From 4302963daa0912e35c7d7f53a1d9d34099f7a749 Mon Sep 17 00:00:00 2001 From: Reimar Döffinger Date: Wed, 31 Jan 2007 22:58:53 +0000 Subject: Move lzo decompression to libavutil Originally committed as revision 7789 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavutil/lzo.c | 273 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 273 insertions(+) create mode 100644 libavutil/lzo.c (limited to 'libavutil/lzo.c') diff --git a/libavutil/lzo.c b/libavutil/lzo.c new file mode 100644 index 0000000000..d3849a743d --- /dev/null +++ b/libavutil/lzo.c @@ -0,0 +1,273 @@ +/* + * 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 "common.h" +//! avoid e.g. MPlayers fast_memcpy, it slows things down here +#undef memcpy +#include +#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 { + uint8_t *in, *in_end; + uint8_t *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) *(uint16_t *)(d) = *(uint16_t *)(s); +#define COPY4(d, s) *(uint32_t *)(d) = *(uint32_t *)(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 uint8_t *src = c->in; + register uint8_t *dst = c->out; + if (cnt > c->in_end - src) { + cnt = FFMAX(c->in_end - src, 0); + c->error |= LZO_INPUT_DEPLETED; + } + if (cnt > c->out_end - dst) { + cnt = FFMAX(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 uint8_t *src = &c->out[-back]; + register uint8_t *dst = c->out; + if (src < c->out_start || src > dst) { + c->error |= LZO_INVALID_BACKPTR; + return; + } + if (cnt > c->out_end - dst) { + cnt = FFMAX(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, void *in, int *inlen) { + int state= 0; + int x; + LZOContext c; + c.in = in; + c.in_end = (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 |= 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 +#include +#include "log.h" +#define MAXSZ (10*1024*1024) +int main(int argc, char *argv[]) { + FILE *in = fopen(argv[1], "rb"); + 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_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"); + return 0; +} +#endif -- cgit v1.2.3