src/common/imagjpeg.cpp

/////////////////////////////////////////////////////////////////////////////
// Name:        src/common/imagjpeg.cpp
// Purpose:     wxImage JPEG handler
// Author:      Vaclav Slavik
// RCS-ID:      $Id: imagjpeg.cpp 43781 2006-12-03 21:59:47Z MW $
// 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"

#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>

#ifdef __SALFORDC__
#undef FAR
#endif

// ----------------------------------------------------------------------------
// 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;

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 {
  struct jpeg_error_mgr pub;    /* "public" fields */

  jmp_buf setjmp_buffer;    /* for return to caller */
};

typedef struct wx_error_mgr * wx_error_ptr;

/*
 * 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_ptr myerr = (wx_error_ptr) 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(myerr->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;
}

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) )
{
    struct jpeg_decompress_struct cinfo;
    struct wx_error_mgr jerr;
    unsigned char *ptr;

    image->Destroy();
    cinfo.err = jpeg_std_error( &jerr.pub );
    jerr.pub.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->Ok()) 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;
    }

    jpeg_start_decompress( &cinfo );

    image->Create( cinfo.image_width, cinfo.image_height );
    if (!image->Ok()) {
        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;
            }
        }
    }

    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 */

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;
}

bool wxJPEGHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbose )
{
    struct jpeg_compress_struct cinfo;
    struct 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.pub);
    jerr.pub.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
    UINT16 resX,
           resY;
    if ( image->HasOption(wxIMAGE_OPTION_RESOLUTIONX) &&
         image->HasOption(wxIMAGE_OPTION_RESOLUTIONY) )
    {
        resX = (UINT16)image->GetOptionInt(wxIMAGE_OPTION_RESOLUTIONX);
        resY = (UINT16)image->GetOptionInt(wxIMAGE_OPTION_RESOLUTIONY);
    }
    else if ( image->HasOption(wxIMAGE_OPTION_RESOLUTION) )
    {
        resX =
        resY = (UINT16)image->GetOptionInt(wxIMAGE_OPTION_RESOLUTION);
    }
    else
    {
        resX =
        resY = 0;
    }

    if ( resX && resY )
    {
        cinfo.X_density = resX;
        cinfo.Y_density = resY;
    }

    // sets the resolution unit field in the output file
    // wxIMAGE_RESOLUTION_INCHES for inches
    // wxIMAGE_RESOLUTION_CM for centimeters
    if ( image->HasOption(wxIMAGE_OPTION_RESOLUTIONUNIT) )
    {
        cinfo.density_unit = (UINT8)image->GetOptionInt(wxIMAGE_OPTION_RESOLUTIONUNIT);
    }

    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)) )
        return false;

