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

   1 #include "mux.h"
   2
   3 #include <assert.h>
   4 #include <stdint.h>
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <string.h>
   8 #include <algorithm>
   9 #include <mutex>
  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 "defs.h"
  25 #include "flags.h"
  26 #include "metrics.h"
  27 #include "timebase.h"
  28
  29 using namespace std;
  30
  31 struct PacketBefore {
  32         PacketBefore(const AVFormatContext *ctx) : ctx(ctx) {}
  33
  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;
  43                 } else {
  44                         return av_compare_ts(a->pts, a_timebase, b->pts, b_timebase) < 0;
  45                 }
  46         }
  47
  48         const AVFormatContext * const ctx;
  49 };
  50
  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)
  53 {
  54         avstream_video = avformat_new_stream(avctx, nullptr);
  55         if (avstream_video == nullptr) {
  56                 fprintf(stderr, "avformat_new_stream() failed\n");
  57                 exit(1);
  58         }
  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;
  63         } else {
  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);
  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         if (global_flags.ycbcr_rec709_coefficients) {
  81                 avstream_video->codecpar->color_space = AVCOL_SPC_BT709;
  82         } else {
  83                 avstream_video->codecpar->color_space = AVCOL_SPC_SMPTE170M;
  84         }
  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;
  88
  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());
  93         }
  94
  95         avstream_audio = avformat_new_stream(avctx, nullptr);
  96         if (avstream_audio == nullptr) {
  97                 fprintf(stderr, "avformat_new_stream() failed\n");
  98                 exit(1);
  99         }
 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");
 103                 exit(1);
 104         }
 105
 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);
 110         }
 111         if (avformat_write_header(avctx, &options) < 0) {
 112                 fprintf(stderr, "avformat_write_header() failed\n");
 113                 exit(1);
 114         }
 115         for (MuxMetrics *metric : metrics) {
 116                 metric->metric_written_bytes += avctx->pb->pos;
 117         }
 118
 119         // Make sure the header is written before the constructor exits.
 120         avio_flush(avctx->pb);
 121
 122         if (write_strategy == WRITE_BACKGROUND) {
 123                 writer_thread = thread(&Mux::thread_func, this);
 124         }
 125 }
 126
 127 Mux::~Mux()
 128 {
 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();
 134         }
 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;
 139         }
 140
 141         if (!(avctx->oformat->flags & AVFMT_NOFILE) &&
 142             !(avctx->flags & AVFMT_FLAG_CUSTOM_IO)) {
 143                 avio_closep(&avctx->pb);
 144         }
 145         avformat_free_context(avctx);
 146 }
 147
 148 void Mux::add_packet(const AVPacket &pkt, int64_t pts, int64_t dts, AVRational timebase, int stream_index_override)
 149 {
 150         AVPacket pkt_copy;
 151         av_init_packet(&pkt_copy);
 152         if (av_packet_ref(&pkt_copy, &pkt) < 0) {
 153                 fprintf(stderr, "av_copy_packet() failed\n");
 154                 exit(1);
 155         }
 156         if (stream_index_override != -1) {
 157                 pkt_copy.stream_index = stream_index_override;
 158         }
 159         if (pkt_copy.stream_index == 0) {
 160                 pkt_copy.pts = av_rescale_q(pts, timebase, avstream_video->time_base);
 161                 pkt_copy.dts = av_rescale_q(dts, timebase, avstream_video->time_base);
 162                 pkt_copy.duration = av_rescale_q(pkt.duration, timebase, avstream_video->time_base);
 163         } else if (pkt_copy.stream_index == 1) {
 164                 pkt_copy.pts = av_rescale_q(pts, timebase, avstream_audio->time_base);
 165                 pkt_copy.dts = av_rescale_q(dts, timebase, avstream_audio->time_base);
 166                 pkt_copy.duration = av_rescale_q(pkt.duration, timebase, avstream_audio->time_base);
