## ffmpeg / libavutil / rational.h @ d370e3e9

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1 | 5ff85f1d | Michael Niedermayer | ```
/*
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2 | 89c9ff50 | Diego Biurrun | ```
* rational numbers
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3 | 5ff85f1d | Michael Niedermayer | ```
* Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
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4 | ```
*
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5 | b78e7197 | Diego Biurrun | ```
* This file is part of FFmpeg.
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6 | ```
*
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7 | ```
* FFmpeg is free software; you can redistribute it and/or
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8 | 5ff85f1d | Michael Niedermayer | ```
* modify it under the terms of the GNU Lesser General Public
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9 | ```
* License as published by the Free Software Foundation; either
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10 | b78e7197 | Diego Biurrun | ```
* version 2.1 of the License, or (at your option) any later version.
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11 | 5ff85f1d | Michael Niedermayer | ```
*
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12 | b78e7197 | Diego Biurrun | ```
* FFmpeg is distributed in the hope that it will be useful,
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13 | 5ff85f1d | Michael Niedermayer | ```
* but WITHOUT ANY WARRANTY; without even the implied warranty of
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14 | ```
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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15 | ```
* Lesser General Public License for more details.
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16 | ```
*
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17 | ```
* You should have received a copy of the GNU Lesser General Public
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18 | b78e7197 | Diego Biurrun | ```
* License along with FFmpeg; if not, write to the Free Software
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19 | 5509bffa | Diego Biurrun | ```
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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20 | 5ff85f1d | Michael Niedermayer | ```
*/
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21 | 115329f1 | Diego Biurrun | |

22 | 5ff85f1d | Michael Niedermayer | ```
/**
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23 | ba87f080 | Diego Biurrun | ```
* @file
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24 | 89c9ff50 | Diego Biurrun | ```
* rational numbers
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25 | 5ff85f1d | Michael Niedermayer | ```
* @author Michael Niedermayer <michaelni@gmx.at>
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26 | ```
*/
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27 | |||

28 | 98790382 | Stefano Sabatini | ```
#ifndef AVUTIL_RATIONAL_H
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29 | ```
#define AVUTIL_RATIONAL_H
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30 | 5ff85f1d | Michael Niedermayer | |

31 | 99545457 | Måns Rullgård | #include <stdint.h> |

32 | dec11269 | Michael Niedermayer | #include <limits.h> |

33 | 2ed6f399 | Måns Rullgård | #include "attributes.h" |

34 | 99545457 | Måns Rullgård | |

35 | 5c07b9e9 | Michael Niedermayer | ```
/**
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36 | 89c9ff50 | Diego Biurrun | ```
* rational number numerator/denominator
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37 | 5c07b9e9 | Michael Niedermayer | ```
*/
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38 | 5ff85f1d | Michael Niedermayer | typedef struct AVRational{ |

39 | 5c07b9e9 | Michael Niedermayer | int num; ///< numerator |

40 | int den; ///< denominator |
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41 | 5ff85f1d | Michael Niedermayer | } AVRational; |

42 | |||

43 | 5c07b9e9 | Michael Niedermayer | ```
/**
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44 | 49bd8e4b | Måns Rullgård | ```
* Compare two rationals.
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45 | 1c95ef8b | Dujardin Bernard | ```
* @param a first rational
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46 | ```
* @param b second rational
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47 | 3a1429ec | Stefano Sabatini | ```
* @return 0 if a==b, 1 if a>b, -1 if a<b, and INT_MIN if one of the
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48 | ```
* values is of the form 0/0
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49 | 5c07b9e9 | Michael Niedermayer | ```
*/
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50 | 5ff85f1d | Michael Niedermayer | static inline int av_cmp_q(AVRational a, AVRational b){ |

51 | ```
const int64_t tmp= a.num * (int64_t)b.den - b.num * (int64_t)a.den;
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52 | |||

53 | 8a47d90b | Michael Niedermayer | if(tmp) return ((tmp ^ a.den ^ b.den)>>63)|1; |

54 | dec11269 | Michael Niedermayer | else if(b.den && a.den) return 0; |

55 | else if(a.num && b.num) return (a.num>>31) - (b.num>>31); |
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56 | else return INT_MIN; |
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57 | 5ff85f1d | Michael Niedermayer | } |

58 | |||

59 | 5c07b9e9 | Michael Niedermayer | ```
/**
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60 | 49bd8e4b | Måns Rullgård | ```
* Convert rational to double.
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61 | 1c95ef8b | Dujardin Bernard | ```
* @param a rational to convert
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62 | ```
* @return (double) a
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63 | 5c07b9e9 | Michael Niedermayer | ```
*/
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64 | 5ff85f1d | Michael Niedermayer | static inline double av_q2d(AVRational a){ |

65 | return a.num / (double) a.den; |
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66 | } |
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67 | |||