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

#endif   // wxUSE_STREAMS

#endif   // wxUSE_LIBJPEG
1	/////////////////////////////////////////////////////////////////////////////
2	// Name: src/common/imagjpeg.cpp
3	// Purpose: wxImage JPEG handler
4	// Author: Vaclav Slavik
5	// RCS-ID: $Id: imagjpeg.cpp 43781 2006-12-03 21:59:47Z MW $
6	// Copyright: (c) Vaclav Slavik
7	// Licence: wxWindows licence
8	/////////////////////////////////////////////////////////////////////////////
9
10	// For compilers that support precompilation, includes "wx.h".
11	#include "wx/wxprec.h"
12
13	#ifdef __BORLANDC__
14	#pragma hdrstop
15	#endif
16
17	#if wxUSE_IMAGE && wxUSE_LIBJPEG
18
19	#include "wx/imagjpeg.h"
20
21	#ifndef WX_PRECOMP
22	#include "wx/log.h"
23	#include "wx/app.h"
24	#include "wx/intl.h"
25	#include "wx/bitmap.h"
26	#include "wx/module.h"
27	#endif
28
29	// A hack based on one from tif_jpeg.c to overcome the problem on Windows
30	// of rpcndr.h defining boolean with a different type to the jpeg headers.
31	//
32	// This hack is only necessary for an external jpeg library, the builtin one
33	// usually used on Windows doesn't use the type boolean, so always works.
34	//
35	#ifdef wxHACK_BOOLEAN
36	#define HAVE_BOOLEAN
37	#define boolean wxHACK_BOOLEAN
38	#endif
39
40	extern "C"
41	{
42	#if defined(__WXMSW__)
43	#define XMD_H
44	#endif
45	#include "jpeglib.h"
46	}
47
48	#ifndef HAVE_WXJPEG_BOOLEAN
49	typedef boolean wxjpeg_boolean;
50	#endif
51
52	#include "wx/filefn.h"
53	#include "wx/wfstream.h"
54
55	// For memcpy
56	#include <string.h>
57	// For JPEG library error handling
58	#include <setjmp.h>
59
60	#ifdef __SALFORDC__
61	#undef FAR
62	#endif
63
64	// ----------------------------------------------------------------------------
65	// types
66	// ----------------------------------------------------------------------------
67
68	// the standard definition of METHODDEF(type) from jmorecfg.h is "static type"
69	// which means that we can't declare the method functions as extern "C" - the
70	// compiler (rightfully) complains about the multiple storage classes in
71	// declaration
72	//
73	// so we only add extern "C" when using our own, modified, jmorecfg.h - and use
74	// whatever we have in the system headers if this is what we use hoping that it
75	// should be ok (can't do anything else)
76	#ifdef JPEG_METHOD_LINKAGE
77	#define CPP_METHODDEF(type) extern "C" METHODDEF(type)
78	#else // not using our jmorecfg.h header
79	#define CPP_METHODDEF(type) METHODDEF(type)
80	#endif
81
82	//-----------------------------------------------------------------------------
83	// wxJPEGHandler
84	//-----------------------------------------------------------------------------
85
86	IMPLEMENT_DYNAMIC_CLASS(wxJPEGHandler,wxImageHandler)
87
88	#if wxUSE_STREAMS
89
90	//------------- JPEG Data Source Manager
91
92	#define JPEG_IO_BUFFER_SIZE 2048
93
94	typedef struct {
95	struct jpeg_source_mgr pub; /* public fields */
96
97	JOCTET* buffer; /* start of buffer */
98	wxInputStream *stream;
99	} wx_source_mgr;
100
101	typedef wx_source_mgr * wx_src_ptr;
102
103	CPP_METHODDEF(void) wx_init_source ( j_decompress_ptr WXUNUSED(cinfo) )
104	{
105	}
106
107	CPP_METHODDEF(wxjpeg_boolean) wx_fill_input_buffer ( j_decompress_ptr cinfo )
108	{
109	wx_src_ptr src = (wx_src_ptr) cinfo->src;
110
111	src->pub.next_input_byte = src->buffer;
112	src->pub.bytes_in_buffer = src->stream->Read(src->buffer, JPEG_IO_BUFFER_SIZE).LastRead();
113
114	if (src->pub.bytes_in_buffer == 0) // check for end-of-stream
115	{
116	// Insert a fake EOI marker
117	src->buffer[0] = 0xFF;
118	src->buffer[1] = JPEG_EOI;
119	src->pub.bytes_in_buffer = 2;
120	}
121	return TRUE;
122	}
123
