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rockbox/apps/plugins/imageviewer/png/tinflate.c
Teruaki Kawashima d055ff4a94 reduce casts between "unsinged char *" and "fb_data *". make calculation precise. maintain spaces. 
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@28428 a1c6a512-1295-4272-9138-f99709370657
2010-11-01 12:13:49 +00:00

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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Original source:
* Copyright (c) 2003 by Joergen Ibsen / Jibz
*
* Rockbox adaptation:
* Copyright (c) 2010 by Marcin Bukat
*
* 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.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
/*
* tinflate - tiny inflate
*
* Copyright (c) 2003 by Joergen Ibsen / Jibz
* All Rights Reserved
*
* http://www.ibsensoftware.com/
*
* This software is provided 'as-is', without any express
* or implied warranty. In no event will the authors be
* held liable for any damages arising from the use of
* this software.
*
* Permission is granted to anyone to use this software
* for any purpose, including commercial applications,
* and to alter it and redistribute it freely, subject to
* the following restrictions:
*
* 1. The origin of this software must not be
* misrepresented; you must not claim that you
* wrote the original software. If you use this
* software in a product, an acknowledgment in
* the product documentation would be appreciated
* but is not required.
*
* 2. Altered source versions must be plainly marked
* as such, and must not be misrepresented as
* being the original software.
*
* 3. This notice may not be removed or altered from
* any source distribution.
*/
#include "tinf.h"
#include <string.h> /* memcpy */
/* ------------------------------ *
* -- internal data structures -- *
* ------------------------------ */
typedef struct {
unsigned short table[16]; /* table of code length counts */
unsigned short trans[288]; /* code -> symbol translation table */
} TINF_TREE;
typedef struct {
unsigned short table[16];
unsigned short trans[32];
} TINF_SDTREE;
typedef struct {
TINF_TREE sltree;
TINF_TREE sdtree;
unsigned char length_bits[30];
unsigned short length_base[30];
unsigned char dist_bits[30];
unsigned short dist_base[30];
unsigned char clcidx[19];
} TINF_TABLES;
typedef struct {
const unsigned char *source;
unsigned int tag;
unsigned int bitcount;
unsigned char *dest;
unsigned int *destLen;
TINF_TREE ltree; /* dynamic length/symbol tree */
TINF_TREE dtree; /* dynamic distance tree */
} TINF_DATA;
/* static tables */
TINF_TABLES tbl = {
.sltree = {
.table = {0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0018,
0x0098, 0x0070, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000},
.trans = {0x0100, 0x0101, 0x0102, 0x0103, 0x0104, 0x0105, 0x0106, 0x0107,
0x0108, 0x0109, 0x010a, 0x010b, 0x010c, 0x010d, 0x010e, 0x010f,
0x0110, 0x0111, 0x0112, 0x0113, 0x0114, 0x0115, 0x0116, 0x0117,
0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007,
0x0008, 0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x000f,
0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x0017,
0x0018, 0x0019, 0x001a, 0x001b, 0x001c, 0x001d, 0x001e, 0x001f,
0x0020, 0x0021, 0x0022, 0x0023, 0x0024, 0x0025, 0x0026, 0x0027,
0x0028, 0x0029, 0x002a, 0x002b, 0x002c, 0x002d, 0x002e, 0x002f,
