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 for (auto& i: _codec_context) {
72 avcodec_free_context (&i);
75 av_frame_free (&_frame);
76 avformat_close_input (&_format_context);
81 avio_read_wrapper (void* data, uint8_t* buffer, int amount)
83 return reinterpret_cast<FFmpeg*>(data)->avio_read (buffer, amount);
88 avio_seek_wrapper (void* data, int64_t offset, int whence)
90 return reinterpret_cast<FFmpeg*>(data)->avio_seek (offset, whence);
95 FFmpeg::ffmpeg_log_callback (void* ptr, int level, const char* fmt, va_list vl)
97 if (level > AV_LOG_WARNING) {
102 static int prefix = 0;
103 av_log_format_line (ptr, level, fmt, vl, line, sizeof (line), &prefix);
105 boost::algorithm::trim (str);
106 dcpomatic_log->log (String::compose ("FFmpeg: %1", str), LogEntry::TYPE_GENERAL);
111 FFmpeg::setup_general ()
113 /* This might not work too well in some cases of multiple FFmpeg decoders,
114 but it's probably good enough.
116 av_log_set_callback (FFmpeg::ffmpeg_log_callback);
118 _file_group.set_paths (_ffmpeg_content->paths ());
119 _avio_buffer = static_cast<uint8_t*> (wrapped_av_malloc(_avio_buffer_size));
120 _avio_context = avio_alloc_context (_avio_buffer, _avio_buffer_size, 0, this, avio_read_wrapper, 0, avio_seek_wrapper);
121 if (!_avio_context) {
122 throw std::bad_alloc ();
124 _format_context = avformat_alloc_context ();
125 if (!_format_context) {
126 throw std::bad_alloc ();
128 _format_context->pb = _avio_context;
130 AVDictionary* options = nullptr;
131 int e = avformat_open_input (&_format_context, 0, 0, &options);
133 throw OpenFileError (_ffmpeg_content->path(0).string(), e, OpenFileError::READ);
136 if (avformat_find_stream_info (_format_context, 0) < 0) {
137 throw DecodeError (_("could not find stream information"));
140 /* Find video stream */
142 optional<int> video_stream_undefined_frame_rate;
144 for (uint32_t i = 0; i < _format_context->nb_streams; ++i) {
145 auto s = _format_context->streams[i];
146 if (s->codecpar->codec_type == AVMEDIA_TYPE_VIDEO && avcodec_find_decoder(s->codecpar->codec_id)) {
147 if (s->avg_frame_rate.num > 0 && s->avg_frame_rate.den > 0) {
148 /* This is definitely our video stream */
151 /* This is our video stream if we don't get a better offer */
152 video_stream_undefined_frame_rate = i;
157 /* Files from iTunes sometimes have two video streams, one with the avg_frame_rate.num and .den set
158 to zero. Only use such a stream if there is no alternative.
160 if (!_video_stream && video_stream_undefined_frame_rate) {
161 _video_stream = video_stream_undefined_frame_rate.get();
164 /* Ignore video streams with crazy frame rates. These are usually things like album art on MP3s. */
165 if (_video_stream && av_q2d(av_guess_frame_rate(_format_context, _format_context->streams[_video_stream.get()], 0)) > 1000) {
166 _video_stream = optional<int>();
