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1 /* | 1 /* |
2 * Copyright (c) 2017 The WebRTC project authors. All Rights Reserved. | 2 * Copyright (c) 2017 The WebRTC project authors. All Rights Reserved. |
3 * | 3 * |
4 * Use of this source code is governed by a BSD-style license | 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 | 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 | 6 * tree. An additional intellectual property rights grant can be found |
7 * in the file PATENTS. All contributing project authors may | 7 * in the file PATENTS. All contributing project authors may |
8 * be found in the AUTHORS file in the root of the source tree. | 8 * be found in the AUTHORS file in the root of the source tree. |
9 */ | 9 */ |
10 | 10 |
11 #ifndef WEBRTC_VOICE_ENGINE_TRANSPORT_FEEDBACK_PACKET_LOSS_TRACKER_H_ | 11 #ifndef WEBRTC_VOICE_ENGINE_TRANSPORT_FEEDBACK_PACKET_LOSS_TRACKER_H_ |
12 #define WEBRTC_VOICE_ENGINE_TRANSPORT_FEEDBACK_PACKET_LOSS_TRACKER_H_ | 12 #define WEBRTC_VOICE_ENGINE_TRANSPORT_FEEDBACK_PACKET_LOSS_TRACKER_H_ |
13 | 13 |
14 #include <map> | 14 #include <map> |
15 | 15 |
16 #include "webrtc/base/optional.h" | 16 #include "webrtc/base/optional.h" |
17 #include "webrtc/modules/include/module_common_types.h" | 17 #include "webrtc/modules/include/module_common_types.h" |
18 | 18 |
19 namespace webrtc { | 19 namespace webrtc { |
20 | 20 |
21 namespace rtcp { | 21 namespace rtcp { |
22 class TransportFeedback; | 22 class TransportFeedback; |
23 } | 23 } |
24 | 24 |
25 class TransportFeedbackPacketLossTracker final { | 25 class TransportFeedbackPacketLossTracker final { |
26 public: | 26 public: |
27 // Up to |max_window_size| latest packet statuses wil be used for calculating | 27 // * Up to |max_window_size| latest packet statuses will be used for |
28 // the packet loss metrics. When less than |min_window_size| samples are | 28 // calculating the packet loss metrics. |
29 // available for making a reliable estimation, GetPacketLossRates() will | 29 // * PLR (packet-loss-rate) is reliably computable once the statuses of |
30 // return false to indicate packet loss metrics are not ready. | 30 // |plr_min_num_packets| packets are known. |
31 TransportFeedbackPacketLossTracker(size_t min_window_size, | 31 // * RPLR (recoverable-packet-loss-rate) is reliably computable once the |
32 size_t max_window_size); | 32 // statuses of |rplr_min_num_pairs| pairs are known. |
| 33 TransportFeedbackPacketLossTracker(size_t max_window_size, |
| 34 size_t plr_min_num_packets, |
| 35 size_t rplr_min_num_pairs); |
33 | 36 |
34 void OnReceivedTransportFeedback(const rtcp::TransportFeedback& feedback); | 37 void OnReceivedTransportFeedback(const rtcp::TransportFeedback& feedback); |
35 | 38 |
36 // Returns true if packet loss rate and packet loss episode duration are ready | 39 // Returns the packet loss rate, if the window has enough packet statuses to |
37 // and assigns respective values to |*packet_loss_rate| and | 40 // reliably compute it. Otherwise, returns empty. |
38 // |*consecutive_packet_loss_rate|. Continuous packet loss rate is defined as | 41 rtc::Optional<float> GetPacketLossRate() const; |
39 // the probability of losing two adjacent packets. | 42 |
40 bool GetPacketLossRates(float* packet_loss_rate, | 43 // Returns the first-order-FEC recoverable packet loss rate, if the window has |
41 float* consecutive_packet_loss_rate) const; | 44 // enough status pairs to reliably compute it. Otherwise, returns empty. |
| 45 rtc::Optional<float> GetRecoverablePacketLossRate() const; |
42 | 46 |
43 // Verifies that the internal states are correct. Only used for tests. | 47 // Verifies that the internal states are correct. Only used for tests. |
44 void Validate() const; | 48 void Validate() const; |
45 | 49 |
46 private: | 50 private: |
47 // PacketStatus is a map from sequence number to its reception status. The | 51 // PacketStatus is a map from sequence number to its reception status. The |
48 // status is true if the corresponding packet is received, and false if it is | 52 // status is true if the corresponding packet is received, and false if it is |
49 // lost. Unknown statuses are not present in the map. | 53 // lost. Unknown statuses are not present in the map. |
