~brian-sidebotham/wxwidgets-cmake/wxpython-2.9.4

/////////////////////////////////////////////////////////////////////////////

// Name:        src/common/imagjpeg.cpp

// Purpose:     wxImage JPEG handler

// Author:      Vaclav Slavik

// RCS-ID:      $Id: imagjpeg.cpp 69759 2011-11-14 13:35:48Z VZ $

// Copyright:   (c) Vaclav Slavik

// Licence:     wxWindows licence

/////////////////////////////////////////////////////////////////////////////

// For compilers that support precompilation, includes "wx.h".

#include "wx/wxprec.h"

#ifdef __BORLANDC__

    #pragma hdrstop

#endif

#if wxUSE_IMAGE && wxUSE_LIBJPEG

#include "wx/imagjpeg.h"

#include "wx/versioninfo.h"

#ifndef WX_PRECOMP

    #include "wx/log.h"

    #include "wx/app.h"

    #include "wx/intl.h"

    #include "wx/bitmap.h"

    #include "wx/module.h"

#endif

// A hack based on one from tif_jpeg.c to overcome the problem on Windows

// of rpcndr.h defining boolean with a different type to the jpeg headers.

//

// This hack is only necessary for an external jpeg library, the builtin one

// usually used on Windows doesn't use the type boolean, so always works.

//

#ifdef wxHACK_BOOLEAN

    #define HAVE_BOOLEAN

    #define boolean wxHACK_BOOLEAN

#endif

extern "C"

{

    #if defined(__WXMSW__)

        #define XMD_H

    #endif

    #include "jpeglib.h"

}

#ifndef HAVE_WXJPEG_BOOLEAN

typedef boolean wxjpeg_boolean;

#endif

#include "wx/filefn.h"

#include "wx/wfstream.h"

// For memcpy

#include <string.h>

// For JPEG library error handling

#include <setjmp.h>

// ----------------------------------------------------------------------------

// types

// ----------------------------------------------------------------------------

// the standard definition of METHODDEF(type) from jmorecfg.h is "static type"

// which means that we can't declare the method functions as extern "C" - the

// compiler (rightfully) complains about the multiple storage classes in

// declaration

//

// so we only add extern "C" when using our own, modified, jmorecfg.h - and use

// whatever we have in the system headers if this is what we use hoping that it

// should be ok (can't do anything else)

#ifdef JPEG_METHOD_LINKAGE

    #define CPP_METHODDEF(type) extern "C" METHODDEF(type)

#else // not using our jmorecfg.h header

    #define CPP_METHODDEF(type) METHODDEF(type)

#endif

//-----------------------------------------------------------------------------

// wxJPEGHandler

//-----------------------------------------------------------------------------

IMPLEMENT_DYNAMIC_CLASS(wxJPEGHandler,wxImageHandler)

#if wxUSE_STREAMS

//------------- JPEG Data Source Manager

#define JPEG_IO_BUFFER_SIZE   2048

typedef struct {

    struct jpeg_source_mgr pub;   /* public fields */

    JOCTET* buffer;               /* start of buffer */

    wxInputStream *stream;

} wx_source_mgr;

typedef wx_source_mgr * wx_src_ptr;

extern "C"

{

CPP_METHODDEF(void) wx_init_source ( j_decompress_ptr WXUNUSED(cinfo) )

{

}

CPP_METHODDEF(wxjpeg_boolean) wx_fill_input_buffer ( j_decompress_ptr cinfo )

{

    wx_src_ptr src = (wx_src_ptr) cinfo->src;

    src->pub.next_input_byte = src->buffer;

    src->pub.bytes_in_buffer = src->stream->Read(src->buffer, JPEG_IO_BUFFER_SIZE).LastRead();

    if (src->pub.bytes_in_buffer == 0) // check for end-of-stream

    {

        // Insert a fake EOI marker

        src->buffer[0] = 0xFF;

        src->buffer[1] = JPEG_EOI;

        src->pub.bytes_in_buffer = 2;

    }

    return TRUE;

}

CPP_METHODDEF(void) wx_skip_input_data ( j_decompress_ptr cinfo, long num_bytes )

{

    if (num_bytes > 0)

    {

        wx_src_ptr src = (wx_src_ptr) cinfo->src;

        while (num_bytes > (long)src->pub.bytes_in_buffer)

        {

            num_bytes -= (long) src->pub.bytes_in_buffer;

            src->pub.fill_input_buffer(cinfo);

        }

        src->pub.next_input_byte += (size_t) num_bytes;

        src->pub.bytes_in_buffer -= (size_t) num_bytes;

