1 #include "shared/mux.h"
15 #include <libavformat/avio.h>
16 #include <libavutil/avutil.h>
17 #include <libavutil/dict.h>
18 #include <libavutil/mathematics.h>
19 #include <libavutil/mem.h>
20 #include <libavutil/pixfmt.h>
21 #include <libavutil/rational.h>
24 #include "shared/metrics.h"
25 #include "shared/shared_defs.h"
26 #include "shared/timebase.h"
31 PacketBefore(const AVFormatContext *ctx) : ctx(ctx) {}
33 bool operator() (const Mux::QueuedPacket &a_qp, const Mux::QueuedPacket &b_qp) const {
34 const AVPacket *a = a_qp.pkt;
35 const AVPacket *b = b_qp.pkt;
36 int64_t a_dts = (a->dts == AV_NOPTS_VALUE ? a->pts : a->dts);
37 int64_t b_dts = (b->dts == AV_NOPTS_VALUE ? b->pts : b->dts);
38 AVRational a_timebase = ctx->streams[a->stream_index]->time_base;
39 AVRational b_timebase = ctx->streams[b->stream_index]->time_base;
40 if (av_compare_ts(a_dts, a_timebase, b_dts, b_timebase) != 0) {
41 return av_compare_ts(a_dts, a_timebase, b_dts, b_timebase) < 0;
43 return av_compare_ts(a->pts, a_timebase, b->pts, b_timebase) < 0;
47 const AVFormatContext * const ctx;
50 Mux::Mux(AVFormatContext *avctx, int width, int height, Codec video_codec, const string &video_extradata, const AVCodecParameters *audio_codecpar, AVColorSpace color_space, int time_base, function<void(int64_t)> write_callback, WriteStrategy write_strategy, const vector<MuxMetrics *> &metrics, WithSubtitles with_subtitles)
51 : write_strategy(write_strategy), avctx(avctx), write_callback(write_callback), metrics(metrics)
53 AVStream *avstream_video = avformat_new_stream(avctx, nullptr);
54 if (avstream_video == nullptr) {
55 fprintf(stderr, "avformat_new_stream() failed\n");
58 avstream_video->time_base = AVRational{1, time_base};
59 avstream_video->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
60 if (video_codec == CODEC_H264) {
61 avstream_video->codecpar->codec_id = AV_CODEC_ID_H264;
62 } else if (video_codec == CODEC_AV1) {
63 avstream_video->codecpar->codec_id = AV_CODEC_ID_AV1;
65 assert(video_codec == CODEC_MJPEG);
66 avstream_video->codecpar->codec_id = AV_CODEC_ID_MJPEG;
68 avstream_video->codecpar->width = width;
69 avstream_video->codecpar->height = height;
71 // Colorspace details. Closely correspond to settings in EffectChain_finalize,
72 // as noted in each comment.
73 // Note that the H.264 stream also contains this information and depending on the
74 // mux, this might simply get ignored. See sps_rbsp().
75 // Note that there's no way to change this per-frame as the H.264 stream
76 // would like to be able to.
77 avstream_video->codecpar->color_primaries = AVCOL_PRI_BT709; // RGB colorspace (inout_format.color_space).
78 avstream_video->codecpar->color_trc = AVCOL_TRC_IEC61966_2_1; // Gamma curve (inout_format.gamma_curve).
79 // YUV colorspace (output_ycbcr_format.luma_coefficients).
80 avstream_video->codecpar->color_space = color_space;
81 avstream_video->codecpar->color_range = AVCOL_RANGE_MPEG; // Full vs. limited range (output_ycbcr_format.full_range).
82 avstream_video->codecpar->chroma_location = AVCHROMA_LOC_LEFT; // Chroma sample location. See chroma_offset_0[] in Mixer::subsample_chroma().
83 avstream_video->codecpar->field_order = AV_FIELD_PROGRESSIVE;
85 if (!video_extradata.empty()) {
86 avstream_video->codecpar->extradata = (uint8_t *)av_malloc(video_extradata.size() + AV_INPUT_BUFFER_PADDING_SIZE);
87 avstream_video->codecpar->extradata_size = video_extradata.size();
88 memcpy(avstream_video->codecpar->extradata, video_extradata.data(), video_extradata.size());
90 streams.push_back(avstream_video);
92 if (audio_codecpar != nullptr) {
93 AVStream *avstream_audio = avformat_new_stream(avctx, nullptr);
94 if (avstream_audio == nullptr) {
95 fprintf(stderr, "avformat_new_stream() failed\n");
98 avstream_audio->time_base = AVRational{1, time_base};
99 if (avcodec_parameters_copy(avstream_audio->codecpar, audio_codecpar) < 0) {
100 fprintf(stderr, "avcodec_parameters_copy() failed\n");
103 streams.push_back(avstream_audio);
106 if (with_subtitles == WITH_SUBTITLES) {
107 AVStream *avstream_subtitles = avformat_new_stream(avctx, nullptr);
108 if (avstream_subtitles == nullptr) {
109 fprintf(stderr, "avformat_new_stream() failed\n");
112 avstream_subtitles->time_base = AVRational{1, time_base};
113 avstream_subtitles->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
114 avstream_subtitles->codecpar->codec_id = AV_CODEC_ID_WEBVTT;
115 avstream_subtitles->disposition = AV_DISPOSITION_METADATA;
116 streams.push_back(avstream_subtitles);
117 subtitle_stream_idx = streams.size() - 1;
120 AVDictionary *options = NULL;
121 vector<pair<string, string>> opts = MUX_OPTS;
122 for (pair<string, string> opt : opts) {
123 av_dict_set(&options, opt.first.c_str(), opt.second.c_str(), 0);
125 int err = avformat_write_header(avctx, &options);
127 char errbuf[AV_ERROR_MAX_STRING_SIZE];
128 av_strerror(err, errbuf, sizeof(errbuf));
129 fprintf(stderr, "avformat_write_header() failed: %s\n", errbuf);
132 for (MuxMetrics *metric : metrics) {
133 metric->metric_written_bytes += avctx->pb->pos;
136 // Make sure the header is written before the constructor exits.
