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>
30 PacketBefore(const AVFormatContext *ctx) : ctx(ctx) {}
32 bool operator() (const Mux::QueuedPacket &a_qp, const Mux::QueuedPacket &b_qp) const {
33 const AVPacket *a = a_qp.pkt;
34 const AVPacket *b = b_qp.pkt;
35 int64_t a_dts = (a->dts == AV_NOPTS_VALUE ? a->pts : a->dts);
36 int64_t b_dts = (b->dts == AV_NOPTS_VALUE ? b->pts : b->dts);
37 AVRational a_timebase = ctx->streams[a->stream_index]->time_base;
38 AVRational b_timebase = ctx->streams[b->stream_index]->time_base;
39 if (av_compare_ts(a_dts, a_timebase, b_dts, b_timebase) != 0) {
40 return av_compare_ts(a_dts, a_timebase, b_dts, b_timebase) < 0;
42 return av_compare_ts(a->pts, a_timebase, b->pts, b_timebase) < 0;
46 const AVFormatContext * const ctx;
49 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)
50 : write_strategy(write_strategy), avctx(avctx), write_callback(write_callback), metrics(metrics)
52 avstream_video = avformat_new_stream(avctx, nullptr);
53 if (avstream_video == nullptr) {
54 fprintf(stderr, "avformat_new_stream() failed\n");
57 avstream_video->time_base = AVRational{1, time_base};
58 avstream_video->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
59 if (video_codec == CODEC_H264) {
60 avstream_video->codecpar->codec_id = AV_CODEC_ID_H264;
61 } else if (video_codec == CODEC_NV12) {
62 avstream_video->codecpar->codec_id = AV_CODEC_ID_RAWVIDEO;
63 avstream_video->codecpar->codec_tag = avcodec_pix_fmt_to_codec_tag(AV_PIX_FMT_NV12);
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 = AVCOL_SPC_BT709;
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());
87 avstream_video->codecpar->extradata_size = video_extradata.size();
88 memcpy(avstream_video->codecpar->extradata, video_extradata.data(), video_extradata.size());
91 avstream_audio = nullptr;
93 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");
105 AVDictionary *options = NULL;
106 vector<pair<string, string>> opts = MUX_OPTS;
107 for (pair<string, string> opt : opts) {
108 av_dict_set(&options, opt.first.c_str(), opt.second.c_str(), 0);
110 if (avformat_write_header(avctx, &options) < 0) {
111 fprintf(stderr, "avformat_write_header() failed\n");
114 for (MuxMetrics *metric : metrics) {
115 metric->metric_written_bytes += avctx->pb->pos;
118 // Make sure the header is written before the constructor exits.
119 avio_flush(avctx->pb);
121 if (write_strategy == WRITE_BACKGROUND) {
122 writer_thread = thread(&Mux::thread_func, this);
128 assert(plug_count == 0);
129 if (write_strategy == WRITE_BACKGROUND) {
130 writer_thread_should_quit = true;
131 packet_queue_ready.notify_all();
132 writer_thread.join();
134 int64_t old_pos = avctx->pb->pos;
135 av_write_trailer(avctx);
136 for (MuxMetrics *metric : metrics) {
137 metric->metric_written_bytes += avctx->pb->pos - old_pos;
140 if (!(avctx->oformat->flags & AVFMT_NOFILE) &&
141 !(avctx->flags & AVFMT_FLAG_CUSTOM_IO)) {
142 avio_closep(&avctx->pb);
144 avformat_free_context(avctx);
147 void Mux::add_packet(const AVPacket &pkt, int64_t pts, int64_t dts, AVRational timebase, int stream_index_override)
150 av_init_packet(&pkt_copy);
151 if (av_packet_ref(&pkt_copy, &pkt) < 0) {
152 fprintf(stderr, "av_copy_packet() failed\n");
155 if (stream_index_override != -1) {
156 pkt_copy.stream_index = stream_index_override;
158 if (pkt_copy.stream_index == 0) {
159 pkt_copy.pts = av_rescale_q(pts, timebase, avstream_video->time_base);
160 pkt_copy.dts = av_rescale_q(dts, timebase, avstream_video->time_base);
161 pkt_copy.duration = av_rescale_q(pkt.duration, timebase, avstream_video->time_base);
162 } else if (pkt_copy.stream_index == 1) {
163 pkt_copy.pts = av_rescale_q(pts, timebase, avstream_audio->time_base);
164 pkt_copy.dts = av_rescale_q(dts, timebase, avstream_audio->time_base);
165 pkt_copy.duration = av_rescale_q(pkt.duration, timebase, avstream_audio->time_base);
171 lock_guard<mutex> lock(mu);
172 if (write_strategy == WriteStrategy::WRITE_BACKGROUND) {
173 packet_queue.push_back(QueuedPacket{ av_packet_clone(&pkt_copy), pts });
174 if (plug_count == 0) packet_queue_ready.notify_all();
175 } else if (plug_count > 0) {
176 packet_queue.push_back(QueuedPacket{ av_packet_clone(&pkt_copy), pts });
178 write_packet_or_die(pkt_copy, pts);
182 av_packet_unref(&pkt_copy);
185 void Mux::write_packet_or_die(const AVPacket &pkt, int64_t unscaled_pts)
187 for (MuxMetrics *metric : metrics) {
188 if (pkt.stream_index == 0) {
189 metric->metric_video_bytes += pkt.size;
190 } else if (pkt.stream_index == 1) {
191 metric->metric_audio_bytes += pkt.size;
196 int64_t old_pos = avctx->pb->pos;
197 if (av_interleaved_write_frame(avctx, const_cast<AVPacket *>(&pkt)) < 0) {
198 fprintf(stderr, "av_interleaved_write_frame() failed\n");
201 avio_flush(avctx->pb);
202 for (MuxMetrics *metric : metrics) {
203 metric->metric_written_bytes += avctx->pb->pos - old_pos;
206 if (pkt.stream_index == 0 && write_callback != nullptr) {
207 write_callback(unscaled_pts);
213 lock_guard<mutex> lock(mu);
219 lock_guard<mutex> lock(mu);
220 if (--plug_count > 0) {
223 assert(plug_count >= 0);
225 sort(packet_queue.begin(), packet_queue.end(), PacketBefore(avctx));
227 if (write_strategy == WRITE_BACKGROUND) {
228 packet_queue_ready.notify_all();
230 for (QueuedPacket &qp : packet_queue) {
231 write_packet_or_die(*qp.pkt, qp.unscaled_pts);
232 av_packet_free(&qp.pkt);
234 packet_queue.clear();
238 void Mux::thread_func()
240 pthread_setname_np(pthread_self(), "Mux");
242 unique_lock<mutex> lock(mu);
244 packet_queue_ready.wait(lock, [this]() {
245 return writer_thread_should_quit || (!packet_queue.empty() && plug_count == 0);
247 if (writer_thread_should_quit && packet_queue.empty()) {
252 assert(!packet_queue.empty() && plug_count == 0);
253 vector<QueuedPacket> packets;
254 swap(packets, packet_queue);
257 for (QueuedPacket &qp : packets) {
258 write_packet_or_die(*qp.pkt, qp.unscaled_pts);
259 av_packet_free(&qp.pkt);
265 void MuxMetrics::init(const vector<pair<string, string>> &labels)
267 // TODO: See if we want to reintroduce these.