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258 lines
9.7 KiB
258 lines
9.7 KiB
/* |
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* copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at> |
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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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* memory handling functions |
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*/ |
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#ifndef AVUTIL_MEM_H |
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#define AVUTIL_MEM_H |
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#include <limits.h> |
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#include <stdint.h> |
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#include "attributes.h" |
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#include "avutil.h" |
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/** |
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* @addtogroup lavu_mem |
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* @{ |
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*/ |
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#if defined(__ICC) && __ICC < 1200 || defined(__SUNPRO_C) |
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#define DECLARE_ALIGNED(n,t,v) t __attribute__ ((aligned (n))) v |
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#define DECLARE_ASM_CONST(n,t,v) const t __attribute__ ((aligned (n))) v |
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#elif defined(__GNUC__) || defined(__clang__) |
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#define DECLARE_ALIGNED(n,t,v) t __attribute__ ((aligned (n))) v |
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#define DECLARE_ASM_CONST(n,t,v) static const t av_used __attribute__ ((aligned (n))) v |
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#elif defined(_MSC_VER) |
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#define DECLARE_ALIGNED(n,t,v) __declspec(align(n)) t v |
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#define DECLARE_ASM_CONST(n,t,v) __declspec(align(n)) static const t v |
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#else |
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#define DECLARE_ALIGNED(n,t,v) t v |
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#define DECLARE_ASM_CONST(n,t,v) static const t v |
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#endif |
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#if AV_GCC_VERSION_AT_LEAST(3,1) |
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#define av_malloc_attrib __attribute__((__malloc__)) |
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#else |
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#define av_malloc_attrib |
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#endif |
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#if AV_GCC_VERSION_AT_LEAST(4,3) |
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#define av_alloc_size(...) __attribute__((alloc_size(__VA_ARGS__))) |
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#else |
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#define av_alloc_size(...) |
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#endif |
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/** |
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* Allocate a block of size bytes with alignment suitable for all |
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* memory accesses (including vectors if available on the CPU). |
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* @param size Size in bytes for the memory block to be allocated. |
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* @return Pointer to the allocated block, NULL if the block cannot |
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* be allocated. |
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* @see av_mallocz() |
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*/ |
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void *av_malloc(size_t size) av_malloc_attrib av_alloc_size(1); |
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/** |
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* Allocate a block of size * nmemb bytes with av_malloc(). |
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* @param nmemb Number of elements |
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* @param size Size of the single element |
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* @return Pointer to the allocated block, NULL if the block cannot |
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* be allocated. |
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* @see av_malloc() |
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*/ |
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av_alloc_size(1, 2) void *av_malloc_array(size_t nmemb, size_t size); |
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/** |
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* Allocate or reallocate a block of memory. |
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* If ptr is NULL and size > 0, allocate a new block. If |
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* size is zero, free the memory block pointed to by ptr. |
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* @param ptr Pointer to a memory block already allocated with |
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* av_realloc() or NULL. |
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* @param size Size in bytes of the memory block to be allocated or |
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* reallocated. |
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* @return Pointer to a newly-reallocated block or NULL if the block |
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* cannot be reallocated or the function is used to free the memory block. |
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* @warning Pointers originating from the av_malloc() family of functions must |
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* not be passed to av_realloc(). The former can be implemented using |
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* memalign() (or other functions), and there is no guarantee that |
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* pointers from such functions can be passed to realloc() at all. |
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* The situation is undefined according to POSIX and may crash with |
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* some libc implementations. |
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* @see av_fast_realloc() |
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*/ |
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void *av_realloc(void *ptr, size_t size) av_alloc_size(2); |
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/** |
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* Allocate or reallocate a block of memory. |
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* If *ptr is NULL and size > 0, allocate a new block. If |
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* size is zero, free the memory block pointed to by ptr. |
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* @param ptr Pointer to a pointer to a memory block already allocated |
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* with av_realloc(), or pointer to a pointer to NULL. |
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* The pointer is updated on success, or freed on failure. |
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* @param size Size in bytes for the memory block to be allocated or |
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* reallocated |
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* @return Zero on success, an AVERROR error code on failure. |
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* @warning Pointers originating from the av_malloc() family of functions must |
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* not be passed to av_reallocp(). The former can be implemented using |
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* memalign() (or other functions), and there is no guarantee that |
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* pointers from such functions can be passed to realloc() at all. |
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* The situation is undefined according to POSIX and may crash with |
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* some libc implementations. |
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*/ |
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int av_reallocp(void *ptr, size_t size); |
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/** |
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* Allocate or reallocate an array. |
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* If ptr is NULL and nmemb > 0, allocate a new block. If |
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* nmemb is zero, free the memory block pointed to by ptr. |
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* @param ptr Pointer to a memory block already allocated with |
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* av_realloc() or NULL. |
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* @param nmemb Number of elements |
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* @param size Size of the single element |
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* @return Pointer to a newly-reallocated block or NULL if the block |
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* cannot be reallocated or the function is used to free the memory block. |
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* @warning Pointers originating from the av_malloc() family of functions must |
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* not be passed to av_realloc(). The former can be implemented using |
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* memalign() (or other functions), and there is no guarantee that |
