2 Copyright (C) 2012-2020 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 "video_decoder.h"
23 #include "raw_image_proxy.h"
26 #include "frame_interval_checker.h"
27 #include "compose.hpp"
35 using std::back_inserter;
36 using std::shared_ptr;
37 using boost::optional;
38 using namespace dcpomatic;
40 VideoDecoder::VideoDecoder (Decoder* parent, shared_ptr<const Content> c)
41 : DecoderPart (parent)
43 , _frame_interval_checker (new FrameIntervalChecker())
48 /** Called by decoder classes when they have a video frame ready.
49 * @param frame Frame index within the content; this does not take into account 3D
50 * so for 3D_ALTERNATE this value goes:
58 VideoDecoder::emit (shared_ptr<const Film> film, shared_ptr<const ImageProxy> image, Frame decoder_frame)
64 double const afr = _content->active_video_frame_rate(film);
65 VideoFrameType const vft = _content->video->frame_type();
67 ContentTime frame_time = ContentTime::from_frames (decoder_frame, afr);
69 /* Do some heuristics to try and spot the case where the user sets content to 3D
70 * when it is not. We try to tell this by looking at the differences in time between
71 * the first few frames. Real 3D content should have two frames for each timestamp.
73 if (_frame_interval_checker) {
74 _frame_interval_checker->feed (frame_time, afr);
75 if (_frame_interval_checker->guess() == FrameIntervalChecker::PROBABLY_NOT_3D && vft == VideoFrameType::THREE_D) {
76 boost::throw_exception (
79 _("The content file %1 is set as 3D but does not appear to contain 3D images. Please set it to 2D. "
80 "You can still make a 3D DCP from this content by ticking the 3D option in the DCP video tab."),
87 if (_frame_interval_checker->guess() != FrameIntervalChecker::AGAIN) {
88 _frame_interval_checker.reset ();
93 Eyes eyes = Eyes::BOTH;
95 /* This is the first data we have received since initialisation or seek. Set
96 the position based on the frame that was given. After this first time
97 we just cound frames, since (as with audio) it seems that ContentTimes
98 are unreliable from FFmpegDecoder. They are much better than audio times
99 but still we get the occasional one which is duplicated. In this case
100 ffmpeg seems to carry on regardless, processing the video frame as normal.
101 If we drop the frame with the duplicated timestamp we obviously lose sync.
103 _position = ContentTime::from_frames (decoder_frame, afr);
104 if (vft == VideoFrameType::THREE_D_ALTERNATE) {
105 frame = decoder_frame / 2;
106 _last_emitted_eyes = Eyes::RIGHT;
108 frame = decoder_frame;
111 if (vft == VideoFrameType::THREE_D || vft == VideoFrameType::THREE_D_ALTERNATE) {
112 DCPOMATIC_ASSERT (_last_emitted_eyes);
113 if (_last_emitted_eyes.get() == Eyes::RIGHT) {
114 frame = _position->frames_round(afr) + 1;
117 frame = _position->frames_round(afr);
121 frame = _position->frames_round(afr) + 1;
126 case VideoFrameType::TWO_D:
127 Data (ContentVideo (image, frame, Eyes::BOTH, Part::WHOLE));
129 case VideoFrameType::THREE_D:
131 Data (ContentVideo (image, frame, eyes, Part::WHOLE));
132 _last_emitted_frame = frame;
133 _last_emitted_eyes = eyes;
136 case VideoFrameType::THREE_D_ALTERNATE:
138 Data (ContentVideo (image, frame, eyes, Part::WHOLE));
139 _last_emitted_eyes = eyes;
142 case VideoFrameType::THREE_D_LEFT_RIGHT:
143 Data (ContentVideo (image, frame, Eyes::LEFT, Part::LEFT_HALF));
144 Data (ContentVideo (image, frame, Eyes::RIGHT, Part::RIGHT_HALF));
146 case VideoFrameType::THREE_D_TOP_BOTTOM:
147 Data (ContentVideo (image, frame, Eyes::LEFT, Part::TOP_HALF));
148 Data (ContentVideo (image, frame, Eyes::RIGHT, Part::BOTTOM_HALF));
150 case VideoFrameType::THREE_D_LEFT:
151 Data (ContentVideo (image, frame, Eyes::LEFT, Part::WHOLE));
153 case VideoFrameType::THREE_D_RIGHT:
154 Data (ContentVideo (image, frame, Eyes::RIGHT, Part::WHOLE));
157 DCPOMATIC_ASSERT (false);
160 _position = ContentTime::from_frames (frame, afr);
164 VideoDecoder::seek ()
166 _position = boost::none;
167 _last_emitted_frame.reset ();
168 _last_emitted_eyes.reset ();
169 _frame_interval_checker.reset (new FrameIntervalChecker());