKeySequence::Quit );
-  exitAct->setStatusTip( tr( "Exit the application" ) );
-  connect( exitAct, SIGNAL( triggered() ), qApp, SLOT( closeAllWindows() ) );
+  actionExit = new QAction( tr( "E&xit" ), this );
+  actionExit->setShortcuts( QKeySequence::Quit );
+  actionExit->setStatusTip( tr( "Exit the application" ) );
+  connect( actionExit, SIGNAL( triggered() ), qApp, SLOT( closeAllWindows() ) );
 
-  closeAct = new QAction( tr( "Cl&ose" ), this );
-  closeAct->setIcon( QIcon( ":/images/close.png" ) );
-  closeAct->setStatusTip( tr( "Close the active window" ) );
-  connect( closeAct, SIGNAL( triggered() ), mdiArea, SLOT( closeActiveSubWindow() ) );
+  actionClose = new QAction( tr( "Cl&ose" ), this );
+  actionClose->setIcon( QIcon( ":/images/close.png" ) );
+  actionClose->setStatusTip( tr( "Close the active window" ) );
+  connect( actionClose, SIGNAL( triggered() ), mdiArea, SLOT( closeActiveSubWindow() ) );
 
-  closeAllAct = new QAction( tr( "Close &All" ), this );
-  closeAllAct->setStatusTip( tr( "Close all the windows" ) );
-  connect( closeAllAct, SIGNAL( triggered() ), mdiArea, SLOT( closeAllSubWindows() ) );
+  actionCloseAll = new QAction( tr( "Close &All" ), this );
+  actionCloseAll->setStatusTip( tr( "Close all the windows" ) );
+  connect( actionCloseAll, SIGNAL( triggered() ), mdiArea, SLOT( closeAllSubWindows() ) );
 
   // ------------ View ------------
 
-  zoomInAct = new QAction( tr( "Zoom &In (25%)" ), this );
-  zoomInAct->setIcon( QIcon( ":/images/zoomin.png" ) );
-  zoomInAct->setShortcut( tr( "Ctrl++" ) );
-  zoomInAct->setStatusTip( tr( "Scale the image up by 25%" ) );
-  connect( zoomInAct, SIGNAL( triggered() ), this, SLOT( zoomIn() ) );
+  mapperZoom = new QSignalMapper( this );
+  connect( mapperZoom, SIGNAL( mapped(int) ), this, SLOT( scaleFrame(int) ) );
 
-  zoomOutAct = new QAction( tr( "Zoom &Out (25%)" ), this );
-  zoomOutAct->setIcon( QIcon( ":/images/zoomout.png" ) );
-  zoomOutAct->setShortcut( tr( "Ctrl+-" ) );
-  zoomOutAct->setStatusTip( tr( "Scale the image down by 25%" ) );
-  connect( zoomOutAct, SIGNAL( triggered() ), this, SLOT( zoomOut() ) );
+  actionZoomIn = new QAction( tr( "Zoom &In (25%)" ), this );
+  actionZoomIn->setIcon( QIcon( ":/images/zoomin.png" ) );
+  actionZoomIn->setShortcut( tr( "Ctrl++" ) );
+  actionZoomIn->setStatusTip( tr( "Scale the image up by 25%" ) );
+  connect( actionZoomIn, SIGNAL( triggered() ), mapperZoom, SLOT( map() ) );
+  mapperZoom->setMapping( actionZoomIn, 125 );
 
-  normalSizeAct = new QAction( tr( "&Normal Size" ), this );
-  normalSizeAct->setIcon( QIcon( ":/images/zoomtonormal.png" ) );
-  normalSizeAct->setShortcut( tr( "Ctrl+N" ) );
-  normalSizeAct->setStatusTip( tr( "Show the image at its original size" ) );
-  connect( normalSizeAct, SIGNAL( triggered() ), this, SLOT( normalSize() ) );
+  actionZoomOut = new QAction( tr( "Zoom &Out (25%)" ), this );
+  actionZoomOut->setIcon( QIcon( ":/images/zoomout.png" ) );
+  actionZoomOut->setShortcut( tr( "Ctrl+-" ) );
+  actionZoomOut->setStatusTip( tr( "Scale the image down by 25%" ) );
+  connect( actionZoomOut, SIGNAL( triggered() ), mapperZoom, SLOT( map() ) );
+  mapperZoom->setMapping( actionZoomOut, 80 );
 
