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;
64 } else if (video_codec == CODEC_NV12) {
65 avstream_video->codecpar->codec_id = AV_CODEC_ID_RAWVIDEO;
66 avstream_video->codecpar->codec_tag = avcodec_pix_fmt_to_codec_tag(AV_PIX_FMT_NV12);
68 assert(video_codec == CODEC_MJPEG);
69 avstream_video->codecpar->codec_id = AV_CODEC_ID_MJPEG;
71 avstream_video->codecpar->width = width;
72 avstream_video->codecpar->height = height;
74 // Colorspace details. Closely correspond to settings in EffectChain_finalize,
75 // as noted in each comment.
76 // Note that the H.264 stream also contains this information and depending on the
77 // mux, this might simply get ignored. See sps_rbsp().
78 // Note that there's no way to change this per-frame as the H.264 stream
79 // would like to be able to.
80 avstream_video->codecpar->color_primaries = AVCOL_PRI_BT709; // RGB colorspace (inout_format.color_space).
81 avstream_video->codecpar->color_trc = AVCOL_TRC_IEC61966_2_1; // Gamma curve (inout_format.gamma_curve).
82 // YUV colorspace (output_ycbcr_format.luma_coefficients).
83 avstream_video->codecpar->color_space = color_space;
84 avstream_video->codecpar->color_range = AVCOL_RANGE_MPEG; // Full vs. limited range (output_ycbcr_format.full_range).
85 avstream_video->codecpar->chroma_location = AVCHROMA_LOC_LEFT; // Chroma sample location. See chroma_offset_0[] in Mixer::subsample_chroma().
86 avstream_video->codecpar->field_order = AV_FIELD_PROGRESSIVE;
88 if (!video_extradata.empty()) {
89 avstream_video->codecpar->extradata = (uint8_t *)av_malloc(video_extradata.size());
90 avstream_video->codecpar->extradata_size = video_extradata.size();
91 memcpy(avstream_video->codecpar->extradata, video_extradata.data(), video_extradata.size());
93 streams.push_back(avstream_video);
95 if (audio_codecpar != nullptr) {
96 AVStream *avstream_audio = avformat_new_stream(avctx, nullptr);
97 if (avstream_audio == nullptr) {
98 fprintf(stderr, "avformat_new_stream() failed\n");
101 avstream_audio->time_base = AVRational{1, time_base};
102 if (avcodec_parameters_copy(avstream_audio->codecpar, audio_codecpar) < 0) {
103 fprintf(stderr, "avcodec_parameters_copy() failed\n");
106 streams.push_back(avstream_audio);
109 if (with_subtitles == WITH_SUBTITLES) {
110 AVStream *avstream_subtitles = avformat_new_stream(avctx, nullptr);
111 if (avstream_subtitles == nullptr) {
112 fprintf(stderr, "avformat_new_stream() failed\n");
115 avstream_subtitles->time_base = AVRational{1, time_base};
116 avstream_subtitles->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
117 avstream_subtitles->codecpar->codec_id = AV_CODEC_ID_WEBVTT;
118 avstream_subtitles->disposition = AV_DISPOSITION_METADATA;
119 streams.push_back(avstream_subtitles);
120 subtitle_stream_idx = streams.size() - 1;
123 AVDictionary *options = NULL;
124 vector<pair<string, string>> opts = MUX_OPTS;
125 for (pair<string, string> opt : opts) {
126 av_dict_set(&options, opt.first.c_str(), opt.second.c_str(), 0);
128 int err = avformat_write_header(avctx, &options);
130 char errbuf[AV_ERROR_MAX_STRING_SIZE];
131 av_strerror(err, errbuf, sizeof(errbuf));
132 fprintf(stderr, "avformat_write_header() failed: %s\n", errbuf);
135 for (MuxMetrics *metric : metrics) {
136 metric->metric_written_bytes += avctx->pb->pos;
139 // Make sure the header is written before the constructor exits.
