/*
* Small jpeg decoder library
*
* Copyright (c) 2006, Luc Saillard <luc@saillard.org>
* All rights reserved.
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* - Neither the name of the author nor the names of its contributors may be
* used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include "tinyjpeg.h"
#include "tinyjpeg-internal.h"
/*******************************************************************************
*
* Colorspace conversion routine
*
*
* Note:
* 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
* R = Y + 1.40200 * Cr
* G = Y - 0.34414 * Cb - 0.71414 * Cr
* B = Y + 1.77200 * Cb
*
******************************************************************************/
static unsigned char clamp(int i)
{
if (i<0)
return 0;
else if (i>255)
return 255;
else
return i;
}
/**
* YCrCb -> RGBA32 (1x1)
* .---.
* | 1 |
* `---'
*/
static void YCrCB_to_RGBA32_1x1(struct jdec_private *priv, int sx, int sy)
{
const unsigned char *Y, *Cb, *Cr;
unsigned char *p;
int i,j;
int offset_to_next_row;
#define SCALEBITS 10
#define ONE_HALF (1UL << (SCALEBITS-1))
#define FIX(x) ((int)((x) * (1UL<<SCALEBITS) + 0.5))
p = priv->plane[0];
Y = priv->Y;
Cb = priv->Cb;
Cr = priv->Cr;
offset_to_next_row = priv->bytes_per_row[0] - 8*4;
for (i = sy; i > 0; i--) {
for (j = sx; j > 0; j--) {
int y, cb, cr;
int add_r, add_g, add_b;
int r, g , b, a;
y = Y[0] << SCALEBITS;
cb = *Cb++ - 128;
cr = *Cr++ - 128;
add_r = FIX(1.40200) * cr + ONE_HALF;
add_g = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;
add_b = FIX(1.77200) * cb + ONE_HALF;
r = (y + add_r) >> SCALEBITS;
*p++ = clamp(r);
g = (y + add_g) >> SCALEBITS;
*p++ = clamp(g);
b = (y + add_b) >> SCALEBITS;
*p++ = clamp(b);
a = 255;
*p++ = a;
Y++;
}
p += offset_to_next_row;
}
#undef SCALEBITS
#undef ONE_HALF
#undef FIX
}
/**
* YCrCb -> RGBA32 (2x1)
* .-------.
* | 1 | 2 |
* `-------'
*/
static void YCrCB_to_RGBA32_2x1(struct jdec_private *priv, int sx, int sy)
{
const unsigned char *Y, *Cb, *Cr;
unsigned char *p;
int i,j;
int offset_to_next_row;
#define SCALEBITS 10
#define ONE_HALF (1UL << (SCALEBITS-1))
#define FIX(x) ((int)((x) * (1UL<<SCALEBITS) + 0.5))
p = priv->plane[0];
Y = priv->Y;
Cb = priv->Cb;
Cr = priv->Cr;
offset_to_next_row = priv->bytes_per_row[0] - 16*4;
for (i = sy; i > 0; i--) {
for (j = sx; j > 0; j -= 2) {
int y, cb, cr;
int add_r, add_g, add_b;
int r, g , b, a;
y = Y[0] << SCALEBITS;
cb = *Cb++ - 128;
cr = *Cr++ - 128;
add_r = FIX(1.40200) * cr + ONE_HALF;
add_g = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;
add_b = FIX(1.77200) * cb + ONE_HALF;
r = (y + add_r) >> SCALEBITS;
*p++ = clamp(r);
g = (y + add_g) >> SCALEBITS;
*p++ = clamp(g);
b = (y + add_b) >> SCALEBITS;
*p++ = clamp(b);
a = 255;
*p++ = a;
if (j > 1) {
y = Y[1] << SCALEBITS;
r = (y + add_r) >> SCALEBITS;
*p++ = clamp(r);
g = (y + add_g) >> SCALEBITS;
*p++ = clamp(g);
b = (y + add_b) >> SCALEBITS;
*p++ = clamp(b);
a = 255;
*p++ = a;
}
Y += 2;
}
p += offset_to_next_row;
}
#undef SCALEBITS
#undef ONE_HALF
#undef FIX
}
/**
* YCrCb -> RGBA32 (1x2)
* .---.