68 | c11c2bc2 | Alexander Strasser | ```
/**
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69 | 49bd8e4b | Måns Rullgård | ```
* Reduce a fraction.
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70 | 804de96a | Diego Biurrun | ```
* This is useful for framerate calculations.
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71 | 674bd4f6 | Diego Biurrun | ```
* @param dst_num destination numerator
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72 | 1c95ef8b | Dujardin Bernard | ```
* @param dst_den destination denominator
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73 | 674bd4f6 | Diego Biurrun | ```
* @param num source numerator
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74 | 1c95ef8b | Dujardin Bernard | ```
* @param den source denominator
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75 | 674bd4f6 | Diego Biurrun | ```
* @param max the maximum allowed for dst_num & dst_den
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76 | c11c2bc2 | Alexander Strasser | ```
* @return 1 if exact, 0 otherwise
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77 | ```
*/
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78 | 674bd4f6 | Diego Biurrun | int av_reduce(int *dst_num, int *dst_den, int64_t num, int64_t den, int64_t max); |

79 | c11c2bc2 | Alexander Strasser | |

80 | 0b006599 | Dujardin Bernard | ```
/**
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81 | 49bd8e4b | Måns Rullgård | ```
* Multiply two rationals.
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82 | 89c9ff50 | Diego Biurrun | ```
* @param b first rational
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83 | ```
* @param c second rational
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84 | ```
* @return b*c
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85 | 0b006599 | Dujardin Bernard | ```
*/
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86 | 85074d3c | Zuxy Meng | AVRational av_mul_q(AVRational b, AVRational c) av_const; |

87 | 0b006599 | Dujardin Bernard | |

88 | ```
/**
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89 | 49bd8e4b | Måns Rullgård | ```
* Divide one rational by another.
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90 | 89c9ff50 | Diego Biurrun | ```
* @param b first rational
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91 | ```
* @param c second rational
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92 | ```
* @return b/c
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93 | 0b006599 | Dujardin Bernard | ```
*/
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94 | 85074d3c | Zuxy Meng | AVRational av_div_q(AVRational b, AVRational c) av_const; |

95 | 0b006599 | Dujardin Bernard | |

96 | ```
/**
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97 | 49bd8e4b | Måns Rullgård | ```
* Add two rationals.
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98 | 89c9ff50 | Diego Biurrun | ```
* @param b first rational
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99 | ```
* @param c second rational
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100 | ```
* @return b+c
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101 | 0b006599 | Dujardin Bernard | ```
*/
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102 | 85074d3c | Zuxy Meng | AVRational av_add_q(AVRational b, AVRational c) av_const; |

103 | 0b006599 | Dujardin Bernard | |

104 | ```
/**
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105 | 49bd8e4b | Måns Rullgård | ```
* Subtract one rational from another.
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106 | 89c9ff50 | Diego Biurrun | ```
* @param b first rational
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107 | ```
* @param c second rational
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108 | ```
* @return b-c
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109 | 0b006599 | Dujardin Bernard | ```
*/
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110 | 85074d3c | Zuxy Meng | AVRational av_sub_q(AVRational b, AVRational c) av_const; |

111 | 0b006599 | Dujardin Bernard | |

112 | ```
/**
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113 | 49bd8e4b | Måns Rullgård | ```
* Convert a double precision floating point number to a rational.
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114 | 6b4ed22f | Stefano Sabatini | ```
* inf is expressed as {1,0} or {-1,0} depending on the sign.
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115 | ```
*
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116 | 0b006599 | Dujardin Bernard | ```
* @param d double to convert
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117 | ```
* @param max the maximum allowed numerator and denominator
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118 | 89c9ff50 | Diego Biurrun | ```
* @return (AVRational) d
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119 | 0b006599 | Dujardin Bernard | ```
*/
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120 | 85074d3c | Zuxy Meng | AVRational av_d2q(double d, int max) av_const; |

121 | 5ff85f1d | Michael Niedermayer | |

122 | 05b90fc0 | Stefano Sabatini | ```
/**
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123 | bf7e799c | Stefano Sabatini | ```
* @return 1 if q1 is nearer to q than q2, -1 if q2 is nearer
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124 | ```
* than q1, 0 if they have the same distance.
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125 | 05b90fc0 | Stefano Sabatini | ```
*/
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126 | ```
int av_nearer_q(AVRational q, AVRational q1, AVRational q2);
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127 | |||

128 | ```
/**
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129 | 49bd8e4b | Måns Rullgård | ```
* Find the nearest value in q_list to q.
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130 | 05b90fc0 | Stefano Sabatini | ```
* @param q_list an array of rationals terminated by {0, 0}
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131 | ```
* @return the index of the nearest value found in the array
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132 | ```
*/
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133 | int av_find_nearest_q_idx(AVRational q, const AVRational* q_list); |
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134 | |||

135 | 98790382 | Stefano Sabatini | #endif /* AVUTIL_RATIONAL_H */ |