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 "timebase.h"
  26
  27 using namespace std;
  28
  29 struct PacketBefore {
  30         PacketBefore(const AVFormatContext *ctx) : ctx(ctx) {}
  31
  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;
  41                 } else {
  42                         return av_compare_ts(a->pts, a_timebase, b->pts, b_timebase) < 0;
  43                 }
  44         }
  45
  46         const AVFormatContext * const ctx;
  47 };
  48
  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)
  51 {
  52         avstream_video = avformat_new_stream(avctx, nullptr);
  53         if (avstream_video == nullptr) {
  54                 fprintf(stderr, "avformat_new_stream() failed\n");
  55                 exit(1);
  56         }
  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 {
  62                 assert(video_codec == CODEC_NV12);
  63                 avstream_video->codecpar->codec_id = AV_CODEC_ID_RAWVIDEO;
  64                 avstream_video->codecpar->codec_tag = avcodec_pix_fmt_to_codec_tag(AV_PIX_FMT_NV12);
  65         }
  66         avstream_video->codecpar->width = width;
  67         avstream_video->codecpar->height = height;
  68
  69         // Colorspace details. Closely correspond to settings in EffectChain_finalize,
  70         // as noted in each comment.
  71         // Note that the H.264 stream also contains this information and depending on the
  72         // mux, this might simply get ignored. See sps_rbsp().
  73         // Note that there's no way to change this per-frame as the H.264 stream
  74         // would like to be able to.
  75         avstream_video->codecpar->color_primaries = AVCOL_PRI_BT709;  // RGB colorspace (inout_format.color_space).
  76         avstream_video->codecpar->color_trc = AVCOL_TRC_IEC61966_2_1;  // Gamma curve (inout_format.gamma_curve).
  77         // YUV colorspace (output_ycbcr_format.luma_coefficients).
  78         avstream_video->codecpar->color_space = AVCOL_SPC_BT709;
  79         avstream_video->codecpar->color_range = AVCOL_RANGE_MPEG;  // Full vs. limited range (output_ycbcr_format.full_range).
  80         avstream_video->codecpar->chroma_location = AVCHROMA_LOC_LEFT;  // Chroma sample location. See chroma_offset_0[] in Mixer::subsample_chroma().
  81         avstream_video->codecpar->field_order = AV_FIELD_PROGRESSIVE;
  82
  83         if (!video_extradata.empty()) {
  84                 avstream_video->codecpar->extradata = (uint8_t *)av_malloc(video_extradata.size());
  85                 avstream_video->codecpar->extradata_size = video_extradata.size();
  86                 memcpy(avstream_video->codecpar->extradata, video_extradata.data(), video_extradata.size());
  87         }
  88
  89         avstream_audio = avformat_new_stream(avctx, nullptr);
  90         if (avstream_audio == nullptr) {
  91                 fprintf(stderr, "avformat_new_stream() failed\n");
  92                 exit(1);
  93         }
  94         avstream_audio->time_base = AVRational{1, time_base};
  95         if (avcodec_parameters_copy(avstream_audio->codecpar, audio_codecpar) < 0) {
  96                 fprintf(stderr, "avcodec_parameters_copy() failed\n");
  97                 exit(1);
  98         }
  99
 100         AVDictionary *options = NULL;
 101         vector<pair<string, string>> opts = MUX_OPTS;
 102         for (pair<string, string> opt : opts) {
 103                 av_dict_set(&options, opt.first.c_str(), opt.second.c_str(), 0);
 104         }
 105         if (avformat_write_header(avctx, &options) < 0) {
 106                 fprintf(stderr, "avformat_write_header() failed\n");
 107                 exit(1);
 108         }
 109         for (MuxMetrics *metric : metrics) {
 110                 metric->metric_written_bytes += avctx->pb->pos;
 111         }
 112
 113         // Make sure the header is written before the constructor exits.
