1f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org/* 2f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org * Copyright 2011 The WebRTC Project Authors. All rights reserved. 3f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org * 4f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org * Use of this source code is governed by a BSD-style license 5f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org * that can be found in the LICENSE file in the root of the source 6f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org * tree. An additional intellectual property rights grant can be found 7f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org * in the file PATENTS. All contributing project authors may 8f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org * be found in the AUTHORS file in the root of the source tree. 9f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org */ 10f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org 11f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org#include "webrtc/base/bandwidthsmoother.h" 12f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org 13f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org#include <limits.h> 14ff689be3c0c59c1be29aaa0697aa0f762566d6c6andresp@webrtc.org#include <algorithm> 15f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org 16f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.orgnamespace rtc { 17f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org 18f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.orgBandwidthSmoother::BandwidthSmoother(int initial_bandwidth_guess, 190c4e06b4c6107a1b94f764e279e4fb4161e905b0Peter Boström uint32_t time_between_increase, 20f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org double percent_increase, 21f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org size_t samples_count_to_average, 22f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org double min_sample_count_percent) 23f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org : time_between_increase_(time_between_increase), 24ff689be3c0c59c1be29aaa0697aa0f762566d6c6andresp@webrtc.org percent_increase_(std::max(1.0, percent_increase)), 25f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org time_at_last_change_(0), 26f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org bandwidth_estimation_(initial_bandwidth_guess), 27f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org accumulator_(samples_count_to_average), 28f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org min_sample_count_percent_( 29ff689be3c0c59c1be29aaa0697aa0f762566d6c6andresp@webrtc.org std::min(1.0, std::max(0.0, min_sample_count_percent))) { 30f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org} 31f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org 3267186fe00cc68cbe03aa66d17fb4962458ca96d2kwiberg@webrtc.orgBandwidthSmoother::~BandwidthSmoother() = default; 3367186fe00cc68cbe03aa66d17fb4962458ca96d2kwiberg@webrtc.org 34f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org// Samples a new bandwidth measurement 35f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org// returns true if the bandwidth estimation changed 360c4e06b4c6107a1b94f764e279e4fb4161e905b0Peter Boströmbool BandwidthSmoother::Sample(uint32_t sample_time, int bandwidth) { 37f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org if (bandwidth < 0) { 38f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org return false; 39f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org } 40f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org 41f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org accumulator_.AddSample(bandwidth); 42f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org 43f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org if (accumulator_.count() < static_cast<size_t>( 44f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org accumulator_.max_count() * min_sample_count_percent_)) { 45f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org // We have not collected enough samples yet. 46f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org return false; 47f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org } 48f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org 49f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org // Replace bandwidth with the mean of sampled bandwidths. 50f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org const int mean_bandwidth = static_cast<int>(accumulator_.ComputeMean()); 51f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org 52f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org if (mean_bandwidth < bandwidth_estimation_) { 53f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org time_at_last_change_ = sample_time; 54f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org bandwidth_estimation_ = mean_bandwidth; 55f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org return true; 56f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org } 57f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org 58f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org const int old_bandwidth_estimation = bandwidth_estimation_; 59f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org const double increase_threshold_d = percent_increase_ * bandwidth_estimation_; 60f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org if (increase_threshold_d > INT_MAX) { 61f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org // If bandwidth goes any higher we would overflow. 62f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org return false; 63f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org } 64f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org 65f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org const int increase_threshold = static_cast<int>(increase_threshold_d); 66f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org if (mean_bandwidth < increase_threshold) { 67f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org time_at_last_change_ = sample_time; 68f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org // The value of bandwidth_estimation remains the same if we don't exceed 69f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org // percent_increase_ * bandwidth_estimation_ for at least 70f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org // time_between_increase_ time. 71f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org } else if (sample_time >= time_at_last_change_ + time_between_increase_) { 72f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org time_at_last_change_ = sample_time; 73f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org if (increase_threshold == 0) { 74f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org // Bandwidth_estimation_ must be zero. Assume a jump from zero to a 75f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org // positive bandwidth means we have regained connectivity. 76f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org bandwidth_estimation_ = mean_bandwidth; 77f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org } else { 78f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org bandwidth_estimation_ = increase_threshold; 79f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org } 80f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org } 81f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org // Else don't make a change. 82f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org 83f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org return old_bandwidth_estimation != bandwidth_estimation_; 84f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org} 85f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org 86f048872e915a3ee229044ec4bc541f6cbf9e4de1henrike@webrtc.org} // namespace rtc 87