2 Copyright (C) 2013-2015 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.
21 #include <libavcodec/avcodec.h>
22 #include <libavformat/avformat.h>
23 #include <libavutil/pixfmt.h>
24 #include <libavutil/pixdesc.h>
26 #include "ffmpeg_examiner.h"
27 #include "ffmpeg_content.h"
29 #include "ffmpeg_audio_stream.h"
30 #include "ffmpeg_subtitle_stream.h"
32 #include "safe_stringstream.h"
40 using boost::shared_ptr;
41 using boost::optional;
43 /** @param job job that the examiner is operating in, or 0 */
44 FFmpegExaminer::FFmpegExaminer (shared_ptr<const FFmpegContent> c, shared_ptr<Job> job)
47 , _need_video_length (false)
49 /* Find audio and subtitle streams */
51 for (uint32_t i = 0; i < _format_context->nb_streams; ++i) {
52 AVStream* s = _format_context->streams[i];
53 if (s->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
55 /* This is a hack; sometimes it seems that _audio_codec_context->channel_layout isn't set up,
56 so bodge it here. No idea why we should have to do this.
59 if (s->codec->channel_layout == 0) {
60 s->codec->channel_layout = av_get_default_channel_layout (s->codec->channels);
63 _audio_streams.push_back (
64 shared_ptr<FFmpegAudioStream> (
65 new FFmpegAudioStream (audio_stream_name (s), s->id, s->codec->sample_rate, s->codec->channels)
69 } else if (s->codec->codec_type == AVMEDIA_TYPE_SUBTITLE) {
70 _subtitle_streams.push_back (shared_ptr<FFmpegSubtitleStream> (new FFmpegSubtitleStream (subtitle_stream_name (s), s->id)));
74 /* See if the header has duration information in it */
75 _need_video_length = _format_context->duration == AV_NOPTS_VALUE;
76 if (!_need_video_length) {
77 _video_length = (double (_format_context->duration) / AV_TIME_BASE) * video_frame_rate().get ();
79 job->sub (_("Finding length"));
80 job->set_progress_unknown ();
84 job->sub (_("Finding subtitles"));
87 /* Run through until we find:
89 * - the first audio for each stream.
90 * - the subtitle periods for each stream.
92 * We have to note subtitle periods as otherwise we have no way of knowing
93 * where we should look for subtitles (video and audio are always present,
98 int r = av_read_frame (_format_context, &_packet);
104 job->set_progress_unknown ();
107 AVCodecContext* context = _format_context->streams[_packet.stream_index]->codec;
109 if (_packet.stream_index == _video_stream) {
110 video_packet (context);
113 bool got_all_audio = true;
115 for (size_t i = 0; i < _audio_streams.size(); ++i) {
116 if (_audio_streams[i]->uses_index (_format_context, _packet.stream_index)) {
117 audio_packet (context, _audio_streams[i]);
119 if (!_audio_streams[i]->first_audio) {
120 got_all_audio = false;
124 for (size_t i = 0; i < _subtitle_streams.size(); ++i) {
125 if (_subtitle_streams[i]->uses_index (_format_context, _packet.stream_index)) {
126 subtitle_packet (context, _subtitle_streams[i]);
130 av_free_packet (&_packet);
132 if (_first_video && got_all_audio && _subtitle_streams.empty ()) {
138 for (LastSubtitleMap::const_iterator i = _last_subtitle_start.begin(); i != _last_subtitle_start.end(); ++i) {
140 i->first->add_subtitle (
143 ContentTime::from_frames (video_length(), video_frame_rate().get_value_or (24))
151 FFmpegExaminer::video_packet (AVCodecContext* context)
153 if (_first_video && !_need_video_length) {
158 if (avcodec_decode_video2 (context, _frame, &frame_finished, &_packet) >= 0 && frame_finished) {
160 _first_video = frame_time (_format_context->streams[_video_stream]);
162 if (_need_video_length) {
163 _video_length = frame_time (
164 _format_context->streams[_video_stream]
165 ).get_value_or (ContentTime ()).frames_round (video_frame_rate().get ());
171 FFmpegExaminer::audio_packet (AVCodecContext* context, shared_ptr<FFmpegAudioStream> stream)
173 if (stream->first_audio) {
178 if (avcodec_decode_audio4 (context, _frame, &frame_finished, &_packet) >= 0 && frame_finished) {
179 stream->first_audio = frame_time (stream->stream (_format_context));
184 FFmpegExaminer::subtitle_packet (AVCodecContext* context, shared_ptr<FFmpegSubtitleStream> stream)
188 if (avcodec_decode_subtitle2 (context, &sub, &frame_finished, &_packet) >= 0 && frame_finished) {
189 FFmpegSubtitlePeriod const period = subtitle_period (sub);
190 LastSubtitleMap::iterator last = _last_subtitle_start.find (stream);
191 if (last != _last_subtitle_start.end() && last->second) {
192 /* We have seen the start of a subtitle but not yet the end. Whatever this is
193 finishes the previous subtitle, so add it */
194 stream->add_subtitle (ContentTimePeriod (last->second.get (), period.from));
195 if (sub.num_rects == 0) {
196 /* This is a `proper' end-of-subtitle */
197 _last_subtitle_start[stream] = optional<ContentTime> ();
199 /* This is just another subtitle, so we start again */
200 _last_subtitle_start[stream] = period.from;
202 } else if (sub.num_rects == 1) {
204 stream->add_subtitle (ContentTimePeriod (period.from, period.to.get ()));
206 _last_subtitle_start[stream] = period.from;
209 avsubtitle_free (&sub);
213 optional<ContentTime>
214 FFmpegExaminer::frame_time (AVStream* s) const
216 optional<ContentTime> t;
218 int64_t const bet = av_frame_get_best_effort_timestamp (_frame);
219 if (bet != AV_NOPTS_VALUE) {
220 t = ContentTime::from_seconds (bet * av_q2d (s->time_base));
227 FFmpegExaminer::video_frame_rate () const
229 /* This use of r_frame_rate is debateable; there's a few different
230 * frame rates in the format context, but this one seems to be the most
233 return av_q2d (av_stream_get_r_frame_rate (_format_context->streams[_video_stream]));
237 FFmpegExaminer::video_size () const
239 return dcp::Size (video_codec_context()->width, video_codec_context()->height);
242 /** @return Length according to our content's header */
244 FFmpegExaminer::video_length () const
246 return max (Frame (1), _video_length);
250 FFmpegExaminer::sample_aspect_ratio () const
252 AVRational sar = av_guess_sample_aspect_ratio (_format_context, _format_context->streams[_video_stream], 0);
254 /* I assume this means that we don't know */
255 return optional<double> ();
257 return double (sar.num) / sar.den;
261 FFmpegExaminer::audio_stream_name (AVStream* s) const
265 n << stream_name (s);
267 if (!n.str().empty()) {
271 n << s->codec->channels << " channels";
277 FFmpegExaminer::subtitle_stream_name (AVStream* s) const
281 n << stream_name (s);
283 if (n.str().empty()) {
291 FFmpegExaminer::stream_name (AVStream* s) const
296 AVDictionaryEntry const * lang = av_dict_get (s->metadata, "language", 0, 0);
301 AVDictionaryEntry const * title = av_dict_get (s->metadata, "title", 0, 0);
303 if (!n.str().empty()) {
314 FFmpegExaminer::bits_per_pixel () const
316 return av_get_bits_per_pixel (av_pix_fmt_desc_get (video_codec_context()->pix_fmt));