ref: 54850de6b0bf55dd409a699be469a133be564028
dir: /jbig2_mmr.c/
/*
jbig2dec
Copyright (C) 2001-2003 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: jbig2_mmr.c,v 1.12 2003/02/05 15:27:42 giles Exp $
*/
/* An implementation of MMR decoding. This is based on the implementation
in Ghostscript.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "os_types.h"
#include <stddef.h>
#include <stdio.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 == 0)
{
a = 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 = 0;
c = 0; /* 0 is white, black is 1 */
while (1)
{
uint32_t word = mmr->word;
if (a0 >= mmr->width)
break;
if ((word >> (32 - 3)) == 1)
{
int white_run, black_run;
jbig2_decode_mmr_consume(mmr, 3);
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;
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;
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 (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 (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 (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 (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 (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 (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;
}