/*

 * gd_jpeg.c: Read and write JPEG (JFIF) format image files using the

 * gd graphics library (http://www.libgd.org).

 *

 * This software is based in part on the work of the Independent JPEG

 * Group.  For more information on the IJG JPEG software (and JPEG

 * documentation, etc.), see ftp://ftp.uu.net/graphics/jpeg/.

 *

 * NOTE: IJG 12-bit JSAMPLE (BITS_IN_JSAMPLE == 12) mode is not

 * supported at all on read in gd 2.0, and is not supported on write

 * except for palette images, which is sort of pointless (TBB). Even that

 * has never been tested according to DB.

 *

 * Copyright 2000 Doug Becker, mailto:thebeckers@home.com

 *

 * Modification 4/18/00 TBB: JPEG_DEBUG rather than just DEBUG,

 * so VC++ builds don't spew to standard output, causing

 * major CGI brain damage

 *

 * 2.0.10: more efficient gdImageCreateFromJpegCtx, thanks to

 * Christian Aberger

 */

/**

 * File: JPEG IO

 *

 * Read and write JPEG images.

 */

#ifdef HAVE_CONFIG_H

#	include "config.h"

#endif

#include <stdlib.h>

#include <setjmp.h>

#include <limits.h>

#include <string.h>

#include "gd.h"

#include "gd_errors.h"

/* TBB: move this up so include files are not brought in */

/* JCE: arrange HAVE_LIBJPEG so that it can be set in gd.h */

#ifdef HAVE_LIBJPEG

#include "gdhelpers.h"

#if defined(_WIN32) && defined(__MINGW32__)

# define HAVE_BOOLEAN

#endif

/* JCE undef two symbols that we don't need anymore but which are

   may be defined in config.h from ./configure but which are

   redefined incompatibly in jpeglib.h */

#undef HAVE_STDDEF_H

#undef HAVE_STDLIB_H

/* 1.8.1: remove dependency on jinclude.h */

#include "jpeglib.h"

#include "jerror.h"

static const char *const GD_JPEG_VERSION = "1.0";

typedef struct _jmpbuf_wrapper {

	jmp_buf jmpbuf;

        int ignore_warning;

}

jmpbuf_wrapper;

static void jpeg_emit_message(j_common_ptr jpeg_info, int level)

{

	char message[JMSG_LENGTH_MAX];

	jmpbuf_wrapper *jmpbufw;

	int ignore_warning = 0;

	jmpbufw = (jmpbuf_wrapper *) jpeg_info->client_data;

	if (jmpbufw != 0) {

		ignore_warning = jmpbufw->ignore_warning;

	}

	(jpeg_info->err->format_message)(jpeg_info,message);

	/* It is a warning message */

	if (level < 0) {

		/* display only the 1st warning, as would do a default libjpeg

		 * unless strace_level >= 3

		 */

		if ((jpeg_info->err->num_warnings == 0) || (jpeg_info->err->trace_level >= 3)) {

			if (!ignore_warning) {

				gd_error("gd-jpeg, libjpeg: recoverable error: %s\n", message);

			}

		}

		jpeg_info->err->num_warnings++;

	} else {

		/* strace msg, Show it if trace_level >= level. */

		if (jpeg_info->err->trace_level >= level) {

			if (!ignore_warning) {

				gd_error("gd-jpeg, libjpeg: strace message: %s\n", message);

			}

		}

	}

}

/* Called by the IJG JPEG library upon encountering a fatal error */

static void fatal_jpeg_error(j_common_ptr cinfo)

{

	jmpbuf_wrapper *jmpbufw;

	char buffer[JMSG_LENGTH_MAX];

	(*cinfo->err->format_message)(cinfo, buffer);

	gd_error_ex(GD_WARNING, "gd-jpeg: JPEG library reports unrecoverable error: %s", buffer);

	jmpbufw = (jmpbuf_wrapper *)cinfo->client_data;

	jpeg_destroy(cinfo);

	if(jmpbufw != 0) {

		longjmp(jmpbufw->jmpbuf, 1);

		gd_error_ex(GD_ERROR, "gd-jpeg: EXTREMELY fatal error: longjmp returned control; terminating\n");

	} else {

		gd_error_ex(GD_ERROR, "gd-jpeg: EXTREMELY fatal error: jmpbuf unrecoverable; terminating\n");

	}

	exit(99);

}

/*

 * Write IM to OUTFILE as a JFIF-formatted JPEG image, using quality

 * QUALITY.  If QUALITY is in the range 0-100, increasing values

 * represent higher quality but also larger image size.  If QUALITY is

 * negative, the IJG JPEG library's default quality is used (which

 * should be near optimal for many applications).  See the IJG JPEG

 * library documentation for more details.

