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67e285ceca
Previously this did a double free (and returned an error). Reported-by: Justin Ruggles Signed-off-by: Martin Storsjö <martin@martin.st>
347 lines
7.7 KiB
C
347 lines
7.7 KiB
C
/*
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* default memory allocator for libavutil
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* Copyright (c) 2002 Fabrice Bellard
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*
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* This file is part of Libav.
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*
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* Libav is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* Libav is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with Libav; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/**
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* @file
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* default memory allocator for libavutil
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*/
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#include "config.h"
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#include <limits.h>
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#include <stdint.h>
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#include <stdlib.h>
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#include <string.h>
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#if HAVE_MALLOC_H
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#include <malloc.h>
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#endif
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#include "avutil.h"
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#include "intreadwrite.h"
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#include "mem.h"
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#ifdef MALLOC_PREFIX
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#define malloc AV_JOIN(MALLOC_PREFIX, malloc)
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#define memalign AV_JOIN(MALLOC_PREFIX, memalign)
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#define posix_memalign AV_JOIN(MALLOC_PREFIX, posix_memalign)
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#define realloc AV_JOIN(MALLOC_PREFIX, realloc)
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#define free AV_JOIN(MALLOC_PREFIX, free)
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void *malloc(size_t size);
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void *memalign(size_t align, size_t size);
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int posix_memalign(void **ptr, size_t align, size_t size);
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void *realloc(void *ptr, size_t size);
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void free(void *ptr);
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#endif /* MALLOC_PREFIX */
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/* You can redefine av_malloc and av_free in your project to use your
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* memory allocator. You do not need to suppress this file because the
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* linker will do it automatically. */
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void *av_malloc(size_t size)
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{
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void *ptr = NULL;
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#if CONFIG_MEMALIGN_HACK
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long diff;
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#endif
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/* let's disallow possibly ambiguous cases */
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if (size > (INT_MAX - 32) || !size)
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return NULL;
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#if CONFIG_MEMALIGN_HACK
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ptr = malloc(size + 32);
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if (!ptr)
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return ptr;
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diff = ((-(long)ptr - 1) & 31) + 1;
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ptr = (char *)ptr + diff;
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((char *)ptr)[-1] = diff;
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#elif HAVE_POSIX_MEMALIGN
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if (posix_memalign(&ptr, 32, size))
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ptr = NULL;
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#elif HAVE_ALIGNED_MALLOC
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ptr = _aligned_malloc(size, 32);
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#elif HAVE_MEMALIGN
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ptr = memalign(32, size);
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/* Why 64?
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* Indeed, we should align it:
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* on 4 for 386
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* on 16 for 486
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* on 32 for 586, PPro - K6-III
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* on 64 for K7 (maybe for P3 too).
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* Because L1 and L2 caches are aligned on those values.
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* But I don't want to code such logic here!
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*/
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/* Why 32?
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* For AVX ASM. SSE / NEON needs only 16.
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* Why not larger? Because I did not see a difference in benchmarks ...
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*/
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/* benchmarks with P3
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* memalign(64) + 1 3071, 3051, 3032
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* memalign(64) + 2 3051, 3032, 3041
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* memalign(64) + 4 2911, 2896, 2915
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* memalign(64) + 8 2545, 2554, 2550
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* memalign(64) + 16 2543, 2572, 2563
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* memalign(64) + 32 2546, 2545, 2571
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* memalign(64) + 64 2570, 2533, 2558
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*
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* BTW, malloc seems to do 8-byte alignment by default here.
