ref: 74eba6a78944ccfada0ab7dc50f6363cfd225cbf
dir: /jbig2_mmr.c/
/* jbig2dec Copyright (C) 2001-2002 artofcode LLC. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. $Id$ */ /* An implementation of MMR decoding. This is based on the implementation in Fitz, which in turn is based on the one in Ghostscript. */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include "os_types.h" #include <stddef.h> #include <stdio.h> #include <string.h> #include "jbig2.h" #include "jbig2_priv.h" #include "jbig2_arith.h" #include "jbig2_generic.h" #include "jbig2_mmr.h" typedef struct { int width; int height; const byte *data; size_t size; int data_index; int bit_index; uint32_t word; } Jbig2MmrCtx; static void jbig2_decode_mmr_init(Jbig2MmrCtx *mmr, int width, int height, const byte *data, size_t size) { int i; uint32_t word = 0; mmr->width = width; mmr->height = height; mmr->data = data; mmr->size = size; mmr->data_index = 0; mmr->bit_index = 0; for (i = 0; i < size && i < 4; i++) word |= (data[i] << ((3 - i) << 3)); mmr->word = word; } static void jbig2_decode_mmr_consume(Jbig2MmrCtx *mmr, int n_bits) { mmr->word <<= n_bits; mmr->bit_index += n_bits; while (mmr->bit_index >= 8) { mmr->bit_index -= 8; if (mmr->data_index + 4 < mmr->size) mmr->word |= (mmr->data[mmr->data_index + 4] << mmr->bit_index); mmr->data_index++; } } /* <raph> the first 2^(initialbits) entries map bit patterns to decodes <raph> let's say initial_bits is 8 for the sake of example <raph> and that the code is 1001 <raph> that means that entries 0x90 .. 0x9f have the entry { val, 4 } <raph> because those are all the bytes that start with the code <raph> and the 4 is the length of the code ... if (n_bits > initial_bits) ... <raph> anyway, in that case, it basically points to a mini table <raph> the n_bits is the maximum length of all codes beginning with that byte <raph> so 2^(n_bits - initial_bits) is the size of the mini-table <raph> peter came up with this, and it makes sense */ typedef struct { short val; short n_bits; } mmr_table_node; /* white decode table (runlength huffman codes) */ const mmr_table_node jbig2_mmr_white_decode[] = { { 256, 12 }, { 272, 12 }, { 29, 8 }, { 30, 8 }, { 45, 8 }, { 46, 8 }, { 22, 7 }, { 22, 7 }, { 23, 7 }, { 23, 7 }, { 47, 8 }, { 48, 8 }, { 13, 6 }, { 13, 6 }, { 13, 6 }, { 13, 6 }, { 20, 7 }, { 20, 7 }, { 33, 8 }, { 34, 8 }, { 35, 8 }, { 36, 8 }, { 37, 8 }, { 38, 8 }, { 19, 7 }, { 19, 7 }, { 31, 8 }, { 32, 8 }, { 1, 6 }, { 1, 6 }, { 1, 6 }, { 1, 6 }, { 12, 6 }, { 12, 6 }, { 12, 6 }, { 12, 6 }, { 53, 8 }, { 54, 8 }, { 26, 7 }, { 26, 7 }, { 39, 8 }, { 40, 8 }, { 41, 8 }, { 42, 8 }, { 43, 8 }, { 44, 8 }, { 21, 7 }, { 21, 7 }, { 28, 7 }, { 28, 7 }, { 61, 8 }, { 62, 8 }, { 63, 8 }, { 0, 8 }, { 320, 8 }, { 384, 8 }, { 10, 5 }, { 