VSHelper.h

/*
* Copyright (c) 2012-2015 Fredrik Mellbin
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/

#ifndef VSHELPER_H
#define VSHELPER_H

#include <limits.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#ifdef _WIN32
#include <malloc.h>
#endif
#include "VapourSynth.h"

/* Visual Studio doesn't recognize inline in c mode */
#if defined(_MSC_VER) && !defined(__cplusplus)
#define inline _inline
#endif

/* A kinda portable definition of the C99 restrict keyword (or its inofficial C++ equivalent) */
#if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L /* Available in C99 */
#define VS_RESTRICT restrict
#elif defined(__cplusplus) || defined(_MSC_VER) /* Almost all relevant C++ compilers support it so just assume it works */
#define VS_RESTRICT __restrict
#else /* Not supported */
#define VS_RESTRICT
#endif

#ifdef _WIN32
#define VS_ALIGNED_MALLOC(pptr, size, alignment) do { *(pptr) = _aligned_malloc((size), (alignment)); } while (0)
#define VS_ALIGNED_FREE(ptr) do { _aligned_free((ptr)); } while (0)
#else
#define VS_ALIGNED_MALLOC(pptr, size, alignment) do { if(posix_memalign((void**)(pptr), (alignment), (size))) *((void**)pptr) = NULL; } while (0)
#define VS_ALIGNED_FREE(ptr) do { free((ptr)); } while (0)
#endif

#define VSMAX(a,b) ((a) > (b) ? (a) : (b))
#define VSMIN(a,b) ((a) > (b) ? (b) : (a))

#ifdef __cplusplus
/* A nicer templated malloc for all the C++ users out there */
template<class T>
static inline T* vs_aligned_malloc(size_t size, size_t alignment) {
#ifdef _WIN32
    return (T*)_aligned_malloc(size, alignment);
#else
    void *tmp = NULL;
    if (posix_memalign(&tmp, alignment, size))
        tmp = 0;
    return (T*)tmp;
#endif
}

static inline void vs_aligned_free(void *ptr) {
    VS_ALIGNED_FREE(ptr);
}
#endif /* __cplusplus */

/* convenience function for checking if the format never changes between frames */
static inline int isConstantFormat(const VSVideoInfo *vi) {
    return vi->height > 0 && vi->width > 0 && vi->format;
}

/* convenience function to check for if two clips have the same format (unknown/changeable will be considered the same too) */
static inline int isSameFormat(const VSVideoInfo *v1, const VSVideoInfo *v2) {
    return v1->height == v2->height && v1->width == v2->width && v1->format == v2->format;
}

/* multiplies and divides a rational number, such as a frame duration, in place and reduces the result */
static inline void muldivRational(int64_t *num, int64_t *den, int64_t mul, int64_t div) {
    int64_t a, b;
    *num *= mul;
    *den *= div;
    a = *num;
    b = *den;
    while (b != 0) {
        int64_t t = a;
        a = b;
        b = t % b;
    }
    if (a < 0)
        a = -a;
    *num /= a;
    *den /= a;
}

/* converts an int64 to int with saturation, useful to silence warnings when reading int properties among other things */
static inline int int64ToIntS(int64_t i) {
    if (i > INT_MAX)
        return INT_MAX;
    else if (i < INT_MIN)
        return INT_MIN;
    else return (int)i;
}

static inline void vs_bitblt(void *dstp, int dst_stride, const void *srcp, int src_stride, int row_size, int height) {
    if (height > 0) {
        if (src_stride == dst_stride && src_stride == row_size) {
            memcpy(dstp, srcp, row_size * height);
        } else {
            int i;
            uint8_t *srcp8 = (uint8_t *)srcp;
            uint8_t *dstp8 = (uint8_t *)dstp;
            for (i = 0; i < height; i++) {
                memcpy(dstp8, srcp8, row_size);
                srcp8 += src_stride;
                dstp8 += dst_stride;
            }
        }
    }
}

/* check if the frame dimensions are valid for a given format */
/* returns non-zero for valid width and height */
static inline int areValidDimensions(const VSFormat *fi, int width, int height) {
    return !(width % (1 << fi->subSamplingW) || height % (1 << fi->subSamplingH));
}

#endif