2 Copyright (C) 2013-2021 Carl Hetherington <cth@carlh.net>
4 This file is part of DCP-o-matic.
6 DCP-o-matic is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 DCP-o-matic is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with DCP-o-matic. If not, see <http://www.gnu.org/licenses/>.
23 #include "ffmpeg_content.h"
25 #include "exceptions.h"
28 #include "dcpomatic_log.h"
29 #include "ffmpeg_subtitle_stream.h"
30 #include "ffmpeg_audio_stream.h"
32 #include "compose.hpp"
34 #include <dcp/raw_convert.h>
36 #include <libavcodec/avcodec.h>
37 #include <libavformat/avformat.h>
38 #include <libswscale/swscale.h>
40 #include <boost/algorithm/string.hpp>
50 using std::shared_ptr;
51 using boost::optional;
52 using dcp::raw_convert;
53 using namespace dcpomatic;
56 boost::mutex FFmpeg::_mutex;
59 FFmpeg::FFmpeg (std::shared_ptr<const FFmpegContent> c)
69 boost::mutex::scoped_lock lm (_mutex);
71 DCPOMATIC_DISABLE_WARNINGS
72 for (uint32_t i = 0; i < _format_context->nb_streams; ++i) {
73 avcodec_close (_format_context->streams[i]->codec);
75 DCPOMATIC_ENABLE_WARNINGS
77 av_frame_free (&_frame);
78 avformat_close_input (&_format_context);
83 avio_read_wrapper (void* data, uint8_t* buffer, int amount)
85 return reinterpret_cast<FFmpeg*>(data)->avio_read (buffer, amount);
90 avio_seek_wrapper (void* data, int64_t offset, int whence)
92 return reinterpret_cast<FFmpeg*>(data)->avio_seek (offset, whence);
97 FFmpeg::ffmpeg_log_callback (void* ptr, int level, const char* fmt, va_list vl)
99 if (level > AV_LOG_WARNING) {
104 static int prefix = 0;
105 av_log_format_line (ptr, level, fmt, vl, line, sizeof (line), &prefix);
107 boost::algorithm::trim (str);
108 dcpomatic_log->log (String::compose ("FFmpeg: %1", str), LogEntry::TYPE_GENERAL);
113 FFmpeg::setup_general ()
115 /* This might not work too well in some cases of multiple FFmpeg decoders,
116 but it's probably good enough.
118 av_log_set_callback (FFmpeg::ffmpeg_log_callback);
120 _file_group.set_paths (_ffmpeg_content->paths ());
121 _avio_buffer = static_cast<uint8_t*> (wrapped_av_malloc(_avio_buffer_size));
122 _avio_context = avio_alloc_context (_avio_buffer, _avio_buffer_size, 0, this, avio_read_wrapper, 0, avio_seek_wrapper);
123 if (!_avio_context) {
124 throw std::bad_alloc ();
126 _format_context = avformat_alloc_context ();
127 if (!_format_context) {
128 throw std::bad_alloc ();
130 _format_context->pb = _avio_context;
132 AVDictionary* options = nullptr;
133 int e = avformat_open_input (&_format_context, 0, 0, &options);
135 throw OpenFileError (_ffmpeg_content->path(0).string(), e, OpenFileError::READ);
138 if (avformat_find_stream_info (_format_context, 0) < 0) {
139 throw DecodeError (_("could not find stream information"));
142 /* Find video stream */
144 optional<int> video_stream_undefined_frame_rate;
146 for (uint32_t i = 0; i < _format_context->nb_streams; ++i) {
147 auto s = _format_context->streams[i];
148 if (s->codecpar->codec_type == AVMEDIA_TYPE_VIDEO && avcodec_find_decoder(s->codecpar->codec_id)) {
149 if (s->avg_frame_rate.num > 0 && s->avg_frame_rate.den > 0) {
150 /* This is definitely our video stream */
153 /* This is our video stream if we don't get a better offer */
154 video_stream_undefined_frame_rate = i;
159 /* Files from iTunes sometimes have two video streams, one with the avg_frame_rate.num and .den set
160 to zero. Only use such a stream if there is no alternative.
162 if (!_video_stream && video_stream_undefined_frame_rate) {
163 _video_stream = video_stream_undefined_frame_rate.get();
166 /* Ignore video streams with crazy frame rates. These are usually things like album art on MP3s. */
167 if (_video_stream && av_q2d(av_guess_frame_rate(_format_context, _format_context->streams[_video_stream.get()], 0)) > 1000) {
168 _video_stream = optional<int>();