-  zoomToFitAct = new QAction( tr( "Zoom to &Fit" ), this );
-  zoomToFitAct->setIcon( QIcon( ":/images/fittowindow.png" ) );
-  zoomToFitAct->setStatusTip( tr( "Zoom in or out to fit on the window." ) );
-  zoomToFitAct->setShortcut( tr( "Ctrl+F" ) );
-  connect( zoomToFitAct, SIGNAL( triggered() ), this, SLOT( zoomToFit() ) );
+  actionNormalSize = new QAction( tr( "&Normal Size" ), this );
+  actionNormalSize->setIcon( QIcon( ":/images/zoomtonormal.png" ) );
+  actionNormalSize->setShortcut( tr( "Ctrl+N" ) );
+  actionNormalSize->setStatusTip( tr( "Show the image at its original size" ) );
+  connect( actionNormalSize, SIGNAL( triggered() ), this, SLOT( normalSize() ) );
+
+  actionZoomToFit = new QAction( tr( "Zoom to &Fit" ), this );
+  actionZoomToFit->setIcon( QIcon( ":/images/fittowindow.png" ) );
+  actionZoomToFit->setStatusTip( tr( "Zoom in or out to fit on the window." ) );
+  actionZoomToFit->setShortcut( tr( "Ctrl+F" ) );
+  connect( actionZoomToFit, SIGNAL( triggered() ), this, SLOT( zoomToFit() ) );
 
   // ------------ Playing ------------
 
   actionVideoPlay = new QAction( "VideoPlay", this );
+  actionVideoPlay->setIcon( QIcon( style()->standardIcon( QStyle::SP_MediaPlay ) ) );
+  connect( actionVideoPlay, SIGNAL( triggered() ), this, SLOT( play() ) );
+
   actionVideoPause = new QAction( "VideoPause", this );
+  actionVideoPause->setIcon( QIcon( style()->standardIcon( QStyle::SP_MediaPause ) ) );
+  connect( actionVideoPause, SIGNAL( triggered() ), this, SLOT( pause() ) );
+
   actionVideoStop = new QAction( "VideoStop", this );
+  actionVideoStop->setIcon( QIcon( style()->standardIcon( QStyle::SP_MediaStop ) ) );
+  connect( actionVideoStop, SIGNAL( triggered() ), this, SLOT( stop() ) );
+
   actionVideoBackward = new QAction( "VideoBackward", this );
+  actionVideoBackward->setIcon( QIcon( style()->standardIcon( QStyle::SP_MediaSeekBackward ) ) );
   actionVideoForward = new QAction( "VideoForward", this );
+  actionVideoForward->setIcon( QIcon( style()->standardIcon( QStyle::SP_MediaSeekForward ) ) );
+
   actionVideoLoop = new QAction( "VideoLoop", this );
   actionVideoLock = new QAction( "VideoLock", this );
   actionVideoInterlace = new QAction( "VideoInterlace", this );
   actionVideoCenter = new QAction( "VideoCenter", this );
-
-  actionVideoPlay->setIcon( QIcon( style()->standardIcon( QStyle::SP_MediaPlay ) ) );
-  actionVideoPause->setIcon( QIcon( style()->standardIcon( QStyle::SP_MediaPause ) ) );
-  actionVideoStop->setIcon( QIcon( style()->standardIcon( QStyle::SP_MediaStop ) ) );
-  actionVideoBackward->setIcon( QIcon( style()->standardIcon( QStyle::SP_MediaSeekBackward ) ) );
-  actionVideoForward->setIcon( QIcon( style()->standardIcon( QStyle::SP_MediaSeekForward ) ) );
   /*
    actionVideoLoop     ->setIcon( QIcon( ":/images/videoloop.png"  ) );
    actionVideoLock     ->setIcon( QIcon( ":/images/lock.png"       ) );
@@ -369,95 +400,103 @@ Void plaYUVerApp::createActions()
    actionVideoCenter   ->setIcon( QIcon( ":/images/center.png"     ) );
    */
 
