gecko/media/libjpeg/jccolor.c

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/*
* jccolor.c
*
* Copyright (C) 1991-1996, Thomas G. Lane.
* Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
* Copyright 2009 D. R. Commander
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains input colorspace conversion routines.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
#include "jsimd.h"
/* Private subobject */
typedef struct {
struct jpeg_color_converter pub; /* public fields */
/* Private state for RGB->YCC conversion */
INT32 * rgb_ycc_tab; /* => table for RGB to YCbCr conversion */
} my_color_converter;
typedef my_color_converter * my_cconvert_ptr;
/**************** RGB -> YCbCr conversion: most common case **************/
/*
* YCbCr is defined per CCIR 601-1, except that Cb and Cr are
* normalized to the range 0..MAXJSAMPLE rather than -0.5 .. 0.5.
* The conversion equations to be implemented are therefore
* Y = 0.29900 * R + 0.58700 * G + 0.11400 * B
* Cb = -0.16874 * R - 0.33126 * G + 0.50000 * B + CENTERJSAMPLE
* Cr = 0.50000 * R - 0.41869 * G - 0.08131 * B + CENTERJSAMPLE
* (These numbers are derived from TIFF 6.0 section 21, dated 3-June-92.)
* Note: older versions of the IJG code used a zero offset of MAXJSAMPLE/2,
* rather than CENTERJSAMPLE, for Cb and Cr. This gave equal positive and
* negative swings for Cb/Cr, but meant that grayscale values (Cb=Cr=0)
* were not represented exactly. Now we sacrifice exact representation of
* maximum red and maximum blue in order to get exact grayscales.
*
* To avoid floating-point arithmetic, we represent the fractional constants
* as integers scaled up by 2^16 (about 4 digits precision); we have to divide
* the products by 2^16, with appropriate rounding, to get the correct answer.
*
* For even more speed, we avoid doing any multiplications in the inner loop
* by precalculating the constants times R,G,B for all possible values.
* For 8-bit JSAMPLEs this is very reasonable (only 256 entries per table);
* for 12-bit samples it is still acceptable. It's not very reasonable for
* 16-bit samples, but if you want lossless storage you shouldn't be changing
* colorspace anyway.
* The CENTERJSAMPLE offsets and the rounding fudge-factor of 0.5 are included
* in the tables to save adding them separately in the inner loop.
*/
#define SCALEBITS 16 /* speediest right-shift on some machines */
#define CBCR_OFFSET ((INT32) CENTERJSAMPLE << SCALEBITS)
#define ONE_HALF ((INT32) 1 << (SCALEBITS-1))
#define FIX(x) ((INT32) ((x) * (1L<<SCALEBITS) + 0.5))
/* We allocate one big table and divide it up into eight parts, instead of
* doing eight alloc_small requests. This lets us use a single table base
* address, which can be held in a register in the inner loops on many
* machines (more than can hold all eight addresses, anyway).
