Add lzo test code
[libav.git] / libavcodec / lzo.c
1 /*
2 * LZO 1x decompression
3 * Copyright (c) 2006 Reimar Doeffinger
4 *
5 * This file is part of FFmpeg.
6 *
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.
11 *
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.
16 *
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
20 */
21 #include "common.h"
22 //! avoid e.g. MPlayers fast_memcpy, it slows things down here
23 #undef memcpy
24 #include <string.h>
25 #include "lzo.h"
26
27 //! define if we may write up to 12 bytes beyond the output buffer
28 #define OUTBUF_PADDED 1
29 //! define if we may read up to 4 bytes beyond the input buffer
30 #define INBUF_PADDED 1
31 typedef struct LZOContext {
32 uint8_t *in, *in_end;
33 uint8_t *out_start, *out, *out_end;
34 int error;
35 } LZOContext;
36
37 /**
38 * \brief read one byte from input buffer, avoiding overrun
39 * \return byte read
40 */
41 static inline int get_byte(LZOContext *c) {
42 if (c->in < c->in_end)
43 return *c->in++;
44 c->error |= LZO_INPUT_DEPLETED;
45 return 1;
46 }
47
48 /**
49 * \brief decode a length value in the coding used by lzo
50 * \param x previous byte value
51 * \param mask bits used from x
52 * \return decoded length value
53 */
54 static inline int get_len(LZOContext *c, int x, int mask) {
55 int cnt = x & mask;
56 if (!cnt) {
57 while (!(x = get_byte(c))) cnt += 255;
58 cnt += mask + x;
59 }
60 return cnt;
61 }
62
63 /**
64 * \brief copy bytes from input to output buffer with checking
65 * \param cnt number of bytes to copy, must be > 0
66 */
67 static inline void copy(LZOContext *c, int cnt) {
68 register uint8_t *src = c->in;
69 register uint8_t *dst = c->out;
70 if (src + cnt > c->in_end) {
71 cnt = c->in_end - src;
72 c->error |= LZO_INPUT_DEPLETED;
73 }
74 if (dst + cnt > c->out_end) {
75 cnt = c->out_end - dst;
76 c->error |= LZO_OUTPUT_FULL;
77 }
78 #if defined(INBUF_PADDED) && defined(OUTBUF_PADDED)
79 dst[0] = src[0];
80 dst[1] = src[1];
81 dst[2] = src[2];
82 dst[3] = src[3];
83 src += 4;
84 dst += 4;
85 cnt -= 4;
86 if (cnt > 0)
87 #endif
88 memcpy(dst, src, cnt);
89 c->in = src + cnt;
90 c->out = dst + cnt;
91 }
92
93 /**
94 * \brief copy previously decoded bytes to current position
95 * \param back how many bytes back we start
96 * \param cnt number of bytes to copy, must be > 0
97 *
98 * cnt > back is valid, this will copy the bytes we just copied,
99 * thus creating a repeating pattern with a period length of back.
100 */
101 static inline void copy_backptr(LZOContext *c, int back, int cnt) {
102 register uint8_t *src = &c->out[-back];
103 register uint8_t *dst = c->out;
104 if (src < c->out_start) {
105 c->error |= LZO_INVALID_BACKPTR;
106 return;
107 }
108 if (dst + cnt > c->out_end) {
109 cnt = c->out_end - dst;
110 c->error |= LZO_OUTPUT_FULL;
111 }
112 if (back == 1) {
113 memset(dst, *src, cnt);
114 dst += cnt;
115 } else {
116 #ifdef OUTBUF_PADDED
117 dst[0] = src[0];
118 dst[1] = src[1];
119 dst[2] = src[2];
120 dst[3] = src[3];
121 src += 4;
122 dst += 4;
123 cnt -= 4;
124 if (cnt > 0) {
125 dst[0] = src[0];
126 dst[1] = src[1];
127 dst[2] = src[2];
128 dst[3] = src[3];
129 dst[4] = src[4];
130 dst[5] = src[5];
131 dst[6] = src[6];
132 dst[7] = src[7];
133 src += 8;
134 dst += 8;