 167         } else {
 168                 assert(false);
 169         }
 170
 171         {
 172                 lock_guard<mutex> lock(mu);
 173                 if (write_strategy == WriteStrategy::WRITE_BACKGROUND) {
 174                         packet_queue.push_back(QueuedPacket{ av_packet_clone(&pkt_copy), pts });
 175                         if (plug_count == 0) packet_queue_ready.notify_all();
 176                 } else if (plug_count > 0) {
 177                         packet_queue.push_back(QueuedPacket{ av_packet_clone(&pkt_copy), pts });
 178                 } else {
 179                         write_packet_or_die(pkt_copy, pts);
 180                 }
 181         }
 182
 183         av_packet_unref(&pkt_copy);
 184 }
 185
 186 void Mux::write_packet_or_die(const AVPacket &pkt, int64_t unscaled_pts)
 187 {
 188         for (MuxMetrics *metric : metrics) {
 189                 if (pkt.stream_index == 0) {
 190                         metric->metric_video_bytes += pkt.size;
 191                 } else if (pkt.stream_index == 1) {
 192                         metric->metric_audio_bytes += pkt.size;
 193                 } else {
 194                         assert(false);
 195                 }
 196         }
 197         int64_t old_pos = avctx->pb->pos;
 198         if (av_interleaved_write_frame(avctx, const_cast<AVPacket *>(&pkt)) < 0) {
 199                 fprintf(stderr, "av_interleaved_write_frame() failed\n");
 200                 exit(1);
 201         }
 202         avio_flush(avctx->pb);
 203         for (MuxMetrics *metric : metrics) {
 204                 metric->metric_written_bytes += avctx->pb->pos - old_pos;
 205         }
 206
 207         if (pkt.stream_index == 0 && write_callback != nullptr) {
 208                 write_callback(unscaled_pts);
 209         }
 210 }
 211
 212 void Mux::plug()
 213 {
 214         lock_guard<mutex> lock(mu);
 215         ++plug_count;
 216 }
 217
 218 void Mux::unplug()
 219 {
 220         lock_guard<mutex> lock(mu);
 221         if (--plug_count > 0) {
 222                 return;
 223         }
 224         assert(plug_count >= 0);
 225
 226         sort(packet_queue.begin(), packet_queue.end(), PacketBefore(avctx));
 227
 228         if (write_strategy == WRITE_BACKGROUND) {
 229                 packet_queue_ready.notify_all();
 230         } else {
 231                 for (QueuedPacket &qp : packet_queue) {
 232                         write_packet_or_die(*qp.pkt, qp.unscaled_pts);
 233                         av_packet_free(&qp.pkt);
 234                 }
 235                 packet_queue.clear();
 236         }
 237 }
 238
 239 void Mux::thread_func()
 240 {
 241         unique_lock<mutex> lock(mu);
 242         for ( ;; ) {
 243                 packet_queue_ready.wait(lock, [this]() {
 244                         return writer_thread_should_quit || (!packet_queue.empty() && plug_count == 0);
 245                 });
 246                 if (writer_thread_should_quit && packet_queue.empty()) {
 247                         // All done.
 248                         break;
 249                 }
 250
 251                 assert(!packet_queue.empty() && plug_count == 0);
 252                 vector<QueuedPacket> packets;
 253                 swap(packets, packet_queue);
 254
 255                 lock.unlock();
 256                 for (QueuedPacket &qp : packets) {
 257                         write_packet_or_die(*qp.pkt, qp.unscaled_pts);
 258                         av_packet_free(&qp.pkt);
 259                 }
 260                 lock.lock();
 261         }
 262 }
 263
 264 void MuxMetrics::init(const vector<pair<string, string>> &labels)
 265 {
 266         vector<pair<string, string>> labels_video = labels;
 267         labels_video.emplace_back("stream", "video");
 268         global_metrics.add("mux_stream_bytes", labels_video, &metric_video_bytes);
 269
 270         vector<pair<string, string>> labels_audio = labels;
 271         labels_audio.emplace_back("stream", "audio");
 272         global_metrics.add("mux_stream_bytes", labels_audio, &metric_audio_bytes);
 273
 274         global_metrics.add("mux_written_bytes", labels, &metric_written_bytes);
 275 }