140 avio_flush(avctx->pb);
142 if (write_strategy == WRITE_BACKGROUND) {
143 writer_thread = thread(&Mux::thread_func, this);
149 assert(plug_count == 0);
150 if (write_strategy == WRITE_BACKGROUND) {
151 writer_thread_should_quit = true;
152 packet_queue_ready.notify_all();
153 writer_thread.join();
155 int64_t old_pos = avctx->pb->pos;
156 av_write_trailer(avctx);
157 for (MuxMetrics *metric : metrics) {
158 metric->metric_written_bytes += avctx->pb->pos - old_pos;
161 if (!(avctx->oformat->flags & AVFMT_NOFILE) &&
162 !(avctx->flags & AVFMT_FLAG_CUSTOM_IO)) {
163 avio_closep(&avctx->pb);
165 avformat_free_context(avctx);
168 void Mux::add_packet(const AVPacket &pkt, int64_t pts, int64_t dts, AVRational timebase, int stream_index_override)
171 av_init_packet(&pkt_copy);
172 if (av_packet_ref(&pkt_copy, &pkt) < 0) {
173 fprintf(stderr, "av_copy_packet() failed\n");
176 if (stream_index_override != -1) {
177 pkt_copy.stream_index = stream_index_override;
179 assert(size_t(pkt_copy.stream_index) < streams.size());
180 AVRational time_base = streams[pkt_copy.stream_index]->time_base;
181 pkt_copy.pts = av_rescale_q(pts, timebase, time_base);
182 pkt_copy.dts = av_rescale_q(dts, timebase, time_base);
183 pkt_copy.duration = av_rescale_q(pkt.duration, timebase, time_base);
186 lock_guard<mutex> lock(mu);
187 if (write_strategy == WriteStrategy::WRITE_BACKGROUND) {
188 packet_queue.push_back(QueuedPacket{ av_packet_clone(&pkt_copy), pts });
190 packet_queue_ready.notify_all();
191 } else if (plug_count > 0) {
192 packet_queue.push_back(QueuedPacket{ av_packet_clone(&pkt_copy), pts });
194 write_packet_or_die(pkt_copy, pts);
198 av_packet_unref(&pkt_copy);
201 void Mux::write_packet_or_die(const AVPacket &pkt, int64_t unscaled_pts)
203 for (MuxMetrics *metric : metrics) {
204 if (pkt.stream_index == 0) {
205 metric->metric_video_bytes += pkt.size;
206 } else if (pkt.stream_index == 1) {
207 metric->metric_audio_bytes += pkt.size;
212 int64_t old_pos = avctx->pb->pos;
213 int err = av_interleaved_write_frame(avctx, const_cast<AVPacket *>(&pkt));
215 char errbuf[AV_ERROR_MAX_STRING_SIZE];
216 av_strerror(err, errbuf, sizeof(errbuf));
217 fprintf(stderr, "av_interleaved_write_frame() failed: %s\n", errbuf);
220 avio_flush(avctx->pb);
221 for (MuxMetrics *metric : metrics) {
222 metric->metric_written_bytes += avctx->pb->pos - old_pos;
225 if (pkt.stream_index == 0 && write_callback != nullptr) {
226 write_callback(unscaled_pts);
232 lock_guard<mutex> lock(mu);
238 lock_guard<mutex> lock(mu);
239 if (--plug_count > 0) {
242 assert(plug_count >= 0);
244 sort(packet_queue.begin(), packet_queue.end(), PacketBefore(avctx));
246 if (write_strategy == WRITE_BACKGROUND) {
247 packet_queue_ready.notify_all();
249 for (QueuedPacket &qp : packet_queue) {
250 write_packet_or_die(*qp.pkt, qp.unscaled_pts);
251 av_packet_free(&qp.pkt);
253 packet_queue.clear();
257 void Mux::thread_func()
259 pthread_setname_np(pthread_self(), "Mux");
261 unique_lock<mutex> lock(mu);
263 packet_queue_ready.wait(lock, [this]() {
264 return writer_thread_should_quit || (!packet_queue.empty() && plug_count == 0);
266 if (writer_thread_should_quit && packet_queue.empty()) {
271 assert(!packet_queue.empty() && plug_count == 0);
272 vector<QueuedPacket> packets;
273 swap(packets, packet_queue);
276 for (QueuedPacket &qp : packets) {
277 write_packet_or_die(*qp.pkt, qp.unscaled_pts);
278 av_packet_free(&qp.pkt);
284 void MuxMetrics::init(const vector<pair<string, string>> &labels)
286 vector<pair<string, string>> labels_video = labels;
287 labels_video.emplace_back("stream", "video");
288 global_metrics.add("mux_stream_bytes", labels_video, &metric_video_bytes);
290 vector<pair<string, string>> labels_audio = labels;
291 labels_audio.emplace_back("stream", "audio");
292 global_metrics.add("mux_stream_bytes", labels_audio, &metric_audio_bytes);
294 global_metrics.add("mux_written_bytes", labels, &metric_written_bytes);