135 cnt -= 8;
136 }
137 #endif
138 if (cnt > 0) {
139 int blocklen = back;
140 while (cnt > blocklen) {
141 memcpy(dst, src, blocklen);
142 dst += blocklen;
143 cnt -= blocklen;
144 blocklen <<= 1;
145 }
146 memcpy(dst, src, cnt);
147 }
148 dst += cnt;
149 }
150 c->out = dst;
151 }
152
153 /**
154 * \brief decode LZO 1x compressed data
155 * \param out output buffer
156 * \param outlen size of output buffer, number of bytes left are returned here
157 * \param in input buffer
158 * \param inlen size of input buffer, number of bytes left are returned here
159 * \return 0 on success, otherwise error flags, see lzo.h
160 *
161 * make sure all buffers are appropriately padded, in must provide
162 * LZO_INPUT_PADDING, out must provide LZO_OUTPUT_PADDING additional bytes
163 */
164 int lzo1x_decode(void *out, int *outlen, void *in, int *inlen) {
165 enum {COPY, BACKPTR} state = COPY;
166 int x;
167 LZOContext c;
168 c.in = in;
169 c.in_end = (uint8_t *)in + *inlen;
170 c.out = c.out_start = out;
171 c.out_end = (uint8_t *)out + * outlen;
172 c.error = 0;
173 x = get_byte(&c);
174 if (x > 17) {
175 copy(&c, x - 17);
176 x = get_byte(&c);
177 if (x < 16) c.error |= LZO_ERROR;
178 }
179 while (!c.error) {
180 int cnt, back;
181 if (x >> 4) {
182 if (x >> 6) {
183 cnt = (x >> 5) - 1;
184 back = (get_byte(&c) << 3) + ((x >> 2) & 7) + 1;
185 } else if (x >> 5) {
186 cnt = get_len(&c, x, 31);
187 x = get_byte(&c);
188 back = (get_byte(&c) << 6) + (x >> 2) + 1;
189 } else {
190 cnt = get_len(&c, x, 7);
191 back = (1 << 14) + ((x & 8) << 11);
192 x = get_byte(&c);
193 back += (get_byte(&c) << 6) + (x >> 2);
194 if (back == (1 << 14)) {
195 if (cnt != 1)
196 c.error |= LZO_ERROR;
197 break;
198 }
199 }
200 } else
201 switch (state) {
202 case COPY:
203 cnt = get_len(&c, x, 15);
204 copy(&c, cnt + 3);
205 x = get_byte(&c);
206 if (x >> 4)
207 continue;
208 cnt = 1;
209 back = (1 << 11) + (get_byte(&c) << 2) + (x >> 2) + 1;
210 break;
211 case BACKPTR:
212 cnt = 0;
213 back = (get_byte(&c) << 2) + (x >> 2) + 1;
214 break;
215 }
216 copy_backptr(&c, back, cnt + 2);
217 cnt = x & 3;
218 state = cnt ? BACKPTR : COPY;
219 if (cnt)
220 copy(&c, cnt);
221 x = get_byte(&c);
222 }
223 *inlen = c.in_end - c.in;
224 *outlen = c.out_end - c.out;
225 return c.error;
226 }
227
228 #ifdef TEST
229 #include <stdio.h>
230 #include <lzo/lzo1x.h>
231 #include "log.h"
232 #define MAXSZ (10*1024*1024)
233 int main(int argc, char *argv[]) {
234 FILE *in = fopen(argv[1], "rb");
235 uint8_t *orig = av_malloc(MAXSZ + 16);
236 uint8_t *comp = av_malloc(2*MAXSZ + 16);
237 uint8_t *decomp = av_malloc(MAXSZ + 16);
238 size_t s = fread(orig, 1, MAXSZ, in);
239 lzo_uint clen = 0;
240 long tmp[LZO1X_MEM_COMPRESS];
241 int inlen, outlen;
242 int i;
243 av_log_level = AV_LOG_DEBUG;
244 lzo1x_999_compress(orig, s, comp, &clen, tmp);
245 for (i = 0; i < 300; i++) {
246 START_TIMER
247 inlen = clen; outlen = MAXSZ;
248 if (lzo1x_decode(decomp, &outlen, comp, &inlen))
249 av_log(NULL, AV_LOG_ERROR, "decompression error\n");
250 STOP_TIMER("lzod")
251 }
252 if (memcmp(orig, decomp, s))
253 av_log(NULL, AV_LOG_ERROR, "decompression incorrect\n");
254 else
255 av_log(NULL, AV_LOG_ERROR, "decompression ok\n");
256 return 0;
257 }
258 #endif