| /* |
| * 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"); |
| fclose(in); |
| return 0; |
| } |
| #endif |
