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"
28 #include <boost/foreach.hpp>
36 using std::back_inserter;
37 using boost::shared_ptr;
38 using boost::optional;
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 && _content->video->frame_type() == VIDEO_FRAME_TYPE_3D) {
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 ();
94 /* This is the first data we have received since initialisation or seek. Set
95 the position based on the frame that was given. After this first time
96 we just cound frames, since (as with audio) it seems that ContentTimes
97 are unreliable from FFmpegDecoder. They are much better than audio times
98 but still we get the occasional one which is duplicated. In this case
99 ffmpeg seems to carry on regardless, processing the video frame as normal.
100 If we drop the frame with the duplicated timestamp we obviously lose sync.
102 _position = ContentTime::from_frames (decoder_frame, afr);
103 if (vft == VIDEO_FRAME_TYPE_3D) {
104 frame = decoder_frame;
105 _last_emitted_eyes = EYES_RIGHT;
106 } else if (vft == VIDEO_FRAME_TYPE_3D_ALTERNATE) {
107 frame = decoder_frame / 2;
108 _last_emitted_eyes = EYES_RIGHT;
110 frame = decoder_frame;
113 if (vft == VIDEO_FRAME_TYPE_3D || vft == VIDEO_FRAME_TYPE_3D_ALTERNATE) {
114 DCPOMATIC_ASSERT (_last_emitted_eyes);
115 if (_last_emitted_eyes.get() == EYES_RIGHT) {
116 frame = _position->frames_round(afr) + 1;
118 frame = _position->frames_round(afr);
121 frame = _position->frames_round(afr) + 1;
125 switch (_content->video->frame_type ()) {
126 case VIDEO_FRAME_TYPE_2D:
127 Data (ContentVideo (image, frame, EYES_BOTH, PART_WHOLE));
129 case VIDEO_FRAME_TYPE_3D:
131 /* We should receive the same frame index twice for 3D; hence we know which
134 bool const same = (_last_emitted_frame && _last_emitted_frame.get() == frame);
135 Eyes const eyes = same ? EYES_RIGHT : EYES_LEFT;
136 Data (ContentVideo (image, frame, eyes, PART_WHOLE));
137 _last_emitted_frame = frame;
138 _last_emitted_eyes = eyes;
141 case VIDEO_FRAME_TYPE_3D_ALTERNATE:
143 DCPOMATIC_ASSERT (_last_emitted_eyes);
144 Eyes const eyes = _last_emitted_eyes.get() == EYES_LEFT ? EYES_RIGHT : EYES_LEFT;
145 Data (ContentVideo (image, frame, eyes, PART_WHOLE));
146 _last_emitted_eyes = eyes;
149 case VIDEO_FRAME_TYPE_3D_LEFT_RIGHT:
150 Data (ContentVideo (image, frame, EYES_LEFT, PART_LEFT_HALF));
151 Data (ContentVideo (image, frame, EYES_RIGHT, PART_RIGHT_HALF));
153 case VIDEO_FRAME_TYPE_3D_TOP_BOTTOM:
154 Data (ContentVideo (image, frame, EYES_LEFT, PART_TOP_HALF));
155 Data (ContentVideo (image, frame, EYES_RIGHT, PART_BOTTOM_HALF));
157 case VIDEO_FRAME_TYPE_3D_LEFT:
158 Data (ContentVideo (image, frame, EYES_LEFT, PART_WHOLE));
160 case VIDEO_FRAME_TYPE_3D_RIGHT:
161 Data (ContentVideo (image, frame, EYES_RIGHT, PART_WHOLE));
164 DCPOMATIC_ASSERT (false);
167 _position = ContentTime::from_frames (frame, afr);
171 VideoDecoder::seek ()
173 _position = boost::none;
174 _last_emitted_frame.reset ();
175 _last_emitted_eyes.reset ();
176 _frame_interval_checker.reset (new FrameIntervalChecker());