/* 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 = 2*cur + tinf_getbit(d);
if (++len == TINF_ARRAY_SIZE(t->table)) {
return TINF_DATA_ERROR;
}
sum += t->table[len];
cur -= t->table[len];
} while (cur >= 0);
sum += cur;
if (sum < 0 || sum >= (int)(TINF_ARRAY_SIZE(t->trans))) {
return TINF_DATA_ERROR;
}
return t->trans[sum];
}
/* inflate next byte of compressed stream */
int uzlib_uncompress(TINF_DATA *d)
{
do {
int res;
/* start a new block */
if (d->btype == -1) {
next_blk:
/* read final block flag */
d->bfinal = tinf_getbit(d);
/* read block type (2 bits) */
d->btype = tinf_read_bits(d, 2, 0);
//printf("Started new block: type=%d final=%d\n", d->btype, d->bfinal);
if (d->btype == 1) {
/* build fixed huffman trees */
tinf_build_fixed_trees(&d->ltree, &d->dtree);
} else if (d->btype == 2) {
/* decode trees from stream */
res = tinf_decode_trees(d, &d->ltree, &d->dtree);
if (res != TINF_OK) {
return res;
}
}
}
/* process current block */
switch (d->btype)
{
case 0:
/* decompress uncompressed block */
res = tinf_inflate_uncompressed_block(d);
break;
case 1:
case 2:
/* decompress block with fixed/dynamic huffman trees */
/* trees were decoded previously, so it's the same routine for both */
res = tinf_inflate_block_data(d, &d->ltree, &d->dtree);
break;
default:
return TINF_DATA_ERROR;
}
if (res == TINF_DONE && !d->bfinal) {
/* the block has ended (without producing more data), but we
can't return without data, so start procesing next block */
goto next_blk;
}
if (res != TINF_OK) {
return res;
}
} while (--d->destSize);
return TINF_OK;
}
/* 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;
}
/* inflate stream from source to dest */
int tinf_uncompress(void *dest, unsigned int *destLen,
const void *source, unsigned int sourceLen,
const unsigned int swapped_btype[3])
{
TINF_DATA d;
int bfinal;
/* initialise data */
d.source = (const unsigned char *)source;
d.bitcount = 0;
d.dest = (unsigned char *)dest;
d.destLen = destLen;
d.sourceLen = 0;
d.sourceSize = sourceLen;
d.destSize = *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 */
if(btype == swapped_btype[0]) {
/* decompress uncompressed block */
res = tinf_inflate_uncompressed_block(&d);
} else if(btype == swapped_btype[1]) {
/* decompress block with fixed huffman trees */
res = tinf_inflate_fixed_block(&d);
} else if(btype == swapped_btype[2]) {
/* decompress block with dynamic huffman trees */
res = tinf_inflate_dynamic_block(&d);
} else {
return TINF_DATA_ERROR;
}
if (res != TINF_OK) return TINF_DATA_ERROR;
} while (!bfinal);
return TINF_OK;
}
/* 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;
/* initialise data */
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 block type (2 bits) */
btype = tinf_read_bits(&d, 3, 0);
/* read final block flag */
bfinal = tinf_getbit(&d);
/* decompress block */
switch (btype)
{
case 7:
/* decompress uncompressed block */
res = tinf_inflate_uncompressed_block(&d);
break;
case 5:
/* decompress block with fixed huffman trees */
res = tinf_inflate_fixed_block(&d);
break;
case 6:
/* decompress block with dynamic huffman trees */
res = tinf_inflate_dynamic_block(&d);
break;
default:
return -1;
}
if (res != TINF_OK) return -1;
} while (!bfinal);
return ((char*)d.source - (char *)source);
}
/* 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 *= 2)
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 = 2*cur + tinf_getbit(d);
++len;
sum += t->table[len];
cur -= t->table[len];
} while (cur >= 0);
return t->trans[sum + cur];
}