    }

}

CPP_METHODDEF(void) wx_term_source ( j_decompress_ptr cinfo )

{

    wx_src_ptr src = (wx_src_ptr) cinfo->src;

    if (src->pub.bytes_in_buffer > 0)

        src->stream->SeekI(-(long)src->pub.bytes_in_buffer, wxFromCurrent);

    delete[] src->buffer;

}

// JPEG error manager:

struct wx_error_mgr : public jpeg_error_mgr

{

  jmp_buf setjmp_buffer;    /* for return to caller */

};

/*

 * Here's the routine that will replace the standard error_exit method:

 */

CPP_METHODDEF(void) wx_error_exit (j_common_ptr cinfo)

{

  /* cinfo->err really points to a wx_error_mgr struct, so coerce pointer */

  wx_error_mgr * const jerr = (wx_error_mgr *) cinfo->err;

  /* Always display the message. */

  /* We could postpone this until after returning, if we chose. */

  (*cinfo->err->output_message) (cinfo);

  /* Return control to the setjmp point */

  longjmp(jerr->setjmp_buffer, 1);

}

/*

 * This will replace the standard output_message method when the user

 * wants us to be silent (verbose==false). We must have such method instead of

 * simply using NULL for cinfo->err->output_message because it's called

 * unconditionally from within libjpeg when there's "garbage input".

 */

CPP_METHODDEF(void) wx_ignore_message (j_common_ptr WXUNUSED(cinfo))

{

}

void wx_jpeg_io_src( j_decompress_ptr cinfo, wxInputStream& infile )

{

    wx_src_ptr src;

    if (cinfo->src == NULL) {    /* first time for this JPEG object? */

        cinfo->src = (struct jpeg_source_mgr *)

            (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,

            sizeof(wx_source_mgr));

    }

    src = (wx_src_ptr) cinfo->src;

    src->pub.bytes_in_buffer = 0; /* forces fill_input_buffer on first read */

    src->buffer = new JOCTET[JPEG_IO_BUFFER_SIZE];

    src->pub.next_input_byte = NULL; /* until buffer loaded */

    src->stream = &infile;

    src->pub.init_source = wx_init_source;

    src->pub.fill_input_buffer = wx_fill_input_buffer;

    src->pub.skip_input_data = wx_skip_input_data;

    src->pub.resync_to_restart = jpeg_resync_to_restart; /* use default method */

    src->pub.term_source = wx_term_source;

}

} // extern "C"

static inline void wx_cmyk_to_rgb(unsigned char* rgb, const unsigned char* cmyk)

{

    register int k = 255 - cmyk[3];

    register int k2 = cmyk[3];

    register int c;

    c = k + k2 * (255 - cmyk[0]) / 255;

    rgb[0] = (unsigned char)((c > 255) ? 0 : (255 - c));

    c = k + k2 * (255 - cmyk[1]) / 255;

    rgb[1] = (unsigned char)((c > 255) ? 0 : (255 - c));

    c = k + k2 * (255 - cmyk[2]) / 255;

    rgb[2] = (unsigned char)((c > 255) ? 0 : (255 - c));

}

// temporarily disable the warning C4611 (interaction between '_setjmp' and

// C++ object destruction is non-portable) - I don't see any dtors here

#ifdef __VISUALC__

    #pragma warning(disable:4611)

#endif /* VC++ */

bool wxJPEGHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbose, int WXUNUSED(index) )

{

    wxCHECK_MSG( image, false, "NULL image pointer" );

    struct jpeg_decompress_struct cinfo;

    wx_error_mgr jerr;

    unsigned char *ptr;

    // save this before calling Destroy()

    const unsigned maxWidth = image->GetOptionInt(wxIMAGE_OPTION_MAX_WIDTH),

                   maxHeight = image->GetOptionInt(wxIMAGE_OPTION_MAX_HEIGHT);

    image->Destroy();

    cinfo.err = jpeg_std_error( &jerr );

    jerr.error_exit = wx_error_exit;

    if (!verbose)

        cinfo.err->output_message = wx_ignore_message;

    /* Establish the setjmp return context for wx_error_exit to use. */

    if (setjmp(jerr.setjmp_buffer)) {

      /* If we get here, the JPEG code has signaled an error.

       * We need to clean up the JPEG object, close the input file, and return.

