391 lines
9.3 KiB
C
391 lines
9.3 KiB
C
/*
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* Small jpeg decoder library
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*
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* Copyright (c) 2006, Luc Saillard <luc@saillard.org>
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* All rights reserved.
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* - Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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*
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* - Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* - Neither the name of the author nor the names of its contributors may be
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* used to endorse or promote products derived from this software without
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* specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <stdint.h>
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#include "tinyjpeg.h"
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#include "tinyjpeg-internal.h"
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/*******************************************************************************
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*
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* Colorspace conversion routine
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*
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*
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* Note:
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* YCbCr is defined per CCIR 601-1, except that Cb and Cr are
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* normalized to the range 0..MAXJSAMPLE rather than -0.5 .. 0.5.
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* The conversion equations to be implemented are therefore
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* R = Y + 1.40200 * Cr
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* G = Y - 0.34414 * Cb - 0.71414 * Cr
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* B = Y + 1.77200 * Cb
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*
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******************************************************************************/
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static unsigned char clamp(int i)
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{
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if (i<0)
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return 0;
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else if (i>255)
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return 255;
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else
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return i;
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}
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/**
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* YCrCb -> BGRA32 (1x1)
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* .---.
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* | 1 |
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* `---'
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*/
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static void YCrCB_to_BGRA32_1x1(struct jdec_private *priv, int sx, int sy)
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{
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const unsigned char *Y, *Cb, *Cr;
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unsigned char *p;
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int i,j;
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int offset_to_next_row;
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#define SCALEBITS 10
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#define ONE_HALF (1UL << (SCALEBITS-1))
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#define FIX(x) ((int)((x) * (1UL<<SCALEBITS) + 0.5))
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p = priv->plane[0];
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Y = priv->Y;
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Cb = priv->Cb;
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Cr = priv->Cr;
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offset_to_next_row = priv->bytes_per_row[0] - 8*4;
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for (i = sy; i > 0; i--) {
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for (j = sx; j > 0; j--) {
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int y, cb, cr;
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int add_r, add_g, add_b;
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int r, g , b, a;
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y = Y[0] << SCALEBITS;
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cb = *Cb++ - 128;
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cr = *Cr++ - 128;
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add_r = FIX(1.40200) * cr + ONE_HALF;
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add_g = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;
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add_b = FIX(1.77200) * cb + ONE_HALF;
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b = (y + add_b) >> SCALEBITS;
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*p++ = clamp(b);
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g = (y + add_g) >> SCALEBITS;
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*p++ = clamp(g);
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r = (y + add_r) >> SCALEBITS;
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*p++ = clamp(r);
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a = 255;
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*p++ = a;
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Y++;
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}
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p += offset_to_next_row;
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}
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#undef SCALEBITS
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#undef ONE_HALF
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#undef FIX
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}
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/*
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* YCrCb -> BGRA32 (2x1)
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* .-------.
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* | 1 | 2 |
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* `-------'
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*/
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static void YCrCB_to_BGRA32_2x1(struct jdec_private *priv, int sx, int sy)
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{
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const unsigned char *Y, *Cb, *Cr;
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unsigned char *p;
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int i,j;
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int offset_to_next_row;
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#define SCALEBITS 10
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#define ONE_HALF (1UL << (SCALEBITS-1))
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#define FIX(x) ((int)((x) * (1UL<<SCALEBITS) + 0.5))
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p = priv->plane[0];
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Y = priv->Y;
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Cb = priv->Cb;
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Cr = priv->Cr;
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offset_to_next_row = priv->bytes_per_row[0] - 16*4;
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for (i = sy; i > 0; i--) {
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for (j = sx; j > 0; j -= 2) {
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int y, cb, cr;
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int add_r, add_g, add_b;
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int r, g , b, a;
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cb = *Cb++ - 128;
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cr = *Cr++ - 128;
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add_r = FIX(1.40200) * cr + ONE_HALF;
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add_g = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;
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add_b = FIX(1.77200) * cb + ONE_HALF;
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y = Y[0] << SCALEBITS;
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b = (y + add_b) >> SCALEBITS;
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*p++ = clamp(b);
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g = (y + add_g) >> SCALEBITS;
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*p++ = clamp(g);
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r = (y + add_r) >> SCALEBITS;
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*p++ = clamp(r);
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a = 255;
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*p++ = a;
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if (j > 1) {
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y = Y[1] << SCALEBITS;
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b = (y + add_b) >> SCALEBITS;
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*p++ = clamp(b);
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g = (y + add_g) >> SCALEBITS;
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*p++ = clamp(g);
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r = (y + add_r) >> SCALEBITS;
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*p++ = clamp(r);
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a = 255;
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*p++ = a;
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}
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Y += 2;
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}
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p += offset_to_next_row;
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}
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#undef SCALEBITS
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#undef ONE_HALF
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#undef FIX
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}
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/*
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* YCrCb -> BGRA32 (1x2)
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* .---.