124	CPP_METHODDEF(void) wx_skip_input_data ( j_decompress_ptr cinfo, long num_bytes )
125	{
126	if (num_bytes > 0)
127	{
128	wx_src_ptr src = (wx_src_ptr) cinfo->src;
129
130	while (num_bytes > (long)src->pub.bytes_in_buffer)
131	{
132	num_bytes -= (long) src->pub.bytes_in_buffer;
133	src->pub.fill_input_buffer(cinfo);
134	}
135	src->pub.next_input_byte += (size_t) num_bytes;
136	src->pub.bytes_in_buffer -= (size_t) num_bytes;
137	}
138	}
139
140	CPP_METHODDEF(void) wx_term_source ( j_decompress_ptr cinfo )
141	{
142	wx_src_ptr src = (wx_src_ptr) cinfo->src;
143
144	if (src->pub.bytes_in_buffer > 0)
145	src->stream->SeekI(-(long)src->pub.bytes_in_buffer, wxFromCurrent);
146	delete[] src->buffer;
147	}
148
149
150	// JPEG error manager:
151
152	struct wx_error_mgr {
153	struct jpeg_error_mgr pub; /* "public" fields */
154
155	jmp_buf setjmp_buffer; /* for return to caller */
156	};
157
158	typedef struct wx_error_mgr * wx_error_ptr;
159
160	/*
161	* Here's the routine that will replace the standard error_exit method:
162	*/
163
164	CPP_METHODDEF(void) wx_error_exit (j_common_ptr cinfo)
165	{
166	/* cinfo->err really points to a wx_error_mgr struct, so coerce pointer */
167	wx_error_ptr myerr = (wx_error_ptr) cinfo->err;
168
169	/* Always display the message. */
170	/* We could postpone this until after returning, if we chose. */
171	(*cinfo->err->output_message) (cinfo);
172
173	/* Return control to the setjmp point */
174	longjmp(myerr->setjmp_buffer, 1);
175	}
176
177	/*
178	* This will replace the standard output_message method when the user
179	* wants us to be silent (verbose==false). We must have such method instead of
180	* simply using NULL for cinfo->err->output_message because it's called
181	* unconditionally from within libjpeg when there's "garbage input".
182	*/
183	CPP_METHODDEF(void) wx_ignore_message (j_common_ptr WXUNUSED(cinfo))
184	{
185	}
186
187	void wx_jpeg_io_src( j_decompress_ptr cinfo, wxInputStream& infile )
188	{
189	wx_src_ptr src;
190
191	if (cinfo->src == NULL) { /* first time for this JPEG object? */
192	cinfo->src = (struct jpeg_source_mgr *)
193	(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
194	sizeof(wx_source_mgr));
195	}
196	src = (wx_src_ptr) cinfo->src;
197	src->pub.bytes_in_buffer = 0; /* forces fill_input_buffer on first read */
198	src->buffer = new JOCTET[JPEG_IO_BUFFER_SIZE];
199	src->pub.next_input_byte = NULL; /* until buffer loaded */
200	src->stream = &infile;
201
202	src->pub.init_source = wx_init_source;
203	src->pub.fill_input_buffer = wx_fill_input_buffer;
204	src->pub.skip_input_data = wx_skip_input_data;
205	src->pub.resync_to_restart = jpeg_resync_to_restart; /* use default method */
206	src->pub.term_source = wx_term_source;
207	}
208
209	static inline void wx_cmyk_to_rgb(unsigned char* rgb, const unsigned char* cmyk)
210	{
211	register int k = 255 - cmyk[3];
212	register int k2 = cmyk[3];
213	register int c;
214
215	c = k + k2 * (255 - cmyk[0]) / 255;
216	rgb[0] = (unsigned char)((c > 255) ? 0 : (255 - c));
217
218	c = k + k2 * (255 - cmyk[1]) / 255;
219	rgb[1] = (unsigned char)((c > 255) ? 0 : (255 - c));
220
221	c = k + k2 * (255 - cmyk[2]) / 255;
222	rgb[2] = (unsigned char)((c > 255) ? 0 : (255 - c));
223	}
224
225	// temporarily disable the warning C4611 (interaction between '_setjmp' and
226	// C++ object destruction is non-portable) - I don't see any dtors here
227	#ifdef __VISUALC__
228	#pragma warning(disable:4611)
229	#endif /* VC++ */
230
231	bool wxJPEGHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbose, int WXUNUSED(index) )
232	{
233	struct jpeg_decompress_struct cinfo;
234	struct wx_error_mgr jerr;
235	unsigned char *ptr;
236
237	image->Destroy();
