diff --git a/src/AvTranscoder/Metadatas/VideoStreamProperties.hpp b/src/AvTranscoder/Metadatas/VideoStreamProperties.hpp
index 93fdf382..4d3b3683 100644
--- a/src/AvTranscoder/Metadatas/VideoStreamProperties.hpp
+++ b/src/AvTranscoder/Metadatas/VideoStreamProperties.hpp
@@ -124,6 +124,7 @@ VideoProperties videoStreamInfo(
 	vp.maxBitRate       = codec_context->rc_max_rate;
 	vp.minBitRate       = codec_context->rc_min_rate;
 	vp.isInterlaced     = false;
+	vp.topFieldFirst    = false;
 
 	vp.ticksPerFrame    = codec_context->ticks_per_frame,
 	vp.width            = codec_context->width,
diff --git a/src/AvTranscoder/common.cpp b/src/AvTranscoder/common.cpp
index add2780b..22e2b157 100644
--- a/src/AvTranscoder/common.cpp
+++ b/src/AvTranscoder/common.cpp
@@ -27,16 +27,14 @@ void ParamSet::set( const std::string& key, const std::string& flag, const bool
 
 	if( ! flagOpt )
 	{
-		std::cout << flag << std::endl << " : " << flagOpt->default_val.i64 << std::endl;
 		throw std::runtime_error( "unknown flag " + flag );
 	}
 
 	error = av_opt_get_int( _objContext, key.c_str(), AV_OPT_SEARCH_CHILDREN, &optVal );
 	if( error != 0 )
 	{
-		std::string err( "", AV_ERROR_MAX_STRING_SIZE );
-		//av_make_error_string( const_cast<char*>(err.c_str()), err.size(), error );
-		av_strerror( error, const_cast<char*>(err.c_str()), err.size() );
+		char err[AV_ERROR_MAX_STRING_SIZE];
+		av_strerror( error, err, AV_ERROR_MAX_STRING_SIZE );
 		throw std::runtime_error( "unknown key " + key + ": " + err );
 	}
 
@@ -48,9 +46,8 @@ void ParamSet::set( const std::string& key, const std::string& flag, const bool
 	error = av_opt_set_int( _objContext, key.c_str(), optVal, AV_OPT_SEARCH_CHILDREN );
 	if( error != 0 )
 	{
-		std::string err( "", AV_ERROR_MAX_STRING_SIZE );
-		//av_make_error_string( const_cast<char*>(err.c_str()), err.size(), error );
-		av_strerror( error, const_cast<char*>(err.c_str()), err.size() );
+		char err[AV_ERROR_MAX_STRING_SIZE];
+		av_strerror( error, err, AV_ERROR_MAX_STRING_SIZE );
 		throw std::runtime_error( "setting " + key + " parameter to " + flag + ": " + err );
 	}
 }
@@ -60,9 +57,8 @@ void ParamSet::set( const std::string& key, const bool value )
 	int error = av_opt_set_int( _objContext, key.c_str(), value, AV_OPT_SEARCH_CHILDREN );
 	if( error != 0 )
 	{
-		std::string err( "", AV_ERROR_MAX_STRING_SIZE );
-		//av_make_error_string( const_cast<char*>(err.c_str()), err.size(), error );
-		av_strerror( error, const_cast<char*>(err.c_str()), err.size() );
+		char err[AV_ERROR_MAX_STRING_SIZE];
+		av_strerror( error, err, AV_ERROR_MAX_STRING_SIZE );
 		throw std::runtime_error( "setting " + key + " parameter to " + ( value ? "true" : "false" ) + ": " + err );
 	}
 }
@@ -76,9 +72,8 @@ void ParamSet::set( const std::string& key, const int value )
 	{
 		std::ostringstream os;
 		os << value;
-		std::string err( "", AV_ERROR_MAX_STRING_SIZE );
-		//av_make_error_string( const_cast<char*>(err.c_str()), err.size(), error );
-		av_strerror( error, const_cast<char*>(err.c_str()), err.size() );
+		char err[AV_ERROR_MAX_STRING_SIZE];
+		av_strerror( error, err, AV_ERROR_MAX_STRING_SIZE );
 		throw std::runtime_error( "setting " + key + " parameter to " + os.str() + ": " + err );
 	}
 }
@@ -93,9 +88,8 @@ void ParamSet::set( const std::string& key, const int num, const int den )
 	{
 		std::ostringstream os;
 		os << num << "/" << den;
-		std::string err( "", AV_ERROR_MAX_STRING_SIZE );
-		//av_make_error_string( const_cast<char*>(err.c_str()), err.size(), error );
-		av_strerror( error, const_cast<char*>(err.c_str()), err.size() );
+		char err[AV_ERROR_MAX_STRING_SIZE];
+		av_strerror( error, err, AV_ERROR_MAX_STRING_SIZE );
 		throw std::runtime_error( "setting " + key + " parameter to " + os.str() + ": " + err );
 	}
 }
@@ -107,9 +101,8 @@ void ParamSet::set( const std::string& key, const double value )
 	{
 		std::ostringstream os;
 		os << value;
-		std::string err( "", AV_ERROR_MAX_STRING_SIZE );
-		//av_make_error_string( const_cast<char*>(err.c_str()), err.size(), error );
-		av_strerror( error, const_cast<char*>(err.c_str()), err.size() );
+		char err[AV_ERROR_MAX_STRING_SIZE];
+		av_strerror( error, err, AV_ERROR_MAX_STRING_SIZE );
 		throw std::runtime_error( "setting " + key + " parameter to " + os.str() + ": " + err );
 	}
 }
@@ -119,9 +112,8 @@ void ParamSet::set( const std::string& key, const std::string& value )
 	int error = av_opt_set( _objContext, key.c_str(), value.c_str(), AV_OPT_SEARCH_CHILDREN );
 	if( error != 0 )
 	{
-		std::string err( "", AV_ERROR_MAX_STRING_SIZE );
-		//av_make_error_string( const_cast<char*>(err.c_str()), err.size(), error );
-		av_strerror( error, const_cast<char*>(err.c_str()), err.size() );
+		char err[AV_ERROR_MAX_STRING_SIZE];
+		av_strerror( error, err, AV_ERROR_MAX_STRING_SIZE );
 		throw std::runtime_error( "setting " + key + " parameter to " + value + ": " + err );
 	}
 }