path: root/src/lib/ffmpeg-0.8/libavutil/mem.pas

(*
 * 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
 *
 * This is a part of the Pascal port of ffmpeg.
 * - Changes and updates by the UltraStar Deluxe Team
 *
 * Conversion of libavutil/mem.h
 * avutil version 50.43.0
 *
 *)

(**
 * @file
 * error code definitions
 *)

(* memory handling functions *)
  
(**
 * Allocate a block of size bytes with alignment suitable for all
 * memory accesses (including vectors if available on the CPU).
 * @param size Size in bytes for the memory block to be allocated.
 * @return Pointer to the allocated block, NULL if the block cannot
 * be allocated.
 * @see av_mallocz()
 *)
function av_malloc(size: size_t): pointer;
  cdecl; external av__util; {av_malloc_attrib av_alloc_size(1)}

(**
 * Allocate or reallocate a block of memory.
 * If ptr is NULL and size > 0, allocate a new block. If 
 * size is zero, free the memory block pointed to by ptr.
 * @param size Size in bytes for the memory block to be allocated or
 * reallocated.
 * @param ptr Pointer to a memory block already allocated with
 * av_malloc(z)() or av_realloc() or NULL.
 * @return Pointer to a newly reallocated block or NULL if the block
 * cannot be allocated or the function is used to free the memory block.
 * @see av_fast_realloc()
 *)
function av_realloc(ptr: pointer; size: size_t): pointer;
  cdecl; external av__util; {av_alloc_size(2)}

(**
 * Allocate or reallocate a block of memory.
 * This function does the same thing as av_realloc, except:
 * - It takes two arguments and checks the result of the multiplication for
 *   integer overflow.
 * - It frees the input block in case of failure, thus avoiding the memory
 *   leak with the classic "buf = realloc(buf); if (!buf) return -1;".
 *)
{ available only in 0.8.5 - 0.8.10
function av_realloc_f(ptr: pointer; nelem: size_t; size: size_t): pointer;
  cdecl; external av__util;
}

(**
 * Free a memory block which has been allocated with av_malloc(z)() or
 * av_realloc().
 * @param ptr Pointer to the memory block which should be freed.
 * @note ptr = NULL is explicitly allowed.
 * @note It is recommended that you use av_freep() instead.
 * @see av_freep()
 *)
procedure av_free(ptr: pointer);
  cdecl; external av__util;

(**
 * Allocate a block of size bytes with alignment suitable for all
 * memory accesses (including vectors if available on the CPU) and
 * zeroes all the bytes of the block.
 * @param size Size in bytes for the memory block to be allocated.
 * @return Pointer to the allocated block, NULL if it cannot be allocated.
 * @see av_malloc()
 *)
function av_mallocz(size: size_t): pointer;
  cdecl; external av__util; {av_malloc_attrib av_alloc_size(1)}

(**
 * Allocate a block of nmemb * size bytes with alignment suitable for all
 * memory accesses (including vectors if available on the CPU) and
 * zero all the bytes of the block.
 * The allocation will fail if nmemb * size is greater than or equal
 * to INT_MAX.
 * @param nmemb
 * @param size
 * @return Pointer to the allocated block, NULL if it cannot be allocated.
 *)
(* available only in 0.8.5 - 0.8.10
function av_calloc(nmemb: size_t; size: size_t): pointer;
  cdecl; external av__util; {av_malloc_attrib}
*)

(**
 * Duplicate the string s.
 * @param s string to be duplicated.
 * @return Pointer to a newly allocated string containing a
 * copy of s or NULL if the string cannot be allocated.
 *)
function av_strdup({const} s: PAnsiChar): PAnsiChar;
  cdecl; external av__util; {av_malloc_attrib}

(**
 * Free a memory block which has been allocated with av_malloc(z)() or
 * av_realloc() and set the pointer pointing to it to NULL.
 * @param ptr Pointer to the pointer to the memory block which should
 * be freed.
 * @see av_free()
 *)
procedure av_freep (ptr: pointer);
  cdecl; external av__util;

(**
 * Add an element to a dynamic array.
 *
 * @param tab_ptr Pointer to the array.
 * @param nb_ptr  Pointer to the number of elements in the array.
 * @param elem    Element to be added.
 *)
procedure av_dynarray_add(tab_ptr: pointer; nb_ptr: PCint; elem: pointer);
  cdecl; external av__util;
  
(**
 * Multiply two size_t values checking for overflow.
 * @return  0 if success, AVERROR(EINVAL) if overflow.
 *)
{ available only in 0.8.5 - 0.8.10
//static inline int av_size_mult(size_t a, size_t b, size_t *r)
}
{
    size_t t = a * b;
    /* Hack inspired from glibc: only try the division if nelem and elsize
     * are both greater than sqrt(SIZE_MAX). */
    if ((a | b) >= ((size_t)1 << (sizeof(size_t) * 4)) && a && t / a != b)
        return AVERROR(EINVAL);
    *r = t;
    return 0;
}