169 /* Hack: if the AVStreams have duplicate IDs, replace them with our
170 own. We use the IDs so that we can cope with VOBs, in which streams
171 move about in index but remain with the same ID in different
172 VOBs. However, some files have duplicate IDs, hence this hack.
175 bool duplicates = false;
176 for (uint32_t i = 0; i < _format_context->nb_streams; ++i) {
177 for (uint32_t j = i + 1; j < _format_context->nb_streams; ++j) {
178 if (_format_context->streams[i]->id == _format_context->streams[j]->id) {
185 /* Put in our own IDs */
186 for (uint32_t i = 0; i < _format_context->nb_streams; ++i) {
187 _format_context->streams[i]->id = i;
191 _frame = av_frame_alloc ();
193 throw std::bad_alloc ();
199 FFmpeg::setup_decoders ()
201 boost::mutex::scoped_lock lm (_mutex);
203 _codec_context.resize (_format_context->nb_streams);
204 for (uint32_t i = 0; i < _format_context->nb_streams; ++i) {
205 auto codec = avcodec_find_decoder (_format_context->streams[i]->codecpar->codec_id);
207 auto context = avcodec_alloc_context3 (codec);
209 throw std::bad_alloc ();
211 _codec_context[i] = context;
213 int r = avcodec_parameters_to_context (context, _format_context->streams[i]->codecpar);
215 throw DecodeError ("avcodec_parameters_to_context", "FFmpeg::setup_decoders", r);
218 context->thread_count = 8;
219 context->thread_type = FF_THREAD_FRAME | FF_THREAD_SLICE;
221 AVDictionary* options = nullptr;
222 /* This option disables decoding of DCA frame footers in our patched version
223 of FFmpeg. I believe these footers are of no use to us, and they can cause
224 problems when FFmpeg fails to decode them (mantis #352).
226 av_dict_set (&options, "disable_footer", "1", 0);
227 /* This allows decoding of some DNxHR 444 and HQX files; see
228 https://trac.ffmpeg.org/ticket/5681
230 av_dict_set_int (&options, "strict", FF_COMPLIANCE_EXPERIMENTAL, 0);
231 /* Enable following of links in files */
232 av_dict_set_int (&options, "enable_drefs", 1, 0);
234 r = avcodec_open2 (context, codec, &options);
236 throw DecodeError (N_("avcodec_open2"), N_("FFmpeg::setup_decoders"), r);
239 dcpomatic_log->log (String::compose ("No codec found for stream %1", i), LogEntry::TYPE_WARNING);
246 FFmpeg::video_codec_context () const
248 if (!_video_stream) {
252 return _codec_context[_video_stream.get()];
257 FFmpeg::subtitle_codec_context () const
259 auto str = _ffmpeg_content->subtitle_stream();
264 return _codec_context[str->index(_format_context)];
269 FFmpeg::avio_read (uint8_t* buffer, int const amount)
271 return _file_group.read (buffer, amount);
276 FFmpeg::avio_seek (int64_t const pos, int whence)
278 if (whence == AVSEEK_SIZE) {
279 return _file_group.length ();
282 return _file_group.seek (pos, whence);
287 FFmpeg::subtitle_period (AVSubtitle const & sub)
289 auto const packet_time = ContentTime::from_seconds (static_cast<double> (sub.pts) / AV_TIME_BASE);
291 if (sub.end_display_time == static_cast<uint32_t> (-1)) {
292 /* End time is not known */
293 return FFmpegSubtitlePeriod (packet_time + ContentTime::from_seconds (sub.start_display_time / 1e3));
296 return FFmpegSubtitlePeriod (
297 packet_time + ContentTime::from_seconds (sub.start_display_time / 1e3),
298 packet_time + ContentTime::from_seconds (sub.end_display_time / 1e3)
303 /** Compute the pts offset to use given a set of audio streams and some video details.
304 * Sometimes these parameters will have just been determined by an Examiner, sometimes
305 * they will have been retrieved from a piece of Content, hence the need for this method
309 FFmpeg::pts_offset (vector<shared_ptr<FFmpegAudioStream>> audio_streams, optional<ContentTime> first_video, double video_frame_rate) const
311 /* Audio and video frame PTS values may not start with 0. We want
312 to fiddle them so that:
314 1. One of them starts at time 0.
315 2. The first video PTS value ends up on a frame boundary.
317 Then we remove big initial gaps in PTS and we allow our
318 insertion of black frames to work.
321 audio_pts_to_use = audio_pts_from_ffmpeg + pts_offset;
322 video_pts_to_use = video_pts_from_ffmpeg + pts_offset;
325 /* First, make one of them start at 0 */
327 auto po = ContentTime::min ();
330 po = - first_video.get ();
333 for (auto i: audio_streams) {
334 if (i->first_audio) {
335 po = max (po, - i->first_audio.get ());
339 /* If the offset is positive we would be pushing things from a -ve PTS to be played.
340 I don't think we ever want to do that, as it seems things at -ve PTS are not meant
341 to be seen (use for alignment bars etc.); see mantis #418.
343 if (po > ContentTime ()) {
347 /* Now adjust so that the video pts starts on a frame */
349 auto const fvc = first_video.get() + po;
350 po += fvc.ceil (video_frame_rate) - fvc;