       */

      if (verbose)

      {

        wxLogError(_("JPEG: Couldn't load - file is probably corrupted."));

      }

      (cinfo.src->term_source)(&cinfo);

      jpeg_destroy_decompress(&cinfo);

      if (image->IsOk()) image->Destroy();

      return false;

    }

    jpeg_create_decompress( &cinfo );

    wx_jpeg_io_src( &cinfo, stream );

    jpeg_read_header( &cinfo, TRUE );

    int bytesPerPixel;

    if ((cinfo.out_color_space == JCS_CMYK) || (cinfo.out_color_space == JCS_YCCK))

    {

        cinfo.out_color_space = JCS_CMYK;

        bytesPerPixel = 4;

    }

    else // all the rest is treated as RGB

    {

        cinfo.out_color_space = JCS_RGB;

        bytesPerPixel = 3;

    }

    // scale the picture to fit in the specified max size if necessary

    if ( maxWidth > 0 || maxHeight > 0 )

    {

        unsigned& scale = cinfo.scale_denom;

        while ( (maxWidth && (cinfo.image_width / scale > maxWidth)) ||

                    (maxHeight && (cinfo.image_height / scale > maxHeight)) )

        {

            scale *= 2;

        }

    }

    jpeg_start_decompress( &cinfo );

    image->Create( cinfo.output_width, cinfo.output_height );

    if (!image->IsOk()) {

        jpeg_finish_decompress( &cinfo );

        jpeg_destroy_decompress( &cinfo );

        return false;

    }

    image->SetMask( false );

    ptr = image->GetData();

    unsigned stride = cinfo.output_width * bytesPerPixel;

    JSAMPARRAY tempbuf = (*cinfo.mem->alloc_sarray)

                            ((j_common_ptr) &cinfo, JPOOL_IMAGE, stride, 1 );

    while ( cinfo.output_scanline < cinfo.output_height )

    {

        jpeg_read_scanlines( &cinfo, tempbuf, 1 );

        if (cinfo.out_color_space == JCS_RGB)

        {

            memcpy( ptr, tempbuf[0], stride );

            ptr += stride;

        }

        else // CMYK

        {

            const unsigned char* inptr = (const unsigned char*) tempbuf[0];

            for (size_t i = 0; i < cinfo.output_width; i++)

            {

                wx_cmyk_to_rgb(ptr, inptr);

                ptr += 3;

                inptr += 4;

            }

        }

    }

    // set up resolution if available: it's part of optional JFIF APP0 chunk

    if ( cinfo.saw_JFIF_marker )

    {

        image->SetOption(wxIMAGE_OPTION_RESOLUTIONX, cinfo.X_density);

        image->SetOption(wxIMAGE_OPTION_RESOLUTIONY, cinfo.Y_density);

        // we use the same values for this option as libjpeg so we don't need

        // any conversion here

        image->SetOption(wxIMAGE_OPTION_RESOLUTIONUNIT, cinfo.density_unit);

    }

    if ( cinfo.image_width != cinfo.output_width || cinfo.image_height != cinfo.output_height )

    {

        // save the original image size

        image->SetOption(wxIMAGE_OPTION_ORIGINAL_WIDTH, cinfo.image_width);

        image->SetOption(wxIMAGE_OPTION_ORIGINAL_HEIGHT, cinfo.image_height);

    }

    jpeg_finish_decompress( &cinfo );

    jpeg_destroy_decompress( &cinfo );

    return true;

}

typedef struct {

    struct jpeg_destination_mgr pub;

    wxOutputStream *stream;

    JOCTET * buffer;

} wx_destination_mgr;

typedef wx_destination_mgr * wx_dest_ptr;

#define OUTPUT_BUF_SIZE  4096    /* choose an efficiently fwrite'able size */

extern "C"

{

CPP_METHODDEF(void) wx_init_destination (j_compress_ptr cinfo)

{

    wx_dest_ptr dest = (wx_dest_ptr) cinfo->dest;

    /* Allocate the output buffer --- it will be released when done with image */

    dest->buffer = (JOCTET *)

        (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,

        OUTPUT_BUF_SIZE * sizeof(JOCTET));

    dest->pub.next_output_byte = dest->buffer;

    dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;

}

CPP_METHODDEF(wxjpeg_boolean) wx_empty_output_buffer (j_compress_ptr cinfo)

{

    wx_dest_ptr dest = (wx_dest_ptr) cinfo->dest;

    dest->stream->Write(dest->buffer, OUTPUT_BUF_SIZE);

    dest->pub.next_output_byte = dest->buffer;

    dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;

    return TRUE;

}

CPP_METHODDEF(void) wx_term_destination (j_compress_ptr cinfo)

