diff --git a/source/InputStream.cpp b/source/InputStream.cpp
index 860147b..23403da 100755
--- a/source/InputStream.cpp
+++ b/source/InputStream.cpp
@@ -126,6 +126,8 @@ Bool InputStream::needFormatDialog( QString filename )
 
 Void InputStream::init( QString filename, UInt width, UInt height, Int input_format, UInt frame_rate )
 {
+  Bool avStatus;
+
   m_uiWidth = width;
   m_uiHeight = height;
   m_uiFrameRate = frame_rate;
@@ -134,7 +136,7 @@ Void InputStream::init( QString filename, UInt width, UInt height, Int input_for
   m_iPixelFormat = input_format;
 
 #ifdef USE_FFMPEG
-  Bool avStatus = m_cLibAvContext.initAvFormat( filename, m_uiWidth, m_uiHeight, m_iPixelFormat, m_uiFrameRate );
+  avStatus = m_cLibAvContext.initAvFormat( filename, m_uiWidth, m_uiHeight, m_iPixelFormat, m_uiFrameRate );
 #endif
 
   if( m_uiWidth <= 0 || m_uiHeight <= 0 )
@@ -147,7 +149,7 @@ Void InputStream::init( QString filename, UInt width, UInt height, Int input_for
 
   UInt64 frame_bytes_input = m_cCurrFrame->getBytesPerFrame();
 
-  if( m_iFileFormat == YUVFormat )
+  if( avStatus )
   {
     m_cFilename = filename;
     m_pFile = fopen( m_cFilename.toLocal8Bit().data(), "rb" );
@@ -182,16 +184,6 @@ Void InputStream::readFrame()
   {
     return;
   }
-  UInt64 frame_bytes_input = m_cCurrFrame->getBytesPerFrame();
-
-#ifdef USE_FFMPEG
-  if( m_cLibAvContext.getStatus() )
-  {
-    m_cLibAvContext.decodeAvFormat();
-    m_cCurrFrame->FrameFromBuffer( m_cLibAvContext.video_dst_data[0], m_iPixelFormat );
-    return;
-  }
-#endif
 
   if( m_uiCurrFrameNum < m_uiTotalFrameNum )
   {
@@ -203,6 +195,17 @@ Void InputStream::readFrame()
     m_uiCurrFrameNum = 0;
     seekInput( m_uiCurrFrameNum );
   }
+
+#ifdef USE_FFMPEG
+  if( m_cLibAvContext.getStatus() )
+  {
+    m_cLibAvContext.decodeAvFormat();
+    m_cCurrFrame->FrameFromBuffer( m_cLibAvContext.video_dst_data[0], m_iPixelFormat );
+    return;
+  }
+#endif
+
+  UInt64 frame_bytes_input = m_cCurrFrame->getBytesPerFrame();
   bytes_read = fread( m_pInputBuffer, sizeof(Pel), frame_bytes_input, m_pFile );
   if( bytes_read != frame_bytes_input )
   {
@@ -255,10 +258,19 @@ cv::Mat InputStream::getFrameCvMat()
 
 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;
+#ifdef USE_FFMPEG
+  if( m_cLibAvContext.getStatus() )
+  {
+    m_cLibAvContext.seekAvFormat( new_frame_num );
+  }
+  else
+#endif
+  {
+    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;
+  }
 }
 
 Bool InputStream::checkErrors( Int error_type )
diff --git a/source/LibAvContextHandle.cpp b/source/LibAvContextHandle.cpp
index 9c7dd19..92055fe 100755
--- a/source/LibAvContextHandle.cpp
+++ b/source/LibAvContextHandle.cpp
@@ -29,8 +29,8 @@
 
 #include <QtDebug>
 
-#include "InputStream.h"
 #include "LibMemAlloc.h"
+#include "PlaYUVerFrame.h"
 
 namespace plaYUVer
 {
@@ -73,13 +73,18 @@ static int open_codec_context( int *stream_idx, AVFormatContext *fmt_ctx, enum A
 
 Void LibAvContextHandle::closeAvFormat()
 {
-  if( video_dec_ctx )
-    avcodec_close( video_dec_ctx );
+  if( m_bHasStream )
+  {
+    if( video_dec_ctx )
+      avcodec_close( video_dec_ctx );
 
-  avformat_close_input( &fmt_ctx );
+    if( fmt_ctx )
+      avformat_close_input( &fmt_ctx );
 
