Function capture

src/audio.cpp:130–251

  }

  void capture(safe::mail_t mail, config_t config, void *channel_data) {
    auto shutdown_event = mail->event<bool>(mail::shutdown);
    if (!config::audio.stream || config.input_only) {
      shutdown_event->view();
      return;
    }
    auto stream = stream_configs[map_stream(config.channels, config.flags[config_t::HIGH_QUALITY])];
    if (config.flags[config_t::CUSTOM_SURROUND_PARAMS]) {
      apply_surround_params(stream, config.customStreamParams);
    }

    auto ref = get_audio_ctx_ref();
    if (!ref) {
      return;
    }

    auto init_failure_fg = util::fail_guard([&shutdown_event]() {
      BOOST_LOG(error) << "Unable to initialize audio capture. The stream will not have audio."sv;

      // Wait for shutdown to be signalled if we fail init.
      // This allows streaming to continue without audio.
      shutdown_event->view();
      return;
    });

    auto &control = ref->control;
    if (!control) {
      return;
    }

    // Order of priority:
    // 1. Virtual sink
    // 2. Audio sink
    // 3. Host
    std::string *sink = &ref->sink.host;
    if (!config::audio.sink.empty()) {
      sink = &config::audio.sink;
    }

    // Prefer the virtual sink if host playback is disabled or there's no other sink
    if (ref->sink.null && (!config.flags[config_t::HOST_AUDIO] || sink->empty())) {
      auto &null = *ref->sink.null;
      switch (stream.channelCount) {
        case 2:
          sink = &null.stereo;
          break;
        case 6:
          sink = &null.surround51;
          break;
        case 8:
          sink = &null.surround71;
          break;
      }
    }

    BOOST_LOG(info) << "Selected audio sink: "sv << *sink;

    // Only the first to start a session may change the default sink