1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
|
/*
* Copyright (c) 2012 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 MODULES_PACING_PACED_SENDER_H_
#define MODULES_PACING_PACED_SENDER_H_
#include <memory>
#include "api/optional.h"
#include "modules/pacing/pacer.h"
#include "modules/pacing/packet_queue.h"
#include "rtc_base/criticalsection.h"
#include "rtc_base/thread_annotations.h"
#include "typedefs.h" // NOLINT(build/include)
namespace webrtc {
class AlrDetector;
class BitrateProber;
class Clock;
class ProbeClusterCreatedObserver;
class RtcEventLog;
class IntervalBudget;
class PacedSender : public Pacer {
public:
class PacketSender {
public:
// Note: packets sent as a result of a callback should not pass by this
// module again.
// Called when it's time to send a queued packet.
// Returns false if packet cannot be sent.
virtual bool TimeToSendPacket(uint32_t ssrc,
uint16_t sequence_number,
int64_t capture_time_ms,
bool retransmission,
const PacedPacketInfo& cluster_info) = 0;
// Called when it's a good time to send a padding data.
// Returns the number of bytes sent.
virtual size_t TimeToSendPadding(size_t bytes,
const PacedPacketInfo& cluster_info) = 0;
protected:
virtual ~PacketSender() {}
};
// Expected max pacer delay in ms. If ExpectedQueueTimeMs() is higher than
// this value, the packet producers should wait (eg drop frames rather than
// encoding them). Bitrate sent may temporarily exceed target set by
// UpdateBitrate() so that this limit will be upheld.
static const int64_t kMaxQueueLengthMs;
// Pacing-rate relative to our target send rate.
// Multiplicative factor that is applied to the target bitrate to calculate
// the number of bytes that can be transmitted per interval.
// Increasing this factor will result in lower delays in cases of bitrate
// overshoots from the encoder.
static const float kDefaultPaceMultiplier;
PacedSender(const Clock* clock,
PacketSender* packet_sender,
RtcEventLog* event_log);
~PacedSender() override;
virtual void CreateProbeCluster(int bitrate_bps);
// Temporarily pause all sending.
void Pause();
// Resume sending packets.
void Resume();
// Enable bitrate probing. Enabled by default, mostly here to simplify
// testing. Must be called before any packets are being sent to have an
// effect.
void SetProbingEnabled(bool enabled);
// Sets the estimated capacity of the network. Must be called once before
// packets can be sent.
// |bitrate_bps| is our estimate of what we are allowed to send on average.
// We will pace out bursts of packets at a bitrate of
// |bitrate_bps| * kDefaultPaceMultiplier.
void SetEstimatedBitrate(uint32_t bitrate_bps) override;
// Sets the minimum send bitrate and maximum padding bitrate requested by send
// streams.
// |min_send_bitrate_bps| might be higher that the estimated available network
// bitrate and if so, the pacer will send with |min_send_bitrate_bps|.
// |max_padding_bitrate_bps| might be higher than the estimate available
// network bitrate and if so, the pacer will send padding packets to reach
// the min of the estimated available bitrate and |max_padding_bitrate_bps|.
void SetSendBitrateLimits(int min_send_bitrate_bps,
int max_padding_bitrate_bps);
// Returns true if we send the packet now, else it will add the packet
// information to the queue and call TimeToSendPacket when it's time to send.
void InsertPacket(RtpPacketSender::Priority priority,
uint32_t ssrc,
uint16_t sequence_number,
int64_t capture_time_ms,
size_t bytes,
bool retransmission) override;
// Returns the time since the oldest queued packet was enqueued.
virtual int64_t QueueInMs() const;
virtual size_t QueueSizePackets() const;
// Returns the time when the first packet was sent, or -1 if no packet is
// sent.
virtual int64_t FirstSentPacketTimeMs() const;
// Returns the number of milliseconds it will take to send the current
// packets in the queue, given the current size and bitrate, ignoring prio.
virtual int64_t ExpectedQueueTimeMs() const;
// Returns time in milliseconds when the current application-limited region
// started or empty result if the sender is currently not application-limited.
//
// Application Limited Region (ALR) refers to operating in a state where the
// traffic on network is limited due to application not having enough
// traffic to meet the current channel capacity.
virtual rtc::Optional<int64_t> GetApplicationLimitedRegionStartTime() const;
// Returns the average time since being enqueued, in milliseconds, for all
// packets currently in the pacer queue, excluding any time the pacer has been
// paused. Returns 0 if queue is empty.
virtual int64_t AverageQueueTimeMs();
// Returns the number of milliseconds until the module want a worker thread
// to call Process.
int64_t TimeUntilNextProcess() override;
// Process any pending packets in the queue(s).
void Process() override;
// Called when the prober is associated with a process thread.
void ProcessThreadAttached(ProcessThread* process_thread) override;
void SetPacingFactor(float pacing_factor);
void SetQueueTimeLimit(int limit_ms);
private:
// Updates the number of bytes that can be sent for the next time interval.
void UpdateBudgetWithElapsedTime(int64_t delta_time_in_ms)
RTC_EXCLUSIVE_LOCKS_REQUIRED(critsect_);
void UpdateBudgetWithBytesSent(size_t bytes)
RTC_EXCLUSIVE_LOCKS_REQUIRED(critsect_);
bool SendPacket(const PacketQueue::Packet& packet,
const PacedPacketInfo& cluster_info)
RTC_EXCLUSIVE_LOCKS_REQUIRED(critsect_);
size_t SendPadding(size_t padding_needed, const PacedPacketInfo& cluster_info)
RTC_EXCLUSIVE_LOCKS_REQUIRED(critsect_);
const Clock* const clock_;
PacketSender* const packet_sender_;
std::unique_ptr<AlrDetector> alr_detector_ RTC_GUARDED_BY(critsect_);
rtc::CriticalSection critsect_;
bool paused_ RTC_GUARDED_BY(critsect_);
// This is the media budget, keeping track of how many bits of media
// we can pace out during the current interval.
std::unique_ptr<IntervalBudget> media_budget_ RTC_GUARDED_BY(critsect_);
// This is the padding budget, keeping track of how many bits of padding we're
// allowed to send out during the current interval. This budget will be
// utilized when there's no media to send.
std::unique_ptr<IntervalBudget> padding_budget_ RTC_GUARDED_BY(critsect_);
std::unique_ptr<BitrateProber> prober_ RTC_GUARDED_BY(critsect_);
bool probing_send_failure_;
// Actual configured bitrates (media_budget_ may temporarily be higher in
// order to meet pace time constraint).
uint32_t estimated_bitrate_bps_ RTC_GUARDED_BY(critsect_);
uint32_t min_send_bitrate_kbps_ RTC_GUARDED_BY(critsect_);
uint32_t max_padding_bitrate_kbps_ RTC_GUARDED_BY(critsect_);
uint32_t pacing_bitrate_kbps_ RTC_GUARDED_BY(critsect_);
int64_t time_last_update_us_ RTC_GUARDED_BY(critsect_);
int64_t first_sent_packet_ms_ RTC_GUARDED_BY(critsect_);
std::unique_ptr<PacketQueue> packets_ RTC_GUARDED_BY(critsect_);
uint64_t packet_counter_;
ProcessThread* process_thread_ = nullptr;
float pacing_factor_ RTC_GUARDED_BY(critsect_);
int64_t queue_time_limit RTC_GUARDED_BY(critsect_);
};
} // namespace webrtc
#endif // MODULES_PACING_PACED_SENDER_H_
|
