481 lines
11 KiB
C
481 lines
11 KiB
C
/* vim: tabstop=4 shiftwidth=4 noexpandtab
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* This file is part of ToaruOS and is released under the terms
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* of the NCSA / University of Illinois License - see LICENSE.md
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* Copyright (C) 2018 K. Lange
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*
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* libtoaru_jpeg: Decode simple JPEGs.
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*
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* Adapted from Raul Aguaviva's Python "micro JPEG visualizer":
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*
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* MIT License
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*
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* Copyright (c) 2017 Raul Aguaviva
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all
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* copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*
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*/
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#include <stdint.h>
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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 <math.h>
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#include <toaru/graphics.h>
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#if 0
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#include <toaru/trace.h>
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#define TRACE_APP_NAME "jpeg"
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#else
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#define TRACE(...)
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#endif
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static sprite_t * sprite = NULL;
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/* Byte swap short (because JPEG uses big-endian values) */
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static void swap16(uint16_t * val) {
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char * a = (char *)val;
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char b = a[0];
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a[0] = a[1];
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a[1] = b;
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}
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/* JPEG compontent zig-zag ordering */
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static int zigzag[] = {
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0, 1, 8, 16, 9, 2, 3, 10,
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17, 24, 32, 25, 18, 11, 4, 5,
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12, 19, 26, 33, 40, 48, 41, 34,
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27, 20, 13, 6, 7, 14, 21, 28,
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35, 42, 49, 56, 57, 50, 43, 36,
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29, 22, 15, 23, 30, 37, 44, 51,
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58, 59, 52, 45, 38, 31, 39, 46,
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53, 60, 61, 54, 47, 55, 62, 63
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};
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static uint8_t quant_mapping[3] = {0};
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static uint8_t quant[8][64];
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static int clamp(int col) {
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if (col > 255) return 255;
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if (col < 0) return 0;
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return col;
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}
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/* YCbCr to RGB conversion */
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static void color_conversion(
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float Y, float Cb, float Cr,
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int *R, int *G, int *B
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) {
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float r = (Cr*(2.0-2.0*0.299) + Y);
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float b = (Cb*(2.0-2.0*0.114) + Y);
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float g = (Y - 0.144 * b - 0.229 * r) / 0.587;
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*R = clamp(r + 128);
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*G = clamp(g + 128);
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*B = clamp(b + 128);
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}
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static int xy_to_lin(int x, int y) {
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return x + y * 8;
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}
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struct huffman_table {
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uint8_t lengths[16];
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uint8_t elements[256];
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} huffman_tables[256] = {0};
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struct stream {
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FILE * file;
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uint8_t byte;
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int have;
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int pos;
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};
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static void define_quant_table(FILE * f, int len) {
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TRACE("Defining quant table");
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while (len > 0) {
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uint8_t hdr;
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fread(&hdr, 1, 1, f);
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fread(&quant[(hdr) & 0xF], 64, 1, f);
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len -= 65;
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}
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TRACE("Done");
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}
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static void baseline_dct(FILE * f, int len) {
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struct dct {
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uint8_t hdr;
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uint16_t height;
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uint16_t width;
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uint8_t components;
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} __attribute__((packed)) dct;
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fread(&dct, sizeof(struct dct), 1, f);
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/* Read image dimensions, each as big-endian 16-bit values */
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swap16(&dct.height);
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swap16(&dct.width);
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/* We read 7 bytes */
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len -= sizeof(struct dct);
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TRACE("Image dimensions are %d×%d", dct.width, dct.height);
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sprite->width = dct.width;
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sprite->height = dct.height;
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sprite->bitmap = malloc(sizeof(uint32_t) * sprite->width * sprite->height);
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sprite->masks = NULL;
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sprite->alpha = 0;
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sprite->blank = 0;
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TRACE("Loading quantization mappings...");
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for (int i = 0; i < dct.components; ++i) {
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/* Quant mapping */
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struct {
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uint8_t id;
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uint8_t samp;
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uint8_t qtb_id;
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} __attribute__((packed)) tmp;
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fread(&tmp, sizeof(tmp), 1, f);
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/* There should only be three of these for the images we support. */
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if (i > 3) {
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abort();
