1 ///////////////////////////////////////////////////////////////////////////
2 //
3 // Copyright (c) 2006, Industrial Light & Magic, a division of Lucas
4 // Digital Ltd. LLC
5 //
6 // All rights reserved.
7 //
8 // Redistribution and use in source and binary forms, with or without
9 // modification, are permitted provided that the following conditions are
10 // met:
11 // * Redistributions of source code must retain the above copyright
12 // notice, this list of conditions and the following disclaimer.
13 // * Redistributions in binary form must reproduce the above
14 // copyright notice, this list of conditions and the following disclaimer
15 // in the documentation and/or other materials provided with the
16 // distribution.
17 // * Neither the name of Industrial Light & Magic nor the names of
18 // its contributors may be used to endorse or promote products derived
19 // from this software without specific prior written permission.
20 //
21 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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27 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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30 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 //
33 ///////////////////////////////////////////////////////////////////////////
34
35
36 #ifndef INCLUDED_IMF_FRAMES_PER_SECOND_H
37 #define INCLUDED_IMF_FRAMES_PER_SECOND_H
38
39 //-----------------------------------------------------------------------------
40 //
41 // Convenience functions related to the framesPerSecond attribute
42 //
43 // Functions that return the exact values for commonly used frame rates:
44 //
45 // name frames per second
46 //
47 // fps_23_976() 23.976023...
48 // fps_24() 24.0 35mm film frames
49 // fps_25() 25.0 PAL video frames
50 // fps_29_97() 29.970029... NTSC video frames
51 // fps_30() 30.0 60Hz HDTV frames
52 // fps_47_952() 47.952047...
53 // fps_48() 48.0
54 // fps_50() 50.0 PAL video fields
55 // fps_59_94() 59.940059... NTSC video fields
56 // fps_60() 60.0 60Hz HDTV fields
57 //
58 // Functions that try to convert inexact frame rates into exact ones:
59 //
60 // Given a frame rate, fps, that is close to one of the pre-defined
61 // frame rates fps_23_976(), fps_29_97(), fps_47_952() or fps_59_94(),
62 // guessExactFps(fps) returns the corresponding pre-defined frame
63 // rate. If fps is not close to one of the pre-defined frame rates,
64 // then guessExactFps(fps) returns Rational(fps).
65 //
66 //-----------------------------------------------------------------------------
67
68 #include <ImfRational.h>
69
70 namespace Imf {
71
fps_23_976()72 inline Rational fps_23_976 () {return Rational (24000, 1001);}
fps_24()73 inline Rational fps_24 () {return Rational (24, 1);}
fps_25()74 inline Rational fps_25 () {return Rational (25, 1);}
fps_29_97()75 inline Rational fps_29_97 () {return Rational (30000, 1001);}
fps_30()76 inline Rational fps_30 () {return Rational (30, 1);}
fps_47_952()77 inline Rational fps_47_952 () {return Rational (48000, 1001);}
fps_48()78 inline Rational fps_48 () {return Rational (48, 1);}
fps_50()79 inline Rational fps_50 () {return Rational (50, 1);}
fps_59_94()80 inline Rational fps_59_94 () {return Rational (60000, 1001);}
fps_60()81 inline Rational fps_60 () {return Rational (60, 1);}
82
83 Rational guessExactFps (double fps);
84 Rational guessExactFps (const Rational &fps);
85
86 } // namespace Imf
87
88 #endif
89