git.sesse.net Git - nageru/blob - shared/mux.cpp

   1 #include "shared/mux.h"
   2
   3 #include <algorithm>
   4 #include <assert.h>
   5 #include <mutex>
   6 #include <stdint.h>
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <string.h>
  10 #include <string>
  11 #include <utility>
  12 #include <vector>
  13
  14 extern "C" {
  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>
  22 }
  23
  24 #include "shared/metrics.h"
  25 #include "shared/shared_defs.h"
  26 #include "shared/timebase.h"
  27
  28 using namespace std;
  29
  30 struct PacketBefore {
  31         PacketBefore(const AVFormatContext *ctx) : ctx(ctx) {}
  32
  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;
  42                 } else {
  43                         return av_compare_ts(a->pts, a_timebase, b->pts, b_timebase) < 0;
  44                 }
  45         }
  46
  47         const AVFormatContext * const ctx;
  48 };
  49
  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)
  52 {
  53         AVStream *avstream_video = avformat_new_stream(avctx, nullptr);
  54         if (avstream_video == nullptr) {
  55                 fprintf(stderr, "avformat_new_stream() failed\n");
  56                 abort();
  57         }
  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 {
  65                 assert(video_codec == CODEC_MJPEG);
  66                 avstream_video->codecpar->codec_id = AV_CODEC_ID_MJPEG;
  67         }
  68         avstream_video->codecpar->width = width;
  69         avstream_video->codecpar->height = height;
  70
  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;
  84
  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());
  89         }
  90         streams.push_back(avstream_video);
  91
  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");
  96                         abort();
  97                 }
  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");
 101                         abort();
 102                 }
 103                 streams.push_back(avstream_audio);
 104         }
 105
 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");
 110                         abort();
 111                 }
 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;
 118         }
 119
 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);
 124         }
 125         int err = avformat_write_header(avctx, &options);
 126         if (err < 0) {
 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);
 130                 exit(EXIT_FAILURE);
 131         }
 132         for (MuxMetrics *metric : metrics) {
 133                 metric->metric_written_bytes += avctx->pb->pos;
 134         }
 135
 136         // Make sure the header is written before the constructor exits.
 137         avio_flush(avctx->pb);
 138
 139         if (write_strategy == WRITE_BACKGROUND) {
 140                 writer_thread = thread(&Mux::thread_func, this);
 141         }
 142 }
 143
 144 Mux::~Mux()
 145 {
 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();
 151         }
 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;
 156         }
 157
 158         if (!(avctx->oformat->flags & AVFMT_NOFILE) &&
 159             !(avctx->flags & AVFMT_FLAG_CUSTOM_IO)) {
 160                 avio_closep(&avctx->pb);
 161         }
 162         avformat_free_context(avctx);
 163 }
 164
 165 void Mux::add_packet(const AVPacket &pkt, int64_t pts, int64_t dts, AVRational timebase, int stream_index_override)
 166 {
 167         assert(pts >= dts);
 168
 169         AVPacket pkt_copy;
 170         av_init_packet(&pkt_copy);
 171         if (av_packet_ref(&pkt_copy, &pkt) < 0) {
 172                 fprintf(stderr, "av_copy_packet() failed\n");
 173                 abort();
 174         }
 175         if (stream_index_override != -1) {
 176                 pkt_copy.stream_index = stream_index_override;
 177         }
 178         assert(size_t(pkt_copy.stream_index) < streams.size());
 179         AVRational time_base = streams[pkt_copy.stream_index]->time_base;
 180         pkt_copy.pts = av_rescale_q(pts, timebase, time_base);
 181         pkt_copy.dts = av_rescale_q(dts, timebase, time_base);
 182         pkt_copy.duration = av_rescale_q(pkt.duration, timebase, time_base);
 183
 184         {
 185                 lock_guard<mutex> lock(mu);