0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035, 0x0036, 0x0037,
0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x003e, 0x003f,
0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047,
0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x004f,
0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057,
0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x005f,
0x0060, 0x0061, 0x0062, 0x0063, 0x0064, 0x0065, 0x0066, 0x0067,
0x0068, 0x0069, 0x006a, 0x006b, 0x006c, 0x006d, 0x006e, 0x006f,
0x0070, 0x0071, 0x0072, 0x0073, 0x0074, 0x0075, 0x0076, 0x0077,
0x0078, 0x0079, 0x007a, 0x007b, 0x007c, 0x007d, 0x007e, 0x007f,
0x0080, 0x0081, 0x0082, 0x0083, 0x0084, 0x0085, 0x0086, 0x0087,
0x0088, 0x0089, 0x008a, 0x008b, 0x008c, 0x008d, 0x008e, 0x008f,
0x0118, 0x0119, 0x011a, 0x011b, 0x011c, 0x011d, 0x011e, 0x011f,
0x0090, 0x0091, 0x0092, 0x0093, 0x0094, 0x0095, 0x0096, 0x0097,
0x0098, 0x0099, 0x009a, 0x009b, 0x009c, 0x009d, 0x009e, 0x009f,
0x00a0, 0x00a1, 0x00a2, 0x00a3, 0x00a4, 0x00a5, 0x00a6, 0x00a7,
0x00a8, 0x00a9, 0x00aa, 0x00ab, 0x00ac, 0x00ad, 0x00ae, 0x00af,
0x00b0, 0x00b1, 0x00b2, 0x00b3, 0x00b4, 0x00b5, 0x00b6, 0x00b7,
0x00b8, 0x00b9, 0x00ba, 0x00bb, 0x00bc, 0x00bd, 0x00be, 0x00bf,
0x00c0, 0x00c1, 0x00c2, 0x00c3, 0x00c4, 0x00c5, 0x00c6, 0x00c7,
0x00c8, 0x00c9, 0x00ca, 0x00cb, 0x00cc, 0x00cd, 0x00ce, 0x00cf,
0x00d0, 0x00d1, 0x00d2, 0x00d3, 0x00d4, 0x00d5, 0x00d6, 0x00d7,
0x00d8, 0x00d9, 0x00da, 0x00db, 0x00dc, 0x00dd, 0x00de, 0x00df,
0x00e0, 0x00e1, 0x00e2, 0x00e3, 0x00e4, 0x00e5, 0x00e6, 0x00e7,
0x00e8, 0x00e9, 0x00ea, 0x00eb, 0x00ec, 0x00ed, 0x00ee, 0x00ef,
0x00f0, 0x00f1, 0x00f2, 0x00f3, 0x00f4, 0x00f5, 0x00f6, 0x00f7,
0x00f8, 0x00f9, 0x00fa, 0x00fb, 0x00fc, 0x00fd, 0x00fe, 0x00ff},
},
.sdtree = {
.table = {0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0020, 0x0000, 0x0000,
0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000},
.trans = {0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007,
0x0008, 0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x000f,
0x0010, 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x0017,
0x0018, 0x0019, 0x001a, 0x001b, 0x001c, 0x001d, 0x001e, 0x001f},
},
.length_bits = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x01, 0x01, 0x01, 0x01, 0x02, 0x02, 0x02, 0x02,
0x03, 0x03, 0x03, 0x03, 0x04, 0x04, 0x04, 0x04,
0x05, 0x05, 0x05, 0x05, 0x00, 0x06},
.length_base = {0x0003, 0x0004, 0x0005, 0x0006, 0x0007, 0x0008, 0x0009, 0x000a,
0x000b, 0x000d, 0x000f, 0x0011, 0x0013, 0x0017, 0x001b, 0x001f,
0x0023, 0x002b, 0x0033, 0x003b, 0x0043, 0x0053, 0x0063, 0x0073,
0x0083, 0x00a3, 0x00c3, 0x00e3, 0x0102, 0x0143},
.dist_bits = {0x00, 0x00, 0x00, 0x00, 0x01, 0x01, 0x02, 0x02,
0x03, 0x03, 0x04, 0x04, 0x05, 0x05, 0x06, 0x06,
0x07, 0x07, 0x08, 0x08, 0x09, 0x09, 0x0a, 0x0a,
0x0b, 0x0b, 0x0c, 0x0c, 0x0d, 0x0d},
.dist_base = {0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0007, 0x0009, 0x000d,
0x0011, 0x0019, 0x0021, 0x0031, 0x0041, 0x0061, 0x0081, 0x00c1,
0x0101, 0x0181, 0x0201, 0x0301, 0x0401, 0x0601, 0x0801, 0x0c01,
0x1001, 0x1801, 0x2001, 0x3001, 0x4001, 0x6001},
.clcidx = {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15},
};
/* ----------------------- *
* -- utility functions -- *
* ----------------------- */
/* given an array of code lengths, build a tree */
static void tinf_build_tree(TINF_TREE *t, const unsigned char *lengths, unsigned int num)