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}
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quant_mapping[i] = tmp.qtb_id;
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/* 3 bytes were read */
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len -= 3;
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}
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/* Skip whatever else might be in this section */
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if (len > 0) {
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fseek(f, len, SEEK_CUR);
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}
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}
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static void define_huffman_table(FILE * f, int len) {
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TRACE("Loading Huffman tables...");
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while (len > 0) {
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/* Read header ID */
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uint8_t hdr;
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fread(&hdr, 1, 1, f);
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len--;
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/* Read length table */
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fread(huffman_tables[hdr].lengths, 16, 1, f);
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len -= 16;
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/* Read Huffman table entries */
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int o = 0;
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for (int i = 0; i < 16; ++i) {
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int l = huffman_tables[hdr].lengths[i];
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fread(&huffman_tables[hdr].elements[o], l, 1, f);
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o += l;
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len -= l;
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}
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}
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/* Skip rest of section */
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if (len > 0) {
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fseek(f, len, SEEK_CUR);
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}
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}
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struct idct {
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double base[64];
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};
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/**
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* norm_coeff[0] = 0.35355339059
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* norm_coeff[1] = 0.5
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*/
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static double cosines[8][8] = {
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{ 0.35355339059,0.35355339059,0.35355339059,0.35355339059,0.35355339059,0.35355339059,0.35355339059,0.35355339059 },
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{ 0.490392640202,0.415734806151,0.27778511651,0.0975451610081,-0.0975451610081,-0.27778511651,-0.415734806151,-0.490392640202 },
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{ 0.461939766256,0.191341716183,-0.191341716183,-0.461939766256,-0.461939766256,-0.191341716183,0.191341716183,0.461939766256 },
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{ 0.415734806151,-0.0975451610081,-0.490392640202,-0.27778511651,0.27778511651,0.490392640202,0.0975451610081,-0.415734806151 },
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{ 0.353553390593,-0.353553390593,-0.353553390593,0.353553390593,0.353553390593,-0.353553390593,-0.353553390593,0.353553390593 },
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{ 0.27778511651,-0.490392640202,0.0975451610081,0.415734806151,-0.415734806151,-0.0975451610081,0.490392640202,-0.27778511651 },
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{ 0.191341716183,-0.461939766256,0.461939766256,-0.191341716183,-0.191341716183,0.461939766256,-0.461939766256,0.191341716183 },
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{ 0.0975451610081,-0.27778511651,0.415734806151,-0.490392640202,0.490392640202,-0.415734806151,0.27778511651,-0.0975451610081 },
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};
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static double premul[8][8][8][8]= {{{{0}}}};
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static void add_idc(struct idct * self, int n, int m, int coeff) {
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for (int y = 0; y < 8; ++y) {
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for (int x = 0; x < 8; ++x) {
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self->base[xy_to_lin(x, y)] += premul[n][m][x][y] * coeff;
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}
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}
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}
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static void add_zigzag(struct idct * self, int zi, int coeff) {
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int i = zigzag[zi];
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int n = i & 0x7;
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int m = i >> 3;
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add_idc(self, n, m, coeff);
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}
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/* Read a bit from the stream */
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static int get_bit(struct stream * st) {
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while ((st->pos >> 3) >= st->have) {
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/* We have finished using the current byte and need to read another one */
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int t = fgetc(st->file);
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if (t < 0) {
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/* EOF */
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st->byte = 0;
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} else {
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st->byte = t;
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}
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if (st->byte == 0xFF) {
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/*
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* If we see 0xFF, it's followed by a 0x00
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* that should be skipped.
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*/
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int tmp = fgetc(st->file);
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if (tmp != 0) {
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/*
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* If it's *not*, we reached the end of the file - but
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* this shouldn't happen.
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*/
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st->byte = 0;
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}
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}
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/* We've seen a new byte */
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st->have++;
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}
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/* Extract appropriate bit from this byte */
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uint8_t b = st->byte;
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int s = 7 - (st->pos & 0x7);
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/* We move forward one position in the bit stream */
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st->pos += 1;
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return (b >> s) & 1;
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}
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/* Advance forward and get the n'th next bit */
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static int get_bitn(struct stream * st, int l) {
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int val = 0;
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for (int i = 0; i < l; ++i) {
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val = val * 2 + get_bit(st);
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}
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return val;
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}
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/*
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* Read a Huffman code by reading bits and using
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* the Huffman table.