{

    wx_dest_ptr dest = (wx_dest_ptr) cinfo->dest;

    size_t datacount = OUTPUT_BUF_SIZE - dest->pub.free_in_buffer;

    /* Write any data remaining in the buffer */

    if (datacount > 0)

        dest->stream->Write(dest->buffer, datacount);

}

GLOBAL(void) wx_jpeg_io_dest (j_compress_ptr cinfo, wxOutputStream& outfile)

{

    wx_dest_ptr dest;

    if (cinfo->dest == NULL) {    /* first time for this JPEG object? */

        cinfo->dest = (struct jpeg_destination_mgr *)

            (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,

            sizeof(wx_destination_mgr));

    }

    dest = (wx_dest_ptr) cinfo->dest;

    dest->pub.init_destination = wx_init_destination;

    dest->pub.empty_output_buffer = wx_empty_output_buffer;

    dest->pub.term_destination = wx_term_destination;

    dest->stream = &outfile;

}

} // extern "C"

bool wxJPEGHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbose )

{

    struct jpeg_compress_struct cinfo;

    wx_error_mgr jerr;

    JSAMPROW row_pointer[1];    /* pointer to JSAMPLE row[s] */

    JSAMPLE *image_buffer;

    int stride;                /* physical row width in image buffer */

    cinfo.err = jpeg_std_error(&jerr);

    jerr.error_exit = wx_error_exit;

    if (!verbose)

        cinfo.err->output_message = wx_ignore_message;

    /* Establish the setjmp return context for wx_error_exit to use. */

    if (setjmp(jerr.setjmp_buffer))

    {

        /* If we get here, the JPEG code has signaled an error.

         * We need to clean up the JPEG object, close the input file, and return.

         */

         if (verbose)

         {

            wxLogError(_("JPEG: Couldn't save image."));

         }

         jpeg_destroy_compress(&cinfo);

         return false;

    }

    jpeg_create_compress(&cinfo);

    wx_jpeg_io_dest(&cinfo, stream);

    cinfo.image_width = image->GetWidth();

    cinfo.image_height = image->GetHeight();

    cinfo.input_components = 3;

    cinfo.in_color_space = JCS_RGB;

    jpeg_set_defaults(&cinfo);

    // TODO: 3rd parameter is force_baseline, what value should this be?

    // Code says: "If force_baseline is TRUE, the computed quantization table entries

    // are limited to 1..255 for JPEG baseline compatibility."

    // 'Quality' is a number between 0 (terrible) and 100 (very good).

    // The default (in jcparam.c, jpeg_set_defaults) is 75,

    // and force_baseline is TRUE.

    if (image->HasOption(wxIMAGE_OPTION_QUALITY))

        jpeg_set_quality(&cinfo, image->GetOptionInt(wxIMAGE_OPTION_QUALITY), TRUE);

    // set the resolution fields in the output file

    int resX, resY;

    wxImageResolution res = GetResolutionFromOptions(*image, &resX, &resY);

    if ( res != wxIMAGE_RESOLUTION_NONE )

    {

        cinfo.X_density = resX;

        cinfo.Y_density = resY;

        // it so happens that wxIMAGE_RESOLUTION_INCHES/CM values are the same

        // ones as used by libjpeg, so we can assign them directly

        cinfo.density_unit = res;

    }

    jpeg_start_compress(&cinfo, TRUE);

    stride = cinfo.image_width * 3;    /* JSAMPLEs per row in image_buffer */

    image_buffer = image->GetData();

    while (cinfo.next_scanline < cinfo.image_height) {

        row_pointer[0] = &image_buffer[cinfo.next_scanline * stride];

        jpeg_write_scanlines( &cinfo, row_pointer, 1 );

    }

    jpeg_finish_compress(&cinfo);

    jpeg_destroy_compress(&cinfo);

    return true;

}

#ifdef __VISUALC__

    #pragma warning(default:4611)

#endif /* VC++ */

bool wxJPEGHandler::DoCanRead( wxInputStream& stream )

{

    unsigned char hdr[2];

    if ( !stream.Read(hdr, WXSIZEOF(hdr)) )     // it's ok to modify the stream position here

        return false;

    return hdr[0] == 0xFF && hdr[1] == 0xD8;

}

#endif   // wxUSE_STREAMS

/*static*/ wxVersionInfo wxJPEGHandler::GetLibraryVersionInfo()

{

    return wxVersionInfo("libjpeg", JPEG_LIB_VERSION/10, JPEG_LIB_VERSION%10);

}

#endif   // wxUSE_LIBJPEG