 */

/*

  Function: gdImageJpeg

    <gdImageJpeg> outputs the specified image to the specified file in

    JPEG format. The file must be open for writing. Under MSDOS and

    all versions of Windows, it is important to use "wb" as opposed to

    simply "w" as the mode when opening the file, and under Unix there

    is no penalty for doing so. <gdImageJpeg> does not close the file;

    your code must do so.

    If _quality_ is negative, the default IJG JPEG quality value (which

    should yield a good general quality / size tradeoff for most

    situations) is used. Otherwise, for practical purposes, _quality_

    should be a value in the range 0-95, higher quality values usually

    implying both higher quality and larger image sizes.

    If you have set image interlacing using <gdImageInterlace>, this

    function will interpret that to mean you wish to output a

    progressive JPEG. Some programs (e.g., Web browsers) can display

    progressive JPEGs incrementally; this can be useful when browsing

    over a relatively slow communications link, for

    example. Progressive JPEGs can also be slightly smaller than

    sequential (non-progressive) JPEGs.

  Variants:

    <gdImageJpegCtx> stores the image using a <gdIOCtx> struct.

    <gdImageJpegPtr> stores the image to RAM.

  Parameters:

    im      - The image to save

    outFile - The FILE pointer to write to.

    quality - Compression quality (0-95, 0 means use the default).

  Returns:

    Nothing.

  Example:

    (start code)

    gdImagePtr im;

    int black, white;

    FILE *out;

    // Create the image

    im = gdImageCreate(100, 100);

    // Allocate background

    white = gdImageColorAllocate(im, 255, 255, 255);

    // Allocate drawing color

    black = gdImageColorAllocate(im, 0, 0, 0);

    // Draw rectangle

    gdImageRectangle(im, 0, 0, 99, 99, black);

    // Open output file in binary mode

    out = fopen("rect.jpg", "wb");

    // Write JPEG using default quality

    gdImageJpeg(im, out, -1);

    // Close file

    fclose(out);

    // Destroy image

    gdImageDestroy(im);

    (end code)

*/

BGD_DECLARE(void) gdImageJpeg(gdImagePtr im, FILE *outFile, int quality)

{

	gdIOCtx *out = gdNewFileCtx(outFile);

	if (out == NULL) return;

	gdImageJpegCtx(im, out, quality);

	out->gd_free(out);

}

/*

  Function: gdImageJpegPtr

    Identical to <gdImageJpeg> except that it returns a pointer to a

    memory area with the JPEG data. This memory must be freed by the

    caller when it is no longer needed.

    The caller *must* invoke <gdFree>, not free().  This is because it

    is not guaranteed that libgd will use the same implementation of

    malloc, free, etc. as your proggram.

    The 'size' parameter receives the total size of the block of

    memory.

  Parameters:

    im      - The image to write

    size    - Output: the size of the resulting image.

    quality - Compression quality.

  Returns:

    A pointer to the JPEG data or NULL if an error occurred.

*/

BGD_DECLARE(void *) gdImageJpegPtr(gdImagePtr im, int *size, int quality)

{

	void *rv;

	gdIOCtx *out = gdNewDynamicCtx(2048, NULL);

	if (out == NULL) return NULL;

	gdImageJpegCtx(im, out, quality);

	rv = gdDPExtractData(out, size);

	out->gd_free(out);

	return rv;

}

void jpeg_gdIOCtx_dest(j_compress_ptr cinfo, gdIOCtx *outfile);

/*

  Function: gdImageJpegCtx

    Write the image as JPEG data via a <gdIOCtx>. See <gdImageJpeg>

    for more details.

  Parameters:

    im      - The image to write.

    outfile - The output sink.

    quality - Image quality. 