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*/
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static int get_code(struct huffman_table * table, struct stream * st) {
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int val = 0;
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int off = 0;
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int ini = 0;
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for (int i = 0; i < 16; ++i) {
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val = val * 2 + get_bit(st);
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if (table->lengths[i] > 0) {
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if (val - ini < table->lengths[i]) {
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return table->elements[off + val - ini];
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}
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ini = ini + table->lengths[i];
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off += table->lengths[i];
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}
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ini *= 2;
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}
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/* Invalid */
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return -1;
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}
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/* Decode Huffman codes to values */
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static int decode(int code, int bits) {
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int l = 1L << (code - 1);
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if (bits >= l) {
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return bits;
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} else {
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return bits - (2 * l - 1);
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}
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}
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/* Build IDCT matrix */
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static struct idct * build_matrix(struct idct * i, struct stream * st, int idx, uint8_t * quant, int oldcoeff, int * outcoeff) {
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memset(i, 0, sizeof(struct idct));
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int code = get_code(&huffman_tables[idx], st);
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int bits = get_bitn(st, code);
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int dccoeff = decode(code, bits) + oldcoeff;
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add_zigzag(i, 0, dccoeff * quant[0]);
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int l = 1;
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while (l < 64) {
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code = get_code(&huffman_tables[16+idx], st);
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if (code == 0) break;
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if (code > 15) {
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l += (code >> 4);
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code = code & 0xF;
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}
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bits = get_bitn(st, code);
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int coeff = decode(code, bits);
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add_zigzag(i, l, coeff * quant[l]);
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l += 1;
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}
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*outcoeff = dccoeff;
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return i;
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}
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/* Set pixel in sprite buffer with bounds checking */
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static void set_pixel(int x, int y, uint32_t color) {
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if ((x < sprite->width) && (y < sprite->height)) {
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SPRITE(sprite,x,y) = color;
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}
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}
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/* Concvert YCbCr values to RGB pixels */
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static void draw_matrix(int x, int y, struct idct * L, struct idct * cb, struct idct * cr) {
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for (int yy = 0; yy < 8; ++yy) {
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for (int xx = 0; xx < 8; ++xx) {
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int o = xy_to_lin(xx,yy);
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int r, g, b;
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color_conversion(L->base[o], cb->base[o], cr->base[o], &r, &g, &b);
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uint32_t c = 0xFF000000 | (r << 16) | (g << 8) | b;
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set_pixel((x * 8 + xx), (y * 8 + yy), c);
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}
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}
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}
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static void start_of_scan(FILE * f, int len) {
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TRACE("Reading image data");
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/* Skip header */
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fseek(f, len, SEEK_CUR);
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/* Initialize bit stream */
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struct stream _st = {0};
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_st.file = f;
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struct stream * st = &_st;
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int old_lum = 0;
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int old_crd = 0;
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int old_cbd = 0;
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for (int y = 0; y < sprite->height / 8 + !!(sprite->height & 0xf); ++y) {
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TRACE("Star row %d", y );
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for (int x = 0; x < sprite->width / 8 + !!(sprite->width & 0xf); ++x) {
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if (y >= 134) {
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TRACE("Start col %d", x);
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}
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/* Build matrices */
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struct idct matL, matCr, matCb;
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build_matrix(&matL, st, 0, quant[quant_mapping[0]], old_lum, &old_lum);
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build_matrix(&matCb, st, 1, quant[quant_mapping[1]], old_cbd, &old_cbd);
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build_matrix(&matCr, st, 1, quant[quant_mapping[2]], old_crd, &old_crd);
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if (y >= 134) {
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TRACE("Draw col %d", x);
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}
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draw_matrix(x, y, &matL, &matCb, &matCr);
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}
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}
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TRACE("Done.");
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}
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int load_sprite_jpg(sprite_t * tsprite, char * filename) {
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FILE * f = fopen(filename, "r");
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if (!f) {
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return 1;
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}
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sprite = tsprite;
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memset(huffman_tables, 0, sizeof(huffman_tables));
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if (premul[0][0][0][0] == 0.0) {
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for (int n = 0; n < 8; ++n) {
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for (int m = 0; m < 8; ++m) {
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for (int y = 0; y < 8; ++y) {
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for (int x = 0; x < 8; ++x) {
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premul[n][m][x][y] = cosines[n][x] * cosines[m][y];
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}
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}
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}
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}
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}
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while (1) {
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/* Read a header */
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uint16_t hdr;
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int r = fread(&hdr, 2, 1, f);
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if (r <= 0) {
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/* EOF */
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break;
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}
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/* These headers are stored big-endian */
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swap16(&hdr);
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if (hdr == 0xffd8) {
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/* No data */
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continue;
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} else if (hdr == 0xffd9) {
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/* End of file */
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break;
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} else {
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/* Regular sections with data start with a length */
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uint16_t len;
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fread(&len, 2, 1, f);
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swap16(&len);
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/* Subtract two because the length includes itself */
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len -= 2;
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if (hdr == 0xffdb) {
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define_quant_table(f, len);
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} else if (hdr == 0xffc0) {
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baseline_dct(f, len);
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} else if (hdr == 0xffc4) {
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define_huffman_table(f, len);
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} else if (hdr == 0xffda) {
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start_of_scan(f, len);
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/* End immediately after reading the data */
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break;
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} else {
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TRACE("Unknown header\n");
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fseek(f, len, SEEK_CUR);
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}
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}
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}
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fclose(f);
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return 0;
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}
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