-  connect( actionVideoPlay, SIGNAL( triggered() ), this, SLOT( play() ) );
-  connect( actionVideoPause, SIGNAL( triggered() ), this, SLOT( pause() ) );
-  connect( actionVideoStop, SIGNAL( triggered() ), this, SLOT( stop() ) );
+  m_pcFrameSlider = new QSlider;
+  m_pcFrameSlider->setOrientation( Qt::Horizontal );
+  m_pcFrameSlider->setMaximumWidth( 100 );
+  m_pcFrameSlider->setMaximumWidth( 300 );
+  m_pcFrameSlider->setSizePolicy( QSizePolicy( QSizePolicy::MinimumExpanding, QSizePolicy::Fixed ) );
+  m_pcFrameSlider->setEnabled( false );
+  connect( m_pcFrameSlider, SIGNAL( valueChanged(int) ), this, SLOT( seekSliderEvent(int) ) );
 
   // ------------ Window ------------
 
-  tileAct = new QAction( tr( "&Tile" ), this );
-  tileAct->setStatusTip( tr( "Tile the windows" ) );
-  connect( tileAct, SIGNAL( triggered() ), mdiArea, SLOT( tileSubWindows() ) );
+  actionTile = new QAction( tr( "&Tile" ), this );
+  actionTile->setStatusTip( tr( "Tile the windows" ) );
+  connect( actionTile, SIGNAL( triggered() ), mdiArea, SLOT( tileSubWindows() ) );
 
-  cascadeAct = new QAction( tr( "&Cascade" ), this );
-  cascadeAct->setStatusTip( tr( "Cascade the windows" ) );
-  connect( cascadeAct, SIGNAL( triggered() ), mdiArea, SLOT( cascadeSubWindows() ) );
+  actionCascade = new QAction( tr( "&Cascade" ), this );
+  actionCascade->setStatusTip( tr( "Cascade the windows" ) );
+  connect( actionCascade, SIGNAL( triggered() ), mdiArea, SLOT( cascadeSubWindows() ) );
 
-  nextAct = new QAction( tr( "Ne&xt" ), this );
-  nextAct->setShortcuts( QKeySequence::NextChild );
-  nextAct->setStatusTip( tr( "Move the focus to the next window" ) );
-  connect( nextAct, SIGNAL( triggered() ), mdiArea, SLOT( activateNextSubWindow() ) );
+  actionNext = new QAction( tr( "Ne&xt" ), this );
+  actionNext->setShortcuts( QKeySequence::NextChild );
+  actionNext->setStatusTip( tr( "Move the focus to the next window" ) );
+  connect( actionNext, SIGNAL( triggered() ), mdiArea, SLOT( activateNextSubWindow() ) );
 
-  previousAct = new QAction( tr( "Pre&vious" ), this );
-  previousAct->setShortcuts( QKeySequence::PreviousChild );
-  previousAct->setStatusTip( tr( "Move the focus to the previous window" ) );
-  connect( previousAct, SIGNAL( triggered() ), mdiArea, SLOT( activatePreviousSubWindow() ) );
+  actionPrevious = new QAction( tr( "Pre&vious" ), this );
+  actionPrevious->setShortcuts( QKeySequence::PreviousChild );
+  actionPrevious->setStatusTip( tr( "Move the focus to the previous window" ) );
+  connect( actionPrevious, SIGNAL( triggered() ), mdiArea, SLOT( activatePreviousSubWindow() ) );
 
-  separatorAct = new QAction( this );
-  separatorAct->setSeparator( true );
+  actionSeparator = new QAction( this );
+  actionSeparator->setSeparator( true );
 
   // ------------ About ------------
 
-  aboutAct = new QAction( tr( "&About" ), this );
-  aboutAct->setStatusTip( tr( "Show the application's About box" ) );
-  connect( aboutAct, SIGNAL( triggered() ), this, SLOT( about() ) );
+  actionAbout = new QAction( tr( "&About" ), this );
+  actionAbout->setStatusTip( tr( "Show the application's About box" ) );
+  connect( actionAbout, SIGNAL( triggered() ), this, SLOT( about() ) );
 