50 typedef std::map<uint16_t, bool> PacketStatus; | 54 typedef std::map<uint16_t, bool> PacketStatus; |
51 typedef PacketStatus::const_iterator PacketStatusIterator; | 55 typedef PacketStatus::const_iterator PacketStatusIterator; |
52 | 56 |
53 void Reset(); | 57 void Reset(); |
| 58 |
54 // ReferenceSequenceNumber() provides a sequence number that defines the | 59 // ReferenceSequenceNumber() provides a sequence number that defines the |
55 // order of packet reception info stored in |packet_status_window_|. In | 60 // order of packet reception info stored in |packet_status_window_|. In |
56 // particular, given any sequence number |x|, | 61 // particular, given any sequence number |x|, |
57 // (2^16 + x - ref_seq_num_) % 2^16 defines its actual position in | 62 // (2^16 + x - ref_seq_num_) % 2^16 defines its actual position in |
58 // |packet_status_window_|. | 63 // |packet_status_window_|. |
59 uint16_t ReferenceSequenceNumber() const; | 64 uint16_t ReferenceSequenceNumber() const; |
60 bool IsOldSequenceNumber(uint16_t seq_num) const; | 65 bool IsOldSequenceNumber(uint16_t seq_num) const; |
61 void InsertPacketStatus(uint16_t seq_num, bool received); | 66 void InsertPacketStatus(uint16_t seq_num, bool received); |
62 void RemoveOldestPacketStatus(); | 67 void RemoveOldestPacketStatus(); |
63 void ApplyPacketStatus(PacketStatusIterator it); | 68 |
64 void UndoPacketStatus(PacketStatusIterator it); | 69 void UpdateMetrics(PacketStatusIterator it, bool apply /* false = undo */); |
| 70 void UpdatePlr(PacketStatusIterator it, bool apply /* false = undo */); |
| 71 void UpdateRplr(PacketStatusIterator it, bool apply /* false = undo */); |
| 72 |
65 PacketStatusIterator PreviousPacketStatus(PacketStatusIterator it); | 73 PacketStatusIterator PreviousPacketStatus(PacketStatusIterator it); |
66 PacketStatusIterator NextPacketStatus(PacketStatusIterator it); | 74 PacketStatusIterator NextPacketStatus(PacketStatusIterator it); |
67 | 75 |
68 const size_t min_window_size_; | |
69 const size_t max_window_size_; | 76 const size_t max_window_size_; |
70 | 77 |
71 PacketStatus packet_status_window_; | 78 PacketStatus packet_status_window_; |
72 // |ref_packet_status_| points to the oldest item in |packet_status_window_|. | 79 // |ref_packet_status_| points to the oldest item in |packet_status_window_|. |
73 PacketStatusIterator ref_packet_status_; | 80 PacketStatusIterator ref_packet_status_; |
74 | 81 |
75 size_t num_received_packets_; | 82 // Packet-loss-rate calculation (lost / all-known-packets). |
76 size_t num_lost_packets_; | 83 struct PlrState { |
77 size_t num_consecutive_losses_; | 84 explicit PlrState(size_t min_num_packets) |
78 size_t num_consecutive_old_reports_; | 85 : min_num_packets_(min_num_packets) { |
| 86 Reset(); |
| 87 } |
| 88 void Reset() { |
| 89 num_received_packets_ = 0; |
| 90 num_lost_packets_ = 0; |
| 91 } |
| 92 rtc::Optional<float> GetMetric() const; |
| 93 const size_t min_num_packets_; |
| 94 size_t num_received_packets_; |
| 95 size_t num_lost_packets_; |
| 96 } plr_state_; |
| 97 |
| 98 // Recoverable packet loss calculation (first-order-FEC recoverable). |
| 99 struct RplrState { |
| 100 explicit RplrState(size_t min_num_pairs) |
| 101 : min_num_pairs_(min_num_pairs) { |
| 102 Reset(); |
| 103 } |
| 104 void Reset() { |
| 105 num_known_pairs_ = 0; |
| 106 num_recoverable_losses_ = 0; |
| 107 } |
| 108 rtc::Optional<float> GetMetric() const; |
| 109 // Recoverable packets are those which were lost, but immediately followed |
| 110 // by a properly received packet. If that second packet carried FEC, |
| 111 // the data from the former (lost) packet could be recovered. |
| 112 // The RPLR is calculated as the fraction of such pairs (lost-received) out |
| 113 // of all pairs of consecutive acked packets. |
| 114 const size_t min_num_pairs_; |
| 115 size_t num_known_pairs_; |
| 116 size_t num_recoverable_losses_; |
| 117 } rplr_state_; |
| 118 |
| 119 size_t num_consecutive_old_reports_; // TODO(elad.alon): Upcoming CL removes. |
79 }; | 120 }; |
80 | 121 |
81 } // namespace webrtc | 122 } // namespace webrtc |
82 | 123 |
83 #endif // WEBRTC_VOICE_ENGINE_TRANSPORT_FEEDBACK_PACKET_LOSS_TRACKER_H_ | 124 #endif // WEBRTC_VOICE_ENGINE_TRANSPORT_FEEDBACK_PACKET_LOSS_TRACKER_H_ |
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