[deb_ffmpeg.git] / ffmpeg / libavutil / lzo.c

/*
 * LZO 1x decompression
 * Copyright (c) 2006 Reimar Doeffinger
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <string.h>

#include "avutil.h"
#include "avassert.h"
#include "common.h"
#include "intreadwrite.h"
#include "lzo.h"

/// Define if we may write up to 12 bytes beyond the output buffer.
#define OUTBUF_PADDED 1
/// Define if we may read up to 8 bytes beyond the input buffer.
#define INBUF_PADDED 1

typedef struct LZOContext {
    const uint8_t *in, *in_end;
    uint8_t *out_start, *out, *out_end;
    int error;
} LZOContext;

/**
 * @brief Reads one byte from the input buffer, avoiding an overrun.
 * @return byte read
 */
static inline int get_byte(LZOContext *c)
{
    if (c->in < c->in_end)
        return *c->in++;
    c->error |= AV_LZO_INPUT_DEPLETED;
    return 1;
}

#ifdef INBUF_PADDED
#define GETB(c) (*(c).in++)
#else
#define GETB(c) get_byte(&(c))
#endif

/**
 * @brief Decodes a length value in the coding used by lzo.
 * @param x previous byte value
 * @param mask bits used from x
 * @return decoded length value
 */
static inline int get_len(LZOContext *c, int x, int mask)
{
    int cnt = x & mask;
    if (!cnt) {
        while (!(x = get_byte(c))) {
            if (cnt >= INT_MAX - 1000) {
                c->error |= AV_LZO_ERROR;
                break;
            }
            cnt += 255;
        }
        cnt += mask + x;
    }
    return cnt;
}

/**
 * @brief Copies bytes from input to output buffer with checking.
 * @param cnt number of bytes to copy, must be >= 0
 */
static inline void copy(LZOContext *c, int cnt)
{
    register const uint8_t *src = c->in;
    register uint8_t *dst       = c->out;
    av_assert0(cnt >= 0);
    if (cnt > c->in_end - src) {
        cnt       = FFMAX(c->in_end - src, 0);
        c->error |= AV_LZO_INPUT_DEPLETED;
    }
    if (cnt > c->out_end - dst) {
        cnt       = FFMAX(c->out_end - dst, 0);
        c->error |= AV_LZO_OUTPUT_FULL;
    }
#if defined(INBUF_PADDED) && defined(OUTBUF_PADDED)
    AV_COPY32U(dst, src);
    src += 4;
    dst += 4;
    cnt -= 4;
    if (cnt > 0)
#endif
    memcpy(dst, src, cnt);
    c->in  = src + cnt;
    c->out = dst + cnt;
}

/**
 * @brief Copies previously decoded bytes to current position.
 * @param back how many bytes back we start, must be > 0
 * @param cnt number of bytes to copy, must be > 0
 *
 * cnt > back is valid, this will copy the bytes we just copied,
 * thus creating a repeating pattern with a period length of back.
 */
static inline void copy_backptr(LZOContext *c, int back, int cnt)
{
    register uint8_t *dst       = c->out;
    av_assert0(cnt > 0);
    if (dst - c->out_start < back) {
        c->error |= AV_LZO_INVALID_BACKPTR;
        return;
    }
    if (cnt > c->out_end - dst) {
        cnt       = FFMAX(c->out_end - dst, 0);
        c->error |= AV_LZO_OUTPUT_FULL;
    }
    av_memcpy_backptr(dst, back, cnt);
    c->out = dst + cnt;
}

