2 Copyright (C) 2012-2021 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/>.
22 #include "compose.hpp"
24 #include "frame_interval_checker.h"
26 #include "j2k_image_proxy.h"
28 #include "raw_image_proxy.h"
29 #include "video_decoder.h"
35 using std::back_inserter;
37 using std::dynamic_pointer_cast;
39 using std::make_shared;
41 using std::shared_ptr;
42 using boost::optional;
43 using namespace dcpomatic;
46 VideoDecoder::VideoDecoder (Decoder* parent, shared_ptr<const Content> c)
47 : DecoderPart (parent)
49 , _frame_interval_checker (new FrameIntervalChecker())
55 /** Called by decoder classes when they have a video frame ready.
56 * @param frame Frame index within the content; this does not take into account 3D
57 * so for 3D_ALTERNATE this value goes:
65 VideoDecoder::emit (shared_ptr<const Film> film, shared_ptr<const ImageProxy> image, Frame decoder_frame)
71 auto const afr = _content->active_video_frame_rate(film);
72 auto const vft = _content->video->frame_type();
74 auto frame_time = ContentTime::from_frames (decoder_frame, afr);
76 /* Do some heuristics to try and spot the case where the user sets content to 3D
77 * when it is not. We try to tell this by looking at the differences in time between
78 * the first few frames. Real 3D content should have two frames for each timestamp.
80 if (_frame_interval_checker) {
81 _frame_interval_checker->feed (frame_time, afr);
82 if (_frame_interval_checker->guess() == FrameIntervalChecker::PROBABLY_NOT_3D && vft == VideoFrameType::THREE_D) {
83 boost::throw_exception (
86 _("The content file %1 is set as 3D but does not appear to contain 3D images. Please set it to 2D. "
87 "You can still make a 3D DCP from this content by ticking the 3D option in the DCP video tab."),
94 if (_frame_interval_checker->guess() != FrameIntervalChecker::AGAIN) {
95 _frame_interval_checker.reset ();
100 Eyes eyes = Eyes::BOTH;
102 /* This is the first data we have received since initialisation or seek. Set
103 the position based on the frame that was given. After this first time
104 we just cound frames, since (as with audio) it seems that ContentTimes
105 are unreliable from FFmpegDecoder. They are much better than audio times
106 but still we get the occasional one which is duplicated. In this case
107 ffmpeg seems to carry on regardless, processing the video frame as normal.
108 If we drop the frame with the duplicated timestamp we obviously lose sync.
111 if (vft == VideoFrameType::THREE_D_ALTERNATE) {
112 frame = decoder_frame / 2;
113 eyes = (decoder_frame % 1) ? Eyes::RIGHT : Eyes::LEFT;
115 frame = decoder_frame;
116 if (vft == VideoFrameType::THREE_D) {
117 auto j2k = dynamic_pointer_cast<const J2KImageProxy>(image);
118 /* At the moment only DCP decoders producers VideoFrameType::THREE_D, so only the J2KImageProxy
119 * knows which eye it is.
121 if (j2k && j2k->eye()) {
122 eyes = j2k->eye().get() == dcp::Eye::LEFT ? Eyes::LEFT : Eyes::RIGHT;
127 _position = ContentTime::from_frames (frame, afr);
129 if (vft == VideoFrameType::THREE_D) {
130 auto j2k = dynamic_pointer_cast<const J2KImageProxy>(image);
131 if (j2k && j2k->eye()) {
132 if (j2k->eye() == dcp::Eye::LEFT) {
133 frame = _position->frames_round(afr) + 1;
136 frame = _position->frames_round(afr);
140 /* This should not happen; see above */
141 frame = _position->frames_round(afr) + 1;
143 } else if (vft == VideoFrameType::THREE_D_ALTERNATE) {
144 DCPOMATIC_ASSERT (_last_emitted_eyes);
145 if (_last_emitted_eyes.get() == Eyes::RIGHT) {
146 frame = _position->frames_round(afr) + 1;
149 frame = _position->frames_round(afr);
153 frame = _position->frames_round(afr) + 1;
158 case VideoFrameType::TWO_D:
159 case VideoFrameType::THREE_D:
160 Data (ContentVideo (image, frame, eyes, Part::WHOLE));
162 case VideoFrameType::THREE_D_ALTERNATE:
164 Data (ContentVideo (image, frame, eyes, Part::WHOLE));
165 _last_emitted_eyes = eyes;
168 case VideoFrameType::THREE_D_LEFT_RIGHT:
169 Data (ContentVideo (image, frame, Eyes::LEFT, Part::LEFT_HALF));
170 Data (ContentVideo (image, frame, Eyes::RIGHT, Part::RIGHT_HALF));
172 case VideoFrameType::THREE_D_TOP_BOTTOM:
173 Data (ContentVideo (image, frame, Eyes::LEFT, Part::TOP_HALF));
174 Data (ContentVideo (image, frame, Eyes::RIGHT, Part::BOTTOM_HALF));
176 case VideoFrameType::THREE_D_LEFT:
177 Data (ContentVideo (image, frame, Eyes::LEFT, Part::WHOLE));
179 case VideoFrameType::THREE_D_RIGHT:
180 Data (ContentVideo (image, frame, Eyes::RIGHT, Part::WHOLE));
183 DCPOMATIC_ASSERT (false);
186 _position = ContentTime::from_frames (frame, afr);
191 VideoDecoder::seek ()
193 _position = boost::none;
194 _last_emitted_eyes.reset ();
195 _frame_interval_checker.reset (new FrameIntervalChecker());