{
unsigned short offs[16];
unsigned int i, sum;
/* clear code length count table */
/* for (i = 0; i < 16; ++i) t->table[i] = 0; */
memset(t->table, 0, sizeof(short)*16);
/* scan symbol lengths, and sum code length counts */
for (i = 0; i < num; ++i) t->table[lengths[i]]++;
t->table[0] = 0;
/* compute offset table for distribution sort */
for (sum = 0, i = 0; i < 16; ++i)
{
offs[i] = sum;
sum += t->table[i];
}
/* create code->symbol translation table (symbols sorted by code) */
for (i = 0; i < num; ++i)
{
if (lengths[i]) t->trans[offs[lengths[i]]++] = i;
}
}
/* ---------------------- *
* -- decode functions -- *
* ---------------------- */
/* get one bit from source stream */
static int tinf_getbit(TINF_DATA *d)
{
unsigned int bit;
/* check if tag is empty */
if (!d->bitcount--)
{
/* load next tag */
d->tag = *d->source++;
d->bitcount = 7;
}
/* shift bit out of tag */
bit = d->tag & 0x01;
d->tag >>= 1;
return bit;
}
/* read a num bit value from a stream and add base */
static unsigned int tinf_read_bits(TINF_DATA *d, int num, int base)
{
unsigned int val = 0;
/* read num bits */
if (num)
{
unsigned int limit = 1 << (num);
unsigned int mask;
for (mask = 1; mask < limit; mask <<= 1)
if (tinf_getbit(d)) val += mask;
}
return val + base;
}
/* given a data stream and a tree, decode a symbol */
static int tinf_decode_symbol(TINF_DATA *d, TINF_TREE *t)
{
int sum = 0, cur = 0, len = 0;
/* get more bits while code value is above sum */
do {
cur = (cur << 1) + tinf_getbit(d);
++len;
sum += t->table[len];
cur -= t->table[len];
} while (cur >= 0);
return t->trans[sum + cur];
}
/* given a data stream, decode dynamic trees from it */
static void tinf_decode_trees(TINF_DATA *d, TINF_TREE *lt, TINF_TREE *dt, TINF_TABLES *tbl)
{
TINF_TREE code_tree;
unsigned char lengths[288+32];
unsigned int hlit, hdist, hclen;
unsigned int i, num, length;
/* get 5 bits HLIT (257-286) */
hlit = tinf_read_bits(d, 5, 257);
/* get 5 bits HDIST (1-32) */
hdist = tinf_read_bits(d, 5, 1);
/* get 4 bits HCLEN (4-19) */
hclen = tinf_read_bits(d, 4, 4);
/* for (i = 0; i < 19; ++i) lengths[i] = 0; */
memset(lengths, 0, sizeof(unsigned char)*19);
/* read code lengths for code length alphabet */
for (i = 0; i < hclen; ++i)
{
/* get 3 bits code length (0-7) */
unsigned int clen = tinf_read_bits(d, 3, 0);
lengths[tbl->clcidx[i]] = clen;
}
/* build code length tree */
tinf_build_tree(&code_tree, lengths, 19);
/* decode code lengths for the dynamic trees */
for (num = 0; num < hlit + hdist; )
{
int sym = tinf_decode_symbol(d, &code_tree);
switch (sym)
{
case 16:
/* copy previous code length 3-6 times (read 2 bits) */
{
unsigned char prev = lengths[num - 1];
for (length = tinf_read_bits(d, 2, 3); length; --length)
{
lengths[num++] = prev;
}
}
break;
case 17:
/* repeat code length 0 for 3-10 times (read 3 bits) */
for (length = tinf_read_bits(d, 3, 3); length; --length)
{
lengths[num++] = 0;
}
break;
case 18:
/* repeat code length 0 for 11-138 times (read 7 bits) */
for (length = tinf_read_bits(d, 7, 11); length; --length)
{
lengths[num++] = 0;
}
break;
default:
/* values 0-15 represent the actual code lengths */
lengths[num++] = sym;
break;
}
}
/* build dynamic trees */
tinf_build_tree(lt, lengths, hlit);
tinf_build_tree(dt, lengths + hlit, hdist);
}
/* ----------------------------- *
* -- block inflate functions -- *