238	cinfo.err = jpeg_std_error( &jerr.pub );
239	jerr.pub.error_exit = wx_error_exit;
240
241	if (!verbose)
242	cinfo.err->output_message = wx_ignore_message;
243
244	/* Establish the setjmp return context for wx_error_exit to use. */
245	if (setjmp(jerr.setjmp_buffer)) {
246	/* If we get here, the JPEG code has signaled an error.
247	* We need to clean up the JPEG object, close the input file, and return.
248	*/
249	if (verbose)
250	wxLogError(_("JPEG: Couldn't load - file is probably corrupted."));
251	(cinfo.src->term_source)(&cinfo);
252	jpeg_destroy_decompress(&cinfo);
253	if (image->Ok()) image->Destroy();
254	return false;
255	}
256
257	jpeg_create_decompress( &cinfo );
258	wx_jpeg_io_src( &cinfo, stream );
259	jpeg_read_header( &cinfo, TRUE );
260
261	int bytesPerPixel;
262	if ((cinfo.out_color_space == JCS_CMYK) \|\| (cinfo.out_color_space == JCS_YCCK))
263	{
264	cinfo.out_color_space = JCS_CMYK;
265	bytesPerPixel = 4;
266	}
267	else // all the rest is treated as RGB
268	{
269	cinfo.out_color_space = JCS_RGB;
270	bytesPerPixel = 3;
271	}
272
273	jpeg_start_decompress( &cinfo );
274
275	image->Create( cinfo.image_width, cinfo.image_height );
276	if (!image->Ok()) {
277	jpeg_finish_decompress( &cinfo );
278	jpeg_destroy_decompress( &cinfo );
279	return false;
280	}
281	image->SetMask( false );
282	ptr = image->GetData();
283
284	unsigned stride = cinfo.output_width * bytesPerPixel;
285	JSAMPARRAY tempbuf = (*cinfo.mem->alloc_sarray)
286	((j_common_ptr) &cinfo, JPOOL_IMAGE, stride, 1 );
287
288	while ( cinfo.output_scanline < cinfo.output_height )
289	{
290	jpeg_read_scanlines( &cinfo, tempbuf, 1 );
291	if (cinfo.out_color_space == JCS_RGB)
292	{
293	memcpy( ptr, tempbuf[0], stride );
294	ptr += stride;
295	}
296	else // CMYK
297	{
298	const unsigned char* inptr = (const unsigned char*) tempbuf[0];
299	for (size_t i = 0; i < cinfo.output_width; i++)
300	{
301	wx_cmyk_to_rgb(ptr, inptr);
302	ptr += 3;
303	inptr += 4;
304	}
305	}
306	}
307
308	jpeg_finish_decompress( &cinfo );
309	jpeg_destroy_decompress( &cinfo );
310	return true;
311	}
312
313	typedef struct {
314	struct jpeg_destination_mgr pub;
315
316	wxOutputStream *stream;
317	JOCTET * buffer;
318	} wx_destination_mgr;
319
320	typedef wx_destination_mgr * wx_dest_ptr;
321
322	#define OUTPUT_BUF_SIZE 4096 /* choose an efficiently fwrite'able size */
323
324	CPP_METHODDEF(void) wx_init_destination (j_compress_ptr cinfo)
325	{
326	wx_dest_ptr dest = (wx_dest_ptr) cinfo->dest;
327
328	/* Allocate the output buffer --- it will be released when done with image */
329	dest->buffer = (JOCTET *)
330	(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
331	OUTPUT_BUF_SIZE * sizeof(JOCTET));
332	dest->pub.next_output_byte = dest->buffer;
333	dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
334	}
335
336	CPP_METHODDEF(wxjpeg_boolean) wx_empty_output_buffer (j_compress_ptr cinfo)
337	{
338	wx_dest_ptr dest = (wx_dest_ptr) cinfo->dest;
339
340	dest->stream->Write(dest->buffer, OUTPUT_BUF_SIZE);
341	dest->pub.next_output_byte = dest->buffer;
342	dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
343	return TRUE;
344	}
345
346	CPP_METHODDEF(void) wx_term_destination (j_compress_ptr cinfo)
347	{
348	wx_dest_ptr dest = (wx_dest_ptr) cinfo->dest;
349	size_t datacount = OUTPUT_BUF_SIZE - dest->pub.free_in_buffer;
350	/* Write any data remaining in the buffer */
351	if (datacount > 0)
352	dest->stream->Write(dest->buffer, datacount);
353	}
354
355	GLOBAL(void) wx_jpeg_io_dest (j_compress_ptr cinfo, wxOutputStream& outfile)
356	{
357	wx_dest_ptr dest;
358
359	if (cinfo->dest == NULL) { /* first time for this JPEG object? */
360	cinfo->dest = (struct jpeg_destination_mgr *)
