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/*
* Copyright (c) 2015 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.
*/
#ifndef CALL_BITRATE_ALLOCATOR_H_
#define CALL_BITRATE_ALLOCATOR_H_
#include <stdint.h>
#include <map>
#include <memory>
#include <string>
#include <utility>
#include <vector>
#include "rtc_base/bitrateallocationstrategy.h"
#include "rtc_base/sequenced_task_checker.h"
namespace webrtc {
class Clock;
// Used by all send streams with adaptive bitrate, to get the currently
// allocated bitrate for the send stream. The current network properties are
// given at the same time, to let the send stream decide about possible loss
// protection.
class BitrateAllocatorObserver {
public:
// Returns the amount of protection used by the BitrateAllocatorObserver
// implementation, as bitrate in bps.
virtual uint32_t OnBitrateUpdated(uint32_t bitrate_bps,
uint8_t fraction_loss,
int64_t rtt,
int64_t bwe_period_ms) = 0;
protected:
virtual ~BitrateAllocatorObserver() {}
};
// Usage: this class will register multiple RtcpBitrateObserver's one at each
// RTCP module. It will aggregate the results and run one bandwidth estimation
// and push the result to the encoders via BitrateAllocatorObserver(s).
class BitrateAllocator {
public:
// Used to get notified when send stream limits such as the minimum send
// bitrate and max padding bitrate is changed.
class LimitObserver {
public:
virtual void OnAllocationLimitsChanged(
uint32_t min_send_bitrate_bps,
uint32_t max_padding_bitrate_bps) = 0;
protected:
virtual ~LimitObserver() {}
};
explicit BitrateAllocator(LimitObserver* limit_observer);
~BitrateAllocator();
// Allocate target_bitrate across the registered BitrateAllocatorObservers.
void OnNetworkChanged(uint32_t target_bitrate_bps,
uint8_t fraction_loss,
int64_t rtt,
int64_t bwe_period_ms);
// Set the start and max send bitrate used by the bandwidth management.
//
// |observer| updates bitrates if already in use.
// |min_bitrate_bps| = 0 equals no min bitrate.
// |max_bitrate_bps| = 0 equals no max bitrate.
// |enforce_min_bitrate| = 'true' will allocate at least |min_bitrate_bps| for
// this observer, even if the BWE is too low, 'false' will allocate 0 to
// the observer if BWE doesn't allow |min_bitrate_bps|.
// Note that |observer|->OnBitrateUpdated() will be called within the scope of
// this method with the current rtt, fraction_loss and available bitrate and
// that the bitrate in OnBitrateUpdated will be zero if the |observer| is
// currently not allowed to send data.
void AddObserver(BitrateAllocatorObserver* observer,
uint32_t min_bitrate_bps,
uint32_t max_bitrate_bps,
uint32_t pad_up_bitrate_bps,
bool enforce_min_bitrate,
std::string track_id,
// TODO(shampson): Take out default value and wire the
// bitrate_priority up to the AudioSendStream::Config and
// VideoSendStream::Config.
double bitrate_priority = 1.0);
// Removes a previously added observer, but will not trigger a new bitrate
// allocation.
void RemoveObserver(BitrateAllocatorObserver* observer);
// Returns initial bitrate allocated for |observer|. If |observer| is not in
// the list of added observers, a best guess is returned.
int GetStartBitrate(BitrateAllocatorObserver* observer);
// Sets external allocation strategy. If strategy is not set default WebRTC
// allocation mechanism will be used. The strategy may be changed during call.
// Setting NULL value will restore default WEBRTC allocation strategy.
void SetBitrateAllocationStrategy(
std::unique_ptr<rtc::BitrateAllocationStrategy>
bitrate_allocation_strategy);
private:
struct ObserverConfig : rtc::BitrateAllocationStrategy::TrackConfig {
ObserverConfig(BitrateAllocatorObserver* observer,
uint32_t min_bitrate_bps,
uint32_t max_bitrate_bps,
uint32_t pad_up_bitrate_bps,
bool enforce_min_bitrate,
std::string track_id,
double bitrate_priority)
: TrackConfig(min_bitrate_bps,
max_bitrate_bps,
enforce_min_bitrate,
track_id),
observer(observer),
pad_up_bitrate_bps(pad_up_bitrate_bps),
allocated_bitrate_bps(-1),
media_ratio(1.0),
bitrate_priority(bitrate_priority) {}
BitrateAllocatorObserver* observer;
uint32_t pad_up_bitrate_bps;
int64_t allocated_bitrate_bps;
double media_ratio; // Part of the total bitrate used for media [0.0, 1.0].