*/

BGD_DECLARE(void) gdImageJpegCtx(gdImagePtr im, gdIOCtx *outfile, int quality)

{

	struct jpeg_compress_struct cinfo;

	struct jpeg_error_mgr jerr;

	int i, j, jidx;

	/* volatile so we can gdFree it on return from longjmp */

	volatile JSAMPROW row = 0;

	JSAMPROW rowptr[1];

	jmpbuf_wrapper jmpbufw;

	JDIMENSION nlines;

	char comment[255];

#ifdef JPEG_DEBUG

	gd_error_ex(GD_DEBUG, "gd-jpeg: gd JPEG version %s\n", GD_JPEG_VERSION);

	gd_error_ex(GD_DEBUG, "gd-jpeg: JPEG library version %d, %d-bit sample values\n", JPEG_LIB_VERSION, BITS_IN_JSAMPLE);

	if (!im->trueColor) {

		for(i = 0; i < im->colorsTotal; i++) {

			if(!im->open[i]) {

				gd_error_ex(GD_DEBUG, "gd-jpeg: gd colormap index %d: (%d, %d, %d)\n", i, im->red[i], im->green[i], im->blue[i]);

			}

		}

	}

#endif /* JPEG_DEBUG */

	memset(&cinfo, 0, sizeof(cinfo));

	memset(&jerr, 0, sizeof(jerr));

	cinfo.err = jpeg_std_error(&jerr);

	cinfo.client_data = &jmpbufw;

	if(setjmp(jmpbufw.jmpbuf) != 0) {

		/* we're here courtesy of longjmp */

		if(row) {

			gdFree(row);

		}

		return;

	}

	cinfo.err->emit_message = jpeg_emit_message;

	cinfo.err->error_exit = fatal_jpeg_error;

	jpeg_create_compress(&cinfo);

	cinfo.image_width = im->sx;

	cinfo.image_height = im->sy;

	cinfo.input_components = 3; /* # of color components per pixel */

	cinfo.in_color_space = JCS_RGB; /* colorspace of input image */

	jpeg_set_defaults(&cinfo);

	cinfo.density_unit = 1;

	cinfo.X_density = im->res_x;

	cinfo.Y_density = im->res_y;

	if(quality >= 0) {

		jpeg_set_quality(&cinfo, quality, TRUE);

		if (quality >= 90) {

			cinfo.comp_info[0].h_samp_factor = 1;

			cinfo.comp_info[0].v_samp_factor = 1;

		}

	}

	/* If user requests interlace, translate that to progressive JPEG */

	if(gdImageGetInterlaced(im)) {

#ifdef JPEG_DEBUG

		gd_error_ex(GD_DEBUG, "gd-jpeg: interlace set, outputting progressive JPEG image\n");

#endif

		jpeg_simple_progression(&cinfo);

	}

	jpeg_gdIOCtx_dest(&cinfo, outfile);

	row = (JSAMPROW)gdCalloc(1, cinfo.image_width * cinfo.input_components * sizeof(JSAMPLE));

	if(row == 0) {

		gd_error("gd-jpeg: error: unable to allocate JPEG row structure: gdCalloc returns NULL\n");

		jpeg_destroy_compress(&cinfo);

		return;

	}

	rowptr[0] = row;

	jpeg_start_compress(&cinfo, TRUE);

	sprintf(comment, "CREATOR: gd-jpeg v%s (using IJG JPEG v%d),", GD_JPEG_VERSION, JPEG_LIB_VERSION);

	if(quality >= 0) {

		sprintf (comment + strlen(comment), " quality = %d\n", quality);

	} else {

		strcat(comment + strlen(comment), " default quality\n");

	}

	jpeg_write_marker(&cinfo, JPEG_COM, (unsigned char *) comment, (unsigned int)strlen(comment));

	if(im->trueColor) {

#if BITS_IN_JSAMPLE == 12

		gd_error(

		        "gd-jpeg: error: jpeg library was compiled for 12-bit\n"

		        "precision. This is mostly useless, because JPEGs on the web are\n"

		        "8-bit and such versions of the jpeg library won't read or write\n"

		        "them. GD doesn't support these unusual images. Edit your\n"

		        "jmorecfg.h file to specify the correct precision and completely\n"

		        "'make clean' and 'make install' libjpeg again. Sorry.\n"

		       );

		goto error;

#endif /* BITS_IN_JSAMPLE == 12 */

		for(i = 0; i < im->sy; i++) {

			for(jidx = 0, j = 0; j < im->sx; j++) {

				int val = im->tpixels[i][j];

				row[jidx++] = gdTrueColorGetRed(val);

				row[jidx++] = gdTrueColorGetGreen(val);

				row[jidx++] = gdTrueColorGetBlue(val);

