boost/gil/extension/io/jpeg/detail/write.hpp
//
// Copyright 2007-2008 Christian Henning, Andreas Pokorny, Lubomir Bourdev
//
// Distributed under the Boost Software License, Version 1.0
// See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt
//
#ifndef BOOST_GIL_EXTENSION_IO_JPEG_DETAIL_WRITE_HPP
#define BOOST_GIL_EXTENSION_IO_JPEG_DETAIL_WRITE_HPP
#include <boost/gil/extension/io/jpeg/tags.hpp>
#include <boost/gil/extension/io/jpeg/detail/supported_types.hpp>
#include <boost/gil/extension/io/jpeg/detail/writer_backend.hpp>
#include <boost/gil/io/base.hpp>
#include <boost/gil/io/device.hpp>
#include <boost/gil/io/dynamic_io_new.hpp>
#include <vector>
namespace boost { namespace gil {
#if BOOST_WORKAROUND(BOOST_MSVC, >= 1400)
#pragma warning(push)
#pragma warning(disable:4512) //assignment operator could not be generated
#pragma warning(disable:4611) //interaction between '_setjmp' and C++ object destruction is non-portable
#endif
namespace detail {
struct jpeg_write_is_supported
{
template< typename View >
struct apply
: public is_write_supported< typename get_pixel_type< View >::type
, jpeg_tag
>
{};
};
} // detail
///
/// JPEG Writer
///
template< typename Device >
class writer< Device
, jpeg_tag
>
: public writer_backend< Device
, jpeg_tag
>
{
public:
using backend_t = writer_backend<Device, jpeg_tag>;
public:
writer( const Device& io_dev
, const image_write_info< jpeg_tag >& info
)
: backend_t( io_dev
, info
)
{}
template<typename View>
void apply( const View& view )
{
write_rows( view );
}
private:
template<typename View>
void write_rows( const View& view )
{
std::vector< pixel< typename channel_type< View >::type
, layout<typename color_space_type< View >::type >
>
> row_buffer( view.width() );
// In case of an error we'll jump back to here and fire an exception.
// @todo Is the buffer above cleaned up when the exception is thrown?
// The strategy right now is to allocate necessary memory before
// the setjmp.
if( setjmp( this->_mark )) { this->raise_error(); }
using channel_t = typename channel_type<typename View::value_type>::type;
this->get()->image_width = JDIMENSION( view.width() );
this->get()->image_height = JDIMENSION( view.height() );
this->get()->input_components = num_channels<View>::value;
this->get()->in_color_space = detail::jpeg_write_support< channel_t
, typename color_space_type< View >::type
>::_color_space;
jpeg_set_defaults( this->get() );
jpeg_set_quality( this->get()
, this->_info._quality
, TRUE
);
// Needs to be done after jpeg_set_defaults() since it's overridding this value back to slow.
this->get()->dct_method = this->_info._dct_method;
// set the pixel dimensions
this->get()->density_unit = this->_info._density_unit;
this->get()->X_density = this->_info._x_density;
this->get()->Y_density = this->_info._y_density;
// done reading header information
jpeg_start_compress( this->get()
, TRUE
);
JSAMPLE* row_addr = reinterpret_cast< JSAMPLE* >( &row_buffer[0] );
for( int y =0; y != view.height(); ++ y )
{
std::copy( view.row_begin( y )
, view.row_end ( y )
, row_buffer.begin()
);
jpeg_write_scanlines( this->get()
, &row_addr
, 1
);
}
jpeg_finish_compress ( this->get() );
}
};
///
/// JPEG Dyamic Image Writer
///
template< typename Device >
class dynamic_image_writer< Device
, jpeg_tag
>
: public writer< Device
, jpeg_tag
>
{
using parent_t = writer<Device, jpeg_tag>;
public:
dynamic_image_writer( const Device& io_dev
, const image_write_info< jpeg_tag >& info
)
: parent_t( io_dev
, info
)
{}
template< typename ...Views >
void apply( const any_image_view< Views... >& views )
{
detail::dynamic_io_fnobj< detail::jpeg_write_is_supported
, parent_t
> op( this );
apply_operation( views, op );
}
};
#if BOOST_WORKAROUND(BOOST_MSVC, >= 1400)
#pragma warning(pop)
#endif
} // gil
} // boost
#endif