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-rw-r--r--ffmpeg1/libavutil/lzo.c241
1 files changed, 241 insertions, 0 deletions
diff --git a/ffmpeg1/libavutil/lzo.c b/ffmpeg1/libavutil/lzo.c
new file mode 100644
index 0000000..221a66b
--- /dev/null
+++ b/ffmpeg1/libavutil/lzo.c
@@ -0,0 +1,241 @@
+/*
+ * 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 "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)))
+ 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;
+ 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;
+ 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");
+ 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);
+ 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
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