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 (shared_ptr<Log> log, int sample_rate, float frames_per_second)
32 : AudioVideoProcessor (log)
33 , _sample_rate (sample_rate)
34 , _frames_per_second (frames_per_second)
37 , _had_first_video (false)
38 , _had_first_audio (false)
44 Matcher::process_video (boost::shared_ptr<Image> image, bool same, boost::shared_ptr<Subtitle> sub, double t)
46 _pixel_format = image->pixel_format ();
47 _size = image->size ();
49 _log->log(String::compose("Matcher video @ %1 [audio=%2, video=%3, pending_audio=%4]", t, _audio_frames, _video_frames, _pending_audio.size()));
55 bool const this_is_first_video = !_had_first_video;
56 _had_first_video = true;
58 if (this_is_first_video && _had_first_audio) {
59 /* First video since we got audio */
63 /* Video before audio is fine, since we can make up an arbitrary difference
64 with audio samples (contrasting with video which is quantised to frames)
67 /* Difference between where this video is and where it should be */
68 double const delta = t - _first_input.get() - _video_frames / _frames_per_second;
69 double const one_frame = 1 / _frames_per_second;
71 if (delta > one_frame) {
72 /* Insert frames to make up the difference */
73 int const extra = rint (delta / one_frame);
74 for (int i = 0; i < extra; ++i) {
76 _log->log (String::compose ("Extra video frame inserted at %1s", _video_frames / _frames_per_second));
80 if (delta > -one_frame) {
81 Video (image, same, sub);
84 /* We are omitting a frame to keep things right */
85 _log->log (String::compose ("Frame removed at %1s", t));
93 Matcher::process_audio (boost::shared_ptr<AudioBuffers> b, double t)
95 _channels = b->channels ();
97 _log->log (String::compose ("Matcher audio @ %1 [video=%2, audio=%3, pending_audio=%4]", t, _video_frames, _audio_frames, _pending_audio.size()));
103 bool const this_is_first_audio = _had_first_audio;
104 _had_first_audio = true;
106 if (!_had_first_video) {
107 /* No video yet; we must postpone these data until we have some */
108 _pending_audio.push_back (AudioRecord (b, t));
109 } else if (this_is_first_audio && !_had_first_video) {
110 /* First audio since we got video */
111 _pending_audio.push_back (AudioRecord (b, t));
112 fix_start (_first_input.get ());
114 /* Normal running. We assume audio time stamps are consecutive */
116 _audio_frames += b->frames ();
121 Matcher::process_end ()
123 if (_audio_frames == 0 || !_pixel_format || !_size || !_channels) {
124 /* We won't do anything */
128 _log->log (String::compose ("Matcher has seen %1 video frames (which equals %2 audio frames) and %3 audio frames",
129 _video_frames, video_frames_to_audio_frames (_video_frames, _sample_rate, _frames_per_second), _audio_frames));
131 match ((double (_audio_frames) / _sample_rate) - (double (_video_frames) / _frames_per_second));
135 Matcher::fix_start (double first_video)
137 assert (!_pending_audio.empty ());
139 _log->log (String::compose ("Fixing start; video at %1, audio at %2", first_video, _pending_audio.front().time));
141 match (first_video - _pending_audio.front().time);
143 for (list<AudioRecord>::iterator i = _pending_audio.begin(); i != _pending_audio.end(); ++i) {
144 process_audio (i->audio, i->time);
147 _pending_audio.clear ();
151 Matcher::match (double extra_video_needed)
153 _log->log (String::compose ("Match %1", extra_video_needed));
155 if (extra_video_needed > 0) {
157 /* Emit black video frames */
159 int const black_video_frames = ceil (extra_video_needed * _frames_per_second);
161 _log->log (String::compose (N_("Emitting %1 frames of black video"), black_video_frames));
163 shared_ptr<Image> black (new SimpleImage (_pixel_format.get(), _size.get(), true));
164 black->make_black ();
165 for (int i = 0; i < black_video_frames; ++i) {
166 Video (black, i != 0, shared_ptr<Subtitle>());
170 extra_video_needed -= black_video_frames / _frames_per_second;
173 if (extra_video_needed < 0) {
177 int64_t to_do = -extra_video_needed * _sample_rate;
178 _log->log (String::compose (N_("Emitting %1 frames of silence"), to_do));
180 /* Do things in half second blocks as I think there may be limits
181 to what FFmpeg (and in particular the resampler) can cope with.
183 int64_t const block = _sample_rate / 2;
184 shared_ptr<AudioBuffers> b (new AudioBuffers (_channels.get(), block));
188 int64_t const this_time = min (to_do, block);
189 b->set_frames (this_time);
191 _audio_frames += b->frames ();
198 Matcher::repeat_last_video ()
201 _last_image.reset (new SimpleImage (_pixel_format.get(), _size.get(), true));
202 _last_image->make_black ();
205 Video (_last_image, true, _last_subtitle);