Line data    Source code

       1             : /*
       2             :  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
       3             :  *
       4             :  *  Use of this source code is governed by a BSD-style license
       5             :  *  that can be found in the LICENSE file in the root of the source
       6             :  *  tree. An additional intellectual property rights grant can be found
       7             :  *  in the file PATENTS.  All contributing project authors may
       8             :  *  be found in the AUTHORS file in the root of the source tree.
       9             :  */
      10             : 
      11             : #include "webrtc/video/vie_remb.h"
      12             : 
      13             : #include <assert.h>
      14             : 
      15             : #include <algorithm>
      16             : 
      17             : #include "webrtc/modules/rtp_rtcp/include/rtp_rtcp.h"
      18             : #include "webrtc/modules/utility/include/process_thread.h"
      19             : #include "webrtc/system_wrappers/include/trace.h"
      20             : 
      21             : namespace webrtc {
      22             : 
      23             : const int kRembSendIntervalMs = 200;
      24             : 
      25             : // % threshold for if we should send a new REMB asap.
      26             : const uint32_t kSendThresholdPercent = 97;
      27             : 
      28           0 : VieRemb::VieRemb(Clock* clock)
      29             :     : clock_(clock),
      30           0 :       last_remb_time_(clock_->TimeInMilliseconds()),
      31             :       last_send_bitrate_(0),
      32           0 :       bitrate_(0) {}
      33             : 
      34           0 : VieRemb::~VieRemb() {}
      35             : 
      36           0 : void VieRemb::AddReceiveChannel(RtpRtcp* rtp_rtcp) {
      37           0 :   assert(rtp_rtcp);
      38             : 
      39           0 :   rtc::CritScope lock(&list_crit_);
      40           0 :   if (std::find(receive_modules_.begin(), receive_modules_.end(), rtp_rtcp) !=
      41           0 :       receive_modules_.end())
      42           0 :     return;
      43             : 
      44             :   // The module probably doesn't have a remote SSRC yet, so don't add it to the
      45             :   // map.
      46           0 :   receive_modules_.push_back(rtp_rtcp);
      47             : }
      48             : 
      49           0 : void VieRemb::RemoveReceiveChannel(RtpRtcp* rtp_rtcp) {
      50           0 :   assert(rtp_rtcp);
      51             : 
      52           0 :   rtc::CritScope lock(&list_crit_);
      53           0 :   for (RtpModules::iterator it = receive_modules_.begin();
      54           0 :        it != receive_modules_.end(); ++it) {
      55           0 :     if ((*it) == rtp_rtcp) {
      56           0 :       receive_modules_.erase(it);
      57           0 :       break;
      58             :     }
      59             :   }
      60           0 : }
      61             : 
      62           0 : void VieRemb::AddRembSender(RtpRtcp* rtp_rtcp) {
      63           0 :   assert(rtp_rtcp);
      64             : 
      65           0 :   rtc::CritScope lock(&list_crit_);
      66             : 
      67             :   // Verify this module hasn't been added earlier.
      68           0 :   if (std::find(rtcp_sender_.begin(), rtcp_sender_.end(), rtp_rtcp) !=
      69           0 :       rtcp_sender_.end())
      70           0 :     return;
      71           0 :   rtcp_sender_.push_back(rtp_rtcp);
      72             : }
      73             : 
      74           0 : void VieRemb::RemoveRembSender(RtpRtcp* rtp_rtcp) {
      75           0 :   assert(rtp_rtcp);
      76             : 
      77           0 :   rtc::CritScope lock(&list_crit_);
      78           0 :   for (RtpModules::iterator it = rtcp_sender_.begin();
      79           0 :        it != rtcp_sender_.end(); ++it) {
      80           0 :     if ((*it) == rtp_rtcp) {
      81           0 :       rtcp_sender_.erase(it);
      82           0 :       return;
      83             :     }
      84             :   }
      85             : }
      86             : 
      87           0 : bool VieRemb::InUse() const {
      88           0 :   rtc::CritScope lock(&list_crit_);
      89           0 :   return !receive_modules_.empty() || !rtcp_sender_.empty();
      90             : }
      91             : 
      92           0 : void VieRemb::OnReceiveBitrateChanged(const std::vector<uint32_t>& ssrcs,
      93             :                                       uint32_t bitrate) {
      94           0 :   RtpRtcp* sender = nullptr;
      95             :   {
      96           0 :     rtc::CritScope lock(&list_crit_);
      97             :     // If we already have an estimate, check if the new total estimate is below
      98             :     // kSendThresholdPercent of the previous estimate.
      99           0 :     if (last_send_bitrate_ > 0) {
     100           0 :       uint32_t new_remb_bitrate = last_send_bitrate_ - bitrate_ + bitrate;
     101             : 
     102           0 :       if (new_remb_bitrate < kSendThresholdPercent * last_send_bitrate_ / 100) {
     103             :         // The new bitrate estimate is less than kSendThresholdPercent % of the
     104             :         // last report. Send a REMB asap.
     105           0 :         last_remb_time_ = clock_->TimeInMilliseconds() - kRembSendIntervalMs;
     106             :       }
     107             :     }
     108           0 :     bitrate_ = bitrate;
     109             : 
     110             :     // Calculate total receive bitrate estimate.
     111           0 :     int64_t now = clock_->TimeInMilliseconds();
     112             : 
     113           0 :     if (now - last_remb_time_ < kRembSendIntervalMs) {
     114           0 :       return;
     115             :     }
     116           0 :     last_remb_time_ = now;
     117             : 
     118           0 :     if (ssrcs.empty() || receive_modules_.empty()) {
     119           0 :       return;
     120             :     }
     121             : 
     122             :     // Send a REMB packet.
     123           0 :     if (!rtcp_sender_.empty()) {
     124           0 :       sender = rtcp_sender_.front();
     125             :     } else {
     126           0 :       sender = receive_modules_.front();
     127             :     }
     128           0 :     last_send_bitrate_ = bitrate_;
     129             :   }
     130             : 
     131           0 :   if (sender) {
     132           0 :     sender->SetREMBData(bitrate_, ssrcs);
     133             :   }
     134             : }
     135             : 
     136             : }  // namespace webrtc