69 lines
2.3 KiB
C++
69 lines
2.3 KiB
C++
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/*
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* Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#include "modules/pacing/interval_budget.h"
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#include <algorithm>
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#include "rtc_base/numerics/safe_conversions.h"
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namespace webrtc {
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namespace {
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constexpr int64_t kWindowMs = 500;
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}
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IntervalBudget::IntervalBudget(int initial_target_rate_kbps)
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: IntervalBudget(initial_target_rate_kbps, false) {}
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IntervalBudget::IntervalBudget(int initial_target_rate_kbps,
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bool can_build_up_underuse)
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: bytes_remaining_(0), can_build_up_underuse_(can_build_up_underuse) {
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set_target_rate_kbps(initial_target_rate_kbps);
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}
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void IntervalBudget::set_target_rate_kbps(int target_rate_kbps) {
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target_rate_kbps_ = target_rate_kbps;
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max_bytes_in_budget_ = (kWindowMs * target_rate_kbps_) / 8;
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bytes_remaining_ = std::min(std::max(-max_bytes_in_budget_, bytes_remaining_),
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max_bytes_in_budget_);
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}
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void IntervalBudget::IncreaseBudget(int64_t delta_time_ms) {
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int64_t bytes = target_rate_kbps_ * delta_time_ms / 8;
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if (bytes_remaining_ < 0 || can_build_up_underuse_) {
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// We overused last interval, compensate this interval.
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bytes_remaining_ = std::min(bytes_remaining_ + bytes, max_bytes_in_budget_);
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} else {
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// If we underused last interval we can't use it this interval.
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bytes_remaining_ = std::min(bytes, max_bytes_in_budget_);
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}
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}
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void IntervalBudget::UseBudget(size_t bytes) {
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bytes_remaining_ = std::max(bytes_remaining_ - static_cast<int>(bytes),
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-max_bytes_in_budget_);
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}
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size_t IntervalBudget::bytes_remaining() const {
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return rtc::saturated_cast<size_t>(std::max<int64_t>(0, bytes_remaining_));
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}
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double IntervalBudget::budget_ratio() const {
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if (max_bytes_in_budget_ == 0)
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return 0.0;
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return static_cast<double>(bytes_remaining_) / max_bytes_in_budget_;
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}
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int IntervalBudget::target_rate_kbps() const {
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return target_rate_kbps_;
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}
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} // namespace webrtc
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