171 /* Hack: if the AVStreams have duplicate IDs, replace them with our
172 own. We use the IDs so that we can cope with VOBs, in which streams
173 move about in index but remain with the same ID in different
174 VOBs. However, some files have duplicate IDs, hence this hack.
177 bool duplicates = false;
178 for (uint32_t i = 0; i < _format_context->nb_streams; ++i) {
179 for (uint32_t j = i + 1; j < _format_context->nb_streams; ++j) {
180 if (_format_context->streams[i]->id == _format_context->streams[j]->id) {
187 /* Put in our own IDs */
188 for (uint32_t i = 0; i < _format_context->nb_streams; ++i) {
189 _format_context->streams[i]->id = i;
193 _frame = av_frame_alloc ();
195 throw DecodeError (N_("could not allocate frame"));
201 FFmpeg::setup_decoders ()
203 boost::mutex::scoped_lock lm (_mutex);
205 DCPOMATIC_DISABLE_WARNINGS
206 for (uint32_t i = 0; i < _format_context->nb_streams; ++i) {
207 auto context = _format_context->streams[i]->codec;
209 context->thread_count = 8;
210 context->thread_type = FF_THREAD_FRAME | FF_THREAD_SLICE;
212 AVCodec* codec = avcodec_find_decoder (context->codec_id);
215 AVDictionary* options = nullptr;
216 /* This option disables decoding of DCA frame footers in our patched version
217 of FFmpeg. I believe these footers are of no use to us, and they can cause
218 problems when FFmpeg fails to decode them (mantis #352).
220 av_dict_set (&options, "disable_footer", "1", 0);
221 /* This allows decoding of some DNxHR 444 and HQX files; see
222 https://trac.ffmpeg.org/ticket/5681
224 av_dict_set_int (&options, "strict", FF_COMPLIANCE_EXPERIMENTAL, 0);
225 /* Enable following of links in files */
226 av_dict_set_int (&options, "enable_drefs", 1, 0);
228 if (avcodec_open2 (context, codec, &options) < 0) {
229 throw DecodeError (N_("could not open decoder"));
232 dcpomatic_log->log (String::compose ("No codec found for stream %1", i), LogEntry::TYPE_WARNING);
235 DCPOMATIC_ENABLE_WARNINGS
239 DCPOMATIC_DISABLE_WARNINGS
241 FFmpeg::video_codec_context () const
243 if (!_video_stream) {
247 return _format_context->streams[_video_stream.get()]->codec;
252 FFmpeg::subtitle_codec_context () const
254 if (!_ffmpeg_content->subtitle_stream()) {
258 return _ffmpeg_content->subtitle_stream()->stream(_format_context)->codec;
260 DCPOMATIC_ENABLE_WARNINGS
264 FFmpeg::avio_read (uint8_t* buffer, int const amount)
266 return _file_group.read (buffer, amount);
271 FFmpeg::avio_seek (int64_t const pos, int whence)
273 if (whence == AVSEEK_SIZE) {
274 return _file_group.length ();
277 return _file_group.seek (pos, whence);
282 FFmpeg::subtitle_period (AVSubtitle const & sub)
284 auto const packet_time = ContentTime::from_seconds (static_cast<double> (sub.pts) / AV_TIME_BASE);
286 if (sub.end_display_time == static_cast<uint32_t> (-1)) {
287 /* End time is not known */
288 return FFmpegSubtitlePeriod (packet_time + ContentTime::from_seconds (sub.start_display_time / 1e3));
291 return FFmpegSubtitlePeriod (
292 packet_time + ContentTime::from_seconds (sub.start_display_time / 1e3),
293 packet_time + ContentTime::from_seconds (sub.end_display_time / 1e3)
298 /** Compute the pts offset to use given a set of audio streams and some video details.
299 * Sometimes these parameters will have just been determined by an Examiner, sometimes
300 * they will have been retrieved from a piece of Content, hence the need for this method
304 FFmpeg::pts_offset (vector<shared_ptr<FFmpegAudioStream>> audio_streams, optional<ContentTime> first_video, double video_frame_rate) const
306 /* Audio and video frame PTS values may not start with 0. We want
307 to fiddle them so that:
309 1. One of them starts at time 0.
310 2. The first video PTS value ends up on a frame boundary.
312 Then we remove big initial gaps in PTS and we allow our
313 insertion of black frames to work.
316 audio_pts_to_use = audio_pts_from_ffmpeg + pts_offset;
317 video_pts_to_use = video_pts_from_ffmpeg + pts_offset;
320 /* First, make one of them start at 0 */
322 auto po = ContentTime::min ();
325 po = - first_video.get ();
328 for (auto i: audio_streams) {
329 if (i->first_audio) {
330 po = max (po, - i->first_audio.get ());
334 /* If the offset is positive we would be pushing things from a -ve PTS to be played.
335 I don't think we ever want to do that, as it seems things at -ve PTS are not meant
336 to be seen (use for alignment bars etc.); see mantis #418.
338 if (po > ContentTime ()) {
342 /* Now adjust so that the video pts starts on a frame */
344 auto const fvc = first_video.get() + po;
345 po += fvc.ceil (video_frame_rate) - fvc;