WEBRTC Encoder Bandwidth Adjustment __JS

uint32_t mediaoptimization::settargetrates (
    uint32_t target_bitrate,
    uint8_t fraction_lost,
    int64_t Round_trip_time_ms,
    vcmprotectioncallback* protection_callback) {
  criticalsectionscoped lock (crit_sect_. Get ());
  ...
   Estimate the overhead costs of the next second as staying the same
    //wrt the source bitrate.
    if (sent_total_rate_bps > 0) {
      protection_overhead_bps = static_cast<uint32_t> (
          target_bitrate *
              static_cast<double> (sent_nack_rate_bps + sent_fec_rate_bps)/
              sent_total_rate_bps +
          0.5);
    }
    //Cap The overhead estimate to 50%.
    if (protection_overhead_bps > TARGET_BITRATE/2)
      protection_overhead_bps = TARGET_BITRATE/2;
  ...

Calculating encoder bandwidth based on NACK and FEC