// The amount of bitrate allocated to this observer relative to all other
// observers. If an observer has twice the bitrate_priority of other
// observers, it should be allocated twice the bitrate above its min.
double bitrate_priority;
};
// Calculates the minimum requested send bitrate and max padding bitrate and
// calls LimitObserver::OnAllocationLimitsChanged.
void UpdateAllocationLimits();
typedef std::vector<ObserverConfig> ObserverConfigs;
ObserverConfigs::iterator FindObserverConfig(
const BitrateAllocatorObserver* observer);
typedef std::multimap<uint32_t, const ObserverConfig*> ObserverSortingMap;
typedef std::map<BitrateAllocatorObserver*, int> ObserverAllocation;
ObserverAllocation AllocateBitrates(uint32_t bitrate);
// Allocates zero bitrate to all observers.
ObserverAllocation ZeroRateAllocation();
// Allocates bitrate to observers when there isn't enough to allocate the
// minimum to all observers.
ObserverAllocation LowRateAllocation(uint32_t bitrate);
// Allocates bitrate to all observers when the available bandwidth is enough
// to allocate the minimum to all observers but not enough to allocate the
// max bitrate of each observer.
ObserverAllocation NormalRateAllocation(uint32_t bitrate,
uint32_t sum_min_bitrates);
// Allocates bitrate to observers when there is enough available bandwidth
// for all observers to be allocated their max bitrate.
ObserverAllocation MaxRateAllocation(uint32_t bitrate,
uint32_t sum_max_bitrates);
uint32_t LastAllocatedBitrate(const ObserverConfig& observer_config);
// The minimum bitrate required by this observer, including enable-hysteresis
// if the observer is in a paused state.
uint32_t MinBitrateWithHysteresis(const ObserverConfig& observer_config);
// Splits |bitrate| evenly to observers already in |allocation|.
// |include_zero_allocations| decides if zero allocations should be part of
// the distribution or not. The allowed max bitrate is |max_multiplier| x
// observer max bitrate.
void DistributeBitrateEvenly(uint32_t bitrate,
bool include_zero_allocations,
int max_multiplier,
ObserverAllocation* allocation);
bool EnoughBitrateForAllObservers(uint32_t bitrate,
uint32_t sum_min_bitrates);
// From the available |bitrate|, each observer will be allocated a
// proportional amount based upon its bitrate priority. If that amount is
// more than the observer's capacity, it will be allocated its capacity, and
// the excess bitrate is still allocated proportionally to other observers.
// Allocating the proportional amount means an observer with twice the
// bitrate_priority of another will be allocated twice the bitrate.
void DistributeBitrateRelatively(
uint32_t bitrate,
const ObserverAllocation& observers_capacities,
ObserverAllocation* allocation);
rtc::SequencedTaskChecker sequenced_checker_;
LimitObserver* const limit_observer_ RTC_GUARDED_BY(&sequenced_checker_);
// Stored in a list to keep track of the insertion order.
ObserverConfigs bitrate_observer_configs_ RTC_GUARDED_BY(&sequenced_checker_);
uint32_t last_bitrate_bps_ RTC_GUARDED_BY(&sequenced_checker_);
uint32_t last_non_zero_bitrate_bps_ RTC_GUARDED_BY(&sequenced_checker_);
uint8_t last_fraction_loss_ RTC_GUARDED_BY(&sequenced_checker_);
int64_t last_rtt_ RTC_GUARDED_BY(&sequenced_checker_);
int64_t last_bwe_period_ms_ RTC_GUARDED_BY(&sequenced_checker_);
// Number of mute events based on too low BWE, not network up/down.
int num_pause_events_ RTC_GUARDED_BY(&sequenced_checker_);
Clock* const clock_ RTC_GUARDED_BY(&sequenced_checker_);
int64_t last_bwe_log_time_ RTC_GUARDED_BY(&sequenced_checker_);
uint32_t total_requested_padding_bitrate_ RTC_GUARDED_BY(&sequenced_checker_);
uint32_t total_requested_min_bitrate_ RTC_GUARDED_BY(&sequenced_checker_);
std::unique_ptr<rtc::BitrateAllocationStrategy> bitrate_allocation_strategy_
RTC_GUARDED_BY(&sequenced_checker_);
};
} // namespace webrtc
#endif // CALL_BITRATE_ALLOCATOR_H_
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