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* | 1 |
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* |---|
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* | 2 |
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* `---'
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*/
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static void YCrCB_to_BGRA32_1x2(struct jdec_private *priv, int sx, int sy)
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{
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const unsigned char *Y, *Cb, *Cr;
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unsigned char *p, *p2;
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int i,j;
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int offset_to_next_row;
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#define SCALEBITS 10
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#define ONE_HALF (1UL << (SCALEBITS-1))
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#define FIX(x) ((int)((x) * (1UL<<SCALEBITS) + 0.5))
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p = priv->plane[0];
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p2 = priv->plane[0] + priv->bytes_per_row[0];
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Y = priv->Y;
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Cb = priv->Cb;
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Cr = priv->Cr;
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offset_to_next_row = 2*priv->bytes_per_row[0] - 8*4;
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for (i = sy; i > 0; i -= 2) {
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for (j = sx; j > 0; j--) {
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int y, cb, cr;
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int add_r, add_g, add_b;
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int r, g , b, a;
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cb = *Cb++ - 128;
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cr = *Cr++ - 128;
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add_r = FIX(1.40200) * cr + ONE_HALF;
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add_g = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;
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add_b = FIX(1.77200) * cb + ONE_HALF;
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y = Y[0] << SCALEBITS;
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b = (y + add_b) >> SCALEBITS;
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*p++ = clamp(b);
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g = (y + add_g) >> SCALEBITS;
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*p++ = clamp(g);
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r = (y + add_r) >> SCALEBITS;
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*p++ = clamp(r);
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a = 255;
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*p++ = a;
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if (i > 1) {
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y = Y[8] << SCALEBITS;
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b = (y + add_b) >> SCALEBITS;
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*p2++ = clamp(b);
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g = (y + add_g) >> SCALEBITS;
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*p2++ = clamp(g);
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r = (y + add_r) >> SCALEBITS;
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*p2++ = clamp(r);
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a = 255;
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*p2++ = a;
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}
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Y++;
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}
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Y += 8;
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p += offset_to_next_row;
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p2 += offset_to_next_row;
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}
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#undef SCALEBITS
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#undef ONE_HALF
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#undef FIX
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}
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/*
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* YCrCb -> BGRA32 (2x2)
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* .-------.
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* | 1 | 2 |
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* |---+---|
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* | 3 | 4 |
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* `-------'
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*/
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static void YCrCB_to_BGRA32_2x2(struct jdec_private *priv, int sx, int sy)
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{
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const unsigned char *Y, *Cb, *Cr;
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unsigned char *p, *p2;
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int i,j;
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int offset_to_next_row;
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#define SCALEBITS 10
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#define ONE_HALF (1UL << (SCALEBITS-1))
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#define FIX(x) ((int)((x) * (1UL<<SCALEBITS) + 0.5))
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p = priv->plane[0];
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p2 = priv->plane[0] + priv->bytes_per_row[0];
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Y = priv->Y;
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Cb = priv->Cb;
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Cr = priv->Cr;
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offset_to_next_row = 2*priv->bytes_per_row[0] - 16*4;
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for (i = sy; i > 0; i -= 2) {
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for (j = sx; j > 0; j -= 2) {
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int y, cb, cr;
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int add_r, add_g, add_b;
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int r, g , b, a;
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cb = *Cb++ - 128;
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cr = *Cr++ - 128;
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add_r = FIX(1.40200) * cr + ONE_HALF;
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add_g = - FIX(0.34414) * cb - FIX(0.71414) * cr + ONE_HALF;
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add_b = FIX(1.77200) * cb + ONE_HALF;
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y = Y[0] << SCALEBITS;
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b = (y + add_b) >> SCALEBITS;
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*p++ = clamp(b);
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g = (y + add_g) >> SCALEBITS;
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*p++ = clamp(g);
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r = (y + add_r) >> SCALEBITS;
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*p++ = clamp(r);
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a = 255;
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*p++ = a;
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if (j > 1) {
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y = Y[1] << SCALEBITS;
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b = (y + add_b) >> SCALEBITS;
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*p++ = clamp(b);
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g = (y + add_g) >> SCALEBITS;
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*p++ = clamp(g);
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r = (y + add_r) >> SCALEBITS;
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*p++ = clamp(r);
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a = 255;
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*p++ = a;
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}
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if (i > 1) {
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y = Y[16+0] << SCALEBITS;
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b = (y + add_b) >> SCALEBITS;
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*p2++ = clamp(b);
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g = (y + add_g) >> SCALEBITS;
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*p2++ = clamp(g);
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r = (y + add_r) >> SCALEBITS;
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*p2++ = clamp(r);
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a = 255;
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*p2++ = a;
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if (j > 1) {
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y = Y[16+1] << SCALEBITS;
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b = (y + add_b) >> SCALEBITS;
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*p2++ = clamp(b);
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g = (y + add_g) >> SCALEBITS;
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*p2++ = clamp(g);
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r = (y + add_r) >> SCALEBITS;
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*p2++ = clamp(r);
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a = 255;
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*p2++ = a;
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}
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}
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Y += 2;
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}
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Y += 16;
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p += offset_to_next_row;
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p2 += offset_to_next_row;
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}
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#undef SCALEBITS
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#undef ONE_HALF
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#undef FIX
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}
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static int initialize_bgra32(struct jdec_private *priv,
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unsigned int *bytes_per_blocklines,
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unsigned int *bytes_per_mcu)
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{
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if (!priv->bytes_per_row[0])
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priv->bytes_per_row[0] = priv->width * 4;
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if (!priv->components[0])
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priv->components[0] = malloc(priv->height * priv->bytes_per_row[0]);
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bytes_per_blocklines[0] = priv->bytes_per_row[0] << 3;
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bytes_per_mcu[0] = 4*8;
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return !priv->components[0];
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}
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static const struct tinyjpeg_colorspace format_bgra32 =
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{
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{
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YCrCB_to_BGRA32_1x1,
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YCrCB_to_BGRA32_1x2,
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YCrCB_to_BGRA32_2x1,
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YCrCB_to_BGRA32_2x2,
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},
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tinyjpeg_decode_mcu_3comp_table,
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initialize_bgra32
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};
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const tinyjpeg_colorspace_t TINYJPEG_FMT_BGRA32 = &format_bgra32;
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