2 Copyright (C) 2012 Carl Hetherington <cth@carlh.net>
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
29 using boost::shared_ptr;
31 Matcher::Matcher (Log* log, int sample_rate, float frames_per_second)
33 , _sample_rate (sample_rate)
34 , _frames_per_second (frames_per_second)
42 Matcher::process_video (boost::shared_ptr<Image> image, bool same, boost::shared_ptr<Subtitle> sub, double t)
44 _pixel_format = image->pixel_format ();
45 _size = image->size ();
47 _log->log(String::compose("Matcher video @ %1 (same=%2)", t, same));
53 if (!_pending_audio.empty() && _video_frames == 0) {
54 /* First video since we got audio */
58 /* Video before audio is fine, since we can make up an arbitrary difference
59 with audio samples (contrasting with video which is quantised to frames)
62 /* Difference between where this video is and where it should be */
63 double const delta = t - _first_input.get() - _video_frames / _frames_per_second;
64 double const one_frame = 1 / _frames_per_second;
66 if (delta > one_frame) {
67 /* Insert frames to make up the difference */
68 int const extra = rint (delta / one_frame);
69 for (int i = 0; i < extra; ++i) {
71 _log->log (String::compose ("Extra video frame inserted at %1s", _video_frames / _frames_per_second));
75 if (delta > -one_frame) {
76 Video (image, same, sub);
79 /* We are omitting a frame to keep things right */
80 _log->log (String::compose ("Frame removed at %1s", t));
88 Matcher::process_audio (boost::shared_ptr<AudioBuffers> b, double t)
90 _channels = b->channels ();
96 if (_video_frames == 0) {
97 /* No video yet; we must postpone these data until we have some */
98 _pending_audio.push_back (AudioRecord (b, t));
99 } else if (_video_frames > 0 && _audio_frames == 0 && _pending_audio.empty()) {
100 /* First audio since we got video */
101 _pending_audio.push_back (AudioRecord (b, t));
102 fix_start (_first_input.get ());
104 /* Normal running. We assume audio time stamps are consecutive */
106 _audio_frames += b->frames ();
111 Matcher::process_end ()
113 if (_audio_frames == 0 || !_pixel_format || !_size || !_channels) {
114 /* We won't do anything */
118 _log->log (String::compose ("Matcher has seen %1 video frames (which equals %2 audio frames) and %3 audio frames",
119 _video_frames, video_frames_to_audio_frames (_video_frames, _sample_rate, _frames_per_second), _audio_frames));
121 match ((double (_audio_frames) / _sample_rate) - (double (_video_frames) / _frames_per_second));
125 Matcher::fix_start (double first_video)
127 assert (!_pending_audio.empty ());
129 _log->log (String::compose ("Fixing start; video at %1, audio at %2", first_video, _pending_audio.front().time));
131 match (first_video - _pending_audio.front().time);
133 for (list<AudioRecord>::iterator i = _pending_audio.begin(); i != _pending_audio.end(); ++i) {
134 process_audio (i->audio, i->time);
137 _pending_audio.clear ();
141 Matcher::match (double extra_video_needed)
143 if (extra_video_needed > 0) {
145 /* Emit black video frames */
147 int const black_video_frames = ceil (extra_video_needed * _frames_per_second);
149 _log->log (String::compose (N_("Emitting %1 frames of black video"), black_video_frames));
151 shared_ptr<Image> black (new SimpleImage (_pixel_format.get(), _size.get(), true));
152 black->make_black ();
153 for (int i = 0; i < black_video_frames; ++i) {
154 Video (black, i != 0, shared_ptr<Subtitle>());
158 extra_video_needed -= black_video_frames / _frames_per_second;
161 if (extra_video_needed < 0) {
165 int64_t to_do = -extra_video_needed * _sample_rate;
166 _log->log (String::compose (N_("Emitted %1 frames of silence"), to_do));
168 /* Do things in half second blocks as I think there may be limits
169 to what FFmpeg (and in particular the resampler) can cope with.
171 int64_t const block = _sample_rate / 2;
172 shared_ptr<AudioBuffers> b (new AudioBuffers (_channels.get(), block));
176 int64_t const this_time = min (to_do, block);
177 b->set_frames (this_time);
179 _audio_frames += b->frames ();
186 Matcher::repeat_last_video ()
189 _last_image.reset (new SimpleImage (_pixel_format.get(), _size.get(), true));
190 _last_image->make_black ();
193 Video (_last_image, true, _last_subtitle);