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 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);
  67         } else {
  68                 assert(video_codec == CODEC_MJPEG);
  69                 avstream_video->codecpar->codec_id = AV_CODEC_ID_MJPEG;
  70         }
  71         avstream_video->codecpar->width = width;
  72         avstream_video->codecpar->height = height;
  73
  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;
  87
  88         if (!video_extradata.empty()) {
  89                 avstream_video->codecpar->extradata = (uint8_t *)av_malloc(video_extradata.size() + AV_INPUT_BUFFER_PADDING_SIZE);
  90                 avstream_video->codecpar->extradata_size = video_extradata.size();
  91                 memcpy(avstream_video->codecpar->extradata, video_extradata.data(), video_extradata.size());
  92         }
  93         streams.push_back(avstream_video);
  94
  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");
  99                         abort();
 100                 }
 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");
 104                         abort();
 105                 }
 106                 streams.push_back(avstream_audio);
 107         }
 108
 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");
 113                         abort();
 114                 }
 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;
 121         }
 122
 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);
 127         }
 128         int err = avformat_write_header(avctx, &options);
 129         if (err < 0) {
 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);
 133                 exit(EXIT_FAILURE);
 134         }
 135         for (MuxMetrics *metric : metrics) {
 136                 metric->metric_written_bytes += avctx->pb->pos;
 137         }
 138
 139         // Make sure the header is written before the constructor exits.
 140         avio_flush(avctx->pb);
 141
 142         if (write_strategy == WRITE_BACKGROUND) {
 143                 writer_thread = thread(&Mux::thread_func, this);
 144         }
 145 }
 146
 147 Mux::~Mux()
 148 {
 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();
 154         }
 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;
 159         }
 160
 161         if (!(avctx->oformat->flags & AVFMT_NOFILE) &&
 162             !(avctx->flags & AVFMT_FLAG_CUSTOM_IO)) {
 163                 avio_closep(&avctx->pb);
 164         }
 165         avformat_free_context(avctx);
 166 }
 167
 168 void Mux::add_packet(const AVPacket &pkt, int64_t pts, int64_t dts, AVRational timebase, int stream_index_override)
 169 {
 170         AVPacket pkt_copy;
 171         av_init_packet(&pkt_copy);
 172         if (av_packet_ref(&pkt_copy, &pkt) < 0) {
 173                 fprintf(stderr, "av_copy_packet() failed\n");
 174                 abort();
 175         }
 176         if (stream_index_override != -1) {
 177                 pkt_copy.stream_index = stream_index_override;
 178         }
 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);
 184
 185         {
 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 });
 189                         if (plug_count == 0)
 190                                 packet_queue_ready.notify_all();
 191                 } else if (plug_count > 0) {
 192                         packet_queue.push_back(QueuedPacket{ av_packet_clone(&pkt_copy), pts });
 193                 } else {
 194                         write_packet_or_die(pkt_copy, pts);
 195                 }
 196         }
 197
 198         av_packet_unref(&pkt_copy);
 199 }
 200
 201 void Mux::write_packet_or_die(const AVPacket &pkt, int64_t unscaled_pts)
 202 {
 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;
 208                 } else {
 209                         assert(false);
 210                 }
 211         }
 212         int64_t old_pos = avctx->pb->pos;
 213         int err = av_interleaved_write_frame(avctx, const_cast<AVPacket *>(&pkt));
 214         if (err < 0) {
 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);
 218                 exit(EXIT_FAILURE);
 219         }
 220         avio_flush(avctx->pb);
 221         for (MuxMetrics *metric : metrics) {
 222                 metric->metric_written_bytes += avctx->pb->pos - old_pos;
 223         }
 224
 225         if (pkt.stream_index == 0 && write_callback != nullptr) {
 226                 write_callback(unscaled_pts);
 227         }
 228 }
 229
 230 void Mux::plug()
 231 {
 232         lock_guard<mutex> lock(mu);
 233         ++plug_count;
 234 }
 235
 236 void Mux::unplug()
 237 {
 238         lock_guard<mutex> lock(mu);
 239         if (--plug_count > 0) {
 240                 return;
 241         }
 242         assert(plug_count >= 0);
 243
 244         sort(packet_queue.begin(), packet_queue.end(), PacketBefore(avctx));
 245
 246         if (write_strategy == WRITE_BACKGROUND) {
 247                 packet_queue_ready.notify_all();
 248         } else {
 249                 for (QueuedPacket &qp : packet_queue) {
 250                         write_packet_or_die(*qp.pkt, qp.unscaled_pts);
 251                         av_packet_free(&qp.pkt);
 252                 }
 253                 packet_queue.clear();
 254         }
 255 }
 256
 257 void Mux::thread_func()
 258 {
 259         pthread_setname_np(pthread_self(), "Mux");
 260
 261         unique_lock<mutex> lock(mu);
 262         for ( ;; ) {
 263                 packet_queue_ready.wait(lock, [this]() {
 264                         return writer_thread_should_quit || (!packet_queue.empty() && plug_count == 0);
 265                 });
 266                 if (writer_thread_should_quit && packet_queue.empty()) {
 267                         // All done.
 268                         break;
 269                 }
 270
 271                 assert(!packet_queue.empty() && plug_count == 0);
 272                 vector<QueuedPacket> packets;
 273                 swap(packets, packet_queue);
 274
 275                 lock.unlock();
 276                 for (QueuedPacket &qp : packets) {
 277                         write_packet_or_die(*qp.pkt, qp.unscaled_pts);
 278                         av_packet_free(&qp.pkt);
 279                 }
 280                 lock.lock();
 281         }
 282 }
 283
 284 void MuxMetrics::init(const vector<pair<string, string>> &labels)
 285 {
 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);
 289
 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);
 293
 294         global_metrics.add("mux_written_bytes", labels, &metric_written_bytes);
 295 }