[unpaker2] RLEW decompression.

This commit is contained in:
lzwdgc 2023-01-10 17:31:26 +03:00
parent b3c0b0489e
commit 9c92592398

View file

@ -37,8 +37,6 @@
using namespace std;
constexpr auto supported_block_size = 32768;
#pragma pack(push, 1)
struct pak {
uint32_t magic;
@ -85,17 +83,46 @@ struct stream {
}
};
void decode_rle(const short *input, const int size, short *&output) {
if (size < 2)
return;
// input ptr, also rle_indicator
const auto rle_indicator = input++;
while (1) {
auto c = *input++;
if ((c & 0xFF00) != (*rle_indicator << 8))
*output++ = c;
else {
uint32_t count = (uint8_t)c;
if (count == (*rle_indicator << 8) + 255)
*output++ = c; // insert indicator byte itself
else {
count += 3;
for (int i = 0; i < count / 2; i++) {
*output++ = *input;
*output++ = *input;
}
for (int i = 0; i < ((count / 2) & 1); i++) {
*output++ = *input;
}
}
}
if (input >= rle_indicator + size)
return;
}
}
void unpack_file(path fn) {
primitives::templates2::mmap_file<uint8_t> f{fn};
stream s{f};
pak p = s;
if (p.block_size != supported_block_size) {
throw std::runtime_error{"block size mismatch"};
}
auto descs = s.span<file_description>(p.n_files);
auto segments = s.span<segment>(p.n_blocks);
std::vector<uint8_t> bbb;
bbb.resize((segments.size() + 1) * supported_block_size);
bbb.resize((segments.size() + 1) * p.block_size * 4);
auto pp = bbb.data();
for (auto &&seg : segments) {
s.p = f.p + seg.offset;
@ -116,19 +143,51 @@ void unpack_file(path fn) {
break;
}
case segment::decode_algorithm::rlew: {
/*short *pps = (short*)pp;
decode_rle((short*)s.p, len, pps);
pp = (uint8_t*)pps;
break;*/
auto base = s.p;
uint16_t flag = s;
uint32_t outlen = 0;
while (s.p < base + len) {
uint8_t w = s;
if (w == 0xfe && (*(uint8_t*)s.p) == flag) {
uint8_t w1 = s;
auto cntr = 0x20e;
uint8_t w2 = s;
while (cntr--) {
uint16_t w = s;
if ((w & 0xFF00) == (flag << 8)) {
uint16_t count = (uint8_t)w;
if (count == 0xff) {
uint16_t w2 = s;
*(decltype(w2) *)pp = w2;
pp += sizeof(w2);
continue;
}
if (count == (flag << 8) + 255) {
throw std::runtime_error{"untested branch"};
*(decltype(w) *)pp = w;
pp += sizeof(w);
continue;
}
uint16_t w2 = s;
count += 3;
while (count--) {
*(decltype(w2)*)pp = w2;
pp += sizeof(w2);
}
/*
*
for (int i = 0; i < count / 2; i++) {
*(decltype(w) *)pp = w2;
pp += sizeof(w2);
*(decltype(w) *)pp = w2;
pp += sizeof(w2);
}
for (int i = 0; i < ((count / 2) & 1); i++) {
*(decltype(w) *)pp = w2;
pp += sizeof(w2);
}*/
} else {
*(decltype(w)*)pp = w;
pp += sizeof(w);
@ -143,9 +202,9 @@ void unpack_file(path fn) {
strm.next_in = s.p;
strm.avail_in = len;
strm.next_out = pp;
strm.avail_out = 1'000'000;
strm.avail_out = p.block_size;
auto r = lzma_auto_decoder(&strm, 1'000'000'000, flags);
auto r = lzma_lzip_decoder(&strm, 10'000'000, flags);
if (r != LZMA_OK) {
throw std::runtime_error{"lzma error"};
}