*/
#define R_Y_OFF 0 /* offset to R => Y section */
#define G_Y_OFF (1*(MAXJSAMPLE+1)) /* offset to G => Y section */
#define B_Y_OFF (2*(MAXJSAMPLE+1)) /* etc. */
#define R_CB_OFF (3*(MAXJSAMPLE+1))
#define G_CB_OFF (4*(MAXJSAMPLE+1))
#define B_CB_OFF (5*(MAXJSAMPLE+1))
#define R_CR_OFF B_CB_OFF /* B=>Cb, R=>Cr are the same */
#define G_CR_OFF (6*(MAXJSAMPLE+1))
#define B_CR_OFF (7*(MAXJSAMPLE+1))
#define TABLE_SIZE (8*(MAXJSAMPLE+1))
#if BITS_IN_JSAMPLE == 8
static const unsigned char red_lut[256] = {
0 , 0 , 1 , 1 , 1 , 1 , 2 , 2 , 2 , 3 , 3 , 3 , 4 , 4 , 4 , 4 ,
5 , 5 , 5 , 6 , 6 , 6 , 7 , 7 , 7 , 7 , 8 , 8 , 8 , 9 , 9 , 9 ,
10, 10, 10, 10, 11, 11, 11, 12, 12, 12, 13, 13, 13, 13, 14, 14,
14, 15, 15, 15, 16, 16, 16, 16, 17, 17, 17, 18, 18, 18, 19, 19,
19, 19, 20, 20, 20, 21, 21, 21, 22, 22, 22, 22, 23, 23, 23, 24,
24, 24, 25, 25, 25, 25, 26, 26, 26, 27, 27, 27, 28, 28, 28, 28,
29, 29, 29, 30, 30, 30, 30, 31, 31, 31, 32, 32, 32, 33, 33, 33,
33, 34, 34, 34, 35, 35, 35, 36, 36, 36, 36, 37, 37, 37, 38, 38,
38, 39, 39, 39, 39, 40, 40, 40, 41, 41, 41, 42, 42, 42, 42, 43,
43, 43, 44, 44, 44, 45, 45, 45, 45, 46, 46, 46, 47, 47, 47, 48,
48, 48, 48, 49, 49, 49, 50, 50, 50, 51, 51, 51, 51, 52, 52, 52,
53, 53, 53, 54, 54, 54, 54, 55, 55, 55, 56, 56, 56, 57, 57, 57,
57, 58, 58, 58, 59, 59, 59, 60, 60, 60, 60, 61, 61, 61, 62, 62,
62, 62, 63, 63, 63, 64, 64, 64, 65, 65, 65, 65, 66, 66, 66, 67,
67, 67, 68, 68, 68, 68, 69, 69, 69, 70, 70, 70, 71, 71, 71, 71,
72, 72, 72, 73, 73, 73, 74, 74, 74, 74, 75, 75, 75, 76, 76, 76
};
static const unsigned char green_lut[256] = {
0 , 1 , 1 , 2 , 2 , 3 , 4 , 4 , 5 , 5 , 6 , 6 ,
7 , 8 , 8 , 9 , 9 , 10 , 11 , 11 , 12 , 12 , 13 , 14 ,
14 , 15 , 15 , 16 , 16 , 17 , 18 , 18 , 19 , 19 , 20 , 21 ,
21 , 22 , 22 , 23 , 23 , 24 , 25 , 25 , 26 , 26 , 27 , 28 ,
28 , 29 , 29 , 30 , 31 , 31 , 32 , 32 , 33 , 33 , 34 , 35 ,
35 , 36 , 36 , 37 , 38 , 38 , 39 , 39 , 40 , 41 , 41 , 42 ,
42 , 43 , 43 , 44 , 45 , 45 , 46 , 46 , 47 , 48 , 48 , 49 ,
49 , 50 , 50 , 51 , 52 , 52 , 53 , 53 , 54 , 55 , 55 , 56 ,
56 , 57 , 58 , 58 , 59 , 59 , 60 , 60 , 61 , 62 , 62 , 63 ,
63 , 64 , 65 , 65 , 66 , 66 , 67 , 68 , 68 , 69 , 69 , 70 ,
70 , 71 , 72 , 72 , 73 , 73 , 74 , 75 , 75 , 76 , 76 , 77 ,
77 , 78 , 79 , 79 , 80 , 80 , 81 , 82 , 82 , 83 , 83 , 84 ,
85 , 85 , 86 , 86 , 87 , 87 , 88 , 89 , 89 , 90 , 90 , 91 ,
92 , 92 , 93 , 93 , 94 , 95 , 95 , 96 , 96 , 97 , 97 , 98 ,
99 , 99 , 100, 100, 101, 102, 102, 103, 103, 104, 104, 105,
106, 106, 107, 107, 108, 109, 109, 110, 110, 111, 112, 112,
113, 113, 114, 114, 115, 116, 116, 117, 117, 118, 119, 119,
120, 120, 121, 122, 122, 123, 123, 124, 124, 125, 126, 126,
127, 127, 128, 129, 129, 130, 130, 131, 131, 132, 133, 133,
134, 134, 135, 136, 136, 137, 137, 138, 139, 139, 140, 140,