-  aboutQtAct = new QAction( tr( "About &Qt" ), this );
-  aboutQtAct->setIcon( QIcon( ":images/qt.png" ) );
-  aboutQtAct->setStatusTip( tr( "Show the Qt library's About box" ) );
-  connect( aboutQtAct, SIGNAL( triggered() ), qApp, SLOT( aboutQt() ) );
+  actionAboutQt = new QAction( tr( "About &Qt" ), this );
+  actionAboutQt->setIcon( QIcon( ":images/qt.png" ) );
+  actionAboutQt->setStatusTip( tr( "Show the Qt library's About box" ) );
+  connect( actionAboutQt, SIGNAL( triggered() ), qApp, SLOT( aboutQt() ) );
 }
 
 Void plaYUVerApp::createMenus()
 {
-  fileMenu = menuBar()->addMenu( tr( "&File" ) );
-  fileMenu->addAction( openAct );
-  fileMenu->addSeparator();
-  fileMenu->addAction( saveAct );
-  fileMenu->addSeparator();
-  fileMenu->addAction( closeAct );
-  fileMenu->addAction( exitAct );
+  menuFile = menuBar()->addMenu( tr( "&File" ) );
+  menuFile->addAction( actionOpen );
+  menuFile->addSeparator();
+  menuFile->addAction( actionSave );
+  menuFile->addSeparator();
+  menuFile->addAction( actionClose );
+  menuFile->addAction( actionExit );
 
-  viewMenu = new QMenu( tr( "&View" ), this );
-  viewMenu->addAction( zoomInAct );
-  viewMenu->addAction( zoomOutAct );
-  viewMenu->addAction( normalSizeAct );
-  viewMenu->addAction( zoomToFitAct );
+  menuView = new QMenu( tr( "&View" ), this );
+  menuView->addAction( actionZoomIn );
+  menuView->addAction( actionZoomOut );
+  menuView->addAction( actionNormalSize );
+  menuView->addAction( actionZoomToFit );
 
-  windowMenu = menuBar()->addMenu( tr( "&Window" ) );
+  menuWindow = menuBar()->addMenu( tr( "&Window" ) );
   updateWindowMenu();
-  connect( windowMenu, SIGNAL( aboutToShow() ), this, SLOT( updateWindowMenu() ) );
+  connect( menuWindow, SIGNAL( aboutToShow() ), this, SLOT( updateWindowMenu() ) );
 
   menuBar()->addSeparator();
 
-  helpMenu = menuBar()->addMenu( tr( "&Help" ) );
-  helpMenu->addAction( aboutAct );
-  helpMenu->addAction( aboutQtAct );
+  menuHelp = menuBar()->addMenu( tr( "&Help" ) );
+  menuHelp->addAction( actionAbout );
+  menuHelp->addAction( actionAboutQt );
 }
 
 Void plaYUVerApp::createToolBars()
 {
-  fileToolBar = addToolBar( tr( "File" ) );
-  fileToolBar->addAction( openAct );
-  fileToolBar->addAction( saveAct );
-  fileToolBar->addAction( closeAct );
+  toolbarFile = addToolBar( tr( "File" ) );
+  toolbarFile->addAction( actionOpen );
+  toolbarFile->addAction( actionSave );
+  toolbarFile->addAction( actionClose );
 
-  viewToolBar = addToolBar( tr( "Zoom" ) );
-  viewToolBar->addAction( zoomInAct );
-  viewToolBar->addAction( zoomOutAct );
-  viewToolBar->addAction( normalSizeAct );
-  viewToolBar->addAction( zoomToFitAct );
+  toolbarView = addToolBar( tr( "Zoom" ) );
+  toolbarView->addAction( actionZoomIn );
+  toolbarView->addAction( actionZoomOut );
+  toolbarView->addAction( actionNormalSize );
+  toolbarView->addAction( actionZoomToFit );
+
+  toolbarVideo = addToolBar( tr( "Video" ) );
+  toolbarVideo->addAction( actionVideoPlay );
+  toolbarVideo->addAction( actionVideoPause );
+  toolbarVideo->addAction( actionVideoStop );
+  /*
+   toolbarVideo->addAction( actionVideoBackward );
+   toolbarVideo->addAction( actionVideoForward );
+   toolbarVideo->addAction( actionVideoLoop );
+   toolbarVideo->addAction( actionVideoLock );
+   toolbarVideo->addAction( actionVideoInterlace );
+   toolbarVideo->addAction( actionVideoCenter );
+   */
+  toolbarVideo->addWidget( m_pcFrameSlider );
 
