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obs-studio/libobs/util/util_uint64.h
Hans Petter Selasky 0e4ea14ba1 libobs: Implement and use better scaling function for 64-bit integers
As os_gettime_ns() gets large the current scaling methods, mostly by casting
to uint64_t, may lead to numerical overflows. Sweep the code and use
util_mul_div64() where applicable.

Signed-off-by: Hans Petter Selasky <hps@selasky.org>
2020-04-05 20:27:28 +02:00

25 lines
976 B
C

/*
* Copyright (c) 2020 Hans Petter Selasky <hps@selasky.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#pragma once
static inline uint64_t util_mul_div64(uint64_t num, uint64_t mul, uint64_t div)
{
const uint64_t rem = num % div;
return (num / div) * mul + (rem * mul) / div;
}