141, 141, 142, 143, 143, 144, 144, 145, 146, 146, 147, 147,
148, 149, 149, 150
};
static const unsigned char blue_lut[256] = {
0 , 0 , 0 , 0 , 0 , 1 , 1 , 1 , 1 , 1 , 1 , 1 , 1 , 1 , 2 , 2 ,
2 , 2 , 2 , 2 , 2 , 2 , 3 , 3 , 3 , 3 , 3 , 3 , 3 , 3 , 3 , 4 ,
4 , 4 , 4 , 4 , 4 , 4 , 4 , 4 , 5 , 5 , 5 , 5 , 5 , 5 , 5 , 5 ,
5 , 6 , 6 , 6 , 6 , 6 , 6 , 6 , 6 , 6 , 7 , 7 , 7 , 7 , 7 , 7 ,
7 , 7 , 8 , 8 , 8 , 8 , 8 , 8 , 8 , 8 , 8 , 9 , 9 , 9 , 9 , 9 ,
9 , 9 , 9 , 9 , 10, 10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11,
11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 13, 13,
13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14, 14, 14, 14,
15, 15, 15, 15, 15, 15, 15, 15, 16, 16, 16, 16, 16, 16, 16, 16,
16, 17, 17, 17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18,
18, 18, 18, 19, 19, 19, 19, 19, 19, 19, 19, 19, 20, 20, 20, 20,
20, 20, 20, 20, 21, 21, 21, 21, 21, 21, 21, 21, 21, 22, 22, 22,
22, 22, 22, 22, 22, 22, 23, 23, 23, 23, 23, 23, 23, 23, 23, 24,
24, 24, 24, 24, 24, 24, 24, 25, 25, 25, 25, 25, 25, 25, 25, 25,
26, 26, 26, 26, 26, 26, 26, 26, 26, 27, 27, 27, 27, 27, 27, 27,
27, 27, 28, 28, 28, 28, 28, 28, 28, 28, 29, 29, 29, 29, 29, 29
};
#endif
/*
* Initialize for RGB->YCC colorspace conversion.
*/
METHODDEF(void)
rgb_ycc_start (j_compress_ptr cinfo)
{
my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
INT32 * rgb_ycc_tab;
INT32 i;
/* Allocate and fill in the conversion tables. */
cconvert->rgb_ycc_tab = rgb_ycc_tab = (INT32 *)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
(TABLE_SIZE * SIZEOF(INT32)));
for (i = 0; i <= MAXJSAMPLE; i++) {
rgb_ycc_tab[i+R_Y_OFF] = FIX(0.29900) * i;
rgb_ycc_tab[i+G_Y_OFF] = FIX(0.58700) * i;
rgb_ycc_tab[i+B_Y_OFF] = FIX(0.11400) * i + ONE_HALF;
rgb_ycc_tab[i+R_CB_OFF] = (-FIX(0.16874)) * i;
rgb_ycc_tab[i+G_CB_OFF] = (-FIX(0.33126)) * i;
/* We use a rounding fudge-factor of 0.5-epsilon for Cb and Cr.
* This ensures that the maximum output will round to MAXJSAMPLE
* not MAXJSAMPLE+1, and thus that we don't have to range-limit.
*/
rgb_ycc_tab[i+B_CB_OFF] = FIX(0.50000) * i + CBCR_OFFSET + ONE_HALF-1;
/* B=>Cb and R=>Cr tables are the same
rgb_ycc_tab[i+R_CR_OFF] = FIX(0.50000) * i + CBCR_OFFSET + ONE_HALF-1;
*/
rgb_ycc_tab[i+G_CR_OFF] = (-FIX(0.41869)) * i;
rgb_ycc_tab[i+B_CR_OFF] = (-FIX(0.08131)) * i;
}
}
/*
* Convert some rows of samples to the JPEG colorspace.
*
* Note that we change from the application's interleaved-pixel format
* to our internal noninterleaved, one-plane-per-component format.
* The input buffer is therefore three times as wide as the output buffer.
*
* A starting row offset is provided only for the output buffer. The caller
* can easily adjust the passed input_buf value to accommodate any row
* offset required on that side.