int av_lzo1x_decode(void *out, int *outlen, const void *in, int *inlen)
{
    int state = 0;
    int x;
    LZOContext c;
    if (*outlen <= 0 || *inlen <= 0) {
        int res = 0;
        if (*outlen <= 0)
            res |= AV_LZO_OUTPUT_FULL;
        if (*inlen <= 0)
            res |= AV_LZO_INPUT_DEPLETED;
        return res;
    }
    c.in      = in;
    c.in_end  = (const uint8_t *)in + *inlen;
    c.out     = c.out_start = out;
    c.out_end = (uint8_t *)out + *outlen;
    c.error   = 0;
    x         = GETB(c);
    if (x > 17) {
        copy(&c, x - 17);
        x = GETB(c);
        if (x < 16)
            c.error |= AV_LZO_ERROR;
    }
    if (c.in > c.in_end)
        c.error |= AV_LZO_INPUT_DEPLETED;
    while (!c.error) {
        int cnt, back;
        if (x > 15) {
            if (x > 63) {
                cnt  = (x >> 5) - 1;
                back = (GETB(c) << 3) + ((x >> 2) & 7) + 1;
            } else if (x > 31) {
                cnt  = get_len(&c, x, 31);
                x    = GETB(c);
                back = (GETB(c) << 6) + (x >> 2) + 1;
            } else {
                cnt   = get_len(&c, x, 7);
                back  = (1 << 14) + ((x & 8) << 11);
                x     = GETB(c);
                back += (GETB(c) << 6) + (x >> 2);
                if (back == (1 << 14)) {
                    if (cnt != 1)
                        c.error |= AV_LZO_ERROR;
                    break;
                }
            }
        } else if (!state) {
            cnt = get_len(&c, x, 15);
            copy(&c, cnt + 3);
            x = GETB(c);
            if (x > 15)
                continue;
            cnt  = 1;
            back = (1 << 11) + (GETB(c) << 2) + (x >> 2) + 1;
        } else {
            cnt  = 0;
            back = (GETB(c) << 2) + (x >> 2) + 1;
        }
        copy_backptr(&c, back, cnt + 2);
        state =
        cnt   = x & 3;
        copy(&c, cnt);
        x = GETB(c);
    }
    *inlen = c.in_end - c.in;
    if (c.in > c.in_end)
        *inlen = 0;
    *outlen = c.out_end - c.out;
    return c.error;
}

#ifdef TEST
#include <stdio.h>
#include <lzo/lzo1x.h>
#include "log.h"
#define MAXSZ (10*1024*1024)

/* Define one of these to 1 if you wish to benchmark liblzo
 * instead of our native implementation. */
#define BENCHMARK_LIBLZO_SAFE   0
#define BENCHMARK_LIBLZO_UNSAFE 0

