text: /*
   *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
   *
   *  Use of this source code is governed by a BSD-style license
   *  that can be found in the LICENSE file in the root of the source
   *  tree. An additional intellectual property rights grant can be found
   *  in the file PATENTS.  All contributing project authors may
   *  be found in the AUTHORS file in the root of the source tree.
   */
  
  #include "structs.h"
  #include "bandwidth_estimator.h"
  #include "entropy_coding.h"
  #include "codec.h"
  
  
  int
  WebRtcIsac_EstimateBandwidth(
      BwEstimatorstr*           bwest_str,
      Bitstr*                   streamdata,
      WebRtc_Word32               packet_size,
      WebRtc_UWord16              rtp_seq_number,
      WebRtc_UWord32              send_ts,
      WebRtc_UWord32              arr_ts,
      enum IsacSamplingRate encoderSampRate,
      enum IsacSamplingRate decoderSampRate)
  {
    WebRtc_Word16  index;
    WebRtc_Word16  frame_samples;
    WebRtc_UWord32 sendTimestampIn16kHz;
    WebRtc_UWord32 arrivalTimestampIn16kHz;
    WebRtc_UWord32 diffSendTime;
    WebRtc_UWord32 diffArrivalTime;
    int err;
  
    /* decode framelength and BW estimation */
    err = WebRtcIsac_DecodeFrameLen(streamdata, &frame_samples);
    if(err < 0)  // error check
    {
      return err;
    }
    err = WebRtcIsac_DecodeSendBW(streamdata, &index);
    if(err < 0)  // error check
    {
      return err;
    }
  
    /* UPDATE ESTIMATES FROM OTHER SIDE */
    err = WebRtcIsac_UpdateUplinkBwImpl(bwest_str, index, encoderSampRate);
    if(err < 0)
    {
      return err;
    }
  
    // We like BWE to work at 16 kHz sampling rate,
    // therefore, we have to change the timestamps accordingly.
    // translate the send timestamp if required
    diffSendTime = (WebRtc_UWord32)((WebRtc_UWord32)send_ts -
                                    (WebRtc_UWord32)bwest_str->senderTimestamp);
    bwest_str->senderTimestamp = send_ts;
  
    diffArrivalTime = (WebRtc_UWord32)((WebRtc_UWord32)arr_ts -
                                       (WebRtc_UWord32)bwest_str->receiverTimestamp);
    bwest_str->receiverTimestamp = arr_ts;
  
    if(decoderSampRate == kIsacSuperWideband)
    {
      diffArrivalTime = (WebRtc_UWord32)diffArrivalTime >> 1;
      diffSendTime = (WebRtc_UWord32)diffSendTime >> 1;
    }
    // arrival timestamp in 16 kHz
    arrivalTimestampIn16kHz = (WebRtc_UWord32)((WebRtc_UWord32)
                                               bwest_str->prev_rec_arr_ts + (WebRtc_UWord32)diffArrivalTime);
    // send timestamp in 16 kHz
    sendTimestampIn16kHz = (WebRtc_UWord32)((WebRtc_UWord32)
                                            bwest_str->prev_rec_send_ts + (WebRtc_UWord32)diffSendTime);
  
    err = WebRtcIsac_UpdateBandwidthEstimator(bwest_str, rtp_seq_number,
                                              (frame_samples * 1000) / FS, sendTimestampIn16kHz,
                                              arrivalTimestampIn16kHz, packet_size);
    // error check
    if(err < 0)
    {
      return err;
    }
  
    return 0;
  }
  