2 Copyright (C) 2012-2016 Carl Hetherington <cth@carlh.net>
4 This file is part of DCP-o-matic.
6 DCP-o-matic is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 DCP-o-matic is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with DCP-o-matic. If not, see <http://www.gnu.org/licenses/>.
21 #include "frame_rate_change.h"
23 #include "compose.hpp"
31 about_equal (double a, double b)
33 return (fabs (a - b) < VIDEO_FRAME_RATE_EPSILON);
37 FrameRateChange::FrameRateChange (double source_, int dcp_)
42 , change_speed (false)
44 if (fabs (source / 2.0 - dcp) < fabs (source - dcp)) {
45 /* The difference between source and DCP frame rate will be lower
46 (i.e. better) if we skip.
49 } else if (fabs (source * 2 - dcp) < fabs (source - dcp)) {
50 /* The difference between source and DCP frame rate would be better
51 if we repeated each frame once; it may be better still if we
52 repeated more than once. Work out the required repeat.
54 repeat = round (dcp / source);
57 speed_up = dcp / (source * factor());
58 change_speed = !about_equal (speed_up, 1.0);
62 FrameRateChange::description () const
66 if (!skip && repeat == 1 && !change_speed) {
67 description = _("Content and DCP have the same rate.\n");
70 description = _("DCP will use every other frame of the content.\n");
71 } else if (repeat == 2) {
72 description = _("Each content frame will be doubled in the DCP.\n");
73 } else if (repeat > 2) {
74 description = String::compose (_("Each content frame will be repeated %1 more times in the DCP.\n"), repeat - 1);
78 double const pc = dcp * 100 / (source * factor());
79 description += String::compose (_("DCP will run at %1%% of the content speed.\n"), pc);