int main(int argc, char *argv[]) {
    FILE *in = fopen(argv[1], "rb");
    int comp_level = argc > 2 ? atoi(argv[2]) : 0;
    uint8_t *orig = av_malloc(MAXSZ + 16);
    uint8_t *comp = av_malloc(2*MAXSZ + 16);
    uint8_t *decomp = av_malloc(MAXSZ + 16);
    size_t s = fread(orig, 1, MAXSZ, in);
    lzo_uint clen = 0;
    long tmp[LZO1X_MEM_COMPRESS];
    int inlen, outlen;
    int i;
    av_log_set_level(AV_LOG_DEBUG);
    if (comp_level == 0) {
        lzo1x_1_compress(orig, s, comp, &clen, tmp);
    } else if (comp_level == 11) {
        lzo1x_1_11_compress(orig, s, comp, &clen, tmp);
    } else if (comp_level == 12) {
        lzo1x_1_12_compress(orig, s, comp, &clen, tmp);
    } else if (comp_level == 15) {
        lzo1x_1_15_compress(orig, s, comp, &clen, tmp);
    } else
        lzo1x_999_compress(orig, s, comp, &clen, tmp);
    for (i = 0; i < 300; i++) {
START_TIMER
        inlen = clen; outlen = MAXSZ;
#if BENCHMARK_LIBLZO_SAFE
        if (lzo1x_decompress_safe(comp, inlen, decomp, &outlen, NULL))
#elif BENCHMARK_LIBLZO_UNSAFE
        if (lzo1x_decompress(comp, inlen, decomp, &outlen, NULL))
#else
        if (av_lzo1x_decode(decomp, &outlen, comp, &inlen))
#endif
            av_log(NULL, AV_LOG_ERROR, "decompression error\n");
STOP_TIMER("lzod")
    }
    if (memcmp(orig, decomp, s))
        av_log(NULL, AV_LOG_ERROR, "decompression incorrect\n");
    else
        av_log(NULL, AV_LOG_ERROR, "decompression OK\n");
    return 0;
}
#endif
Commit	Line	Data
2ba45a60 DM	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
	22	#include <string.h>
	23
	24	#include "avutil.h"
	25	#include "avassert.h"
	26	#include "common.h"
	27	#include "intreadwrite.h"
	28	#include "lzo.h"
	29
	30	/// Define if we may write up to 12 bytes beyond the output buffer.
	31	#define OUTBUF_PADDED 1
	32	/// Define if we may read up to 8 bytes beyond the input buffer.
	33	#define INBUF_PADDED 1
	34
	35	typedef struct LZOContext {
	36	const uint8_t in, in_end;
	37	uint8_t out_start, out, *out_end;
	38	int error;
	39	} LZOContext;
	40
	41	/**
	42	* @brief Reads one byte from the input buffer, avoiding an overrun.
	43	* @return byte read
	44	*/
	45	static inline int get_byte(LZOContext *c)
	46	{
	47	if (c->in < c->in_end)
	48	return *c->in++;
	49	c->error \|= AV_LZO_INPUT_DEPLETED;
	50	return 1;
	51	}
	52
	53	#ifdef INBUF_PADDED
	54	#define GETB(c) (*(c).in++)
	55	#else
	56	#define GETB(c) get_byte(&(c))
	57	#endif
	58
	59	/**
	60	* @brief Decodes a length value in the coding used by lzo.
	61	* @param x previous byte value
	62	* @param mask bits used from x
	63	* @return decoded length value
	64	*/
65	static inline int get_len(LZOContext *c, int x, int mask)
66	{
67	int cnt = x & mask;
68	if (!cnt) {
69	while (!(x = get_byte(c))) {
70	if (cnt >= INT_MAX - 1000) {
71	c->error \|= AV_LZO_ERROR;
72	break;
73	}
74	cnt += 255;
75	}
76	cnt += mask + x;
77	}
78	return cnt;
79	}
80
81	/**
82	* @brief Copies bytes from input to output buffer with checking.
83	* @param cnt number of bytes to copy, must be >= 0
84	*/
85	static inline void copy(LZOContext *c, int cnt)
86	{
87	register const uint8_t *src = c->in;
88	register uint8_t *dst = c->out;
89	av_assert0(cnt >= 0);
90	if (cnt > c->in_end - src) {
91	cnt = FFMAX(c->in_end - src, 0);
92	c->error \|= AV_LZO_INPUT_DEPLETED;
93	}
94	if (cnt > c->out_end - dst) {
95	cnt = FFMAX(c->out_end - dst, 0);
96	c->error \|= AV_LZO_OUTPUT_FULL;
97	}
98	#if defined(INBUF_PADDED) && defined(OUTBUF_PADDED)
99	AV_COPY32U(dst, src);
100	src += 4;
101	dst += 4;
102	cnt -= 4;
103	if (cnt > 0)
104	#endif
105	memcpy(dst, src, cnt);
106	c->in = src + cnt;
107	c->out = dst + cnt;
108	}
109
110	/**
111	* @brief Copies previously decoded bytes to current position.
112	* @param back how many bytes back we start, must be > 0
113	* @param cnt number of bytes to copy, must be > 0
114	*
115	* cnt > back is valid, this will copy the bytes we just copied,