			}

			nlines = jpeg_write_scanlines(&cinfo, rowptr, 1);

			if(nlines != 1) {

				gd_error("gd_jpeg: warning: jpeg_write_scanlines returns %u -- expected 1\n", nlines);

			}

		}

	} else {

		for(i = 0; i < im->sy; i++) {

			for(jidx = 0, j = 0; j < im->sx; j++) {

				int idx = im->pixels[i][j];

				/*

				 * NB: Although gd RGB values are ints, their max value is

				 * 255 (see the documentation for gdImageColorAllocate())

				 * -- perfect for 8-bit JPEG encoding (which is the norm)

				 */

#if BITS_IN_JSAMPLE == 8

				row[jidx++] = im->red[idx];

				row[jidx++] = im->green[idx];

				row[jidx++] = im->blue[idx];

#elif BITS_IN_JSAMPLE == 12

				row[jidx++] = im->red[idx] << 4;

				row[jidx++] = im->green[idx] << 4;

				row[jidx++] = im->blue[idx] << 4;

#else

#error IJG JPEG library BITS_IN_JSAMPLE value must be 8 or 12

#endif

			}

			nlines = jpeg_write_scanlines(&cinfo, rowptr, 1);

			if(nlines != 1) {

				gd_error("gd_jpeg: warning: jpeg_write_scanlines"

				         " returns %u -- expected 1\n", nlines);

			}

		}

	}

	jpeg_finish_compress(&cinfo);

	jpeg_destroy_compress(&cinfo);

	gdFree(row);

}

/*

  Function: gdImageCreateFromJpeg

  See <gdImageCreateFromJpegEx>.

*/

BGD_DECLARE(gdImagePtr) gdImageCreateFromJpeg(FILE *inFile)

{

	return gdImageCreateFromJpegEx(inFile, 1);

}

/*

  Function: gdImageCreateFromJpegEx

    <gdImageCreateFromJpegEx> is called to load truecolor images from

    JPEG format files. Invoke <gdImageCreateFromJpegEx> with an

    already opened pointer to a file containing the desired

    image. <gdImageCreateFromJpegEx> returns a <gdImagePtr> to the new

    truecolor image, or NULL if unable to load the image (most often

    because the file is corrupt or does not contain a JPEG

    image). <gdImageCreateFromJpegEx> does not close the file.

    You can inspect the sx and sy members of the image to determine

    its size. The image must eventually be destroyed using

    <gdImageDestroy>.

    *The returned image is always a truecolor image.*

  Variants:

    <gdImageCreateFromJpegPtrEx> creates an image from JPEG data

    already in memory.

    <gdImageCreateFromJpegCtxEx> reads its data via the function

    pointers in a <gdIOCtx> structure.

    <gdImageCreateFromJpeg>, <gdImageCreateFromJpegPtr> and

    <gdImageCreateFromJpegCtx> are equivalent to calling their

    _Ex_-named counterparts with an ignore_warning set to 1

    (i.e. TRUE).

  Parameters:

    infile          - The input FILE pointer.

    ignore_warning  - Flag.  If true, ignores recoverable warnings.

  Returns:

    A pointer to the new *truecolor* image.  This will need to be

    destroyed with <gdImageDestroy> once it is no longer needed.

    On error, returns NULL.

  Example:

    (start code)

    gdImagePtr im;

    FILE *in;

    in = fopen("myjpeg.jpg", "rb");

    im = gdImageCreateFromJpegEx(in, GD_TRUE);

    fclose(in);

    // ... Use the image ...

    gdImageDestroy(im);

    (end code)

*/

BGD_DECLARE(gdImagePtr) gdImageCreateFromJpegEx(FILE *inFile, int ignore_warning)

{

	gdImagePtr im;

	gdIOCtx *in = gdNewFileCtx(inFile);

	if (in == NULL) return NULL;

	im = gdImageCreateFromJpegCtxEx(in, ignore_warning);

	in->gd_free(in);

	return im;

}

/*

  Function: gdImageCreateFromJpegPtr

  Parameters:

    size    - size of JPEG data in bytes.

    data    - pointer to JPEG data.

  See <gdImageCreateFromJpegEx>.

*/

BGD_DECLARE(gdImagePtr) gdImageCreateFromJpegPtr(int size, void *data)

{

	return gdImageCreateFromJpegPtrEx(size, data, 1);

}

/*

  Function: gdImageCreateFromJpegPtrEx

  Parameters:

    size            - size of JPEG data in bytes.

    data            - pointer to JPEG data.

    ignore_warning  - if true, ignore recoverable warnings

  See <gdImageCreateFromJpegEx>.