*/
METHODDEF(void)
rgb_ycc_convert (j_compress_ptr cinfo,
JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
JDIMENSION output_row, int num_rows)
{
my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
register int r, g, b;
register INT32 * ctab = cconvert->rgb_ycc_tab;
register JSAMPROW inptr;
register JSAMPROW outptr0, outptr1, outptr2;
register JDIMENSION col;
JDIMENSION num_cols = cinfo->image_width;
while (--num_rows >= 0) {
inptr = *input_buf++;
outptr0 = output_buf[0][output_row];
outptr1 = output_buf[1][output_row];
outptr2 = output_buf[2][output_row];
output_row++;
for (col = 0; col < num_cols; col++) {
r = GETJSAMPLE(inptr[rgb_red[cinfo->in_color_space]]);
g = GETJSAMPLE(inptr[rgb_green[cinfo->in_color_space]]);
b = GETJSAMPLE(inptr[rgb_blue[cinfo->in_color_space]]);
inptr += rgb_pixelsize[cinfo->in_color_space];
/* If the inputs are 0..MAXJSAMPLE, the outputs of these equations
* must be too; we do not need an explicit range-limiting operation.
* Hence the value being shifted is never negative, and we don't
* need the general RIGHT_SHIFT macro.
*/
/* Y */
outptr0[col] = (JSAMPLE)
((ctab[r+R_Y_OFF] + ctab[g+G_Y_OFF] + ctab[b+B_Y_OFF])
>> SCALEBITS);
/* Cb */
outptr1[col] = (JSAMPLE)
((ctab[r+R_CB_OFF] + ctab[g+G_CB_OFF] + ctab[b+B_CB_OFF])
>> SCALEBITS);
/* Cr */
outptr2[col] = (JSAMPLE)
((ctab[r+R_CR_OFF] + ctab[g+G_CR_OFF] + ctab[b+B_CR_OFF])
>> SCALEBITS);
}
}
}
/**************** Cases other than RGB -> YCbCr **************/
/*
* Convert some rows of samples to the JPEG colorspace.
* This version handles RGB->grayscale conversion, which is the same
* as the RGB->Y portion of RGB->YCbCr.
* We assume rgb_ycc_start has been called (we only use the Y tables).
*/
METHODDEF(void)
rgb_gray_convert (j_compress_ptr cinfo,
JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
JDIMENSION output_row, int num_rows)
{
#if BITS_IN_JSAMPLE != 8
register INT32 * ctab = cconvert->rgb_ycc_tab;
#endif
register JSAMPROW inptr;
register JSAMPROW outptr;
JSAMPLE *maxoutptr;
JDIMENSION num_cols = cinfo->image_width;
int rindex = rgb_red[cinfo->in_color_space];
int gindex = rgb_green[cinfo->in_color_space];
int bindex = rgb_blue[cinfo->in_color_space];
int rgbstride = rgb_pixelsize[cinfo->in_color_space];
while (--num_rows >= 0) {
inptr = *input_buf++;
outptr = output_buf[0][output_row];
maxoutptr = &outptr[num_cols];
output_row++;
for (; outptr < maxoutptr; outptr++, inptr += rgbstride) {
/* Y */
#if BITS_IN_JSAMPLE == 8
*outptr = red_lut[inptr[rindex]] + green_lut[inptr[gindex]]
+ blue_lut[inptr[bindex]];
#else
*outptr = (JSAMPLE)
((ctab[GETJSAMPLE(inptr[rindex])+R_Y_OFF]
+ ctab[GETJSAMPLE(inptr[gindex])+G_Y_OFF]
+ ctab[GETJSAMPLE(inptr[bindex])+B_Y_OFF])
>> SCALEBITS);
#endif
}
}
}
/*
* Convert some rows of samples to the JPEG colorspace.
* This version handles Adobe-style CMYK->YCCK conversion,
* where we convert R=1-C, G=1-M, and B=1-Y to YCbCr using the same
* conversion as above, while passing K (black) unchanged.
* We assume rgb_ycc_start has been called.
