diff options
Diffstat (limited to 'src/lib/ffmpeg_examiner.cc')
| -rw-r--r-- | src/lib/ffmpeg_examiner.cc | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/src/lib/ffmpeg_examiner.cc b/src/lib/ffmpeg_examiner.cc new file mode 100644 index 000000000..ceeaee112 --- /dev/null +++ b/src/lib/ffmpeg_examiner.cc @@ -0,0 +1,166 @@ +/* + Copyright (C) 2013 Carl Hetherington <cth@carlh.net> + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + +*/ + +extern "C" { +#include <libavcodec/avcodec.h> +#include <libavformat/avformat.h> +} +#include "ffmpeg_examiner.h" +#include "ffmpeg_content.h" + +using std::string; +using std::cout; +using std::stringstream; +using boost::shared_ptr; +using boost::optional; + +FFmpegExaminer::FFmpegExaminer (shared_ptr<const FFmpegContent> c) + : FFmpeg (c) +{ + /* Find audio and subtitle streams */ + + for (uint32_t i = 0; i < _format_context->nb_streams; ++i) { + AVStream* s = _format_context->streams[i]; + if (s->codec->codec_type == AVMEDIA_TYPE_AUDIO) { + + /* This is a hack; sometimes it seems that _audio_codec_context->channel_layout isn't set up, + so bodge it here. No idea why we should have to do this. + */ + + if (s->codec->channel_layout == 0) { + s->codec->channel_layout = av_get_default_channel_layout (s->codec->channels); + } + + _audio_streams.push_back ( + shared_ptr<FFmpegAudioStream> ( + new FFmpegAudioStream (stream_name (s), i, s->codec->sample_rate, s->codec->channels) + ) + ); + + } else if (s->codec->codec_type == AVMEDIA_TYPE_SUBTITLE) { + _subtitle_streams.push_back (shared_ptr<FFmpegSubtitleStream> (new FFmpegSubtitleStream (stream_name (s), i))); + } + } + + /* Run through until we find the first audio (for each stream) and video */ + + while (1) { + int r = av_read_frame (_format_context, &_packet); + if (r < 0) { + break; + } + + int frame_finished; + avcodec_get_frame_defaults (_frame); + + AVCodecContext* context = _format_context->streams[_packet.stream_index]->codec; + + if (_packet.stream_index == _video_stream && !_first_video) { + if (avcodec_decode_video2 (context, _frame, &frame_finished, &_packet) >= 0 && frame_finished) { + _first_video = frame_time (_video_stream); + } + } else { + for (size_t i = 0; i < _audio_streams.size(); ++i) { + if (_packet.stream_index == _audio_streams[i]->id && !_audio_streams[i]->first_audio) { + if (avcodec_decode_audio4 (context, _frame, &frame_finished, &_packet) >= 0 && frame_finished) { + _audio_streams[i]->first_audio = frame_time (_audio_streams[i]->id); + } + } + } + } + + bool have_all_audio = true; + size_t i = 0; + while (i < _audio_streams.size() && have_all_audio) { + have_all_audio = _audio_streams[i]->first_audio; + ++i; + } + + av_free_packet (&_packet); + + if (_first_video && have_all_audio) { + break; + } + } +} + +optional<double> +FFmpegExaminer::frame_time (int stream) const +{ + optional<double> t; + + int64_t const bet = av_frame_get_best_effort_timestamp (_frame); + if (bet != AV_NOPTS_VALUE) { + t = bet * av_q2d (_format_context->streams[stream]->time_base); + } + + return t; +} + +float +FFmpegExaminer::video_frame_rate () const +{ + AVStream* s = _format_context->streams[_video_stream]; + + if (s->avg_frame_rate.num && s->avg_frame_rate.den) { + return av_q2d (s->avg_frame_rate); + } + + return av_q2d (s->r_frame_rate); +} + +libdcp::Size +FFmpegExaminer::video_size () const +{ + return libdcp::Size (video_codec_context()->width, video_codec_context()->height); +} + +/** @return Length (in video frames) according to our content's header */ +VideoContent::Frame +FFmpegExaminer::video_length () const +{ + return (double (_format_context->duration) / AV_TIME_BASE) * video_frame_rate(); +} + +string +FFmpegExaminer::stream_name (AVStream* s) const +{ + stringstream n; + + if (s->metadata) { + AVDictionaryEntry const * lang = av_dict_get (s->metadata, "language", 0, 0); + if (lang) { + n << lang->value; + } + + AVDictionaryEntry const * title = av_dict_get (s->metadata, "title", 0, 0); + if (title) { + if (!n.str().empty()) { + n << " "; + } + n << title->value; + } + } + + if (n.str().empty()) { + n << "unknown"; + } + + return n.str (); +} |