gstreamer/gst/matroska/lzo.c
2016-02-08 00:11:55 +00:00

292 lines
7.3 KiB
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
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gst/gst.h>
#include <stdlib.h>
#include <string.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 guint8 *in, *in_end;
guint8 *out_start, *out, *out_end;
int error;
} LZOContext;
/*
* \brief read one byte from input buffer, avoiding overrun
* \return byte read
*/
static inline int
get_byte (LZOContext * c)
{
if (c->in < c->in_end)
return *c->in++;
c->error |= LZO_INPUT_DEPLETED;
return 1;
}
#ifdef INBUF_PADDED
#define GETB(c) (*(c).in++)
#else
#define GETB(c) get_byte(&(c))
#endif
/*
* \brief decode 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)))
cnt += 255;
cnt += mask + x;
}
return cnt;
}
/*#define UNALIGNED_LOADSTORE */
#define BUILTIN_MEMCPY
#ifdef UNALIGNED_LOADSTORE
#define COPY2(d, s) *(guint16 *)(d) = *(guint16 *)(s);
#define COPY4(d, s) *(guint32 *)(d) = *(guint32 *)(s);
#elif defined(BUILTIN_MEMCPY)
#define COPY2(d, s) memcpy(d, s, 2);
#define COPY4(d, s) memcpy(d, s, 4);
#else
#define COPY2(d, s) (d)[0] = (s)[0]; (d)[1] = (s)[1];
#define COPY4(d, s) (d)[0] = (s)[0]; (d)[1] = (s)[1]; (d)[2] = (s)[2]; (d)[3] = (s)[3];
#endif
/*
* \brief copy 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 guint8 *src = c->in;
register guint8 *dst = c->out;
if (cnt > c->in_end - src) {
cnt = MAX (c->in_end - src, 0);
c->error |= LZO_INPUT_DEPLETED;
}
if (cnt > c->out_end - dst) {
cnt = MAX (c->out_end - dst, 0);
c->error |= LZO_OUTPUT_FULL;
}
#if defined(INBUF_PADDED) && defined(OUTBUF_PADDED)
COPY4 (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 copy previously decoded bytes to current position
* \param back how many bytes back we start
* \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 const guint8 *src = &c->out[-back];
register guint8 *dst = c->out;
if (src < c->out_start || src > dst) {
c->error |= LZO_INVALID_BACKPTR;
return;
}
if (cnt > c->out_end - dst) {
cnt = MAX (c->out_end - dst, 0);
c->error |= LZO_OUTPUT_FULL;
}
if (back == 1) {
memset (dst, *src, cnt);
dst += cnt;
} else {
#ifdef OUTBUF_PADDED
COPY2 (dst, src);
COPY2 (dst + 2, src + 2);
src += 4;
dst += 4;
cnt -= 4;
if (cnt > 0) {
COPY2 (dst, src);
COPY2 (dst + 2, src + 2);
COPY2 (dst + 4, src + 4);
COPY2 (dst + 6, src + 6);
src += 8;
dst += 8;
cnt -= 8;
}
#endif
if (cnt > 0) {
int blocklen = back;
while (cnt > blocklen) {
memcpy (dst, src, blocklen);
dst += blocklen;
cnt -= blocklen;
blocklen <<= 1;
}
memcpy (dst, src, cnt);
}
dst += cnt;
}
c->out = dst;
}
/*
* \brief decode LZO 1x compressed data
* \param out output buffer
* \param outlen size of output buffer, number of bytes left are returned here
* \param in input buffer
* \param inlen size of input buffer, number of bytes left are returned here
* \return 0 on success, otherwise error flags, see lzo.h
*
* make sure all buffers are appropriately padded, in must provide
* LZO_INPUT_PADDING, out must provide LZO_OUTPUT_PADDING additional bytes
*/
int
lzo1x_decode (void *out, int *outlen, const void *in, int *inlen)
{
int state = 0;
int x;
LZOContext c;
c.in = in;
c.in_end = (const guint8 *) in + *inlen;
c.out = c.out_start = out;
c.out_end = (guint8 *) out + *outlen;
c.error = 0;
x = GETB (c);
if (x > 17) {
copy (&c, x - 17);
x = GETB (c);
if (x < 16)
c.error |= LZO_ERROR;
}
if (c.in > c.in_end)
c.error |= 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 |= 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)
int
main (int argc, char *argv[])
{
FILE *in = fopen (argv[1], "rb");
guint8 *orig = av_malloc (MAXSZ + 16);
guint8 *comp = av_malloc (2 * MAXSZ + 16);
guint8 *decomp = av_malloc (MAXSZ + 16);
gsize s = fread (orig, 1, MAXSZ, in);
lzo_uint clen = 0;
long tmp[LZO1X_MEM_COMPRESS];
int inlen, outlen;
int i;
av_log_level = AV_LOG_DEBUG;
lzo1x_999_compress (orig, s, comp, &clen, tmp);
for (i = 0; i < 300; i++) {
START_TIMER inlen = clen;
outlen = MAXSZ;
#ifdef LIBLZO
if (lzo1x_decompress_safe (comp, inlen, decomp, &outlen, NULL))
#elif defined(LIBLZO_UNSAFE)
if (lzo1x_decompress (comp, inlen, decomp, &outlen, NULL))
#else
if (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");
fclose (in);
return 0;
}
#endif