*/
METHODDEF(void)
cmyk_ycck_convert (j_compress_ptr cinfo,
JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
JDIMENSION output_row, int num_rows)
{
my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
register int r, g, b;
register INT32 * ctab = cconvert->rgb_ycc_tab;
register JSAMPROW inptr;
register JSAMPROW outptr0, outptr1, outptr2, outptr3;
register JDIMENSION col;
JDIMENSION num_cols = cinfo->image_width;
while (--num_rows >= 0) {
inptr = *input_buf++;
outptr0 = output_buf[0][output_row];
outptr1 = output_buf[1][output_row];
outptr2 = output_buf[2][output_row];
outptr3 = output_buf[3][output_row];
output_row++;
for (col = 0; col < num_cols; col++) {
r = MAXJSAMPLE - GETJSAMPLE(inptr[0]);
g = MAXJSAMPLE - GETJSAMPLE(inptr[1]);
b = MAXJSAMPLE - GETJSAMPLE(inptr[2]);
/* K passes through as-is */
outptr3[col] = inptr[3]; /* don't need GETJSAMPLE here */
inptr += 4;
/* If the inputs are 0..MAXJSAMPLE, the outputs of these equations
* must be too; we do not need an explicit range-limiting operation.
* Hence the value being shifted is never negative, and we don't
* need the general RIGHT_SHIFT macro.
*/
/* Y */
outptr0[col] = (JSAMPLE)
((ctab[r+R_Y_OFF] + ctab[g+G_Y_OFF] + ctab[b+B_Y_OFF])
>> SCALEBITS);
/* Cb */
outptr1[col] = (JSAMPLE)
((ctab[r+R_CB_OFF] + ctab[g+G_CB_OFF] + ctab[b+B_CB_OFF])
>> SCALEBITS);
/* Cr */
outptr2[col] = (JSAMPLE)
((ctab[r+R_CR_OFF] + ctab[g+G_CR_OFF] + ctab[b+B_CR_OFF])
>> SCALEBITS);
}
}
}
/*
* Convert some rows of samples to the JPEG colorspace.
* This version handles grayscale output with no conversion.
* The source can be either plain grayscale or YCbCr (since Y == gray).
*/
METHODDEF(void)
grayscale_convert (j_compress_ptr cinfo,
JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
JDIMENSION output_row, int num_rows)
{
register JSAMPROW inptr;
register JSAMPROW outptr;
register JDIMENSION col;
JDIMENSION num_cols = cinfo->image_width;
int instride = cinfo->input_components;
while (--num_rows >= 0) {
inptr = *input_buf++;
outptr = output_buf[0][output_row];
output_row++;
for (col = 0; col < num_cols; col++) {
outptr[col] = inptr[0]; /* don't need GETJSAMPLE() here */
inptr += instride;
}
}
}
/*
* Convert some rows of samples to the JPEG colorspace.
* This version handles multi-component colorspaces without conversion.
* We assume input_components == num_components.
*/
METHODDEF(void)
null_convert (j_compress_ptr cinfo,
JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
JDIMENSION output_row, int num_rows)
{
register JSAMPROW inptr;
register JSAMPROW outptr;
register JDIMENSION col;
register int ci;
int nc = cinfo->num_components;
JDIMENSION num_cols = cinfo->image_width;
while (--num_rows >= 0) {
/* It seems fastest to make a separate pass for each component. */
for (ci = 0; ci < nc; ci++) {
inptr = *input_buf;
outptr = output_buf[ci][output_row];
for (col = 0; col < num_cols; col++) {
outptr[col] = inptr[ci]; /* don't need GETJSAMPLE() here */
inptr += nc;
}
}
input_buf++;
output_row++;
}
}
/*
* Empty method for start_pass.
*/
METHODDEF(void)
null_method (j_compress_ptr cinfo)
{
/* no work needed */
}
/*
* Module initialization routine for input colorspace conversion.
