2 Copyright (C) 2013 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>
24 #include "ffmpeg_examiner.h"
25 #include "ffmpeg_content.h"
30 using std::stringstream;
31 using boost::shared_ptr;
32 using boost::optional;
34 FFmpegExaminer::FFmpegExaminer (shared_ptr<const FFmpegContent> c)
37 /* Find audio and subtitle streams */
39 for (uint32_t i = 0; i < _format_context->nb_streams; ++i) {
40 AVStream* s = _format_context->streams[i];
41 if (s->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
43 /* This is a hack; sometimes it seems that _audio_codec_context->channel_layout isn't set up,
44 so bodge it here. No idea why we should have to do this.
47 if (s->codec->channel_layout == 0) {
48 s->codec->channel_layout = av_get_default_channel_layout (s->codec->channels);
51 _audio_streams.push_back (
52 shared_ptr<FFmpegAudioStream> (
53 new FFmpegAudioStream (stream_name (s), i, s->codec->sample_rate, s->codec->channels)
57 } else if (s->codec->codec_type == AVMEDIA_TYPE_SUBTITLE) {
58 _subtitle_streams.push_back (shared_ptr<FFmpegSubtitleStream> (new FFmpegSubtitleStream (stream_name (s), i)));
62 /* Run through until we find the first audio (for each stream) and video */
65 int r = av_read_frame (_format_context, &_packet);
71 avcodec_get_frame_defaults (_frame);
73 AVCodecContext* context = _format_context->streams[_packet.stream_index]->codec;
75 if (_packet.stream_index == _video_stream && !_first_video) {
76 if (avcodec_decode_video2 (context, _frame, &frame_finished, &_packet) >= 0 && frame_finished) {
77 _first_video = frame_time (_video_stream);
80 for (size_t i = 0; i < _audio_streams.size(); ++i) {
81 if (_packet.stream_index == _audio_streams[i]->id && !_audio_streams[i]->first_audio) {
82 if (avcodec_decode_audio4 (context, _frame, &frame_finished, &_packet) >= 0 && frame_finished) {
83 _audio_streams[i]->first_audio = frame_time (_audio_streams[i]->id);
89 bool have_all_audio = true;
91 while (i < _audio_streams.size() && have_all_audio) {
92 have_all_audio = _audio_streams[i]->first_audio;
96 av_free_packet (&_packet);
98 if (_first_video && have_all_audio) {
105 FFmpegExaminer::frame_time (int stream) const
109 int64_t const bet = av_frame_get_best_effort_timestamp (_frame);
110 if (bet != AV_NOPTS_VALUE) {
111 t = bet * av_q2d (_format_context->streams[stream]->time_base);
118 FFmpegExaminer::video_frame_rate () const
120 AVStream* s = _format_context->streams[_video_stream];
122 if (s->avg_frame_rate.num && s->avg_frame_rate.den) {
123 return av_q2d (s->avg_frame_rate);
126 return av_q2d (s->r_frame_rate);
130 FFmpegExaminer::video_size () const
132 return libdcp::Size (video_codec_context()->width, video_codec_context()->height);
135 /** @return Length (in video frames) according to our content's header */
137 FFmpegExaminer::video_length () const
139 VideoContent::Frame const length = (double (_format_context->duration) / AV_TIME_BASE) * video_frame_rate();
140 return max (1, length);
144 FFmpegExaminer::stream_name (AVStream* s) const
149 AVDictionaryEntry const * lang = av_dict_get (s->metadata, "language", 0, 0);
154 AVDictionaryEntry const * title = av_dict_get (s->metadata, "title", 0, 0);
156 if (!n.str().empty()) {
163 if (!n.str().empty()) {
167 n << s->codec->channels << " channels";