-  videoToolBar = addToolBar( tr( "Video" ) );
-  videoToolBar->addAction( actionVideoPlay );
-  videoToolBar->addAction( actionVideoPause );
-  videoToolBar->addAction( actionVideoStop );
-  videoToolBar->addAction( actionVideoBackward );
-  videoToolBar->addAction( actionVideoForward );
-  videoToolBar->addAction( actionVideoLoop );
-  videoToolBar->addAction( actionVideoLock );
-  videoToolBar->addAction( actionVideoInterlace );
-  videoToolBar->addAction( actionVideoCenter );
 }
 
 Void plaYUVerApp::createStatusBar()
@@ -489,13 +528,13 @@ void plaYUVerApp::dropEvent( QDropEvent *event )
 
     m_cLastOpenPath = QFileInfo( fileName ).path();
 
-    QMdiSubWindow *existing = findImageInterface( fileName );
+    QMdiSubWindow *existing = findSubWindow( fileName );
     if( !existing )
     {
-      SubWindowHandle *interfaceChild = new SubWindowHandle( this );  //createImageInterface();
+      SubWindowHandle *interfaceChild = new SubWindowHandle( this );  //createSubWindow();
       if( interfaceChild->loadFile( fileName ) )
       {
-        addImageInterface( interfaceChild );
+        addSubWindow( interfaceChild );
         statusBar()->showMessage( tr( "File loaded" ), 2000 );
         interfaceChild->show();
       }
@@ -523,14 +562,14 @@ Void plaYUVerApp::writeSettings()
   settings.setValue( "size", size() );
 }
 
-SubWindowHandle *plaYUVerApp::activeImageInterface()
+SubWindowHandle *plaYUVerApp::activeSubWindow()
 {
-  if( QMdiSubWindow *activeImageInterface = mdiArea->activeSubWindow() )
-    return qobject_cast<SubWindowHandle *>( activeImageInterface );
+  if( QMdiSubWindow *activeSubWindow = mdiArea->activeSubWindow() )
+    return qobject_cast<SubWindowHandle *>( activeSubWindow );
   return 0;
 }
 
-QMdiSubWindow *plaYUVerApp::findImageInterface( const QString &fileName )
+QMdiSubWindow *plaYUVerApp::findSubWindow( const QString &fileName )
 {
   QString canonicalFilePath = QFileInfo( fileName ).canonicalFilePath();
 
@@ -542,7 +581,7 @@ QMdiSubWindow *plaYUVerApp::findImageInterface( const QString &fileName )
   return 0;
 }
 
-void plaYUVerApp::setActiveImageInterface( QWidget *window )
+void plaYUVerApp::setActiveSubWindow( QWidget *window )
 {
   if( !window )
     return;
diff --git a/source/plaYUVerApp.h b/source/plaYUVerApp.h
index e054d17..bd3b8db 100644
--- a/source/plaYUVerApp.h
+++ b/source/plaYUVerApp.h
@@ -26,15 +26,14 @@
 
 #include "config.h"
 
+#if( QT_VERSION_PLAYUVER == 5 )
+#include <QtWidgets>
+#elif( QT_VERSION_PLAYUVER == 4 )
+#include <QtGui>
+#endif
 #include <QMainWindow>
 #include "TypeDef.h"
 
-class QAction;
-class QMenu;
-class QMdiArea;
-class QMdiSubWindow;
-class QSignalMapper;
-
 namespace plaYUVer
 {
 
@@ -50,7 +49,7 @@ public:
 protected:
   Void closeEvent( QCloseEvent *event );
 
-private slots:
+private Q_SLOTS:
 
