jpeg.hpp

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/*
  CLAW - a C++ Library Absolutely Wonderful
 
  CLAW is a free library without any particular aim but being useful to
  anyone.
 
  Copyright (C) 2005-2011 Julien Jorge
 
  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.
 
  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Lesser General Public License for more details.
 
  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 
  contact: julien.jorge@stuff-o-matic.com
*/
#ifndef __CLAW_JPEG_HPP__
#define __CLAW_JPEG_HPP__
 
#include <claw/graphic/image.hpp>
 
#include <cstdio>
#include <iostream>
#include <setjmp.h>
#include <string>
 
extern "C"
{
#include <jpeglib.h>
}
 
namespace claw
{
  namespace graphic
  {
    class jpeg : public image
    {
    public:
      struct error_manager
      {
        struct jpeg_error_mgr pub;

        jmp_buf setjmp_buffer;

        std::string error_string;
 
      }; // struct error_manager

      class reader
      {
        // classes that need to be accessible from jpeg callbacks.
      public:
        struct source_manager
        {
        public:
          source_manager(std::istream& is);
          ~source_manager();
 
          boolean fill_input_buffer();
          void skip_input_data(long num_bytes);
 
        public:
          struct jpeg_source_mgr pub;
 
        private:
          std::istream& m_input;

          const JOCTET* m_buffer;

          const unsigned int m_buffer_size;

          unsigned int m_stream_size;

          unsigned int m_stream_position;
 
        }; // struct source_manager
 
      private:
        class RGB_to_pixel32
        {
        public:
          rgba_pixel_8 operator()(const JSAMPLE* pixel) const;
        }; // class RGB_to_pixel32

        class grayscale_to_pixel32
        {
        public:
          rgba_pixel_8 operator()(const JSAMPLE* pixel) const;
        }; // class grayscale_to_pixel32
 
      public:
        reader(image& img);
        reader(image& img, std::istream& f);
 
        void load(std::istream& f);
 
      private:
        template <class Convert>
        void read_data(jpeg_decompress_struct& cinfo,
                       const Convert& pixel_convert);
 
        void read_from_file(std::istream& f);
        void decompress(std::istream& f, jpeg_decompress_struct& cinfo);
 
        void create_decompress_info(jpeg_decompress_struct& cinfo,
                                    source_manager& infile) const;
 
      private:
        image& m_image;
 
      }; // class reader

      class writer
      {
      public:
        struct options
        {
        public:
          options();
          options(unsigned char compression_quality_, bool progressive_);
 
        public:
          unsigned char quality;

          bool progressive;
 
        }; // struct options
 
        // classes that need to be accessible from jpeg callbacks.

        struct destination_manager
        {
        public:
          destination_manager(std::ostream& os);
          ~destination_manager();
 
          void flush();
          void term();
 
        public:
          struct jpeg_destination_mgr pub;
 
        private:
          std::ostream& m_output;

          JOCTET* m_buffer;

          const unsigned int m_buffer_size;
 
        }; // struct destination_manager
 
      public:
        writer(const image& img);
        writer(const image& img, std::ostream& f,
               const options& opt = options());
 
        void save(std::ostream& f, const options& opt = options()) const;
 
      private:
        void set_options(jpeg_compress_struct& cinfo,
                         const options& opt) const;
        void save_image(jpeg_compress_struct& cinfo) const;
 
        void copy_pixel_line(JSAMPLE* data, unsigned int y) const;
 
        void create_compress_info(jpeg_compress_struct& cinfo,
                                  destination_manager& outfile) const;
 
      private:
        const image& m_image;

        static const unsigned int s_rgb_pixel_size;
 
      }; // class writer
 
    public:
      jpeg(unsigned int w, unsigned int h);
      jpeg(const image& that);
      jpeg(std::istream& f);
 
      void save(std::ostream& os,
                const writer::options& opt = writer::options()) const;
 
    }; // class jpeg
  }
}
 
#include <claw/graphic/jpeg_reader.tpp>
 
#endif // __CLAW_JPEG_HPP__