// --------------------------------------------------------------------//	just rename xvid_malloc, xvid_free in xvid to mp4_malloc, mp4_free// --------------------------------------------------------------------#include <stdlib.h>#include <stdio.h>#include "../portab.h"#include "mem_align.h"#if defined(MP4LIB_MASTER) || defined(MP4LIB_HOST)/***************************************************************************** * mp4_malloc * * This function allocates 'size' bytes (usable by the user) on the heap and * takes care of the requested 'alignment'. * In order to align the allocated memory block, the mp4_malloc allocates * 'size' bytes + 'alignment' bytes. So try to keep alignment very small * when allocating small pieces of memory. * * NB : a block allocated by mp4_malloc _must_ be freed with mp4_free *      (the libc free will return an error) * * Returned value : - NULL on error *                  - Pointer to the allocated aligned block * ****************************************************************************/void *mp4_malloc(size_t size,			uint8_t alignment){	uint8_t *mem_ptr;	if (!alignment) {		/* We have not to satisfy any alignment */		if ((mem_ptr = (uint8_t *) MALLOC(size + 1)) != NULL) {			/* Store (mem_ptr - "real allocated memory") in *(mem_ptr-1) */			*mem_ptr = 1;			/* Return the mem_ptr pointer */			return (void *)(mem_ptr+1);		}	} else {		uint8_t *tmp;		/*		 * Allocate the required size memory + alignment so we		 * can realign the data if necessary		 */		if ((tmp = (uint8_t *) MALLOC(size + alignment)) != NULL) {			/* Align the tmp pointer */			mem_ptr =				(uint8_t *) ((ptr_t) (tmp + alignment - 1) &							 (~(ptr_t) (alignment - 1)));			/*			 * Special case where malloc have already satisfied the alignment			 * We must add alignment to mem_ptr because we must store			 * (mem_ptr - tmp) in *(mem_ptr-1)			 * If we do not add alignment to mem_ptr then *(mem_ptr-1) points			 * to a forbidden memory space			 */			if (mem_ptr == tmp)				mem_ptr += alignment;			/*			 * (mem_ptr - tmp) is stored in *(mem_ptr-1) so we are able to retrieve			 * the real malloc block allocated and free it in mp4_free			 */			*(mem_ptr - 1) = (uint8_t) (mem_ptr - tmp);			/* Return the aligned pointer */			return (void *) mem_ptr;		}	}	return NULL;}/***************************************************************************** * mp4_free * * Free a previously 'mp4_malloc' allocated block. Does not free NULL * references. * * Returned value : None. * ****************************************************************************/voidmp4_free(void *mem_ptr){	/* *(mem_ptr - 1) give us the offset to the real malloc block */	if (mem_ptr)		FREE((uint8_t *) mem_ptr - *((uint8_t *) mem_ptr - 1));}#endif