3 * Copyright (c) 2006 Reimar Doeffinger
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
26 #include "intreadwrite.h"
29 /// Define if we may write up to 12 bytes beyond the output buffer.
30 #define OUTBUF_PADDED 1
31 /// Define if we may read up to 8 bytes beyond the input buffer.
32 #define INBUF_PADDED 1
34 typedef struct LZOContext {
35 const uint8_t *in, *in_end;
36 uint8_t *out_start, *out, *out_end;
41 * @brief Reads one byte from the input buffer, avoiding an overrun.
44 static inline int get_byte(LZOContext *c)
46 if (c->in < c->in_end)
48 c->error |= AV_LZO_INPUT_DEPLETED;
53 #define GETB(c) (*(c).in++)
55 #define GETB(c) get_byte(&(c))
59 * @brief Decodes a length value in the coding used by lzo.
60 * @param x previous byte value
61 * @param mask bits used from x
62 * @return decoded length value
64 static inline int get_len(LZOContext *c, int x, int mask)
68 while (!(x = get_byte(c)))
76 * @brief Copies bytes from input to output buffer with checking.
77 * @param cnt number of bytes to copy, must be >= 0
79 static inline void copy(LZOContext *c, int cnt)
81 register const uint8_t *src = c->in;
82 register uint8_t *dst = c->out;
83 if (cnt > c->in_end - src) {
84 cnt = FFMAX(c->in_end - src, 0);
85 c->error |= AV_LZO_INPUT_DEPLETED;
87 if (cnt > c->out_end - dst) {
88 cnt = FFMAX(c->out_end - dst, 0);
89 c->error |= AV_LZO_OUTPUT_FULL;
91 #if defined(INBUF_PADDED) && defined(OUTBUF_PADDED)
98 memcpy(dst, src, cnt);
104 * @brief Copies previously decoded bytes to current position.
105 * @param back how many bytes back we start, must be > 0
106 * @param cnt number of bytes to copy, must be >= 0
108 * cnt > back is valid, this will copy the bytes we just copied,
109 * thus creating a repeating pattern with a period length of back.
111 static inline void copy_backptr(LZOContext *c, int back, int cnt)
113 register const uint8_t *src = &c->out[-back];
114 register uint8_t *dst = c->out;
115 if (src < c->out_start || src > dst) {
116 c->error |= AV_LZO_INVALID_BACKPTR;
119 if (cnt > c->out_end - dst) {
120 cnt = FFMAX(c->out_end - dst, 0);
121 c->error |= AV_LZO_OUTPUT_FULL;
123 av_memcpy_backptr(dst, back, cnt);
127 int av_lzo1x_decode(void *out, int *outlen, const void *in, int *inlen)
132 if (*outlen <= 0 || *inlen <= 0) {
135 res |= AV_LZO_OUTPUT_FULL;
137 res |= AV_LZO_INPUT_DEPLETED;
141 c.in_end = (const uint8_t *)in + *inlen;
142 c.out = c.out_start = out;
143 c.out_end = (uint8_t *)out + *outlen;
150 c.error |= AV_LZO_ERROR;
153 c.error |= AV_LZO_INPUT_DEPLETED;
159 back = (GETB(c) << 3) + ((x >> 2) & 7) + 1;
161 cnt = get_len(&c, x, 31);
163 back = (GETB(c) << 6) + (x >> 2) + 1;
165 cnt = get_len(&c, x, 7);
166 back = (1 << 14) + ((x & 8) << 11);
168 back += (GETB(c) << 6) + (x >> 2);
169 if (back == (1 << 14)) {
171 c.error |= AV_LZO_ERROR;
176 cnt = get_len(&c, x, 15);
182 back = (1 << 11) + (GETB(c) << 2) + (x >> 2) + 1;
185 back = (GETB(c) << 2) + (x >> 2) + 1;
187 copy_backptr(&c, back, cnt + 2);
193 *inlen = c.in_end - c.in;
196 *outlen = c.out_end - c.out;
202 #include <lzo/lzo1x.h>
204 #define MAXSZ (10*1024*1024)
206 /* Define one of these to 1 if you wish to benchmark liblzo
207 * instead of our native implementation. */
208 #define BENCHMARK_LIBLZO_SAFE 0
209 #define BENCHMARK_LIBLZO_UNSAFE 0
211 int main(int argc, char *argv[]) {
212 FILE *in = fopen(argv[1], "rb");
213 uint8_t *orig = av_malloc(MAXSZ + 16);
214 uint8_t *comp = av_malloc(2*MAXSZ + 16);
215 uint8_t *decomp = av_malloc(MAXSZ + 16);
216 size_t s = fread(orig, 1, MAXSZ, in);
218 long tmp[LZO1X_MEM_COMPRESS];
221 av_log_set_level(AV_LOG_DEBUG);
222 lzo1x_999_compress(orig, s, comp, &clen, tmp);
223 for (i = 0; i < 300; i++) {
225 inlen = clen; outlen = MAXSZ;
226 #if BENCHMARK_LIBLZO_SAFE
227 if (lzo1x_decompress_safe(comp, inlen, decomp, &outlen, NULL))
228 #elif BENCHMARK_LIBLZO_UNSAFE
229 if (lzo1x_decompress(comp, inlen, decomp, &outlen, NULL))
231 if (av_lzo1x_decode(decomp, &outlen, comp, &inlen))
233 av_log(NULL, AV_LOG_ERROR, "decompression error\n");
236 if (memcmp(orig, decomp, s))
237 av_log(NULL, AV_LOG_ERROR, "decompression incorrect\n");
239 av_log(NULL, AV_LOG_ERROR, "decompression OK\n");