Move lzo decompression to libavutil
[libav.git] / libavutil / lzo.c
CommitLineData
517840c6
RD
1/*
2 * LZO 1x decompression
3 * Copyright (c) 2006 Reimar Doeffinger
4 *
b78e7197
DB
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
517840c6
RD
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
b78e7197 10 * version 2.1 of the License, or (at your option) any later version.
517840c6 11 *
b78e7197 12 * FFmpeg is distributed in the hope that it will be useful,
517840c6
RD
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.
16 *
17 * You should have received a copy of the GNU Lesser General Public
b78e7197 18 * License along with FFmpeg; if not, write to the Free Software
5509bffa 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
517840c6
RD
20 */
21#include "common.h"
f53a2931
RD
22//! avoid e.g. MPlayers fast_memcpy, it slows things down here
23#undef memcpy
24#include <string.h>
517840c6
RD
25#include "lzo.h"
26
f53a2931
RD
27//! define if we may write up to 12 bytes beyond the output buffer
28#define OUTBUF_PADDED 1
a737f1df 29//! define if we may read up to 8 bytes beyond the input buffer
f53a2931 30#define INBUF_PADDED 1
517840c6
RD
31typedef struct LZOContext {
32 uint8_t *in, *in_end;
f53a2931 33 uint8_t *out_start, *out, *out_end;
517840c6
RD
34 int error;
35} LZOContext;
36
37/**
38 * \brief read one byte from input buffer, avoiding overrun
39 * \return byte read
40 */
41static inline int get_byte(LZOContext *c) {
42 if (c->in < c->in_end)
43 return *c->in++;
44 c->error |= LZO_INPUT_DEPLETED;
d3c71c50 45 return 1;
517840c6
RD
46}
47
a737f1df
RD
48#ifdef INBUF_PADDED
49#define GETB(c) (*(c).in++)
50#else
51#define GETB(c) get_byte(&(c))
52#endif
53
517840c6
RD
54/**
55 * \brief decode a length value in the coding used by lzo
56 * \param x previous byte value
57 * \param mask bits used from x
58 * \return decoded length value
59 */
60static inline int get_len(LZOContext *c, int x, int mask) {
61 int cnt = x & mask;
62 if (!cnt) {
63 while (!(x = get_byte(c))) cnt += 255;
64 cnt += mask + x;
65 }
66 return cnt;
67}
68
1db8c21c
RD
69//#define UNALIGNED_LOADSTORE
70#define BUILTIN_MEMCPY
71#ifdef UNALIGNED_LOADSTORE
72#define COPY2(d, s) *(uint16_t *)(d) = *(uint16_t *)(s);
73#define COPY4(d, s) *(uint32_t *)(d) = *(uint32_t *)(s);
74#elif defined(BUILTIN_MEMCPY)
75#define COPY2(d, s) memcpy(d, s, 2);
76#define COPY4(d, s) memcpy(d, s, 4);
77#else
78#define COPY2(d, s) (d)[0] = (s)[0]; (d)[1] = (s)[1];
79#define COPY4(d, s) (d)[0] = (s)[0]; (d)[1] = (s)[1]; (d)[2] = (s)[2]; (d)[3] = (s)[3];
80#endif
81
517840c6
RD
82/**
83 * \brief copy bytes from input to output buffer with checking
9b2c14df 84 * \param cnt number of bytes to copy, must be >= 0
517840c6
RD
85 */
86static inline void copy(LZOContext *c, int cnt) {
f53a2931
RD
87 register uint8_t *src = c->in;
88 register uint8_t *dst = c->out;
c0a8b876 89 if (cnt > c->in_end - src) {
c215e403 90 cnt = FFMAX(c->in_end - src, 0);
517840c6
RD
91 c->error |= LZO_INPUT_DEPLETED;
92 }
c0a8b876 93 if (cnt > c->out_end - dst) {
c215e403 94 cnt = FFMAX(c->out_end - dst, 0);
517840c6
RD
95 c->error |= LZO_OUTPUT_FULL;
96 }
f53a2931 97#if defined(INBUF_PADDED) && defined(OUTBUF_PADDED)
1db8c21c 98 COPY4(dst, src);
f53a2931
RD
99 src += 4;
100 dst += 4;
101 cnt -= 4;
102 if (cnt > 0)
103#endif
104 memcpy(dst, src, cnt);
105 c->in = src + cnt;
106 c->out = dst + cnt;
517840c6
RD
107}
108
109/**
110 * \brief copy previously decoded bytes to current position
111 * \param back how many bytes back we start
9b2c14df 112 * \param cnt number of bytes to copy, must be >= 0
517840c6 113 *
f53a2931
RD
114 * cnt > back is valid, this will copy the bytes we just copied,
115 * thus creating a repeating pattern with a period length of back.
