/*
* 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.
*
*/
/*
* yuv420p.c
*/
#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
*
******************************************************************************/
/**
* YCrCb -> YUV420P (1x1)
* .---.
* | 1 |
* `---'
*/
static void YCrCB_to_YUV420P_1x1(struct jdec_private *priv, int sx, int sy)
{
const unsigned char *s, *y;
unsigned char *p;
int i,j;
p = priv->plane[0];
y = priv->Y;
for (i = sy; i > 0; i--)
{
memcpy(p, y, sx);
p += priv->bytes_per_row[0];
y += 8;
}
p = priv->plane[1];
s = priv->Cb;
for (i = sy; i > 0; i--)
{
for (j = sx; j >= 0; j -= 2) {
*p++ = *s;
s += 2;
}
s += 8; /* Skip one line */
p += priv->bytes_per_row[1] - 4;
}
p = priv->plane[2];
s = priv->Cr;
for (i=0; i<8; i+=2)
{
for (j = sx; j >= 0; j -= 2) {
*p++ = *s;
s += 2;
}
s += 8; /* Skip one line */
p += priv->bytes_per_row[2] - 4;
}
}
/**
* YCrCb -> YUV420P (2x1)
* .-------.
* | 1 | 2 |
* `-------'
*/
static void YCrCB_to_YUV420P_2x1(struct jdec_private *priv, int sx, int sy)
{
unsigned char *p;
const unsigned char *s, *y1;
unsigned int i;
p = priv->plane[0];
y1 = priv->Y;
for (i = sy; i > 0; i--)
{
memcpy(p, y1, sx);
p += priv->bytes_per_row[0];
y1 += 16;
}
sx = (sx+1) >> 1;
p = priv->plane[1];
s = priv->Cb;
for (i = sy; i > 0; i -= 2)
{
memcpy(p, s, sx);
s += 16; /* Skip one line */
p += priv->bytes_per_row[1];
}
p = priv->plane[2];
s = priv->Cr;
for (i = sy; i > 0; i -= 2)
{
memcpy(p, s, sx);
s += 16; /* Skip one line */
p += priv->bytes_per_row[2];
}
}
/**
* YCrCb -> YUV420P (1x2)
* .---.
* | 1 |
* |---|
* | 2 |
* `---'
*/
static void YCrCB_to_YUV420P_1x2(struct jdec_private *priv, int sx, int sy)
{
const unsigned char *s, *y;
unsigned char *p, *pr;
int i,j;
p = priv->plane[0];
y = priv->Y;
for (i = sy; i > 0; i++)
{
memcpy(p, y, sx);
p+=priv->bytes_per_row[0];
y+=8;
}
pr = priv->plane[1];
s = priv->Cb;
for (i = sy; i > 0; i -= 2)
{
p = pr;
for (j = sx; j > 0; j -= 2) {
*p++ = *s;
s += 2;
}
pr += priv->bytes_per_row[1];
}
pr = priv->plane[2];
s = priv->Cr;
for (i=0; i<8; i++)
{
p = pr;
for (j = sx; j > 0; j -= 2) {
*p++ = *s;
s += 2;
}
pr += priv->bytes_per_row[2] - 4;
}
}
/**
* YCrCb -> YUV420P (2x2)
* .-------.
* | 1 | 2 |
* |---+---|
* | 3 | 4 |
* `-------'
*/
static void YCrCB_to_YUV420P_2x2(struct jdec_private *priv, int sx, int sy)
{
unsigned char *p;
const unsigned char *s, *y1;
unsigned int i;
p = priv->plane[0];
y1 = priv->Y;
for (i = sy; i > 0; i--)
{
memcpy(p, y1, sx);
p += priv->bytes_per_row[0];
y1 += 16;
}
sx = (sx+1) >> 1;
p = priv->plane[1];
s = priv->Cb;
for (i = sy; i > 0; i -= 2)
{
memcpy(p, s, sx);
s += 8;
p += priv->bytes_per_row[1];
}
p = priv->plane[2];
s = priv->Cr;
for (i = sy; i > 0; i -= 2)
{
memcpy(p, s, sx);
s += 8;
p += priv->bytes_per_row[2];
}
}
static int initialize_yuv420p(struct jdec_private *priv,
unsigned int *bytes_per_blocklines,
unsigned int *bytes_per_mcu)
{
int half_height = (priv->height + 1) >> 2;
int half_width = (priv->width + 1) >> 2;
if (!priv->bytes_per_row[0])
priv->bytes_per_row[0] = priv->width;
if (!priv->components[0])
priv->components[0] = malloc(priv->height * priv->bytes_per_row[0]);
if (!priv->bytes_per_row[1])
priv->bytes_per_row[1] = half_width;
if (!priv->components[1])
priv->components[1] = malloc(half_height * priv->bytes_per_row[1]);
if (!priv->bytes_per_row[2])
priv->bytes_per_row[2] = half_width;
if (!priv->components[2])
priv->components[2] = malloc(half_height * priv->bytes_per_row[2]);
bytes_per_mcu[0] = 8;
bytes_per_mcu[1] = 4;
bytes_per_mcu[2] = 4;
bytes_per_blocklines[0] = priv->width << 3;
bytes_per_blocklines[1] = half_width << 2;
bytes_per_blocklines[2] = half_width << 2;
/* Return nonzero on failure */
return !priv->components[0] || !priv->components[1] || !priv->components[2];
}
static const struct tinyjpeg_colorspace format_yuv420p =
{
{
YCrCB_to_YUV420P_1x1,
YCrCB_to_YUV420P_1x2,
YCrCB_to_YUV420P_2x1,
YCrCB_to_YUV420P_2x2,
},
tinyjpeg_decode_mcu_3comp_table,
initialize_yuv420p
};
const tinyjpeg_colorspace_t TINYJPEG_FMT_YUV420P = &format_yuv420p;