/*************************************************************************** * __________ __ ___. * 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 /* 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; }