static DWORD rng_decompress(BYTE *out, BYTE *in, DWORD in_len)
{
qsmodel qsm;
rangecoder rc;
int ch, syfreq, ltfreq;
DWORD act_uncomprlen = 0;
/* make an alphabet with 257 symbols, use 256 as end-of-file */
initqsmodel(&qsm, 257, 12, 2000, NULL, 0);
/* unknown crypt_index[0], seems to be always 0x00 */
start_decoding(&rc, in + 1);
while (1) {
ltfreq = decode_culshift(&rc, 12);
ch = qsgetsym(&qsm, ltfreq);
if (ch == 256) /* check for end-of-file */
break;
out[act_uncomprlen++] = ch;
qsgetfreq(&qsm, ch, &syfreq, <freq);
decode_update(&rc, syfreq, ltfreq, 1 << 12);
qsupdate(&qsm, ch);
}
qsgetfreq(&qsm, 256, &syfreq, <freq);
decode_update(&rc, syfreq, ltfreq, 1 << 12);
done_decoding(&rc);
deleteqsmodel(&qsm);
return act_uncomprlen;
}
int unpack(FILE* out,FILE* in)
{
freq cf;
rangecoder rc;
struct buffer buffer;
struct ari_model model;
size_t processed=0;
buffer.offset = 0;
buffer.len_power = 1+BLOCKSIZE_POWER;
buffer.len = 1<<buffer.len_power;
buffer.len_mask = buffer.len - 1;
buffer.data = malloc(buffer.len);
rc.in = in;
model_setup(&model);
if(!buffer.data)
return -2;
if (start_decoding(&rc) != 0) {
return -1;
}
while ( (cf = decode_culfreq(&rc,2)) ) {
freq i, blocksize;
decode_update(&rc,1,1,2);
blocksize = decode_short(&rc) | ((size_t)decode_short(&rc)) <<16;
for (i=0; i<blocksize; i++) {
freq symbol;
cf = decode_culfreq(&rc,model.counts[SYMBOLS]);
symbol = model_get_symbol(&model, cf);
decode_update(&rc, model.counts[symbol+1]-model.counts[symbol],model.counts[symbol],model.counts[SYMBOLS]);
model_update_freq(&model,symbol);
/*fprintf(stderr,"Decoding:%d(%c),%ld,%ld\n",symbol,symbol,counts[symbol+1]-counts[symbol],counts[symbol]);*/
if(symbol > 0xff) {
const uint8_t extra_bits = code_to_length[symbol-0x100].extra_bits;
const size_t extra_data = decode_culshift(&rc, extra_bits);
const size_t length = code_to_length[symbol-0x100].start + extra_data;
size_t distance;
size_t distance_hi;
decode_update_shift(&rc, 1, extra_data, extra_bits);
distance = decode_culshift(&rc,8);
decode_update_shift(&rc, 1, distance, 8);
distance_hi = decode_culshift(&rc,8);
decode_update_shift(&rc, 1, distance_hi, 8);
distance |= distance_hi<<8;
/* fprintf(stderr,"Retrieved length,distance:%ld,%ld\n",length,distance);*/
buffer.offset = copy_back_bytes(&buffer,buffer.offset,distance,length);
}
else {
buffer.data[buffer.offset++] = symbol;
if(buffer.offset >= buffer.len) {
buffer.offset = 0;
fwrite(buffer.data,1,buffer.len,out);
}
}
}
processed += blocksize;
if(processed > 1<<19) {
done_decoding(&rc);
start_decoding(&rc);
processed=0;
}
/*fprintf(stderr,"%ld;;%d\n",blocksize,model.counts[SYMBOLS]);*/
}
fwrite(buffer.data,1,buffer.offset,out);
done_decoding(&rc);
model_done(&model);
free(buffer.data);
fclose(out);
return 0;
}