10, 5 }, { 10, 5 }, { 10, 5 }, { 10, 5 }, { 10, 5 }, { 10, 5 }, { 10, 5 }, { 11, 5 }, { 11, 5 }, { 11, 5 }, { 11, 5 }, { 11, 5 }, { 11, 5 }, { 11, 5 }, { 11, 5 }, { 27, 7 }, { 27, 7 }, { 59, 8 }, { 60, 8 }, { 288, 9 }, { 290, 9 }, { 18, 7 }, { 18, 7 }, { 24, 7 }, { 24, 7 }, { 49, 8 }, { 50, 8 }, { 51, 8 }, { 52, 8 }, { 25, 7 }, { 25, 7 }, { 55, 8 }, { 56, 8 }, { 57, 8 }, { 58, 8 }, { 192, 6 }, { 192, 6 }, { 192, 6 }, { 192, 6 }, { 1664, 6 }, { 1664, 6 }, { 1664, 6 }, { 1664, 6 }, { 448, 8 }, { 512, 8 }, { 292, 9 }, { 640, 8 }, { 576, 8 }, { 294, 9 }, { 296, 9 }, { 298, 9 }, { 300, 9 }, { 302, 9 }, { 256, 7 }, { 256, 7 }, { 2, 4 }, { 2, 4 }, { 2, 4 }, { 2, 4 }, { 2, 4 }, { 2, 4 }, { 2, 4 }, { 2, 4 }, { 2, 4 }, { 2, 4 }, { 2, 4 }, { 2, 4 }, { 2, 4 }, { 2, 4 }, { 2, 4 }, { 2, 4 }, { 3, 4 }, { 3, 4 }, { 3, 4 }, { 3, 4 }, { 3, 4 }, { 3, 4 }, { 3, 4 }, { 3, 4 }, { 3, 4 }, { 3, 4 }, { 3, 4 }, { 3, 4 }, { 3, 4 }, { 3, 4 }, { 3, 4 }, { 3, 4 }, { 128, 5 }, { 128, 5 }, { 128, 5 }, { 128, 5 }, { 128, 5 }, { 128, 5 }, { 128, 5 }, { 128, 5 }, { 8, 5 }, { 8, 5 }, { 8, 5 }, { 8, 5 }, { 8, 5 }, { 8, 5 }, { 8, 5 }, { 8, 5 }, { 9, 5 }, { 9, 5 }, { 9, 5 }, { 9, 5 }, { 9, 5 }, { 9, 5 }, { 9, 5 }, { 9, 5 }, { 16, 6 }, { 16, 6 }, { 16, 6 }, { 16, 6 }, { 17, 6 }, { 17, 6 }, { 17, 6 }, { 17, 6 }, { 4, 4 }, { 4, 4 }, { 4, 4 }, { 4, 4 }, { 4, 4 }, { 4, 4 }, { 4, 4 }, { 4, 4 }, { 4, 4 }, { 4, 4 }, { 4, 4 }, { 4, 4 }, { 4, 4 }, { 4, 4 }, { 4, 4 }, { 4, 4 }, { 5, 4 }, { 5, 4 }, { 5, 4 }, { 5, 4 }, { 5, 4 }, { 5, 4 }, { 5, 4 }, { 5, 4 }, { 5, 4 }, { 5, 4 }, { 5, 4 }, { 5, 4 }, { 5, 4 }, { 5, 4 }, { 5, 4 }, { 5, 4 }, { 14, 6 }, { 14, 6 }, { 14, 6 }, { 14, 6 }, { 15, 6 }, { 15, 6 }, { 15, 6 }, { 15, 6 }, { 64, 5 }, { 64, 5 }, { 64, 5 }, { 64, 5 }, { 64, 5 }, { 64, 5 }, { 64, 5 }, { 64, 5 }, { 6, 4 }, { 6, 4 }, { 6, 4 }, { 6, 4 }, { 6, 4 }, { 6, 4 }, { 6, 4 }, { 6, 4 }, { 6, 4 }, { 6, 4 }, { 6, 4 }, { 6, 4 }, { 6, 4 }, { 6, 4 }, { 6, 4 }, { 6, 4 }, { 7, 4 }, { 7, 4 }, { 7, 4 }, { 7, 4 }, { 7, 4 }, { 7, 4 }, { 7, 4 }, { 7, 4 }, { 7, 4 }, { 7, 4 }, { 7, 4 }, { 7, 4 }, { 7, 4 }, { 7, 4 }, { 7, 4 }, { 7, 4 }, { -2, 3 }, { -2, 3 }, { -1, 0 }, { -1, 0 }, { -1, 0 }, { -1, 0 }, { -1, 0 }, { -1, 0 }, { -1, 0 }, { -1, 0 }, { -1, 0 }, { -1, 0 }, { -1, 0 }, { -1, 0 }, { -1, 0 }, { -3, 4 }, { 1792, 3 }, { 1792, 3 }, { 1984, 4 }, { 2048, 4 }, { 2112, 4 }, { 2176, 4 }, { 2240, 4 }, { 2304, 4 }, { 1856, 3 }, { 1856, 3 }, { 1920, 3 }, { 1920, 3 }, { 2368, 4 }, { 2432, 4 }, { 2496, 4 }, { 2560, 4 }, { 1472, 1 }, { 1536, 1 }, { 1600, 1 }, { 1728, 1 }, { 704, 1 }, { 768, 1 }, { 832, 1 }, { 896, 1 }, { 960, 1 }, { 1024, 1 }, { 1088, 1 }, { 1152, 1 }, { 1216, 1 }, { 1280, 1 }, { 1344, 1 }, { 1408, 1 } }; /* black decode table (runlength huffman codes) */ const mmr_table_node