xref: /aosp_15_r20/external/libvpx/vpx_util/vpx_timestamp.h (revision fb1b10ab9aebc7c7068eedab379b749d7e3900be)
1*fb1b10abSAndroid Build Coastguard Worker /*
2*fb1b10abSAndroid Build Coastguard Worker  *  Copyright (c) 2019 The WebM project authors. All Rights Reserved.
3*fb1b10abSAndroid Build Coastguard Worker  *
4*fb1b10abSAndroid Build Coastguard Worker  *  Use of this source code is governed by a BSD-style license
5*fb1b10abSAndroid Build Coastguard Worker  *  that can be found in the LICENSE file in the root of the source
6*fb1b10abSAndroid Build Coastguard Worker  *  tree. An additional intellectual property rights grant can be found
7*fb1b10abSAndroid Build Coastguard Worker  *  in the file PATENTS.  All contributing project authors may
8*fb1b10abSAndroid Build Coastguard Worker  *  be found in the AUTHORS file in the root of the source tree.
9*fb1b10abSAndroid Build Coastguard Worker  */
10*fb1b10abSAndroid Build Coastguard Worker 
11*fb1b10abSAndroid Build Coastguard Worker #ifndef VPX_VPX_UTIL_VPX_TIMESTAMP_H_
12*fb1b10abSAndroid Build Coastguard Worker #define VPX_VPX_UTIL_VPX_TIMESTAMP_H_
13*fb1b10abSAndroid Build Coastguard Worker 
14*fb1b10abSAndroid Build Coastguard Worker #include <assert.h>
15*fb1b10abSAndroid Build Coastguard Worker 
16*fb1b10abSAndroid Build Coastguard Worker #ifdef __cplusplus
17*fb1b10abSAndroid Build Coastguard Worker extern "C" {
18*fb1b10abSAndroid Build Coastguard Worker #endif  // __cplusplus
19*fb1b10abSAndroid Build Coastguard Worker 
20*fb1b10abSAndroid Build Coastguard Worker // Rational Number with an int64 numerator
21*fb1b10abSAndroid Build Coastguard Worker typedef struct vpx_rational64 {
22*fb1b10abSAndroid Build Coastguard Worker   int64_t num;       // fraction numerator
23*fb1b10abSAndroid Build Coastguard Worker   int den;           // fraction denominator
24*fb1b10abSAndroid Build Coastguard Worker } vpx_rational64_t;  // alias for struct vpx_rational64_t
25*fb1b10abSAndroid Build Coastguard Worker 
gcd(int64_t a,int b)26*fb1b10abSAndroid Build Coastguard Worker static INLINE int gcd(int64_t a, int b) {
27*fb1b10abSAndroid Build Coastguard Worker   int r;  // remainder
28*fb1b10abSAndroid Build Coastguard Worker   assert(a >= 0);
29*fb1b10abSAndroid Build Coastguard Worker   assert(b > 0);
30*fb1b10abSAndroid Build Coastguard Worker   while (b != 0) {
31*fb1b10abSAndroid Build Coastguard Worker     r = (int)(a % b);
32*fb1b10abSAndroid Build Coastguard Worker     a = b;
33*fb1b10abSAndroid Build Coastguard Worker     b = r;
34*fb1b10abSAndroid Build Coastguard Worker   }
35*fb1b10abSAndroid Build Coastguard Worker 
36*fb1b10abSAndroid Build Coastguard Worker   return (int)a;
37*fb1b10abSAndroid Build Coastguard Worker }
38*fb1b10abSAndroid Build Coastguard Worker 
reduce_ratio(vpx_rational64_t * ratio)39*fb1b10abSAndroid Build Coastguard Worker static INLINE void reduce_ratio(vpx_rational64_t *ratio) {
40*fb1b10abSAndroid Build Coastguard Worker   const int denom = gcd(ratio->num, ratio->den);
41*fb1b10abSAndroid Build Coastguard Worker   ratio->num /= denom;
42*fb1b10abSAndroid Build Coastguard Worker   ratio->den /= denom;
43*fb1b10abSAndroid Build Coastguard Worker }
44*fb1b10abSAndroid Build Coastguard Worker 
45*fb1b10abSAndroid Build Coastguard Worker #ifdef __cplusplus
46*fb1b10abSAndroid Build Coastguard Worker }  // extern "C"
47*fb1b10abSAndroid Build Coastguard Worker #endif  // __cplusplus
48*fb1b10abSAndroid Build Coastguard Worker 
49*fb1b10abSAndroid Build Coastguard Worker #endif  // VPX_VPX_UTIL_VPX_TIMESTAMP_H_
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