116	* thus creating a repeating pattern with a period length of back.
117	*/
118	static inline void copy_backptr(LZOContext *c, int back, int cnt)
119	{
120	register uint8_t *dst = c->out;
121	av_assert0(cnt > 0);
122	if (dst - c->out_start < back) {
123	c->error \|= AV_LZO_INVALID_BACKPTR;
124	return;
125	}
126	if (cnt > c->out_end - dst) {
127	cnt = FFMAX(c->out_end - dst, 0);
128	c->error \|= AV_LZO_OUTPUT_FULL;
129	}
130	av_memcpy_backptr(dst, back, cnt);
131	c->out = dst + cnt;
132	}
133
134	int av_lzo1x_decode(void out, int outlen, const void in, int inlen)
135	{
136	int state = 0;
137	int x;
138	LZOContext c;
139	if (outlen <= 0 \|\| inlen <= 0) {
140	int res = 0;
141	if (*outlen <= 0)
142	res \|= AV_LZO_OUTPUT_FULL;
143	if (*inlen <= 0)
144	res \|= AV_LZO_INPUT_DEPLETED;
145	return res;
146	}
147	c.in = in;
148	c.in_end = (const uint8_t )in + inlen;
149	c.out = c.out_start = out;
150	c.out_end = (uint8_t )out + outlen;
151	c.error = 0;
152	x = GETB(c);
153	if (x > 17) {
154	copy(&c, x - 17);
155	x = GETB(c);
156	if (x < 16)
157	c.error \|= AV_LZO_ERROR;
158	}
159	if (c.in > c.in_end)
160	c.error \|= AV_LZO_INPUT_DEPLETED;
161	while (!c.error) {
162	int cnt, back;
163	if (x > 15) {
164	if (x > 63) {
165	cnt = (x >> 5) - 1;
166	back = (GETB(c) << 3) + ((x >> 2) & 7) + 1;
167	} else if (x > 31) {
168	cnt = get_len(&c, x, 31);
169	x = GETB(c);
170	back = (GETB(c) << 6) + (x >> 2) + 1;
171	} else {
172	cnt = get_len(&c, x, 7);
173	back = (1 << 14) + ((x & 8) << 11);
174	x = GETB(c);
175	back += (GETB(c) << 6) + (x >> 2);
176	if (back == (1 << 14)) {
177	if (cnt != 1)
178	c.error \|= AV_LZO_ERROR;
179	break;
180	}
181	}
182	} else if (!state) {
183	cnt = get_len(&c, x, 15);
184	copy(&c, cnt + 3);
185	x = GETB(c);
186	if (x > 15)
187	continue;
188	cnt = 1;
189	back = (1 << 11) + (GETB(c) << 2) + (x >> 2) + 1;
190	} else {
191	cnt = 0;
192	back = (GETB(c) << 2) + (x >> 2) + 1;
193	}
194	copy_backptr(&c, back, cnt + 2);
195	state =
196	cnt = x & 3;
197	copy(&c, cnt);
198	x = GETB(c);
199	}
200	*inlen = c.in_end - c.in;
201	if (c.in > c.in_end)
202	*inlen = 0;
203	*outlen = c.out_end - c.out;
204	return c.error;
205	}
206
207	#ifdef TEST
208	#include <stdio.h>
209	#include <lzo/lzo1x.h>
210	#include "log.h"
211	#define MAXSZ (1010241024)
212
213	/* Define one of these to 1 if you wish to benchmark liblzo
214	* instead of our native implementation. */
215	#define BENCHMARK_LIBLZO_SAFE 0
216	#define BENCHMARK_LIBLZO_UNSAFE 0
217
218	int main(int argc, char *argv[]) {
219	FILE *in = fopen(argv[1], "rb");
220	int comp_level = argc > 2 ? atoi(argv[2]) : 0;
221	uint8_t *orig = av_malloc(MAXSZ + 16);
222	uint8_t comp = av_malloc(2MAXSZ + 16);
223	uint8_t *decomp = av_malloc(MAXSZ + 16);
224	size_t s = fread(orig, 1, MAXSZ, in);
225	lzo_uint clen = 0;
226	long tmp[LZO1X_MEM_COMPRESS];
227	int inlen, outlen;
228	int i;
229	av_log_set_level(AV_LOG_DEBUG);
230	if (comp_level == 0) {
231	lzo1x_1_compress(orig, s, comp, &clen, tmp);
232	} else if (comp_level == 11) {
233	lzo1x_1_11_compress(orig, s, comp, &clen, tmp);
234	} else if (comp_level == 12) {
235	lzo1x_1_12_compress(orig, s, comp, &clen, tmp);
236	} else if (comp_level == 15) {
237	lzo1x_1_15_compress(orig, s, comp, &clen, tmp);
238	} else
239	lzo1x_999_compress(orig, s, comp, &clen, tmp);
240	for (i = 0; i < 300; i++) {
241	START_TIMER
242	inlen = clen; outlen = MAXSZ;
243	#if BENCHMARK_LIBLZO_SAFE
244	if (lzo1x_decompress_safe(comp, inlen, decomp, &outlen, NULL))
245	#elif BENCHMARK_LIBLZO_UNSAFE
246	if (lzo1x_decompress(comp, inlen, decomp, &outlen, NULL))
247	#else
248	if (av_lzo1x_decode(decomp, &outlen, comp, &inlen))
249	#endif
250	av_log(NULL, AV_LOG_ERROR, "decompression error\n");
251	STOP_TIMER("lzod")
252	}
253	if (memcmp(orig, decomp, s))
254	av_log(NULL, AV_LOG_ERROR, "decompression incorrect\n");
255	else
256	av_log(NULL, AV_LOG_ERROR, "decompression OK\n");
257	return 0;
258	}
259	#endif