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 DCPOMATIC_DISABLE_WARNINGS
147 for (uint32_t i = 0; i < _format_context->nb_streams; ++i) {
148 auto s = _format_context->streams[i];
149 if (s->codec->codec_type == AVMEDIA_TYPE_VIDEO && avcodec_find_decoder(s->codec->codec_id)) {
150 if (s->avg_frame_rate.num > 0 && s->avg_frame_rate.den > 0) {
151 /* This is definitely our video stream */
154 /* This is our video stream if we don't get a better offer */
155 video_stream_undefined_frame_rate = i;
159 DCPOMATIC_ENABLE_WARNINGS
161 /* Files from iTunes sometimes have two video streams, one with the avg_frame_rate.num and .den set
162 to zero. Only use such a stream if there is no alternative.
164 if (!_video_stream && video_stream_undefined_frame_rate) {
165 _video_stream = video_stream_undefined_frame_rate.get();
168 /* Ignore video streams with crazy frame rates. These are usually things like album art on MP3s. */
169 if (_video_stream && av_q2d(av_guess_frame_rate(_format_context, _format_context->streams[_video_stream.get()], 0)) > 1000) {
170 _video_stream = optional<int>();
173 /* Hack: if the AVStreams have duplicate IDs, replace them with our
174 own. We use the IDs so that we can cope with VOBs, in which streams
175 move about in index but remain with the same ID in different
176 VOBs. However, some files have duplicate IDs, hence this hack.
179 bool duplicates = false;
180 for (uint32_t i = 0; i < _format_context->nb_streams; ++i) {
181 for (uint32_t j = i + 1; j < _format_context->nb_streams; ++j) {
182 if (_format_context->streams[i]->id == _format_context->streams[j]->id) {
189 /* Put in our own IDs */
190 for (uint32_t i = 0; i < _format_context->nb_streams; ++i) {
191 _format_context->streams[i]->id = i;
195 _frame = av_frame_alloc ();
197 throw DecodeError (N_("could not allocate frame"));
203 FFmpeg::setup_decoders ()
205 boost::mutex::scoped_lock lm (_mutex);
207 DCPOMATIC_DISABLE_WARNINGS
208 for (uint32_t i = 0; i < _format_context->nb_streams; ++i) {
209 auto context = _format_context->streams[i]->codec;
211 context->thread_count = 8;
212 context->thread_type = FF_THREAD_FRAME | FF_THREAD_SLICE;
214 AVCodec* codec = avcodec_find_decoder (context->codec_id);
217 AVDictionary* options = nullptr;
218 /* This option disables decoding of DCA frame footers in our patched version
219 of FFmpeg. I believe these footers are of no use to us, and they can cause
220 problems when FFmpeg fails to decode them (mantis #352).
222 av_dict_set (&options, "disable_footer", "1", 0);
223 /* This allows decoding of some DNxHR 444 and HQX files; see
224 https://trac.ffmpeg.org/ticket/5681
226 av_dict_set_int (&options, "strict", FF_COMPLIANCE_EXPERIMENTAL, 0);
227 /* Enable following of links in files */
228 av_dict_set_int (&options, "enable_drefs", 1, 0);
230 if (avcodec_open2 (context, codec, &options) < 0) {
231 throw DecodeError (N_("could not open decoder"));
234 dcpomatic_log->log (String::compose ("No codec found for stream %1", i), LogEntry::TYPE_WARNING);
237 DCPOMATIC_ENABLE_WARNINGS
241 DCPOMATIC_DISABLE_WARNINGS
243 FFmpeg::video_codec_context () const
245 if (!_video_stream) {
249 return _format_context->streams[_video_stream.get()]->codec;
254 FFmpeg::subtitle_codec_context () const
256 if (!_ffmpeg_content->subtitle_stream()) {
260 return _ffmpeg_content->subtitle_stream()->stream(_format_context)->codec;
262 DCPOMATIC_ENABLE_WARNINGS
266 FFmpeg::avio_read (uint8_t* buffer, int const amount)
268 return _file_group.read (buffer, amount);
273 FFmpeg::avio_seek (int64_t const pos, int whence)
275 if (whence == AVSEEK_SIZE) {
276 return _file_group.length ();
279 return _file_group.seek (pos, whence);
284 FFmpeg::subtitle_period (AVSubtitle const & sub)
286 auto const packet_time = ContentTime::from_seconds (static_cast<double> (sub.pts) / AV_TIME_BASE);
288 if (sub.end_display_time == static_cast<uint32_t> (-1)) {
289 /* End time is not known */
290 return FFmpegSubtitlePeriod (packet_time + ContentTime::from_seconds (sub.start_display_time / 1e3));
293 return FFmpegSubtitlePeriod (
294 packet_time + ContentTime::from_seconds (sub.start_display_time / 1e3),
295 packet_time + ContentTime::from_seconds (sub.end_display_time / 1e3)
300 /** Compute the pts offset to use given a set of audio streams and some video details.
301 * Sometimes these parameters will have just been determined by an Examiner, sometimes
302 * they will have been retrieved from a piece of Content, hence the need for this method
306 FFmpeg::pts_offset (vector<shared_ptr<FFmpegAudioStream>> audio_streams, optional<ContentTime> first_video, double video_frame_rate) const
308 /* Audio and video frame PTS values may not start with 0. We want
309 to fiddle them so that:
311 1. One of them starts at time 0.
312 2. The first video PTS value ends up on a frame boundary.
314 Then we remove big initial gaps in PTS and we allow our
315 insertion of black frames to work.
318 audio_pts_to_use = audio_pts_from_ffmpeg + pts_offset;
319 video_pts_to_use = video_pts_from_ffmpeg + pts_offset;
322 /* First, make one of them start at 0 */
324 auto po = ContentTime::min ();
327 po = - first_video.get ();
330 for (auto i: audio_streams) {
331 if (i->first_audio) {
332 po = max (po, - i->first_audio.get ());
336 /* If the offset is positive we would be pushing things from a -ve PTS to be played.
337 I don't think we ever want to do that, as it seems things at -ve PTS are not meant
338 to be seen (use for alignment bars etc.); see mantis #418.
340 if (po > ContentTime ()) {
344 /* Now adjust so that the video pts starts on a frame */
346 auto const fvc = first_video.get() + po;
347 po += fvc.ceil (video_frame_rate) - fvc;