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*/
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#else
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ptr = malloc(size);
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#endif
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return ptr;
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}
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void *av_realloc(void *ptr, size_t size)
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{
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#if CONFIG_MEMALIGN_HACK
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int diff;
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#endif
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/* let's disallow possibly ambiguous cases */
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if (size > (INT_MAX - 16))
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return NULL;
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#if CONFIG_MEMALIGN_HACK
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//FIXME this isn't aligned correctly, though it probably isn't needed
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if (!ptr)
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return av_malloc(size);
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diff = ((char *)ptr)[-1];
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return (char *)realloc((char *)ptr - diff, size + diff) + diff;
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#elif HAVE_ALIGNED_MALLOC
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return _aligned_realloc(ptr, size, 32);
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#else
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return realloc(ptr, size);
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#endif
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}
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int av_reallocp(void *ptr, size_t size)
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{
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void **ptrptr = ptr;
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void *ret;
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if (!size) {
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av_freep(ptr);
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return 0;
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}
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ret = av_realloc(*ptrptr, size);
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if (!ret) {
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av_freep(ptr);
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return AVERROR(ENOMEM);
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}
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*ptrptr = ret;
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return 0;
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}
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void *av_realloc_array(void *ptr, size_t nmemb, size_t size)
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{
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if (!size || nmemb >= INT_MAX / size)
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return NULL;
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return av_realloc(ptr, nmemb * size);
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}
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int av_reallocp_array(void *ptr, size_t nmemb, size_t size)
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{
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void **ptrptr = ptr;
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void *ret;
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if (!size || nmemb >= INT_MAX / size)
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return AVERROR(ENOMEM);
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if (!nmemb) {
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av_freep(ptr);
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return 0;
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}
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ret = av_realloc(*ptrptr, nmemb * size);
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if (!ret) {
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av_freep(ptr);
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return AVERROR(ENOMEM);
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}
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*ptrptr = ret;
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return 0;
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}
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void av_free(void *ptr)
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{
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#if CONFIG_MEMALIGN_HACK
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if (ptr)
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free((char *)ptr - ((char *)ptr)[-1]);
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#elif HAVE_ALIGNED_MALLOC
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_aligned_free(ptr);
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#else
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free(ptr);
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#endif
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}
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void av_freep(void *arg)
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{
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void **ptr = (void **)arg;
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av_free(*ptr);
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*ptr = NULL;
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}
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void *av_mallocz(size_t size)
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{
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void *ptr = av_malloc(size);
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if (ptr)
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memset(ptr, 0, size);
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return ptr;
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}
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char *av_strdup(const char *s)
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{
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char *ptr = NULL;
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if (s) {
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int len = strlen(s) + 1;
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ptr = av_malloc(len);
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if (ptr)
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memcpy(ptr, s, len);
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}
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return ptr;
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}
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static void fill16(uint8_t *dst, int len)
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{
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uint32_t v = AV_RN16(dst - 2);
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v |= v << 16;
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while (len >= 4) {
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AV_WN32(dst, v);
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dst += 4;
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len -= 4;
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}
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while (len--) {
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*dst = dst[-2];
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dst++;
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}
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}
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static void fill24(uint8_t *dst, int len)
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{
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#if HAVE_BIGENDIAN
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uint32_t v = AV_RB24(dst - 3);
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uint32_t a = v << 8 | v >> 16;
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uint32_t b = v << 16 | v >> 8;
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uint32_t c = v << 24 | v;
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#else
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uint32_t v = AV_RL24(dst - 3);
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uint32_t a = v | v << 24;
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uint32_t b = v >> 8 | v << 16;
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uint32_t c = v >> 16 | v << 8;
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#endif
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while (len >= 12) {
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AV_WN32(dst, a);
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AV_WN32(dst + 4, b);
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AV_WN32(dst + 8, c);
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dst += 12;
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len -= 12;
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}
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if (len >= 4) {
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AV_WN32(dst, a);
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dst += 4;
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len -= 4;
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}
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if (len >= 4) {
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AV_WN32(dst, b);
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dst += 4;
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len -= 4;
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}
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while (len--) {
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*dst = dst[-3];
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dst++;
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}
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}
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static void fill32(uint8_t *dst, int len)
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{
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uint32_t v = AV_RN32(dst - 4);
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while (len >= 4) {
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AV_WN32(dst, v);
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dst += 4;
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len -= 4;
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}
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while (len--) {
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*dst = dst[-4];
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dst++;
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}
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}
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void av_memcpy_backptr(uint8_t *dst, int back, int cnt)
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{
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const uint8_t *src = &dst[-back];
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if (!back)
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return;
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if (back == 1) {
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memset(dst, *src, cnt);
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} else if (back == 2) {
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fill16(dst, cnt);
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} else if (back == 3) {
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fill24(dst, cnt);
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} else if (back == 4) {
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fill32(dst, cnt);
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} else {
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if (cnt >= 16) {
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int blocklen = back;
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while (cnt > blocklen) {
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memcpy(dst, src, blocklen);
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dst += blocklen;
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cnt -= blocklen;
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blocklen <<= 1;
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}
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memcpy(dst, src, cnt);
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return;
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}
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if (cnt >= 8) {
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AV_COPY32U(dst, src);
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AV_COPY32U(dst + 4, src + 4);
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src += 8;
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dst += 8;
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cnt -= 8;
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}
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if (cnt >= 4) {
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AV_COPY32U(dst, src);
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src += 4;
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dst += 4;
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cnt -= 4;
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}
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if (cnt >= 2) {
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AV_COPY16U(dst, src);
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src += 2;
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dst += 2;
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cnt -= 2;
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}
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if (cnt)
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*dst = *src;
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}
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}
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