   //! File functions
   void open();
@@ -61,17 +60,21 @@ private slots:
   void pause();
   void stop();
   void playEvent();
+  void seekSliderEvent(int new_frame_num );
+  /**
+   * Scale the image by a given factor
+   * @param factor factor of scale. Ex: 120 scale the image up by 20% and
+   *        80 scale the image down by 25%
+   */
+  void scaleFrame( int ratio = 100 );
 
-  //! View functions
-  void zoomIn();
-  void zoomOut();
   void normalSize();
   void zoomToFit();
 
   //!  Show a message box with some information about the plaYUVerApp App
   void about();
-  void updateMenus();
 
+  void chageSubWindowSelection();
   void updateWindowMenu();
 
   /*
@@ -80,57 +83,59 @@ private slots:
   void dragEnterEvent(QDragEnterEvent *event);
   void dropEvent(QDropEvent *event);
 
-  SubWindowHandle *createImageInterface();
-  void addImageInterface( SubWindowHandle *child );
-  void setActiveImageInterface( QWidget *window );
+  void setActiveSubWindow( QWidget *window );
 
 private:
+  QMdiArea *mdiArea;
+
+  QString m_cLastOpenPath;
+  QTimer *playingTimer;
+
+  Void updateMenus();
+
   Void createActions();
   Void createMenus();
   Void createToolBars();
   Void createStatusBar();
+
   Void readSettings();
   Void writeSettings();
-  SubWindowHandle *activeImageInterface();
-  QMdiSubWindow *findImageInterface( const QString &fileName );
 
-  /**
-   * Scale the image by a given factor
-   * @param factor factor of scale. Ex: 1.2 scale the image up by 20% and
-   *        0.8 scale the image down by 25%
-   */
-  Void scaleImage( Double factor );
+  Void addSubWindow( SubWindowHandle *child );
+  SubWindowHandle *createSubWindow();
+  SubWindowHandle *activeSubWindow();
+  QMdiSubWindow *findSubWindow( const QString &fileName );
 
-  QString m_cLastOpenPath;
+  QSlider *m_pcFrameSlider;
 
-  QTimer *playingTimer;
-  QMdiArea *mdiArea;
-  QSignalMapper *windowMapper;
+  QSignalMapper *mapperZoom;
+  QSignalMapper *mapperWindow;
 
-  QMenu *fileMenu;
-  QMenu *viewMenu;
-  QMenu *windowMenu;
-  QMenu *helpMenu;
-  QToolBar *fileToolBar;
-  QToolBar *viewToolBar;
-  QToolBar *videoToolBar;
+  QMenu *menuFile;
+  QMenu *menuView;
+  QMenu *menuWindow;
+  QMenu *menuHelp;
 
-  QAction *openAct;
-  QAction *saveAct;
-  QAction *exitAct;
-  QAction *closeAct;
-  QAction *closeAllAct;
+  QToolBar *toolbarFile;
+  QToolBar *toolbarView;
+  QToolBar *toolbarVideo;
 
-  QAction *zoomInAct;
-  QAction *zoomOutAct;
-  QAction *normalSizeAct;
-  QAction *zoomToFitAct;
+  QAction *actionOpen;
+  QAction *actionSave;
+  QAction *actionExit;
+  QAction *actionClose;
+  QAction *actionCloseAll;
 
-  QAction *tileAct;
-  QAction *cascadeAct;
-  QAction *nextAct;
-  QAction *previousAct;
-  QAction *separatorAct;
+  QAction *actionZoomIn;
+  QAction *actionZoomOut;
+  QAction *actionNormalSize;
+  QAction *actionZoomToFit;
+
+  QAction *actionTile;
+  QAction *actionCascade;
+  QAction *actionNext;
+  QAction *actionPrevious;
+  QAction *actionSeparator;
 
   // Video actions.
   QAction *actionVideoPlay;
@@ -143,8 +148,8 @@ private:
   QAction *actionVideoInterlace;
   QAction *actionVideoCenter;
 
-  QAction *aboutAct;
-  QAction *aboutQtAct;
+  QAction *actionAbout;
+  QAction *actionAboutQt;
 
 };