517840c6
RD
116 */
117static inline void copy_backptr(LZOContext *c, int back, int cnt) {
f53a2931
RD
118 register uint8_t *src = &c->out[-back];
119 register uint8_t *dst = c->out;
cf0ef3dc 120 if (src < c->out_start || src > dst) {
517840c6
RD
121 c->error |= LZO_INVALID_BACKPTR;
122 return;
123 }
c0a8b876 124 if (cnt > c->out_end - dst) {
c215e403 125 cnt = FFMAX(c->out_end - dst, 0);
517840c6
RD
126 c->error |= LZO_OUTPUT_FULL;
127 }
f53a2931
RD
128 if (back == 1) {
129 memset(dst, *src, cnt);
130 dst += cnt;
131 } else {
132#ifdef OUTBUF_PADDED
1db8c21c
RD
133 COPY2(dst, src);
134 COPY2(dst + 2, src + 2);
f53a2931
RD
135 src += 4;
136 dst += 4;
137 cnt -= 4;
138 if (cnt > 0) {
1db8c21c
RD
139 COPY2(dst, src);
140 COPY2(dst + 2, src + 2);
141 COPY2(dst + 4, src + 4);
142 COPY2(dst + 6, src + 6);
f53a2931
RD
143 src += 8;
144 dst += 8;
145 cnt -= 8;
146 }
147#endif
148 if (cnt > 0) {
149 int blocklen = back;
150 while (cnt > blocklen) {
151 memcpy(dst, src, blocklen);
152 dst += blocklen;
153 cnt -= blocklen;
154 blocklen <<= 1;
155 }
156 memcpy(dst, src, cnt);
157 }
158 dst += cnt;
159 }
160 c->out = dst;
517840c6
RD
161}
162
163/**
164 * \brief decode LZO 1x compressed data
165 * \param out output buffer
166 * \param outlen size of output buffer, number of bytes left are returned here
167 * \param in input buffer
168 * \param inlen size of input buffer, number of bytes left are returned here
169 * \return 0 on success, otherwise error flags, see lzo.h
f53a2931
RD
170 *
171 * make sure all buffers are appropriately padded, in must provide
172 * LZO_INPUT_PADDING, out must provide LZO_OUTPUT_PADDING additional bytes
517840c6
RD
173 */
174int lzo1x_decode(void *out, int *outlen, void *in, int *inlen) {
bf47272f 175 int state= 0;
517840c6
RD
176 int x;
177 LZOContext c;
178 c.in = in;
214019ed 179 c.in_end = (uint8_t *)in + *inlen;
f53a2931 180 c.out = c.out_start = out;
214019ed 181 c.out_end = (uint8_t *)out + * outlen;
517840c6 182 c.error = 0;
a737f1df 183 x = GETB(c);
517840c6
RD
184 if (x > 17) {
185 copy(&c, x - 17);
a737f1df 186 x = GETB(c);
517840c6
RD
187 if (x < 16) c.error |= LZO_ERROR;
188 }
5fe9c42c
RD
189 if (c.in > c.in_end)
190 c.error |= LZO_INPUT_DEPLETED;
517840c6
RD
191 while (!c.error) {
192 int cnt, back;
801778bc
MN
193 if (x > 15) {
194 if (x > 63) {
517840c6 195 cnt = (x >> 5) - 1;
