Move lzo decompression to libavutil

Originally committed as revision 7789 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 273 insertions, 0 deletions

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 <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 {
+    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 <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");
+    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