*/

BGD_DECLARE(gdImagePtr) gdImageCreateFromJpegPtrEx(int size, void *data, int ignore_warning)

{

	gdImagePtr im;

	gdIOCtx *in = gdNewDynamicCtxEx(size, data, 0);

	if(!in) {

		return 0;

	}

	im = gdImageCreateFromJpegCtxEx(in, ignore_warning);

	in->gd_free(in);

	return im;

}

void jpeg_gdIOCtx_src(j_decompress_ptr cinfo, gdIOCtx *infile);

static int CMYKToRGB(int c, int m, int y, int k, int inverted);

/*

  Function: gdImageCreateFromJpegCtx

  See <gdImageCreateFromJpeg>.

*/

BGD_DECLARE(gdImagePtr) gdImageCreateFromJpegCtx(gdIOCtx *infile)

{

	return gdImageCreateFromJpegCtxEx(infile, 1);

}

/*

  Function: gdImageCreateFromJpegCtxEx

  See <gdImageCreateFromJpeg>.

*/

BGD_DECLARE(gdImagePtr) gdImageCreateFromJpegCtxEx(gdIOCtx *infile, int ignore_warning)

{

	struct jpeg_decompress_struct cinfo;

	struct jpeg_error_mgr jerr;

	jmpbuf_wrapper jmpbufw;

	/* volatile so we can gdFree them after longjmp */

	volatile JSAMPROW row = 0;

	volatile gdImagePtr im = 0;

	JSAMPROW rowptr[1];

	JDIMENSION i, j;

	int retval;

	JDIMENSION nrows;

	int channels = 3;

	int inverted = 0;

#ifdef JPEG_DEBUG

	gd_error_ex(GD_DEBUG, "gd-jpeg: gd JPEG version %s\n", GD_JPEG_VERSION);

	gd_error_ex(GD_DEBUG, "gd-jpeg: JPEG library version %d, %d-bit sample values\n", JPEG_LIB_VERSION, BITS_IN_JSAMPLE);

	gd_error_ex(GD_DEBUG, "sizeof: %d\n", sizeof(struct jpeg_decompress_struct));

#endif

	memset(&cinfo, 0, sizeof(cinfo));

	memset(&jerr, 0, sizeof(jerr));

	jmpbufw.ignore_warning = ignore_warning;

	cinfo.err = jpeg_std_error(&jerr);

	cinfo.client_data = &jmpbufw;

	cinfo.err->emit_message = jpeg_emit_message;

	if(setjmp(jmpbufw.jmpbuf) != 0) {

		/* we're here courtesy of longjmp */

		if(row) {

			gdFree(row);

		}

		if(im) {

			gdImageDestroy(im);

		}

		return 0;

	}

	cinfo.err->error_exit = fatal_jpeg_error;

	jpeg_create_decompress(&cinfo);

	jpeg_gdIOCtx_src(&cinfo, infile);

	/* 2.0.22: save the APP14 marker to check for Adobe Photoshop CMYK

	 * files with inverted components.

	 */

	jpeg_save_markers(&cinfo, JPEG_APP0 + 14, 256);

	retval = jpeg_read_header(&cinfo, TRUE);

	if(retval != JPEG_HEADER_OK) {

		gd_error("gd-jpeg: warning: jpeg_read_header returns"

		         " %d, expected %d\n", retval, JPEG_HEADER_OK);

	}

	if(cinfo.image_height > INT_MAX) {

		gd_error("gd-jpeg: warning: JPEG image height (%u) is"

		         " greater than INT_MAX (%d) (and thus greater than"

		         " gd can handle)", cinfo.image_height, INT_MAX);

	}

	if(cinfo.image_width > INT_MAX) {

		gd_error("gd-jpeg: warning: JPEG image width (%u) is"

		         " greater than INT_MAX (%d) (and thus greater than"

		         " gd can handle)\n", cinfo.image_width, INT_MAX);

	}

	im = gdImageCreateTrueColor((int)cinfo.image_width, (int)cinfo.image_height);

	if(im == 0) {

		gd_error("gd-jpeg error: cannot allocate gdImage struct\n");

		goto error;

	}

	/* check if the resolution is specified */

	switch (cinfo.density_unit) {

	case 1:

		im->res_x = cinfo.X_density;

		im->res_y = cinfo.Y_density;

		break;

	case 2:

		im->res_x = DPCM2DPI(cinfo.X_density);

		im->res_y = DPCM2DPI(cinfo.Y_density);

		break;

	}

	/* 2.0.22: very basic support for reading CMYK colorspace files. Nice for

	 * thumbnails but there's no support for fussy adjustment of the

	 * assumed properties of inks and paper.