a737f1df 196 back = (GETB(c) << 3) + ((x >> 2) & 7) + 1;
801778bc 197 } else if (x > 31) {
517840c6 198 cnt = get_len(&c, x, 31);
a737f1df
RD
199 x = GETB(c);
200 back = (GETB(c) << 6) + (x >> 2) + 1;
517840c6
RD
201 } else {
202 cnt = get_len(&c, x, 7);
203 back = (1 << 14) + ((x & 8) << 11);
a737f1df
RD
204 x = GETB(c);
205 back += (GETB(c) << 6) + (x >> 2);
517840c6
RD
206 if (back == (1 << 14)) {
207 if (cnt != 1)
208 c.error |= LZO_ERROR;
209 break;
210 }
211 }
bf47272f 212 } else if(!state){
517840c6
RD
213 cnt = get_len(&c, x, 15);
214 copy(&c, cnt + 3);
a737f1df 215 x = GETB(c);
960e48f8 216 if (x > 15)
517840c6
RD
217 continue;
218 cnt = 1;
a737f1df 219 back = (1 << 11) + (GETB(c) << 2) + (x >> 2) + 1;
bf47272f 220 } else {
517840c6 221 cnt = 0;
a737f1df 222 back = (GETB(c) << 2) + (x >> 2) + 1;
517840c6
RD
223 }
224 copy_backptr(&c, back, cnt + 2);
bf47272f 225 state=
517840c6 226 cnt = x & 3;
56f8647a 227 copy(&c, cnt);
a737f1df 228 x = GETB(c);
517840c6
RD
229 }
230 *inlen = c.in_end - c.in;
a737f1df
RD
231 if (c.in > c.in_end)
232 *inlen = 0;
517840c6
RD
233 *outlen = c.out_end - c.out;
234 return c.error;
235}
266aa26c
RD
236
237#ifdef TEST
238#include <stdio.h>
239#include <lzo/lzo1x.h>
240#include "log.h"
241#define MAXSZ (10*1024*1024)
242int main(int argc, char *argv[]) {
243 FILE *in = fopen(argv[1], "rb");
244 uint8_t *orig = av_malloc(MAXSZ + 16);
245 uint8_t *comp = av_malloc(2*MAXSZ + 16);
246 uint8_t *decomp = av_malloc(MAXSZ + 16);
247 size_t s = fread(orig, 1, MAXSZ, in);
248 lzo_uint clen = 0;
249 long tmp[LZO1X_MEM_COMPRESS];
250 int inlen, outlen;
251 int i;
252 av_log_level = AV_LOG_DEBUG;
253 lzo1x_999_compress(orig, s, comp, &clen, tmp);
254 for (i = 0; i < 300; i++) {
255START_TIMER
256 inlen = clen; outlen = MAXSZ;
d62a0c1e
RD
257#ifdef LIBLZO
258 if (lzo1x_decompress_safe(comp, inlen, decomp, &outlen, NULL))
259#elif defined(LIBLZO_UNSAFE)
260 if (lzo1x_decompress(comp, inlen, decomp, &outlen, NULL))
261#else
266aa26c 262 if (lzo1x_decode(decomp, &outlen, comp, &inlen))
d62a0c1e 263#endif
266aa26c
RD
264 av_log(NULL, AV_LOG_ERROR, "decompression error\n");
265STOP_TIMER("lzod")
266 }
267 if (memcmp(orig, decomp, s))
268 av_log(NULL, AV_LOG_ERROR, "decompression incorrect\n");
269 else
270 av_log(NULL, AV_LOG_ERROR, "decompression ok\n");
271 return 0;
272}
273#endif