jbig2_mmr_black_decode[] = { { 128, 12 }, { 160, 13 }, { 224, 12 }, { 256, 12 }, { 10, 7 }, { 11, 7 }, { 288, 12 }, { 12, 7 }, { 9, 6 }, { 9, 6 }, { 8, 6 }, { 8, 6 }, { 7, 5 }, { 7, 5 }, { 7, 5 }, { 7, 5 }, { 6, 4 }, { 6, 4 }, { 6, 4 }, { 6, 4 }, { 6, 4 }, { 6, 4 }, { 6, 4 }, { 6, 4 }, { 5, 4 }, { 5, 4 }, { 5, 4 }, { 5, 4 }, { 5, 4 }, { 5, 4 }, { 5, 4 }, { 5, 4 }, { 1, 3 }, { 1, 3 }, { 1, 3 }, { 1, 3 }, { 1, 3 }, { 1, 3 }, { 1, 3 }, { 1, 3 }, { 1, 3 }, { 1, 3 }, { 1, 3 }, { 1, 3 }, { 1, 3 }, { 1, 3 }, { 1, 3 }, { 1, 3 }, { 4, 3 }, { 4, 3 }, { 4, 3 }, { 4, 3 }, { 4, 3 }, { 4, 3 }, { 4, 3 }, { 4, 3 }, { 4, 3 }, { 4, 3 }, { 4, 3 }, { 4, 3 }, { 4, 3 }, { 4, 3 }, { 4, 3 }, { 4, 3 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 3, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { 2, 2 }, { -2, 4 }, { -2, 4 }, { -1, 0 }, { -1, 0 }, { -1, 0 }, { -1, 0 }, { -1, 0 }, { -1, 0 }, { -1, 0 }, { -1, 0 }, { -1, 0 }, { -1, 0 }, { -1, 0 }, { -1, 0 }, { -1, 0 }, { -3, 5 }, { 1792, 4 }, { 1792, 4 }, { 1984, 5 }, { 2048, 5 }, { 2112, 5 }, { 2176, 5 }, { 2240, 5 }, { 2304, 5 }, { 1856, 4 }, { 1856, 4 }, { 1920, 4 }, { 1920, 4 }, { 2368, 5 }, { 2432, 5 }, { 2496, 5 }, { 2560, 5 }, { 18, 3 }, { 18, 3 }, { 18, 3 }, { 18, 3 }, { 18, 3 }, { 18, 3 }, { 18, 3 }, { 18, 3 }, { 52, 5 }, { 52, 5 }, { 640, 6 }, { 704, 6 }, { 768, 6 }, { 832, 6 }, { 55, 5 }, { 55, 5 }, { 56, 5 }, { 56, 5 }, { 1280, 6 }, { 1344, 6 }, { 1408, 6 }, { 1472, 6 }, { 59, 5 }, { 59, 5 }, { 60, 5 }, { 60, 5 }, { 1536, 6 }, { 1600, 6 }, { 24, 4 }, { 24, 4 }, { 24, 4 }, { 24, 4 }, { 25, 4 }, { 25, 4 }, { 25, 4 }, { 25, 4 }, { 1664, 6 }, { 1728, 6 }, { 320, 5 }, { 320, 5 }, { 384, 5 }, { 384, 5 }, { 448, 5 }, { 448, 5 }, { 512, 6 }, { 576, 6 }, { 53, 5 }, { 53, 5 }, { 54, 5 }, { 54, 5 }, { 896, 6 }, { 960, 6 }, { 1024, 6 }, { 1088, 6 }, { 1152, 6 }, { 1216, 6 }, { 64, 3 }, { 64, 3 }, { 64, 3 }, { 64, 3 }, { 64, 3 }, { 64, 3 }, { 64, 3 }, { 64, 3 }, { 13, 1 }, { 13, 1 }, { 13, 1 }, { 13, 1 }, { 13, 1 }, { 13, 1 }, { 13, 1 }, { 13, 1 }, { 13, 1 }, { 13, 1 }, { 13, 1 }, { 13, 1 }, { 13, 1 }, { 13, 1 }, { 13, 1 }, { 13, 1 }, { 23, 4 }, { 23, 4 }, { 50, 5 }, { 51, 5 }, { 44, 5 }, { 45, 5 }, { 46, 5 }, { 47, 5 }, { 57, 5 }, { 58, 5 }, { 61, 5 }, { 256, 5 }, { 16, 3 }, { 16, 3 }, { 16, 3 }, { 16, 3 }, { 17, 3 }, { 17, 3 }, { 17, 3 }, { 17, 3 }, { 48, 5 }, { 49, 5 }, { 62, 5 }, { 63, 5 }, { 30, 5 }, { 31, 5 }, { 32, 5 }, { 33, 5 }, { 40, 5 }, { 41, 5 }, { 22, 4 }, { 22, 4 }, { 14, 1 }, { 14, 1 }, { 14, 1 }, { 14, 1 }, { 14, 1 }, { 14, 1 }, { 14, 1 }, { 14, 1 }, { 14, 1 }, { 14, 1 }, { 14, 1 }, { 14, 1 }, { 14, 1 }, { 14, 1 }, { 14, 1 }, { 14, 1 }, { 15, 2 }, { 15, 2 }, { 15, 2 }, { 15, 2 }, { 15, 2 }, { 15, 2 }, { 15, 2 }, { 15, 2 }, { 128, 5 }, { 192, 5 }, { 26, 5 }, { 27, 5 }, { 28, 5 }, { 29, 5 }, { 19, 4 }, { 19, 4 }, { 20, 4 }, { 20, 4 }, { 34, 5 }, { 35, 5 }, { 36, 5 }, { 37, 5 }, { 38, 5 }, { 39, 5 }, { 21, 4 }, { 21, 4 }, { 42, 5 }, { 43, 5 }, { 0, 3 }, { 0, 3 }, { 0, 3 }, { 0, 3 } }; #define getbit(buf, x) ( ( buf[x >> 3] >> ( 7 - (x & 7) ) ) & 1 ) static int jbig2_find_changing_element(const byte *line, int x, int w) { int a, b; if (line == 0) return w; if (x == -1) { a = 0; x = 0; } else { a = getbit(line, x); x ++; } while (x < w) { b = getbit(line, x); if (a != b) break; x++; } return x; } static int jbig2_find_changing_element_of_color(const byte *line, int x, int w, int color) { if (line == 0) return w; x = jbig2_find_changing_element(line, x, w); if (x < w && getbit(line, x) != color) x = jbig2_find_changing_element(line, x, w); return x; } static const byte lm[8] = { 0xFF, 0x7F, 0x3F, 0x1F, 0x0F, 0x07, 0x03, 0x01 }; static const byte rm[8] = { 0x00, 0x80, 0xC0, 0xE0, 0xF0, 0xF8, 0xFC, 0xFE }; static void jbig2_set_bits(byte *line, int x0, int x1) { int a0, a1, b0, b1, a; a0 = x0 >> 3; a1 = x1 >> 3; b0 = x0 & 7; b1 = x1 & 7; if (a0 == a1) { line[a0] |= lm[b0] & rm[b1]; } else { line[a0] |= lm[b0]; for (a = a0 + 1; a < a1; a++) line[a] = 0xFF; line[a1] |= rm[b1]; } } static int jbig2_decode_get_code(Jbig2MmrCtx *mmr, const mmr_table_node *table, int initial_bits) { uint32_t word = mmr->word; int table_ix = word >> (32 - initial_bits); int val = table[table_ix].val; int n_bits = table[table_ix].n_bits; if (n_bits > initial_bits) { int mask = (1 << (32 - initial_bits)) - 1; table_ix = val + ((word & mask) >> (32 - n_bits)); val = table[table_ix].val; n_bits = initial_bits + table[table_ix].n_bits; } jbig2_decode_mmr_consume(mmr, n_bits); return val; } static int jbig2_decode_get_run(Jbig2MmrCtx *mmr, const mmr_table_node *table, int initial_bits) { int result = 0; int val; do { val = jbig2_decode_get_code(mmr, table, initial_bits); result += val; } while (val >= 64); return result; } static void jbig2_decode_mmr_line(Jbig2MmrCtx *mmr, const byte *ref, byte *dst) { int a0, a1, a2, b1, b2; int c; a0 = -1; c = 0; /* 0 is white, black is 1 */ while (1) { uint32_t word = mmr->word; /* printf ("%08x\n", word); */ if (a0 >= mmr->width) break; if ((word >> (32 - 3)) == 1) { int white_run, black_run; jbig2_decode_mmr_consume(mmr, 3); if (a0 == -1) a0 = 0; if (c == 0) { white_run = jbig2_decode_get_run(mmr, jbig2_mmr_white_decode, 8); black_run = jbig2_decode_get_run(mmr, jbig2_mmr_black_decode, 7); a1 = a0 + white_run; a2 = a1 + black_run; if (a1 > mmr->width) a1 = mmr->width; if (a2 > mmr->width) a2 = mmr->width; jbig2_set_bits(dst, a1, a2); a0 = a2; /* printf ("H %d %d\n", white_run, black_run); */ } else { black_run = jbig2_decode_get_run(mmr, jbig2_mmr_black_decode, 7); white_run = jbig2_decode_get_run(mmr, jbig2_mmr_white_decode, 8); a1 = a0 + black_run; a2 = a1 + white_run; if (a1 > mmr->width) a1 = mmr->width; if (a2 > mmr->width) a2 = mmr->width; jbig2_set_bits(dst, a0, a1); a0 = a2; /* printf ("H %d %d\n", black_run, white_run); */ } } else if ((word >> (32 - 4)) == 1) { /* printf ("P\n"); */ jbig2_decode_mmr_consume(mmr, 4); b1 = jbig2_find_changing_element_of_color(ref, a0, mmr->width, !c); b2 = jbig2_find_changing_element(ref, b1, mmr->width); if (c) jbig2_set_bits(dst, a0, b2); a0 = b2; } else if ((word >> (32 - 1)) == 1) { /* printf ("V(0)\n"); */ jbig2_decode_mmr_consume(mmr, 1); b1 = jbig2_find_changing_element_of_color(ref, a0, mmr->width, !c); if (c) jbig2_set_bits(dst, a0, b1); a0 = b1; c = !c; } else if ((word >> (32 - 3)) == 3) { /* printf ("VR(1)\n"); */ jbig2_decode_mmr_consume(mmr, 3); b1 = jbig2_find_changing_element_of_color(ref, a0, mmr->width, !c); if (b1 + 1 > mmr->width) break; if (c) jbig2_set_bits(dst, a0, b1 + 1); a0 = b1 + 1; c = !c; } else if ((word >> (32 - 6)) == 3) { /* printf ("VR(2)\n"); */ jbig2_decode_mmr_consume(mmr, 6); b1 = jbig2_find_changing_element_of_color(ref, a0, mmr->width, !c); if (b1 + 2 > mmr->width) break; if (c) jbig2_set_bits(dst, a0, b1 + 2); a0 = b1 + 2; c = !c; } else if ((word >> (32 - 7)) == 3) { /* printf ("VR(3)\n"); */ jbig2_decode_mmr_consume(mmr, 7); b1 = jbig2_find_changing_element_of_color(ref, a0, mmr->width, !c); if (b1 + 3 > mmr->width) break; if (c) jbig2_set_bits(dst, a0, b1 + 3); a0 = b1 + 3; c = !c; } else if ((word >> (32 - 3)) == 2) { /* printf ("VL(1)\n"); */ jbig2_decode_mmr_consume(mmr, 3); b1 = jbig2_find_changing_element_of_color(ref, a0, mmr->width, !c); if (b1 - 1 < 0) break; if (c) jbig2_set_bits(dst, a0, b1 - 1); a0 = b1 - 1; c = !c; } else if ((word >> (32 - 6)) == 2) { /* printf ("VL(2)\n"); */ jbig2_decode_mmr_consume(mmr, 6); b1 = jbig2_find_changing_element_of_color(ref, a0, mmr->width, !c); if (b1 - 2 < 0) break; if (c) jbig2_set_bits(dst, a0, b1 - 2); a0 = b1 - 2; c = !c; } else if ((word >> (32 - 7)) == 2) { /* printf ("VL(3)\n"); */ jbig2_decode_mmr_consume(mmr, 7); b1 = jbig2_find_changing_element_of_color(ref, a0, mmr->width, !c); if (b1 - 3 < 0) break; if (c) jbig2_set_bits(dst, a0, b1 - 3); a0 = b1 - 3; c = !c; } else break; } } int jbig2_decode_generic_mmr(Jbig2Ctx *ctx, Jbig2Segment *segment, const Jbig2GenericRegionParams *params, const byte *data, size_t size, Jbig2Image *image) { Jbig2MmrCtx mmr; const int rowstride = image->stride; byte *dst = image->data; byte *ref = NULL; int y; jbig2_decode_mmr_init(&mmr, image->width, image->height, data, size); for (y = 0; y < image->height; y++) { memset(dst, 0, rowstride); jbig2_decode_mmr_line(&mmr, ref, dst); ref = dst; dst += rowstride; } return 0; }