usbloadergx/source/utils/lz77.c

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/*******************************************************************************
* lz77.c
*
* Copyright (c) 2009 The Lemon Man
* Copyright (c) 2009 Nicksasa
* Copyright (c) 2009 WiiPower
*
* Distributed under the terms of the GNU General Public License (v2)
* See http://www.gnu.org/licenses/gpl-2.0.txt for more info.
*
* Description:
* -----------
*
******************************************************************************/
#include <gccore.h>
#include <malloc.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include "lz77.h"
#define ALIGN32(x) (((x) + 31) & ~31)
u32 packBytes(int a, int b, int c, int d)
{
return (d << 24) | (c << 16) | (b << 8) | (a);
}
s32 __decompressLZ77_11(u8 *in, u32 inputLen, u8 **output, u32 *outputLen)
{
int x, y;
u8 *out = NULL;
u32 compressedPos = 0x4;
u32 decompressedPos = 0x0;
u32 decompressedSize = 0;
decompressedSize = packBytes(in[0], in[1], in[2], in[3]) >> 8;
if (!decompressedSize)
{
decompressedSize = packBytes(in[4], in[5], in[6], in[7]);
compressedPos += 0x4;
}
printf("Decompressed size : %i\n", decompressedSize);
out = memalign(32, ALIGN32(decompressedSize));
if (out == NULL)
{
printf("Out of memory\n");
return -1;
}
while (compressedPos < inputLen && decompressedPos < decompressedSize)
{
u8 byteFlag = in[compressedPos];
compressedPos++;
for (x = 7; x >= 0; x--)
{
if ((byteFlag & (1 << x)) > 0)
{
u8 first = in[compressedPos];
u8 second = in[compressedPos + 1];
u32 pos, copyLen;
if (first < 0x20)
{
u8 third = in[compressedPos + 2];
if (first >= 0x10)
{
u32 fourth = in[compressedPos + 3];
pos = (u32)(((third & 0xF) << 8) | fourth) + 1;
copyLen = (u32)((second << 4) | ((first & 0xF) << 12) | (third >> 4)) + 273;
compressedPos += 4;
} else
{
pos = (u32)(((second & 0xF) << 8) | third) + 1;
copyLen = (u32)(((first & 0xF) << 4) | (second >> 4)) + 17;
compressedPos += 3;
}
} else
{
pos = (u32)(((first & 0xF) << 8) | second) + 1;
copyLen = (u32)(first >> 4) + 1;
compressedPos += 2;
}
for (y = 0; y < (int) copyLen; y++)
{
out[decompressedPos + y] = out[decompressedPos - pos + y];
}
decompressedPos += copyLen;
} else
{
out[decompressedPos] = in[compressedPos];
decompressedPos++;
compressedPos++;
}
if (compressedPos >= inputLen || decompressedPos >= decompressedSize)
break;
}
}
*output = out;
*outputLen = decompressedSize;
return 0;
}
s32 __decompressLZ77_10(u8 *in, u32 inputLen, u8 **output, u32 *outputLen)
{
int x, y;
u8 *out = NULL;
u32 compressedPos = 0;
u32 decompressedSize = 0x4;
u32 decompressedPos = 0;
decompressedSize = packBytes(in[0], in[1], in[2], in[3]) >> 8;
//int compressionType = (packBytes(in[0], in[1], in[2], in[3]) >> 4) & 0xF;
printf("Decompressed size : %i\n", decompressedSize);
out = memalign(32, ALIGN32(decompressedSize));
if (out == NULL)
{
printf("Out of memory\n");
return -1;
}
compressedPos += 0x4;
while (decompressedPos < decompressedSize)
{
u8 flag = *(u8*)(in + compressedPos);
compressedPos += 1;
for (x = 0; x < 8; x++)
{
if (flag & 0x80)
{
u8 first = in[compressedPos];
u8 second = in[compressedPos + 1];
u16 pos = (u16)((((first << 8) + second) & 0xFFF) + 1);
u8 copyLen = (u8)(3 + ((first >> 4) & 0xF));
for (y = 0; y < copyLen; y++)
{
out[decompressedPos + y] = out[decompressedPos - pos + (y % pos)];
}
compressedPos += 2;
decompressedPos += copyLen;
} else
{
out[decompressedPos] = in[compressedPos];
compressedPos += 1;
decompressedPos += 1;
}
flag <<= 1;
if (decompressedPos >= decompressedSize)
break;
}
}
*output = out;
*outputLen = decompressedSize;
return 0;
}
int isLZ77compressed(u8 *buffer)
{
if ((buffer[0] == LZ77_0x10_FLAG) || (buffer[0] == LZ77_0x11_FLAG))
{
return 1;
}
return 0;
}
int decompressLZ77content(u8 *buffer, u32 length, u8 **output, u32 *outputLen)
{
int ret;
switch (buffer[0])
{
case LZ77_0x10_FLAG:
ret = __decompressLZ77_10(buffer, length, output, outputLen);
break;
case LZ77_0x11_FLAG:
ret = __decompressLZ77_11(buffer, length, output, outputLen);
break;
default:
ret = -1;
break;
}
return ret;
}