mirror of
https://github.com/DarkStore-3DS/Project_CTR.git
synced 2026-07-03 00:39:14 +00:00
jakcron
108 lines
2.2 KiB
C
108 lines
2.2 KiB
C
#include <stdio.h>
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#include <string.h>
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#include <stdlib.h>
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#include "lzss.h"
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uint32_t getle32(const uint8_t* p)
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{
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return (p[0]<<0) | (p[1]<<8) | (p[2]<<16) | (p[3]<<24);
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}
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uint32_t lzss_get_decompressed_size(uint8_t* compressed, uint32_t compressedsize)
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{
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uint8_t* footer = compressed + compressedsize - 8;
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//uint32_t buffertopandbottom = getle32(footer+0);
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uint32_t originalbottom = getle32(footer+4);
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return originalbottom + compressedsize;
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}
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int lzss_decompress(uint8_t* compressed, uint32_t compressedsize, uint8_t* decompressed, uint32_t decompressedsize)
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{
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uint8_t* footer = compressed + compressedsize - 8;
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uint32_t buffertopandbottom = getle32(footer+0);
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//uint32_t originalbottom = getle32(footer+4);
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uint32_t i, j;
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uint32_t out = decompressedsize;
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uint32_t index = compressedsize - ((buffertopandbottom>>24)&0xFF);
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uint32_t segmentoffset;
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uint32_t segmentsize;
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uint8_t control;
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uint32_t stopindex = compressedsize - (buffertopandbottom&0xFFFFFF);
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memset(decompressed, 0, decompressedsize);
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memcpy(decompressed, compressed, compressedsize);
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while(index > stopindex)
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{
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control = compressed[--index];
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for(i=0; i<8; i++)
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{
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if (index <= stopindex)
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break;
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if (index <= 0)
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break;
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if (out <= 0)
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break;
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if (control & 0x80)
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{
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if (index < 2)
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{
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fprintf(stderr, "Error, compression out of bounds\n");
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goto clean;
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}
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index -= 2;
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segmentoffset = compressed[index] | (compressed[index+1]<<8);
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segmentsize = ((segmentoffset >> 12)&15)+3;
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segmentoffset &= 0x0FFF;
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segmentoffset += 2;
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if (out < segmentsize)
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{
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fprintf(stderr, "Error, compression out of bounds\n");
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goto clean;
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}
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for(j=0; j<segmentsize; j++)
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{
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uint8_t data;
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if (out+segmentoffset >= decompressedsize)
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{
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fprintf(stderr, "Error, compression out of bounds\n");
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goto clean;
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}
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data = decompressed[out+segmentoffset];
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decompressed[--out] = data;
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}
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}
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else
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{
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if (out < 1)
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{
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fprintf(stderr, "Error, compression out of bounds\n");
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goto clean;
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}
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decompressed[--out] = compressed[--index];
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}
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control <<= 1;
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}
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}
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return 1;
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clean:
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return 0;
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}
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