	 */

	if((cinfo.jpeg_color_space == JCS_CMYK) || (cinfo.jpeg_color_space == JCS_YCCK)) {

		cinfo.out_color_space = JCS_CMYK;

	} else {

		cinfo.out_color_space = JCS_RGB;

	}

	if(jpeg_start_decompress(&cinfo) != TRUE) {

		gd_error("gd-jpeg: warning: jpeg_start_decompress"

		        " reports suspended data source\n");

	}

#ifdef JPEG_DEBUG

	gd_error_ex(GD_DEBUG, "gd-jpeg: JPEG image information:");

	if(cinfo.saw_JFIF_marker) {

		gd_error_ex(GD_DEBUG, " JFIF version %d.%.2d", (int)cinfo.JFIF_major_version, (int)cinfo.JFIF_minor_version);

	} else if(cinfo.saw_Adobe_marker) {

		gd_error_ex(GD_DEBUG, " Adobe format");

	} else {

		gd_error_ex(GD_DEBUG, " UNKNOWN format");

	}

	gd_error_ex(GD_DEBUG, " %ux%u (raw) / %ux%u (scaled) %d-bit", cinfo.image_width,

		    cinfo.image_height, cinfo.output_width,

		    cinfo.output_height, cinfo.data_precision

		);

	gd_error_ex(GD_DEBUG, " %s", (cinfo.progressive_mode ? "progressive" : "baseline"));

	gd_error_ex(GD_DEBUG, " image, %d quantized colors, ", cinfo.actual_number_of_colors);

	switch(cinfo.jpeg_color_space) {

	case JCS_GRAYSCALE:

		gd_error_ex(GD_DEBUG, "grayscale");

		break;

	case JCS_RGB:

		gd_error_ex(GD_DEBUG, "RGB");

		break;

	case JCS_YCbCr:

		gd_error_ex(GD_DEBUG, "YCbCr (a.k.a. YUV)");

		break;

	case JCS_CMYK:

		gd_error_ex(GD_DEBUG, "CMYK");

		break;

	case JCS_YCCK:

		gd_error_ex(GD_DEBUG, "YCbCrK");

		break;

	default:

		gd_error_ex(GD_DEBUG, "UNKNOWN (value: %d)", (int)cinfo.jpeg_color_space);

		break;

	}

	gd_error_ex(GD_DEBUG, " colorspace\n");

	fflush(stdout);

#endif /* JPEG_DEBUG */

	/* REMOVED by TBB 2/12/01. This field of the structure is

	 * documented as private, and sure enough it's gone in the

	 * latest libjpeg, replaced by something else. Unfortunately

	 * there is still no right way to find out if the file was

	 * progressive or not; just declare your intent before you

	 * write one by calling gdImageInterlace(im, 1) yourself.

	 * After all, we're not really supposed to rework JPEGs and

	 * write them out again anyway. Lossy compression, remember? */

#if 0

	gdImageInterlace (im, cinfo.progressive_mode != 0);

#endif

	if(cinfo.out_color_space == JCS_RGB) {

		if(cinfo.output_components != 3) {

			gd_error("gd-jpeg: error: JPEG color quantization"

			         " request resulted in output_components == %d"

			         " (expected 3 for RGB)\n", cinfo.output_components);

			goto error;

		}

		channels = 3;

	} else if(cinfo.out_color_space == JCS_CMYK) {

		jpeg_saved_marker_ptr marker;

		if(cinfo.output_components != 4) {

			gd_error("gd-jpeg: error: JPEG color quantization"

			         " request resulted in output_components == %d"

			         " (expected 4 for CMYK)\n", cinfo.output_components);

			goto error;

		}

		channels = 4;

		marker = cinfo.marker_list;

		while(marker) {

			if(	(marker->marker == (JPEG_APP0 + 14)) &&

			        (marker->data_length >= 12) &&

			        (!strncmp((const char *)marker->data, "Adobe", 5))) {

				inverted = 1;

				break;

			}

			marker = marker->next;

