1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
|
(*
* rational numbers
* Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* This is a part of Pascal porting of ffmpeg.
* - Originally by Victor Zinetz for Delphi and Free Pascal on Windows.
* - For Mac OS X, some modifications were made by The Creative CAT, denoted as CAT
* in the source codes.
* - Changes and updates by the UltraStar Deluxe Team
*
* Conversion of libavutil/rational.h
* avutil version 50.43.0
*
*)
unit rational;
{$IFDEF FPC}
{$MODE DELPHI}
{$PACKENUM 4} (* use 4-byte enums *)
{$PACKRECORDS C} (* C/C++-compatible record packing *)
{$ELSE}
{$MINENUMSIZE 4} (* use 4-byte enums *)
{$ENDIF}
{$I switches.inc}
interface
uses
ctypes,
UConfig;
type
(*
* rational number numerator/denominator
*)
PAVRational = ^TAVRational;
TAVRational = record
num: cint; ///< numerator
den: cint; ///< denominator
end;
TAVRationalArray = array[0 .. (MaxInt div SizeOf(TAVRational))-1] of TAVRational;
PAVRationalArray = ^TAVRationalArray;
(**
* Compare two rationals.
* @param a first rational
* @param b second rational
* @return 0 if a==b, 1 if a>b and -1 if a<b
*)
function av_cmp_q(a: TAVRational; b: TAVRational): cint; {$IFDEF HasInline}inline;{$ENDIF}
(**
* Convert rational to double.
* @param a rational to convert
* @return (double) a
*)
function av_q2d(a: TAVRational): cdouble; {$IFDEF HasInline}inline;{$ENDIF}
(**
* Reduce a fraction.
* This is useful for framerate calculations.
* @param dst_num destination numerator
* @param dst_den destination denominator
* @param num source numerator
* @param den source denominator
* @param max the maximum allowed for dst_num & dst_den
* @return 1 if exact, 0 otherwise
*)
function av_reduce(dst_num: PCint; dst_den: PCint; num: cint64; den: cint64; max: cint64): cint;
cdecl; external av__util;
(**
* Multiply two rationals.
* @param b first rational
* @param c second rational
* @return b*c
*)
function av_mul_q(b: TAVRational; c: TAVRational): TAVRational;
cdecl; external av__util; {av_const}
(**
* Divide one rational by another.
* @param b first rational
* @param c second rational
* @return b/c
*)
function av_div_q(b: TAVRational; c: TAVRational): TAVRational;
cdecl; external av__util; {av_const}
(**
* Add two rationals.
* @param b first rational
* @param c second rational
* @return b+c
*)
function av_add_q(b: TAVRational; c: TAVRational): TAVRational;
cdecl; external av__util; {av_const}
(**
* Subtract one rational from another.
* @param b first rational
* @param c second rational
* @return b-c
*)
function av_sub_q(b: TAVRational; c: TAVRational): TAVRational;
cdecl; external av__util; {av_const}
(**
* Convert a double precision floating point number to a rational.
* inf is expressed as {1,0} or {-1,0} depending on the sign.
*
* @param d double to convert
* @param max the maximum allowed numerator and denominator
* @return (AVRational) d
*)
function av_d2q(d: cdouble; max: cint): TAVRational;
cdecl; external av__util; {av_const}
(**
* @return 1 if q1 is nearer to q than q2, -1 if q2 is nearer
* than q1, 0 if they have the same distance.
*)
function av_nearer_q(q, q1, q2: TAVRational): cint;
cdecl; external av__util;
(**
* Find the nearest value in q_list to q.
* @param q_list an array of rationals terminated by {0, 0}
* @return the index of the nearest value found in the array
*)
function av_find_nearest_q_idx(q: TAVRational; q_list: {const} PAVRationalArray): cint;
cdecl; external av__util;
implementation
// This corresponds to the old c version and should be updated to
// the new c version.
function av_cmp_q (a: TAVRational; b: TAVRational): cint;
var
tmp: cint64;
begin
tmp := a.num * cint64(b.den) - b.num * cint64(a.den);
if (tmp <> 0) then
Result := (tmp shr 63) or 1
else
Result := 0
end;
function av_q2d(a: TAVRational): cdouble;
begin
Result := a.num / a.den;
end;
end.
|