-  av_free( frame );
-  av_free( video_dst_data[0] );
+    av_free( frame );
+    av_free( video_dst_data[0] );
+  }
+  m_bHasStream = false;
 }
 
 Bool LibAvContextHandle::initAvFormat( QString filename, UInt& width, UInt& height, Int& pixel_format, UInt& frame_rate )
@@ -99,14 +104,31 @@ Bool LibAvContextHandle::initAvFormat( QString filename, UInt& width, UInt& heig
   m_bHasStream = false;
 
   char *src_filename = filename.toLocal8Bit().data();
-
-  FILE *video_dst_file = NULL;
+  AVDictionary *format_opts = NULL;
 
   /* register all formats and codecs */
   av_register_all();
 
+  if( width >= 0 && height >= 0 )
+  {
+    Char aux_string[10];
+    sprintf( aux_string, "%dx%d", width, height );
+    av_dict_set( &format_opts, "video_size", aux_string, 0 );
+  }
+  switch( pixel_format )
+  {
+  case PlaYUVerFrame::NO_FMT:
+    break;
+  case PlaYUVerFrame::YUV420:
+    av_dict_set( &format_opts, "pixel_format", av_get_pix_fmt_name( AV_PIX_FMT_YUV420P ), 0 );
+    break;
+  case PlaYUVerFrame::YUV400:
+    av_dict_set( &format_opts, "pixel_format", av_get_pix_fmt_name( AV_PIX_FMT_GRAY8 ), 0 );
+    break;
+  }
+
   /* open input file, and allocate format context */
-  if( avformat_open_input( &fmt_ctx, src_filename, NULL, NULL ) < 0 )
+  if( avformat_open_input( &fmt_ctx, src_filename, NULL, &format_opts ) < 0 )
   {
     qDebug( ) << " Could not open source file %s !!!" << filename << endl;
     return false;
@@ -135,6 +157,20 @@ Bool LibAvContextHandle::initAvFormat( QString filename, UInt& width, UInt& heig
     video_dst_bufsize = ret;
   }
 
+  Double fr = 30;
+  if( video_stream->avg_frame_rate.den && video_stream->avg_frame_rate.num )
+    fr = av_q2d( video_stream->avg_frame_rate );
+#if FF_API_R_FRAME_RATE
+  else if( video_stream->r_frame_rate.den && video_stream->r_frame_rate.num )
+    fr = av_q2d( video_stream->r_frame_rate );
+#endif
+  else if( video_stream->time_base.den && video_stream->time_base.num )
+    fr = 1 / av_q2d( video_stream->time_base );
+  else if( video_stream->codec->time_base.den && video_stream->codec->time_base.num )
+    fr = 1 / av_q2d( video_stream->codec->time_base );
+
+  frame_rate = ( UInt )fr;
+
   width = video_dec_ctx->width;
   height = video_dec_ctx->height;
   switch( video_dec_ctx->pix_fmt )
@@ -220,6 +256,11 @@ Bool LibAvContextHandle::decodeAvFormat()
   true;
 }
 
+Void LibAvContextHandle::seekAvFormat( UInt frame_num )
+{
+  av_seek_frame( fmt_ctx, video_stream_idx, frame_num, AVSEEK_FLAG_ANY );
+}
+
 }  // NAMESPACE
 
 #endif
diff --git a/source/LibAvContextHandle.h b/source/LibAvContextHandle.h
index 5a7e065..c361bdf 100755
--- a/source/LibAvContextHandle.h
+++ b/source/LibAvContextHandle.h
@@ -50,6 +50,8 @@ public:
   Void closeAvFormat();
   Bool decodeAvFormat();
 
+  Void seekAvFormat( UInt frame_num );
+
   Bool getStatus()
   {
     return m_bHasStream;
diff --git a/source/PlaYUVerFrame.h b/source/PlaYUVerFrame.h
index 2e9ed47..0cf6f06 100755
--- a/source/PlaYUVerFrame.h
+++ b/source/PlaYUVerFrame.h
@@ -44,7 +44,7 @@ public:
 
   enum InputStreamColorSpace
   {
-    YUV420, YUV400, YUV422, RGB,
+    NO_FMT = -1, YUV420, YUV400, YUV422, RGB,
   };
 
   UInt64 getBytesPerFrame();