 114         avio_flush(avctx->pb);
 115
 116         if (write_strategy == WRITE_BACKGROUND) {
 117                 writer_thread = thread(&Mux::thread_func, this);
 118         }
 119 }
 120
 121 Mux::~Mux()
 122 {
 123         assert(plug_count == 0);
 124         if (write_strategy == WRITE_BACKGROUND) {
 125                 writer_thread_should_quit = true;
 126                 packet_queue_ready.notify_all();
 127                 writer_thread.join();
 128         }
 129         int64_t old_pos = avctx->pb->pos;
 130         av_write_trailer(avctx);
 131         for (MuxMetrics *metric : metrics) {
 132                 metric->metric_written_bytes += avctx->pb->pos - old_pos;
 133         }
 134
 135         if (!(avctx->oformat->flags & AVFMT_NOFILE) &&
 136             !(avctx->flags & AVFMT_FLAG_CUSTOM_IO)) {
 137                 avio_closep(&avctx->pb);
 138         }
 139         avformat_free_context(avctx);
 140 }
 141
 142 void Mux::add_packet(const AVPacket &pkt, int64_t pts, int64_t dts, AVRational timebase, int stream_index_override)
 143 {
 144         AVPacket pkt_copy;
 145         av_init_packet(&pkt_copy);
 146         if (av_packet_ref(&pkt_copy, &pkt) < 0) {
 147                 fprintf(stderr, "av_copy_packet() failed\n");
 148                 exit(1);
 149         }
 150         if (stream_index_override != -1) {
 151                 pkt_copy.stream_index = stream_index_override;
 152         }
 153         if (pkt_copy.stream_index == 0) {
 154                 pkt_copy.pts = av_rescale_q(pts, timebase, avstream_video->time_base);
 155                 pkt_copy.dts = av_rescale_q(dts, timebase, avstream_video->time_base);
 156                 pkt_copy.duration = av_rescale_q(pkt.duration, timebase, avstream_video->time_base);
 157         } else if (pkt_copy.stream_index == 1) {
 158                 pkt_copy.pts = av_rescale_q(pts, timebase, avstream_audio->time_base);
 159                 pkt_copy.dts = av_rescale_q(dts, timebase, avstream_audio->time_base);
 160                 pkt_copy.duration = av_rescale_q(pkt.duration, timebase, avstream_audio->time_base);
 161         } else {
 162                 assert(false);
 163         }
 164
 165         {
 166                 lock_guard<mutex> lock(mu);
 167                 if (write_strategy == WriteStrategy::WRITE_BACKGROUND) {
 168                         packet_queue.push_back(QueuedPacket{ av_packet_clone(&pkt_copy), pts });
 169                         if (plug_count == 0) packet_queue_ready.notify_all();
 170                 } else if (plug_count > 0) {
 171                         packet_queue.push_back(QueuedPacket{ av_packet_clone(&pkt_copy), pts });
 172                 } else {
 173                         write_packet_or_die(pkt_copy, pts);
 174                 }
 175         }
 176
 177         av_packet_unref(&pkt_copy);
 178 }
 179
 180 void Mux::write_packet_or_die(const AVPacket &pkt, int64_t unscaled_pts)
 181 {
 182         for (MuxMetrics *metric : metrics) {
 183                 if (pkt.stream_index == 0) {
 184                         metric->metric_video_bytes += pkt.size;
 185                 } else if (pkt.stream_index == 1) {
 186                         metric->metric_audio_bytes += pkt.size;
 187                 } else {
 188                         assert(false);
 189                 }
 190         }
 191         int64_t old_pos = avctx->pb->pos;
 192         if (av_interleaved_write_frame(avctx, const_cast<AVPacket *>(&pkt)) < 0) {
 193                 fprintf(stderr, "av_interleaved_write_frame() failed\n");
 194                 exit(1);
 195         }
 196         avio_flush(avctx->pb);
 197         for (MuxMetrics *metric : metrics) {
 198                 metric->metric_written_bytes += avctx->pb->pos - old_pos;
 199         }
 200
 201         if (pkt.stream_index == 0 && write_callback != nullptr) {
 202                 write_callback(unscaled_pts);
 203         }
 204 }
 205
 206 void Mux::plug()
 207 {
 208         lock_guard<mutex> lock(mu);
 209         ++plug_count;
 210 }
 211
 212 void Mux::unplug()
 213 {
 214         lock_guard<mutex> lock(mu);
 215         if (--plug_count > 0) {
 216                 return;
 217         }
 218         assert(plug_count >= 0);
 219
 220         sort(packet_queue.begin(), packet_queue.end(), PacketBefore(avctx));
 221
 222         if (write_strategy == WRITE_BACKGROUND) {
 223                 packet_queue_ready.notify_all();
 224         } else {
 225                 for (QueuedPacket &qp : packet_queue) {
 226                         write_packet_or_die(*qp.pkt, qp.unscaled_pts);
 227                         av_packet_free(&qp.pkt);
 228                 }
 229                 packet_queue.clear();
 230         }
 231 }
 232
 233 void Mux::thread_func()
 234 {
 235         unique_lock<mutex> lock(mu);
 236         for ( ;; ) {
 237                 packet_queue_ready.wait(lock, [this]() {
 238                         return writer_thread_should_quit || (!packet_queue.empty() && plug_count == 0);
 239                 });
 240                 if (writer_thread_should_quit && packet_queue.empty()) {
 241                         // All done.
 242                         break;
 243                 }
 244
 245                 assert(!packet_queue.empty() && plug_count == 0);
 246                 vector<QueuedPacket> packets;
 247                 swap(packets, packet_queue);
 248
 249                 lock.unlock();
 250                 for (QueuedPacket &qp : packets) {
 251                         write_packet_or_die(*qp.pkt, qp.unscaled_pts);
 252                         av_packet_free(&qp.pkt);
 253                 }
 254                 lock.lock();
 255         }
 256 }
 257
 258 void MuxMetrics::init(const vector<pair<string, string>> &labels)
 259 {
 260         // TODO: See if we want to reintroduce these.
 261 }