* | 1 |
* |---|
* | 2 |
* `---'
*/
static void YCrCB_to_RGBA32_1x2(struct jdec_private *priv, int sx, int sy)
{
const unsigned char *Y, *Cb, *Cr;
unsigned char *p, *p2;
int i,j;
int offset_to_next_row;
#define SCALEBITS 10
#define ONE_HALF (1UL << (SCALEBITS-1))
#define FIX(x) ((int)((x) * (1UL<<SCALEBITS) + 0.5))
p = priv->plane[0];
p2 = priv->plane[0] + priv->bytes_per_row[0];
Y = priv->Y;
Cb = priv->Cb;
Cr = priv->Cr;
offset_to_next_row = 2*priv->bytes_per_row[0] - 8*4;
for (i = sy; i > 0; i -= 2) {
for (j = sx; j > 0; j--) {
int y, cb, cr;
int add_r, add_g, add_b;
int r, g , b, a;
cb = *Cb++ - 128;
cr = *Cr++ - 128;
add_r = FIX(1.40200) * cr + ONE_HALF;
add_g = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;
add_b = FIX(1.77200) * cb + ONE_HALF;
y = Y[0] << SCALEBITS;
r = (y + add_r) >> SCALEBITS;
*p++ = clamp(r);
g = (y + add_g) >> SCALEBITS;
*p++ = clamp(g);
b = (y + add_b) >> SCALEBITS;
*p++ = clamp(b);
a = 255;
*p++ = a;
if (i > 1) {
y = Y[8] << SCALEBITS;
r = (y + add_r) >> SCALEBITS;
*p2++ = clamp(r);
g = (y + add_g) >> SCALEBITS;
*p2++ = clamp(g);
b = (y + add_b) >> SCALEBITS;
*p2++ = clamp(b);
a = 255;
*p2++ = a;
}
Y++;
}
Y += 8;
p += offset_to_next_row;
p2 += offset_to_next_row;
}
#undef SCALEBITS
#undef ONE_HALF
#undef FIX
}
/**
* YCrCb -> RGBA32 (2x2)
* .-------.
* | 1 | 2 |
* |---+---|
* | 3 | 4 |
* `-------'
*/
static void YCrCB_to_RGBA32_2x2(struct jdec_private *priv, int sx, int sy)
{
const unsigned char *Y, *Cb, *Cr;
unsigned char *p, *p2;
int i,j;
int offset_to_next_row;
#define SCALEBITS 10
#define ONE_HALF (1UL << (SCALEBITS-1))
#define FIX(x) ((int)((x) * (1UL<<SCALEBITS) + 0.5))
p = priv->plane[0];
p2 = priv->plane[0] + priv->bytes_per_row[0];
Y = priv->Y;
Cb = priv->Cb;
Cr = priv->Cr;
offset_to_next_row = 2*priv->bytes_per_row[0] - 16*4;
for (i = sy; i > 0; i -= 2) {
for (j = sx; i > 0; j -= 2) {
int y, cb, cr;
int add_r, add_g, add_b;
int r, g , b, a;
cb = *Cb++ - 128;
cr = *Cr++ - 128;
add_r = FIX(1.40200) * cr + ONE_HALF;
add_g = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;
add_b = FIX(1.77200) * cb + ONE_HALF;
y = Y[0] << SCALEBITS;
r = (y + add_r) >> SCALEBITS;
*p++ = clamp(r);
g = (y + add_g) >> SCALEBITS;
*p++ = clamp(g);
b = (y + add_b) >> SCALEBITS;
*p++ = clamp(b);
a = 255;
*p++ = a;
if (j > 1) {
y = Y[1] << SCALEBITS;
r = (y + add_r) >> SCALEBITS;
*p++ = clamp(r);
g = (y + add_g) >> SCALEBITS;
*p++ = clamp(g);
b = (y + add_b) >> SCALEBITS;
*p++ = clamp(b);
a = 255;
*p++ = a;
}
if (i > 1) {
y = Y[16+0] << SCALEBITS;
r = (y + add_r) >> SCALEBITS;
*p2++ = clamp(r);
g = (y + add_g) >> SCALEBITS;
*p2++ = clamp(g);
b = (y + add_b) >> SCALEBITS;
*p2++ = clamp(b);
a = 255;
*p2++ = a;
if (j > 1) {
y = Y[16+1] << SCALEBITS;
r = (y + add_r) >> SCALEBITS;
*p2++ = clamp(r);
g = (y + add_g) >> SCALEBITS;
*p2++ = clamp(g);
b = (y + add_b) >> SCALEBITS;
*p2++ = clamp(b);
a = 255;
*p2++ = a;
}
}
Y += 2;
}
Y += 16;
p += offset_to_next_row;
p2 += offset_to_next_row;
}
#undef SCALEBITS
#undef ONE_HALF
#undef FIX
}
static int initialize_rgba32(struct jdec_private *priv,
unsigned int *bytes_per_blocklines,
unsigned int *bytes_per_mcu)
{
if (!priv->bytes_per_row[0])
priv->bytes_per_row[0] = priv->width * 4;
if (!priv->components[0])
priv->components[0] = malloc(priv->height * priv->bytes_per_row[0]);
bytes_per_blocklines[0] = priv->bytes_per_row[0] << 3;
bytes_per_mcu[0] = 4*8;
return !priv->components[0];
}
static const struct tinyjpeg_colorspace format_rgba32 =
{
{
YCrCB_to_RGBA32_1x1,
YCrCB_to_RGBA32_1x2,
YCrCB_to_RGBA32_2x1,
YCrCB_to_RGBA32_2x2,
},
tinyjpeg_decode_mcu_3comp_table,
initialize_rgba32
};
const tinyjpeg_colorspace_t TINYJPEG_FMT_RGBA32 = &format_rgba32;