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

#if wxUSE_IMAGE && wxUSE_LIBJPEG

#include "wx/imagjpeg.h"

#ifndef WX_PRECOMP
    #include "wx/log.h"
    #include "wx/app.h"
    #include "wx/intl.h"
#endif

#include "wx/bitmap.h"
#include "wx/debug.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/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. */
  (*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;
}


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