* ----------------------------- */
/* given a stream and two trees, inflate a block of data */
static int tinf_inflate_block_data(TINF_DATA *d, TINF_TREE *lt, TINF_TREE *dt, TINF_TABLES *tbl)
{
/* remember current output position */
unsigned char *start = d->dest;
while (1)
{
int sym = tinf_decode_symbol(d, lt);
/* check for end of block */
if (sym == 256)
{
*d->destLen += d->dest - start;
return TINF_OK;
}
if (sym < 256)
{
*d->dest++ = sym;
} else {
int length, dist, offs;
int i;
sym -= 257;
/* possibly get more bits from length code */
length = tinf_read_bits(d, tbl->length_bits[sym], tbl->length_base[sym]);
dist = tinf_decode_symbol(d, dt);
/* possibly get more bits from distance code */
offs = tinf_read_bits(d, tbl->dist_bits[dist], tbl->dist_base[dist]);
/* copy match */
for (i = 0; i < length; ++i)
{
d->dest[i] = d->dest[i - offs];
}
d->dest += length;
}
}
}
/* inflate an uncompressed block of data */
static int tinf_inflate_uncompressed_block(TINF_DATA *d)
{
unsigned int length, invlength;
/* unsigned int i; */
/* get length */
length = d->source[1];
length = (length << 8) + d->source[0];
/* get one's complement of length */
invlength = d->source[3];
invlength = (invlength << 8) + d->source[2];
/* check length */
if (length != (~invlength & 0x0000ffff)) return TINF_DATA_ERROR;
d->source += 4;
/* copy block */
/* for (i = length; i; --i) *d->dest++ = *d->source++; */
memcpy(d->dest, d->source, sizeof(unsigned char)*length);
d->dest += sizeof(unsigned char)*length;
d->source += sizeof(unsigned char)*length;
/* make sure we start next block on a byte boundary */
d->bitcount = 0;
*d->destLen += length;
return TINF_OK;
}
/* inflate a block of data compressed with fixed huffman trees */
static int tinf_inflate_fixed_block(TINF_DATA *d, TINF_TABLES *tbl)
{
/* decode block using fixed trees */
return tinf_inflate_block_data(d, &tbl->sltree, &tbl->sdtree, tbl);
}
/* inflate a block of data compressed with dynamic huffman trees */
static int tinf_inflate_dynamic_block(TINF_DATA *d, TINF_TABLES *tbl)
{
/* decode trees from stream */
tinf_decode_trees(d, &d->ltree, &d->dtree, tbl);
/* decode block using decoded trees */
return tinf_inflate_block_data(d, &d->ltree, &d->dtree, tbl);
}
/* ---------------------- *
* -- public functions -- *
* ---------------------- */
/* inflate stream from source to dest */
int tinf_uncompress(void *dest, unsigned int *destLen,
const void *source, unsigned int sourceLen)
{
TINF_DATA d;
int bfinal;
d.source = (const unsigned char *)source;
d.bitcount = 0;
d.dest = (unsigned char *)dest;
d.destLen = destLen;
*destLen = 0;
do {
unsigned int btype;
int res;
/* read final block flag */
bfinal = tinf_getbit(&d);
/* read block type (2 bits) */
btype = tinf_read_bits(&d, 2, 0);
/* decompress block */
switch (btype)
{
case 0:
/* decompress uncompressed block */
res = tinf_inflate_uncompressed_block(&d);
break;
case 1:
/* decompress block with fixed huffman trees */
res = tinf_inflate_fixed_block(&d,&tbl);
break;
case 2:
/* decompress block with dynamic huffman trees */
res = tinf_inflate_dynamic_block(&d,&tbl);
break;
default:
return TINF_DATA_ERROR;
}
if (res != TINF_OK) return TINF_DATA_ERROR;
if (d.source > (unsigned char *)source + sourceLen)
return TINF_DATA_ERROR;
} while (!bfinal);
return TINF_OK;
}
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