 186                 if (write_strategy == WriteStrategy::WRITE_BACKGROUND) {
 187                         packet_queue.push_back(QueuedPacket{ av_packet_clone(&pkt_copy), pts });
 188                         if (plug_count == 0)
 189                                 packet_queue_ready.notify_all();
 190                 } else if (plug_count > 0) {
 191                         packet_queue.push_back(QueuedPacket{ av_packet_clone(&pkt_copy), pts });
 192                 } else {
 193                         write_packet_or_die(pkt_copy, pts);
 194                 }
 195         }
 196
 197         av_packet_unref(&pkt_copy);
 198 }
 199
 200 void Mux::write_packet_or_die(const AVPacket &pkt, int64_t unscaled_pts)
 201 {
 202         for (MuxMetrics *metric : metrics) {
 203                 if (pkt.stream_index == 0) {
 204                         metric->metric_video_bytes += pkt.size;
 205                 } else if (pkt.stream_index == 1) {
 206                         metric->metric_audio_bytes += pkt.size;
 207                 } else {
 208                         assert(false);
 209                 }
 210         }
 211         int64_t old_pos = avctx->pb->pos;
 212         int err = av_interleaved_write_frame(avctx, const_cast<AVPacket *>(&pkt));
 213         if (err < 0) {
 214                 char errbuf[AV_ERROR_MAX_STRING_SIZE];
 215                 av_strerror(err, errbuf, sizeof(errbuf));
 216                 fprintf(stderr, "av_interleaved_write_frame() failed: %s\n", errbuf);
 217                 exit(EXIT_FAILURE);
 218         }
 219         avio_flush(avctx->pb);
 220         for (MuxMetrics *metric : metrics) {
 221                 metric->metric_written_bytes += avctx->pb->pos - old_pos;
 222         }
 223
 224         if (pkt.stream_index == 0 && write_callback != nullptr) {
 225                 write_callback(unscaled_pts);
 226         }
 227 }
 228
 229 void Mux::plug()
 230 {
 231         lock_guard<mutex> lock(mu);
 232         ++plug_count;
 233 }
 234
 235 void Mux::unplug()
 236 {
 237         lock_guard<mutex> lock(mu);
 238         if (--plug_count > 0) {
 239                 return;
 240         }
 241         assert(plug_count >= 0);
 242
 243         sort(packet_queue.begin(), packet_queue.end(), PacketBefore(avctx));
 244
 245         if (write_strategy == WRITE_BACKGROUND) {
 246                 packet_queue_ready.notify_all();
 247         } else {
 248                 for (QueuedPacket &qp : packet_queue) {
 249                         write_packet_or_die(*qp.pkt, qp.unscaled_pts);
 250                         av_packet_free(&qp.pkt);
 251                 }
 252                 packet_queue.clear();
 253         }
 254 }
 255
 256 void Mux::thread_func()
 257 {
 258         pthread_setname_np(pthread_self(), "Mux");
 259
 260         unique_lock<mutex> lock(mu);
 261         for ( ;; ) {
 262                 packet_queue_ready.wait(lock, [this]() {
 263                         return writer_thread_should_quit || (!packet_queue.empty() && plug_count == 0);
 264                 });
 265                 if (writer_thread_should_quit && packet_queue.empty()) {
 266                         // All done.
 267                         break;
 268                 }
 269
 270                 assert(!packet_queue.empty() && plug_count == 0);
 271                 vector<QueuedPacket> packets;
 272                 swap(packets, packet_queue);
 273
 274                 lock.unlock();
 275                 for (QueuedPacket &qp : packets) {
 276                         write_packet_or_die(*qp.pkt, qp.unscaled_pts);
 277                         av_packet_free(&qp.pkt);
 278                 }
 279                 lock.lock();
 280         }
 281 }
 282
 283 void MuxMetrics::init(const vector<pair<string, string>> &labels)
 284 {
 285         vector<pair<string, string>> labels_video = labels;
 286         labels_video.emplace_back("stream", "video");
 287         global_metrics.add("mux_stream_bytes", labels_video, &metric_video_bytes);
 288
 289         vector<pair<string, string>> labels_audio = labels;
 290         labels_audio.emplace_back("stream", "audio");
 291         global_metrics.add("mux_stream_bytes", labels_audio, &metric_audio_bytes);
 292
 293         global_metrics.add("mux_written_bytes", labels, &metric_written_bytes);
 294 }