src/common/imagjpeg.cpp

/////////////////////////////////////////////////////////////////////////////
// Name:        src/common/imagjpeg.cpp
// Purpose:     wxImage JPEG handler
// Author:      Vaclav Slavik
// RCS-ID:      $Id$
// Copyright:   (c) Vaclav Slavik
// Licence:     wxWindows licence
/////////////////////////////////////////////////////////////////////////////

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

#ifdef __BORLANDC__
#pragma hdrstop
#endif

#include "wx/defs.h"

#if wxUSE_IMAGE && wxUSE_LIBJPEG

#include "wx/imagjpeg.h"
#include "wx/bitmap.h"
#include "wx/debug.h"
#include "wx/log.h"
#include "wx/app.h"

// NB: Some compilers define boolean type in Windows headers
//     (e.g. Watcom C++, but not Open Watcom).
//     This causes a conflict with jmorecfg.h header from libjpeg, so we have
//     to make sure libjpeg won't try to define boolean itself. This is done by
//     defining HAVE_BOOLEAN.
#if defined(__WXMSW__) && (defined(__MWERKS__) || defined(__DIGITALMARS__))
    #define HAVE_BOOLEAN
    #include "wx/msw/wrapwin.h"
#endif

extern "C"
{
    #if defined(__WXMSW__)
        #define XMD_H
    #endif
    #include "jpeglib.h"
}

#include "wx/filefn.h"
#include "wx/wfstream.h"
#include "wx/intl.h"
#include "wx/module.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(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. */
  if (cinfo->err->output_message) (*cinfo->err->output_message) (cinfo);

  /* Return control to the setjmp point */
  longjmp(myerr->setjmp_buffer, 1);
}

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;
}


// 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;
    JSAMPARRAY tempbuf;
    unsigned char *ptr;
    unsigned stride;

    image->Destroy();
    cinfo.err = jpeg_std_error( &jerr.pub );
    jerr.pub.error_exit = wx_error_exit;

    if (!verbose) cinfo.err->output_message=NULL;

    /* 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 );
    cinfo.out_color_space = JCS_RGB;
    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();
    stride = cinfo.output_width * 3;
    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 );
        memcpy( ptr, tempbuf[0], stride );
        ptr += stride;
    }
    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(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=NULL;

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