lzfu.c
Go to the documentation of this file.00001
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00012 #include "define.h"
00013 #include "lzfu.h"
00014
00015
00016 #define LZFU_COMPRESSED 0x75465a4c
00017 #define LZFU_UNCOMPRESSED 0x414c454d
00018
00019
00020 #define LZFU_INITDICT "{\\rtf1\\ansi\\mac\\deff0\\deftab720{\\fonttbl;}" \
00021 "{\\f0\\fnil \\froman \\fswiss \\fmodern \\fscrip" \
00022 "t \\fdecor MS Sans SerifSymbolArialTimes Ne" \
00023 "w RomanCourier{\\colortbl\\red0\\green0\\blue0" \
00024 "\r\n\\par \\pard\\plain\\f0\\fs20\\b\\i\\u\\tab" \
00025 "\\tx"
00026
00027 #define LZFU_INITLENGTH 207
00028
00029
00030 typedef struct _lzfuheader {
00031 uint32_t cbSize;
00032 uint32_t cbRawSize;
00033 uint32_t dwMagic;
00034 uint32_t dwCRC;
00035 } lzfuheader;
00036
00037
00038 char* pst_lzfu_decompress(char* rtfcomp, uint32_t compsize, size_t *size) {
00039 unsigned char dict[4096];
00040 unsigned int dict_length = 0;
00041 lzfuheader lzfuhdr;
00042 unsigned char flags;
00043 unsigned char flag_mask;
00044 uint32_t i;
00045 char *out_buf;
00046 uint32_t out_ptr = 0;
00047 uint32_t out_size;
00048 uint32_t in_ptr;
00049 uint32_t in_size;
00050
00051 memcpy(dict, LZFU_INITDICT, LZFU_INITLENGTH);
00052 memset(dict + LZFU_INITLENGTH, 0, sizeof(dict) - LZFU_INITLENGTH);
00053 dict_length = LZFU_INITLENGTH;
00054
00055 memcpy(&lzfuhdr, rtfcomp, sizeof(lzfuhdr));
00056 LE32_CPU(lzfuhdr.cbSize);
00057 LE32_CPU(lzfuhdr.cbRawSize);
00058 LE32_CPU(lzfuhdr.dwMagic);
00059 LE32_CPU(lzfuhdr.dwCRC);
00060
00061
00062
00063
00064
00065 out_size = lzfuhdr.cbRawSize;
00066 out_buf = (char*)pst_malloc(out_size);
00067 in_ptr = sizeof(lzfuhdr);
00068
00069
00070 in_size = (lzfuhdr.cbSize + 4 < compsize) ? lzfuhdr.cbSize + 4 : compsize;
00071 while (in_ptr < in_size) {
00072 flags = (unsigned char)(rtfcomp[in_ptr++]);
00073 flag_mask = 1;
00074 while (flag_mask) {
00075 if (flag_mask & flags) {
00076
00077 if (in_ptr+1 < in_size) {
00078
00079 uint16_t blkhdr, offset, length;
00080 memcpy(&blkhdr, rtfcomp+in_ptr, 2);
00081 LE16_CPU(blkhdr);
00082 in_ptr += 2;
00083
00084 blkhdr = (((blkhdr&0xFF00)>>8)+
00085 ((blkhdr&0x00FF)<<8));
00086
00087 offset = (blkhdr&0xFFF0)>>4;
00088
00089 length = (blkhdr&0x000F)+2;
00090
00091 for (i=0; i < length; i++) {
00092 unsigned char c1;
00093 c1 = dict[(offset+i)%4096];
00094 dict[dict_length] = c1;
00095 dict_length = (dict_length+1) % 4096;
00096 if (out_ptr < out_size) out_buf[out_ptr++] = (char)c1;
00097
00098
00099 dict[dict_length] = 0;
00100 }
00101 }
00102 } else {
00103
00104 if (in_ptr < in_size) {
00105
00106 char c1 = rtfcomp[in_ptr++];
00107 dict[dict_length] = c1;
00108 dict_length = (dict_length+1)%4096;
00109 if (out_ptr < out_size) out_buf[out_ptr++] = (char)c1;
00110
00111
00112 dict[dict_length] = 0;
00113 }
00114 }
00115 flag_mask <<= 1;
00116 }
00117 }
00118 *size = out_ptr;
00119 return out_buf;
00120 }