*/
GLOBAL(void)
jinit_color_converter (j_compress_ptr cinfo)
{
my_cconvert_ptr cconvert;
cconvert = (my_cconvert_ptr)
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
SIZEOF(my_color_converter));
cinfo->cconvert = (struct jpeg_color_converter *) cconvert;
/* set start_pass to null method until we find out differently */
cconvert->pub.start_pass = null_method;
/* Make sure input_components agrees with in_color_space */
switch (cinfo->in_color_space) {
case JCS_GRAYSCALE:
if (cinfo->input_components != 1)
ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
break;
case JCS_RGB:
case JCS_EXT_RGB:
case JCS_EXT_RGBX:
case JCS_EXT_BGR:
case JCS_EXT_BGRX:
case JCS_EXT_XBGR:
case JCS_EXT_XRGB:
if (cinfo->input_components != rgb_pixelsize[cinfo->in_color_space])
ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
break;
case JCS_YCbCr:
if (cinfo->input_components != 3)
ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
break;
case JCS_CMYK:
case JCS_YCCK:
if (cinfo->input_components != 4)
ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
break;
default: /* JCS_UNKNOWN can be anything */
if (cinfo->input_components < 1)
ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
break;
}
/* Check num_components, set conversion method based on requested space */
switch (cinfo->jpeg_color_space) {
case JCS_GRAYSCALE:
if (cinfo->num_components != 1)
ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
if (cinfo->in_color_space == JCS_GRAYSCALE)
cconvert->pub.color_convert = grayscale_convert;
else if (cinfo->in_color_space == JCS_RGB ||
cinfo->in_color_space == JCS_EXT_RGB ||
cinfo->in_color_space == JCS_EXT_RGBX ||
cinfo->in_color_space == JCS_EXT_BGR ||
cinfo->in_color_space == JCS_EXT_BGRX ||
cinfo->in_color_space == JCS_EXT_XBGR ||
cinfo->in_color_space == JCS_EXT_XRGB) {
cconvert->pub.start_pass = rgb_ycc_start;
cconvert->pub.color_convert = rgb_gray_convert;
} else if (cinfo->in_color_space == JCS_YCbCr)
cconvert->pub.color_convert = grayscale_convert;
else
ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
break;
case JCS_RGB:
case JCS_EXT_RGB:
case JCS_EXT_RGBX:
case JCS_EXT_BGR:
case JCS_EXT_BGRX:
case JCS_EXT_XBGR:
case JCS_EXT_XRGB:
if (cinfo->num_components != 3)
ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
if (cinfo->in_color_space == cinfo->jpeg_color_space &&
rgb_pixelsize[cinfo->in_color_space] == 3)
cconvert->pub.color_convert = null_convert;
else
ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
break;
case JCS_YCbCr:
if (cinfo->num_components != 3)
ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
if (cinfo->in_color_space == JCS_RGB ||
cinfo->in_color_space == JCS_EXT_RGB ||
cinfo->in_color_space == JCS_EXT_RGBX ||
cinfo->in_color_space == JCS_EXT_BGR ||
cinfo->in_color_space == JCS_EXT_BGRX ||
cinfo->in_color_space == JCS_EXT_XBGR ||
cinfo->in_color_space == JCS_EXT_XRGB) {
if (jsimd_can_rgb_ycc())
cconvert->pub.color_convert = jsimd_rgb_ycc_convert;
else {
cconvert->pub.start_pass = rgb_ycc_start;
cconvert->pub.color_convert = rgb_ycc_convert;
}
} else if (cinfo->in_color_space == JCS_YCbCr)
cconvert->pub.color_convert = null_convert;
else
ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
break;
case JCS_CMYK:
if (cinfo->num_components != 4)
ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
if (cinfo->in_color_space == JCS_CMYK)
cconvert->pub.color_convert = null_convert;
else
ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
break;
case JCS_YCCK:
if (cinfo->num_components != 4)
ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
if (cinfo->in_color_space == JCS_CMYK) {
cconvert->pub.start_pass = rgb_ycc_start;
cconvert->pub.color_convert = cmyk_ycck_convert;
} else if (cinfo->in_color_space == JCS_YCCK)
cconvert->pub.color_convert = null_convert;
else
ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
break;
default: /* allow null conversion of JCS_UNKNOWN */
if (cinfo->jpeg_color_space != cinfo->in_color_space ||
cinfo->num_components != cinfo->input_components)
ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
cconvert->pub.color_convert = null_convert;
break;
}
}