137 avio_flush(avctx->pb);
139 if (write_strategy == WRITE_BACKGROUND) {
140 writer_thread = thread(&Mux::thread_func, this);
146 assert(plug_count == 0);
147 if (write_strategy == WRITE_BACKGROUND) {
148 writer_thread_should_quit = true;
149 packet_queue_ready.notify_all();
150 writer_thread.join();
152 int64_t old_pos = avctx->pb->pos;
153 av_write_trailer(avctx);
154 for (MuxMetrics *metric : metrics) {
155 metric->metric_written_bytes += avctx->pb->pos - old_pos;
158 if (!(avctx->oformat->flags & AVFMT_NOFILE) &&
159 !(avctx->flags & AVFMT_FLAG_CUSTOM_IO)) {
160 avio_closep(&avctx->pb);
162 avformat_free_context(avctx);
165 void Mux::add_packet(const AVPacket &pkt, int64_t pts, int64_t dts, AVRational timebase, int stream_index_override)
168 av_init_packet(&pkt_copy);
169 if (av_packet_ref(&pkt_copy, &pkt) < 0) {
170 fprintf(stderr, "av_copy_packet() failed\n");
173 if (stream_index_override != -1) {
174 pkt_copy.stream_index = stream_index_override;
176 assert(size_t(pkt_copy.stream_index) < streams.size());
177 AVRational time_base = streams[pkt_copy.stream_index]->time_base;
178 pkt_copy.pts = av_rescale_q(pts, timebase, time_base);
179 pkt_copy.dts = av_rescale_q(dts, timebase, time_base);
180 pkt_copy.duration = av_rescale_q(pkt.duration, timebase, time_base);
183 lock_guard<mutex> lock(mu);
184 if (write_strategy == WriteStrategy::WRITE_BACKGROUND) {
185 packet_queue.push_back(QueuedPacket{ av_packet_clone(&pkt_copy), pts });
187 packet_queue_ready.notify_all();
188 } else if (plug_count > 0) {
189 packet_queue.push_back(QueuedPacket{ av_packet_clone(&pkt_copy), pts });
191 write_packet_or_die(pkt_copy, pts);
195 av_packet_unref(&pkt_copy);
198 void Mux::write_packet_or_die(const AVPacket &pkt, int64_t unscaled_pts)
200 for (MuxMetrics *metric : metrics) {
201 if (pkt.stream_index == 0) {
202 metric->metric_video_bytes += pkt.size;
203 } else if (pkt.stream_index == 1) {
204 metric->metric_audio_bytes += pkt.size;
209 int64_t old_pos = avctx->pb->pos;
210 int err = av_interleaved_write_frame(avctx, const_cast<AVPacket *>(&pkt));
212 char errbuf[AV_ERROR_MAX_STRING_SIZE];
213 av_strerror(err, errbuf, sizeof(errbuf));
214 fprintf(stderr, "av_interleaved_write_frame() failed: %s\n", errbuf);
217 avio_flush(avctx->pb);
218 for (MuxMetrics *metric : metrics) {
219 metric->metric_written_bytes += avctx->pb->pos - old_pos;
222 if (pkt.stream_index == 0 && write_callback != nullptr) {
223 write_callback(unscaled_pts);
229 lock_guard<mutex> lock(mu);
235 lock_guard<mutex> lock(mu);
236 if (--plug_count > 0) {
239 assert(plug_count >= 0);
241 sort(packet_queue.begin(), packet_queue.end(), PacketBefore(avctx));
243 if (write_strategy == WRITE_BACKGROUND) {
244 packet_queue_ready.notify_all();
246 for (QueuedPacket &qp : packet_queue) {
247 write_packet_or_die(*qp.pkt, qp.unscaled_pts);
248 av_packet_free(&qp.pkt);
250 packet_queue.clear();
254 void Mux::thread_func()
256 pthread_setname_np(pthread_self(), "Mux");
258 unique_lock<mutex> lock(mu);
260 packet_queue_ready.wait(lock, [this]() {
261 return writer_thread_should_quit || (!packet_queue.empty() && plug_count == 0);
263 if (writer_thread_should_quit && packet_queue.empty()) {
268 assert(!packet_queue.empty() && plug_count == 0);
269 vector<QueuedPacket> packets;
270 swap(packets, packet_queue);
273 for (QueuedPacket &qp : packets) {
274 write_packet_or_die(*qp.pkt, qp.unscaled_pts);
275 av_packet_free(&qp.pkt);
281 void MuxMetrics::init(const vector<pair<string, string>> &labels)
283 vector<pair<string, string>> labels_video = labels;
284 labels_video.emplace_back("stream", "video");
285 global_metrics.add("mux_stream_bytes", labels_video, &metric_video_bytes);
287 vector<pair<string, string>> labels_audio = labels;
288 labels_audio.emplace_back("stream", "audio");
289 global_metrics.add("mux_stream_bytes", labels_audio, &metric_audio_bytes);
291 global_metrics.add("mux_written_bytes", labels, &metric_written_bytes);