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>
32 PacketBefore(const AVFormatContext *ctx) : ctx(ctx) {}
34 bool operator() (const Mux::QueuedPacket &a_qp, const Mux::QueuedPacket &b_qp) const {
35 const AVPacket *a = a_qp.pkt;
36 const AVPacket *b = b_qp.pkt;
37 int64_t a_dts = (a->dts == AV_NOPTS_VALUE ? a->pts : a->dts);
38 int64_t b_dts = (b->dts == AV_NOPTS_VALUE ? b->pts : b->dts);
39 AVRational a_timebase = ctx->streams[a->stream_index]->time_base;
40 AVRational b_timebase = ctx->streams[b->stream_index]->time_base;
41 if (av_compare_ts(a_dts, a_timebase, b_dts, b_timebase) != 0) {
42 return av_compare_ts(a_dts, a_timebase, b_dts, b_timebase) < 0;
44 return av_compare_ts(a->pts, a_timebase, b->pts, b_timebase) < 0;
48 const AVFormatContext * const ctx;
51 Mux::Mux(AVFormatContext *avctx, int width, int height, Codec video_codec, const string &video_extradata, const AVCodecParameters *audio_codecpar, int time_base, std::function<void(int64_t)> write_callback, WriteStrategy write_strategy, const vector<MuxMetrics *> &metrics)
52 : write_strategy(write_strategy), avctx(avctx), write_callback(write_callback), metrics(metrics)
54 avstream_video = avformat_new_stream(avctx, nullptr);
55 if (avstream_video == nullptr) {
56 fprintf(stderr, "avformat_new_stream() failed\n");
59 avstream_video->time_base = AVRational{1, time_base};
60 avstream_video->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
61 if (video_codec == CODEC_H264) {
62 avstream_video->codecpar->codec_id = AV_CODEC_ID_H264;
64 assert(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 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 if (global_flags.ycbcr_rec709_coefficients) {
81 avstream_video->codecpar->color_space = AVCOL_SPC_BT709;
83 avstream_video->codecpar->color_space = AVCOL_SPC_SMPTE170M;
85 avstream_video->codecpar->color_range = AVCOL_RANGE_MPEG; // Full vs. limited range (output_ycbcr_format.full_range).
86 avstream_video->codecpar->chroma_location = AVCHROMA_LOC_LEFT; // Chroma sample location. See chroma_offset_0[] in Mixer::subsample_chroma().
87 avstream_video->codecpar->field_order = AV_FIELD_PROGRESSIVE;
89 if (!video_extradata.empty()) {
90 avstream_video->codecpar->extradata = (uint8_t *)av_malloc(video_extradata.size());
91 avstream_video->codecpar->extradata_size = video_extradata.size();
92 memcpy(avstream_video->codecpar->extradata, video_extradata.data(), video_extradata.size());
95 avstream_audio = avformat_new_stream(avctx, nullptr);
96 if (avstream_audio == nullptr) {
97 fprintf(stderr, "avformat_new_stream() failed\n");
100 avstream_audio->time_base = AVRational{1, time_base};
101 if (avcodec_parameters_copy(avstream_audio->codecpar, audio_codecpar) < 0) {
102 fprintf(stderr, "avcodec_parameters_copy() failed\n");
106 AVDictionary *options = NULL;
107 vector<pair<string, string>> opts = MUX_OPTS;
108 for (pair<string, string> opt : opts) {
109 av_dict_set(&options, opt.first.c_str(), opt.second.c_str(), 0);
111 if (avformat_write_header(avctx, &options) < 0) {
112 fprintf(stderr, "avformat_write_header() failed\n");
115 for (MuxMetrics *metric : metrics) {
116 metric->metric_written_bytes += avctx->pb->pos;
119 // Make sure the header is written before the constructor exits.