361	(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
362	sizeof(wx_destination_mgr));
363	}
364
365	dest = (wx_dest_ptr) cinfo->dest;
366	dest->pub.init_destination = wx_init_destination;
367	dest->pub.empty_output_buffer = wx_empty_output_buffer;
368	dest->pub.term_destination = wx_term_destination;
369	dest->stream = &outfile;
370	}
371
372	bool wxJPEGHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbose )
373	{
374	struct jpeg_compress_struct cinfo;
375	struct wx_error_mgr jerr;
376	JSAMPROW row_pointer[1]; /* pointer to JSAMPLE row[s] */
377	JSAMPLE *image_buffer;
378	int stride; /* physical row width in image buffer */
379
380	cinfo.err = jpeg_std_error(&jerr.pub);
381	jerr.pub.error_exit = wx_error_exit;
382
383	if (!verbose)
384	cinfo.err->output_message = wx_ignore_message;
385
386	/* Establish the setjmp return context for wx_error_exit to use. */
387	if (setjmp(jerr.setjmp_buffer))
388	{
389	/* If we get here, the JPEG code has signaled an error.
390	* We need to clean up the JPEG object, close the input file, and return.
391	*/
392	if (verbose)
393	wxLogError(_("JPEG: Couldn't save image."));
394	jpeg_destroy_compress(&cinfo);
395	return false;
396	}
397
398	jpeg_create_compress(&cinfo);
399	wx_jpeg_io_dest(&cinfo, stream);
400
401	cinfo.image_width = image->GetWidth();
402	cinfo.image_height = image->GetHeight();
403	cinfo.input_components = 3;
404	cinfo.in_color_space = JCS_RGB;
405	jpeg_set_defaults(&cinfo);
406
407	// TODO: 3rd parameter is force_baseline, what value should this be?
408	// Code says: "If force_baseline is TRUE, the computed quantization table entries
409	// are limited to 1..255 for JPEG baseline compatibility."
410	// 'Quality' is a number between 0 (terrible) and 100 (very good).
411	// The default (in jcparam.c, jpeg_set_defaults) is 75,
412	// and force_baseline is TRUE.
413	if (image->HasOption(wxIMAGE_OPTION_QUALITY))
414	jpeg_set_quality(&cinfo, image->GetOptionInt(wxIMAGE_OPTION_QUALITY), TRUE);
415
416	// set the resolution fields in the output file
417	UINT16 resX,
418	resY;
419	if ( image->HasOption(wxIMAGE_OPTION_RESOLUTIONX) &&
420	image->HasOption(wxIMAGE_OPTION_RESOLUTIONY) )
421	{
422	resX = (UINT16)image->GetOptionInt(wxIMAGE_OPTION_RESOLUTIONX);
423	resY = (UINT16)image->GetOptionInt(wxIMAGE_OPTION_RESOLUTIONY);
424	}
425	else if ( image->HasOption(wxIMAGE_OPTION_RESOLUTION) )
426	{
427	resX =
428	resY = (UINT16)image->GetOptionInt(wxIMAGE_OPTION_RESOLUTION);
429	}
430	else
431	{
432	resX =
433	resY = 0;
434	}
435
436	if ( resX && resY )
437	{
438	cinfo.X_density = resX;
439	cinfo.Y_density = resY;
440	}
441
442	// sets the resolution unit field in the output file
443	// wxIMAGE_RESOLUTION_INCHES for inches
444	// wxIMAGE_RESOLUTION_CM for centimeters
445	if ( image->HasOption(wxIMAGE_OPTION_RESOLUTIONUNIT) )
446	{
447	cinfo.density_unit = (UINT8)image->GetOptionInt(wxIMAGE_OPTION_RESOLUTIONUNIT);
448	}
449
450	jpeg_start_compress(&cinfo, TRUE);
451
452	stride = cinfo.image_width * 3; /* JSAMPLEs per row in image_buffer */
453	image_buffer = image->GetData();
454	while (cinfo.next_scanline < cinfo.image_height) {
455	row_pointer[0] = &image_buffer[cinfo.next_scanline * stride];
456	jpeg_write_scanlines( &cinfo, row_pointer, 1 );
457	}
458	jpeg_finish_compress(&cinfo);
459	jpeg_destroy_compress(&cinfo);
460
461	return true;
462	}
463
464	#ifdef __VISUALC__
465	#pragma warning(default:4611)
466	#endif /* VC++ */
467
468	bool wxJPEGHandler::DoCanRead( wxInputStream& stream )
469	{
470	unsigned char hdr[2];
471
472	if ( !stream.Read(hdr, WXSIZEOF(hdr)) )
473	return false;
474
475	return hdr[0] == 0xFF && hdr[1] == 0xD8;
476	}
477
478	#endif // wxUSE_STREAMS
479
480	#endif // wxUSE_LIBJPEG