		}

	} else {

		gd_error("gd-jpeg: error: unexpected colorspace\n");

		goto error;

	}

#if BITS_IN_JSAMPLE == 12

	gd_error_ex(GD_ERROR,

		    "gd-jpeg: error: jpeg library was compiled for 12-bit\n"

		    "precision. This is mostly useless, because JPEGs on the web are\n"

		    "8-bit and such versions of the jpeg library won't read or write\n"

		    "them. GD doesn't support these unusual images. Edit your\n"

		    "jmorecfg.h file to specify the correct precision and completely\n"

		    "'make clean' and 'make install' libjpeg again. Sorry.\n");

	goto error;

#endif /* BITS_IN_JSAMPLE == 12 */

	row = gdCalloc(cinfo.output_width *channels, sizeof(JSAMPLE));

	if(row == 0) {

		gd_error("gd-jpeg: error: unable to allocate row for"

		         " JPEG scanline: gdCalloc returns NULL\n");

		goto error;

	}

	rowptr[0] = row;

	if(cinfo.out_color_space == JCS_CMYK) {

		for(i = 0; i < cinfo.output_height; i++) {

			register JSAMPROW currow = row;

			register int *tpix = im->tpixels[i];

			nrows = jpeg_read_scanlines(&cinfo, rowptr, 1);

			if(nrows != 1) {

				gd_error("gd-jpeg: error: jpeg_read_scanlines"

				         " returns %u, expected 1\n", nrows);

				goto error;

			}

			for(j = 0; j < cinfo.output_width; j++, currow += 4, tpix++) {

				*tpix = CMYKToRGB(currow[0], currow[1], currow[2], currow[3], inverted);

			}

		}

	} else {

		for(i = 0; i < cinfo.output_height; i++) {

			register JSAMPROW currow = row;

			register int *tpix = im->tpixels[i];

			nrows = jpeg_read_scanlines(&cinfo, rowptr, 1);

			if(nrows != 1) {

				gd_error("gd-jpeg: error: jpeg_read_scanlines"

				         " returns %u, expected 1\n", nrows);

				goto error;

			}

			for(j = 0; j < cinfo.output_width; j++, currow += 3, tpix++) {

				*tpix = gdTrueColor(currow[0], currow[1], currow[2]);

			}

		}

	}

	if(jpeg_finish_decompress (&cinfo) != TRUE) {

		gd_error("gd-jpeg: warning: jpeg_finish_decompress"

		         " reports suspended data source\n");

	}

	/* TBB 2.0.29: we should do our best to read whatever we can read, and a

	 * warning is a warning. A fatal error on warnings doesn't make sense. */

#if 0

	/* This was originally added by Truxton Fulton */

	if (cinfo.err->num_warnings > 0)

		goto error;

#endif

	jpeg_destroy_decompress(&cinfo);

	gdFree(row);

	return im;

error:

	jpeg_destroy_decompress(&cinfo);

	if(row) {

		gdFree(row);

	}

	if(im) {

		gdImageDestroy(im);

	}

	return 0;

}

/* A very basic conversion approach, TBB */

static int CMYKToRGB(int c, int m, int y, int k, int inverted)

{

	if(inverted) {

		c = 255 - c;

		m = 255 - m;

		y = 255 - y;

		k = 255 - k;

	}

	return gdTrueColor(

	           (255 - c) * (255 - k) / 255,

	           (255 - m) * (255 - k) / 255,

	           (255 - y) * (255 - k) / 255

	       );

#if 0

	if (inverted) {

		c = 255 - c;

		m = 255 - m;

		y = 255 - y;

		k = 255 - k;

	}

	c = c * (255 - k) / 255 + k;

	if (c > 255) {

		c = 255;

	}

	if (c < 0) {

		c = 0;

	}

	m = m * (255 - k) / 255 + k;

	if (m > 255) {

		m = 255;

	}

	if (m < 0) {

		m = 0;

	}

	y = y * (255 - k) / 255 + k;

	if (y > 255) {

		y = 255;

	}

	if (y < 0) {

		y = 0;

	}

	c = 255 - c;

	m = 255 - m;

	y = 255 - y;

	return gdTrueColor (c, m, y);

#endif

}

/*

 * gdIOCtx JPEG data sources and sinks, T. Boutell

 * almost a simple global replace from T. Lane's stdio versions.

 */

/* Expanded data source object for gdIOCtx input */

typedef struct {