120 avio_flush(avctx->pb);
122 if (write_strategy == WRITE_BACKGROUND) {
123 writer_thread = thread(&Mux::thread_func, this);
129 assert(plug_count == 0);
130 if (write_strategy == WRITE_BACKGROUND) {
131 writer_thread_should_quit = true;
132 packet_queue_ready.notify_all();
133 writer_thread.join();
135 int64_t old_pos = avctx->pb->pos;
136 av_write_trailer(avctx);
137 for (MuxMetrics *metric : metrics) {
138 metric->metric_written_bytes += avctx->pb->pos - old_pos;
141 if (!(avctx->oformat->flags & AVFMT_NOFILE) &&
142 !(avctx->flags & AVFMT_FLAG_CUSTOM_IO)) {
143 avio_closep(&avctx->pb);
145 avformat_free_context(avctx);
148 void Mux::add_packet(const AVPacket &pkt, int64_t pts, int64_t dts, AVRational timebase)
151 av_init_packet(&pkt_copy);
152 if (av_packet_ref(&pkt_copy, &pkt) < 0) {
153 fprintf(stderr, "av_copy_packet() failed\n");
156 if (pkt.stream_index == 0) {
157 pkt_copy.pts = av_rescale_q(pts, timebase, avstream_video->time_base);
158 pkt_copy.dts = av_rescale_q(dts, timebase, avstream_video->time_base);
159 pkt_copy.duration = av_rescale_q(pkt.duration, timebase, avstream_video->time_base);
160 } else if (pkt.stream_index == 1) {
161 pkt_copy.pts = av_rescale_q(pts, timebase, avstream_audio->time_base);
162 pkt_copy.dts = av_rescale_q(dts, timebase, avstream_audio->time_base);
163 pkt_copy.duration = av_rescale_q(pkt.duration, timebase, avstream_audio->time_base);
169 lock_guard<mutex> lock(mu);
170 if (write_strategy == WriteStrategy::WRITE_BACKGROUND) {
171 packet_queue.push_back(QueuedPacket{ av_packet_clone(&pkt_copy), pts });
172 if (plug_count == 0) packet_queue_ready.notify_all();
173 } else if (plug_count > 0) {
174 packet_queue.push_back(QueuedPacket{ av_packet_clone(&pkt_copy), pts });
176 write_packet_or_die(pkt_copy, pts);
180 av_packet_unref(&pkt_copy);
183 void Mux::write_packet_or_die(const AVPacket &pkt, int64_t unscaled_pts)
185 for (MuxMetrics *metric : metrics) {
186 if (pkt.stream_index == 0) {
187 metric->metric_video_bytes += pkt.size;
188 } else if (pkt.stream_index == 1) {
189 metric->metric_audio_bytes += pkt.size;
194 int64_t old_pos = avctx->pb->pos;
195 if (av_interleaved_write_frame(avctx, const_cast<AVPacket *>(&pkt)) < 0) {
196 fprintf(stderr, "av_interleaved_write_frame() failed\n");
199 avio_flush(avctx->pb);
200 for (MuxMetrics *metric : metrics) {
201 metric->metric_written_bytes += avctx->pb->pos - old_pos;
204 if (pkt.stream_index == 0 && write_callback != nullptr) {
205 write_callback(unscaled_pts);
211 lock_guard<mutex> lock(mu);
217 lock_guard<mutex> lock(mu);
218 if (--plug_count > 0) {
221 assert(plug_count >= 0);
223 sort(packet_queue.begin(), packet_queue.end(), PacketBefore(avctx));
225 if (write_strategy == WRITE_BACKGROUND) {
226 packet_queue_ready.notify_all();
228 for (QueuedPacket &qp : packet_queue) {
229 write_packet_or_die(*qp.pkt, qp.unscaled_pts);
230 av_packet_free(&qp.pkt);
232 packet_queue.clear();
236 void Mux::thread_func()
238 unique_lock<mutex> lock(mu);
240 packet_queue_ready.wait(lock, [this]() {
241 return writer_thread_should_quit || (!packet_queue.empty() && plug_count == 0);
243 if (writer_thread_should_quit && packet_queue.empty()) {
248 assert(!packet_queue.empty() && plug_count == 0);
249 vector<QueuedPacket> packets;
250 swap(packets, packet_queue);
253 for (QueuedPacket &qp : packets) {
254 write_packet_or_die(*qp.pkt, qp.unscaled_pts);
255 av_packet_free(&qp.pkt);
261 void MuxMetrics::init(const vector<pair<string, string>> &labels)
263 vector<pair<string, string>> labels_video = labels;
264 labels_video.emplace_back("stream", "video");
265 global_metrics.add("mux_stream_bytes", labels_video, &metric_video_bytes);
267 vector<pair<string, string>> labels_audio = labels;
268 labels_audio.emplace_back("stream", "audio");
269 global_metrics.add("mux_stream_bytes", labels_audio, &metric_audio_bytes);
271 global_metrics.add("mux_written_bytes", labels, &metric_written_bytes);