Libav 0.7.1
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00001 /* 00002 * LZO 1x decompression 00003 * Copyright (c) 2006 Reimar Doeffinger 00004 * 00005 * This file is part of Libav. 00006 * 00007 * Libav is free software; you can redistribute it and/or 00008 * modify it under the terms of the GNU Lesser General Public 00009 * License as published by the Free Software Foundation; either 00010 * version 2.1 of the License, or (at your option) any later version. 00011 * 00012 * Libav is distributed in the hope that it will be useful, 00013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00015 * Lesser General Public License for more details. 00016 * 00017 * You should have received a copy of the GNU Lesser General Public 00018 * License along with Libav; if not, write to the Free Software 00019 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00020 */ 00021 00022 #include "avutil.h" 00023 #include "common.h" 00025 #undef memcpy 00026 #include <string.h> 00027 #include "lzo.h" 00028 00030 #define OUTBUF_PADDED 1 00031 00032 #define INBUF_PADDED 1 00033 typedef struct LZOContext { 00034 const uint8_t *in, *in_end; 00035 uint8_t *out_start, *out, *out_end; 00036 int error; 00037 } LZOContext; 00038 00043 static inline int get_byte(LZOContext *c) { 00044 if (c->in < c->in_end) 00045 return *c->in++; 00046 c->error |= AV_LZO_INPUT_DEPLETED; 00047 return 1; 00048 } 00049 00050 #ifdef INBUF_PADDED 00051 #define GETB(c) (*(c).in++) 00052 #else 00053 #define GETB(c) get_byte(&(c)) 00054 #endif 00055 00062 static inline int get_len(LZOContext *c, int x, int mask) { 00063 int cnt = x & mask; 00064 if (!cnt) { 00065 while (!(x = get_byte(c))) cnt += 255; 00066 cnt += mask + x; 00067 } 00068 return cnt; 00069 } 00070 00071 //#define UNALIGNED_LOADSTORE 00072 #define BUILTIN_MEMCPY 00073 #ifdef UNALIGNED_LOADSTORE 00074 #define COPY2(d, s) *(uint16_t *)(d) = *(uint16_t *)(s); 00075 #define COPY4(d, s) *(uint32_t *)(d) = *(uint32_t *)(s); 00076 #elif defined(BUILTIN_MEMCPY) 00077 #define COPY2(d, s) memcpy(d, s, 2); 00078 #define COPY4(d, s) memcpy(d, s, 4); 00079 #else 00080 #define COPY2(d, s) (d)[0] = (s)[0]; (d)[1] = (s)[1]; 00081 #define COPY4(d, s) (d)[0] = (s)[0]; (d)[1] = (s)[1]; (d)[2] = (s)[2]; (d)[3] = (s)[3]; 00082 #endif 00083 00088 static inline void copy(LZOContext *c, int cnt) { 00089 register const uint8_t *src = c->in; 00090 register uint8_t *dst = c->out; 00091 if (cnt > c->in_end - src) { 00092 cnt = FFMAX(c->in_end - src, 0); 00093 c->error |= AV_LZO_INPUT_DEPLETED; 00094 } 00095 if (cnt > c->out_end - dst) { 00096 cnt = FFMAX(c->out_end - dst, 0); 00097 c->error |= AV_LZO_OUTPUT_FULL; 00098 } 00099 #if defined(INBUF_PADDED) && defined(OUTBUF_PADDED) 00100 COPY4(dst, src); 00101 src += 4; 00102 dst += 4; 00103 cnt -= 4; 00104 if (cnt > 0) 00105 #endif 00106 memcpy(dst, src, cnt); 00107 c->in = src + cnt; 00108 c->out = dst + cnt; 00109 } 00110 00111 static inline void memcpy_backptr(uint8_t *dst, int back, int cnt); 00112 00121 static inline void copy_backptr(LZOContext *c, int back, int cnt) { 00122 register const uint8_t *src = &c->out[-back]; 00123 register uint8_t *dst = c->out; 00124 if (src < c->out_start || src > dst) { 00125 c->error |= AV_LZO_INVALID_BACKPTR; 00126 return; 00127 } 00128 if (cnt > c->out_end - dst) { 00129 cnt = FFMAX(c->out_end - dst, 0); 00130 c->error |= AV_LZO_OUTPUT_FULL; 00131 } 00132 memcpy_backptr(dst, back, cnt); 00133 c->out = dst + cnt; 00134 } 00135 00136 static inline void memcpy_backptr(uint8_t *dst, int back, int cnt) { 00137 const uint8_t *src = &dst[-back]; 00138 if (back == 1) { 00139 memset(dst, *src, cnt); 00140 } else { 00141 #ifdef OUTBUF_PADDED 00142 COPY2(dst, src); 00143 COPY2(dst + 2, src + 2); 00144 src += 4; 00145 dst += 4; 00146 cnt -= 4; 00147 if (cnt > 0) { 00148 COPY2(dst, src); 00149 COPY2(dst + 2, src + 2); 00150 COPY2(dst + 4, src + 4); 00151 COPY2(dst + 6, src + 6); 00152 src += 8; 00153 dst += 8; 00154 cnt -= 8; 00155 } 00156 #endif 00157 if (cnt > 0) { 00158 int blocklen = back; 00159 while (cnt > blocklen) { 00160 memcpy(dst, src, blocklen); 00161 dst += blocklen; 00162 cnt -= blocklen; 00163 blocklen <<= 1; 00164 } 00165 memcpy(dst, src, cnt); 00166 } 00167 } 00168 } 00169 00170 void av_memcpy_backptr(uint8_t *dst, int back, int cnt) { 00171 memcpy_backptr(dst, back, cnt); 00172 } 00173 00174 int av_lzo1x_decode(void *out, int *outlen, const void *in, int *inlen) { 00175 int state= 0; 00176 int x; 00177 LZOContext c; 00178 if (!*outlen || !*inlen) { 00179 int res = 0; 00180 if (!*outlen) 00181 res |= AV_LZO_OUTPUT_FULL; 00182 if (!*inlen) 00183 res |= AV_LZO_INPUT_DEPLETED; 00184 return res; 00185 } 00186 c.in = in; 00187 c.in_end = (const uint8_t *)in + *inlen; 00188 c.out = c.out_start = out; 00189 c.out_end = (uint8_t *)out + * outlen; 00190 c.error = 0; 00191 x = GETB(c); 00192 if (x > 17) { 00193 copy(&c, x - 17); 00194 x = GETB(c); 00195 if (x < 16) c.error |= AV_LZO_ERROR; 00196 } 00197 if (c.in > c.in_end) 00198 c.error |= AV_LZO_INPUT_DEPLETED; 00199 while (!c.error) { 00200 int cnt, back; 00201 if (x > 15) { 00202 if (x > 63) { 00203 cnt = (x >> 5) - 1; 00204 back = (GETB(c) << 3) + ((x >> 2) & 7) + 1; 00205 } else if (x > 31) { 00206 cnt = get_len(&c, x, 31); 00207 x = GETB(c); 00208 back = (GETB(c) << 6) + (x >> 2) + 1; 00209 } else { 00210 cnt = get_len(&c, x, 7); 00211 back = (1 << 14) + ((x & 8) << 11); 00212 x = GETB(c); 00213 back += (GETB(c) << 6) + (x >> 2); 00214 if (back == (1 << 14)) { 00215 if (cnt != 1) 00216 c.error |= AV_LZO_ERROR; 00217 break; 00218 } 00219 } 00220 } else if(!state){ 00221 cnt = get_len(&c, x, 15); 00222 copy(&c, cnt + 3); 00223 x = GETB(c); 00224 if (x > 15) 00225 continue; 00226 cnt = 1; 00227 back = (1 << 11) + (GETB(c) << 2) + (x >> 2) + 1; 00228 } else { 00229 cnt = 0; 00230 back = (GETB(c) << 2) + (x >> 2) + 1; 00231 } 00232 copy_backptr(&c, back, cnt + 2); 00233 state= 00234 cnt = x & 3; 00235 copy(&c, cnt); 00236 x = GETB(c); 00237 } 00238 *inlen = c.in_end - c.in; 00239 if (c.in > c.in_end) 00240 *inlen = 0; 00241 *outlen = c.out_end - c.out; 00242 return c.error; 00243 } 00244 00245 #ifdef TEST 00246 #include <stdio.h> 00247 #include <lzo/lzo1x.h> 00248 #include "log.h" 00249 #define MAXSZ (10*1024*1024) 00250 00251 /* Define one of these to 1 if you wish to benchmark liblzo 00252 * instead of our native implementation. */ 00253 #define BENCHMARK_LIBLZO_SAFE 0 00254 #define BENCHMARK_LIBLZO_UNSAFE 0 00255 00256 int main(int argc, char *argv[]) { 00257 FILE *in = fopen(argv[1], "rb"); 00258 uint8_t *orig = av_malloc(MAXSZ + 16); 00259 uint8_t *comp = av_malloc(2*MAXSZ + 16); 00260 uint8_t *decomp = av_malloc(MAXSZ + 16); 00261 size_t s = fread(orig, 1, MAXSZ, in); 00262 lzo_uint clen = 0; 00263 long tmp[LZO1X_MEM_COMPRESS]; 00264 int inlen, outlen; 00265 int i; 00266 av_log_set_level(AV_LOG_DEBUG); 00267 lzo1x_999_compress(orig, s, comp, &clen, tmp); 00268 for (i = 0; i < 300; i++) { 00269 START_TIMER 00270 inlen = clen; outlen = MAXSZ; 00271 #if BENCHMARK_LIBLZO_SAFE 00272 if (lzo1x_decompress_safe(comp, inlen, decomp, &outlen, NULL)) 00273 #elif BENCHMARK_LIBLZO_UNSAFE 00274 if (lzo1x_decompress(comp, inlen, decomp, &outlen, NULL)) 00275 #else 00276 if (av_lzo1x_decode(decomp, &outlen, comp, &inlen)) 00277 #endif 00278 av_log(NULL, AV_LOG_ERROR, "decompression error\n"); 00279 STOP_TIMER("lzod") 00280 } 00281 if (memcmp(orig, decomp, s)) 00282 av_log(NULL, AV_LOG_ERROR, "decompression incorrect\n"); 00283 else 00284 av_log(NULL, AV_LOG_ERROR, "decompression OK\n"); 00285 return 0; 00286 } 00287 #endif