diff --git a/lib/PlaYUVerFrame.cpp b/lib/PlaYUVerFrame.cpp
index 854f8ec..e546cba 100644
--- a/lib/PlaYUVerFrame.cpp
+++ b/lib/PlaYUVerFrame.cpp
@@ -120,7 +120,7 @@ Int PlaYUVerFrame::getColorSpace() const
   return m_pcPelFormat->colorSpace;
 }
 
-Int PlaYUVerFrame::getNumberChannels() const
+UInt PlaYUVerFrame::getNumberChannels() const
 {
   return m_pcPelFormat->numberChannels;
 }
diff --git a/lib/PlaYUVerFrame.h b/lib/PlaYUVerFrame.h
index a3824b1..d0562a4 100644
--- a/lib/PlaYUVerFrame.h
+++ b/lib/PlaYUVerFrame.h
@@ -102,7 +102,7 @@ public:
   static UInt64 getBytesPerFrame( UInt, UInt, Int );
 
   Int getColorSpace() const;
-  Int getNumberChannels() const;
+  UInt getNumberChannels() const;
   UInt getChromaWidth() const;
   UInt getChromaHeight() const;
   UInt getChromaLength() const;
diff --git a/lib/PlaYUVerStream.cpp b/lib/PlaYUVerStream.cpp
index 2d5d1c6..6ce5d58 100644
--- a/lib/PlaYUVerStream.cpp
+++ b/lib/PlaYUVerStream.cpp
@@ -162,10 +162,13 @@ Bool PlaYUVerStream::open( std::string filename, std::string resolution, std::st
   UInt height;
   Int input_format = -1;
 
-  sscanf( resolution.c_str(), "%ux%u", &width, &height );
-  if( width <= 0 || height <= 0 )
+  if( resolution.size() > 0 )
   {
-    return false;
+    sscanf( resolution.c_str(), "%ux%u", &width, &height );
+    if( width <= 0 || height <= 0 )
+    {
+      return false;
+    }
   }
   for( UInt i = 0; i < PlaYUVerFrame::supportedPixelFormatListNames().size(); i++ )
   {
@@ -175,11 +178,7 @@ Bool PlaYUVerStream::open( std::string filename, std::string resolution, std::st
       break;
     }
   }
-  if( width > 0 && height > 0 && input_format >= 0 )
-  {
-    return open( filename, width, height, input_format, frame_rate, bInput );
-  }
-  return false;
+  return open( filename, width, height, input_format, frame_rate, bInput );
 }
 
 Bool PlaYUVerStream::open( std::string filename, UInt width, UInt height, Int input_format, UInt frame_rate, Bool bInput )
@@ -480,7 +479,7 @@ Void PlaYUVerStream::readFrame()
   if( !m_bInit || !m_bIsInput )
     return;
 
-  if( m_iCurrFrameNum + 1 >= ( Int64 )m_uiTotalFrameNum )
+  if( m_iCurrFrameNum + ( m_uiFrameBufferSize - 1 )>= ( Int64 )m_uiTotalFrameNum )
   {
     m_iErrorStatus = LAST_FRAME;
     m_pcNextFrame = NULL;
@@ -597,7 +596,7 @@ Bool PlaYUVerStream::saveFrame( const std::string& filename, PlaYUVerFrame *save
     else
     {
       cv::Mat* image;
-      saveFrame->getCvMat( (Void**)&image );
+      saveFrame->getCvMat( ( Void** )&image );
       return cv::imwrite( filename, *image );
     }