scummvm/image/codecs/indeo/mem.h
2021-12-26 18:48:43 +01:00

110 lines
3.0 KiB
C++

/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#include "common/scummsys.h"
/* Common memory code used by the Indeo decoder
*
* Original copyright note: * Intel Indeo 4 (IV41, IV42, etc.) video decoder for ffmpeg
* written, produced, and directed by Alan Smithee
*/
#ifndef IMAGE_CODECS_INDEO_MEM_H
#define IMAGE_CODECS_INDEO_MEM_H
namespace Image {
namespace Indeo {
#define FF_ARRAY_ELEMS(a) (sizeof(a) / sizeof((a)[0]))
#define FFALIGN(x, a) (((x) + (a)-1) & ~((a)-1))
#define FFSIGN(a) ((a) > 0 ? 1 : -1)
#define MAX_INTEGER 0x7ffffff
/**
* Free a memory block which has been allocated with a function of av_malloc()
* or av_realloc() family, and set the pointer pointing to it to `NULL`.
*
* @param ptr Pointer to the pointer to the memory block which should be freed
* @note `*ptr = NULL` is safe and leads to no action.
*/
extern void avFreeP(void *arg);
/**
* Allocate, reallocate, or free a block of memory.
*
* This function does the same thing as av_realloc(), except:
* - It takes two size arguments and allocates `nelem * elsize` bytes,
* after checking 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
* @code{.c}
* buf = realloc(buf);
* if (!buf)
* return -1;
* @endcode
* pattern.
*/
extern void *avReallocF(void *ptr, size_t nelem, size_t elsize);
/**
* Reverse "nbits" bits of the value "val" and return the result
* in the least significant bits.
*/
extern uint16 invertBits(uint16 val, int nbits);
/**
* Swap the order of the bytes in the passed value
*/
extern uint32 bitswap32(uint32 x);
/**
* Clip a signed integer value into the 0-255 range.
* @param a value to clip
* @return clipped value
*/
inline uint8 avClipUint8(int a) {
if (a & (~0xFF))
return (-a) >> 31;
else
return a;
}
/**
* Clip a signed integer to an unsigned power of two range.
* @param a value to clip
* @param p bit position to clip at
* @return clipped value
*/
inline unsigned avClipUintp2(int a, int p) {
if (a & ~((1 << p) - 1))
return -a >> 31 & ((1 << p) - 1);
else
return a;
}
extern const uint8 ffZigZagDirect[64];
} // End of namespace Indeo
} // End of namespace Image
#endif