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* pointers from such functions can be passed to realloc() at all. |
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* The situation is undefined according to POSIX and may crash with |
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* some libc implementations. |
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*/ |
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av_alloc_size(2, 3) void *av_realloc_array(void *ptr, size_t nmemb, size_t size); |
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/** |
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* Allocate or reallocate an array through a pointer to a pointer. |
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* If *ptr is NULL and nmemb > 0, allocate a new block. If |
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* nmemb is zero, free the memory block pointed to by ptr. |
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* @param ptr Pointer to a pointer to a memory block already allocated |
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* with av_realloc(), or pointer to a pointer to NULL. |
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* The pointer is updated on success, or freed on failure. |
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* @param nmemb Number of elements |
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* @param size Size of the single element |
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* @return Zero on success, an AVERROR error code on failure. |
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* @warning Pointers originating from the av_malloc() family of functions must |
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* not be passed to av_realloc(). The former can be implemented using |
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* memalign() (or other functions), and there is no guarantee that |
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* pointers from such functions can be passed to realloc() at all. |
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* The situation is undefined according to POSIX and may crash with |
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* some libc implementations. |
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*/ |
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av_alloc_size(2, 3) int av_reallocp_array(void *ptr, size_t nmemb, size_t size); |
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/** |
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* Free a memory block which has been allocated with av_malloc(z)() or |
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* av_realloc(). |
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* @param ptr Pointer to the memory block which should be freed. |
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* @note ptr = NULL is explicitly allowed. |
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* @note It is recommended that you use av_freep() instead. |
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* @see av_freep() |
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*/ |
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void av_free(void *ptr); |
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/** |
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* Allocate a block of size bytes with alignment suitable for all |
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* memory accesses (including vectors if available on the CPU) and |
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* zero all the bytes of the block. |
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* @param size Size in bytes for the memory block to be allocated. |
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* @return Pointer to the allocated block, NULL if it cannot be allocated. |
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* @see av_malloc() |
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*/ |
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void *av_mallocz(size_t size) av_malloc_attrib av_alloc_size(1); |
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/** |
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* Allocate a block of size * nmemb bytes with av_mallocz(). |
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* @param nmemb Number of elements |
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* @param size Size of the single element |
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* @return Pointer to the allocated block, NULL if the block cannot |
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* be allocated. |
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* @see av_mallocz() |
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* @see av_malloc_array() |
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*/ |
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av_alloc_size(1, 2) void *av_mallocz_array(size_t nmemb, size_t size); |
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/** |
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* Duplicate the string s. |
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* @param s string to be duplicated |
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* @return Pointer to a newly-allocated string containing a |
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* copy of s or NULL if the string cannot be allocated. |
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*/ |
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char *av_strdup(const char *s) av_malloc_attrib; |
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/** |
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* Duplicate a substring of the string s. |
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* @param s string to be duplicated |
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* @param len the maximum length of the resulting string (not counting the |
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* terminating byte). |
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* @return Pointer to a newly-allocated string containing a |
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* copy of s or NULL if the string cannot be allocated. |
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*/ |
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char *av_strndup(const char *s, size_t len) av_malloc_attrib; |
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/** |
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* Free a memory block which has been allocated with av_malloc(z)() or |
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* av_realloc() and set the pointer pointing to it to NULL. |
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* @param ptr Pointer to the pointer to the memory block which should |
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* be freed. |
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* @see av_free() |
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*/ |
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void av_freep(void *ptr); |
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/** |
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* deliberately overlapping memcpy implementation |
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* @param dst destination buffer |
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* @param back how many bytes back we start (the initial size of the overlapping window) |
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* @param cnt number of bytes to copy, must be >= 0 |
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* |
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* cnt > back is valid, this will copy the bytes we just copied, |
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* thus creating a repeating pattern with a period length of back. |
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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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* Reallocate the given block if it is not large enough, otherwise do nothing. |
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* |
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* @see av_realloc |
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*/ |
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void *av_fast_realloc(void *ptr, unsigned int *size, size_t min_size); |
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/** |
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* Allocate a buffer, reusing the given one if large enough. |
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* |
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* Contrary to av_fast_realloc the current buffer contents might not be |
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* preserved and on error the old buffer is freed, thus no special |
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* handling to avoid memleaks is necessary. |
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* |
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* @param ptr pointer to pointer to already allocated buffer, overwritten with pointer to new buffer |
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* @param size size of the buffer *ptr points to |
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* @param min_size minimum size of *ptr buffer after returning, *ptr will be NULL and |
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* *size 0 if an error occurred. |
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*/ |
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void av_fast_malloc(void *ptr, unsigned int *size, size_t min_size); |
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/** |
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* @} |
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*/ |
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#endif /* AVUTIL_MEM_H */
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