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
|
/*
* Copyright (c) 2014 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.
*/
#include "webrtc/video_engine/report_block_stats.h"
namespace webrtc {
namespace {
int FractionLost(uint32_t num_lost_sequence_numbers,
uint32_t num_sequence_numbers) {
if (num_sequence_numbers == 0) {
return 0;
}
return ((num_lost_sequence_numbers * 255) + (num_sequence_numbers / 2)) /
num_sequence_numbers;
}
} // namespace
// Helper class for rtcp statistics.
ReportBlockStats::ReportBlockStats()
: num_sequence_numbers_(0),
num_lost_sequence_numbers_(0) {
}
void ReportBlockStats::Store(const RtcpStatistics& rtcp_stats,
uint32_t remote_ssrc,
uint32_t source_ssrc) {
RTCPReportBlock block;
block.cumulativeLost = rtcp_stats.cumulative_lost;
block.fractionLost = rtcp_stats.fraction_lost;
block.extendedHighSeqNum = rtcp_stats.extended_max_sequence_number;
block.jitter = rtcp_stats.jitter;
block.remoteSSRC = remote_ssrc;
block.sourceSSRC = source_ssrc;
uint32_t num_sequence_numbers = 0;
uint32_t num_lost_sequence_numbers = 0;
StoreAndAddPacketIncrement(
block, &num_sequence_numbers, &num_lost_sequence_numbers);
}
RTCPReportBlock ReportBlockStats::AggregateAndStore(
const ReportBlockVector& report_blocks) {
RTCPReportBlock aggregate;
if (report_blocks.empty()) {
return aggregate;
}
uint32_t num_sequence_numbers = 0;
uint32_t num_lost_sequence_numbers = 0;
ReportBlockVector::const_iterator report_block = report_blocks.begin();
for (; report_block != report_blocks.end(); ++report_block) {
aggregate.cumulativeLost += report_block->cumulativeLost;
aggregate.jitter += report_block->jitter;
StoreAndAddPacketIncrement(*report_block,
&num_sequence_numbers,
&num_lost_sequence_numbers);
}
if (report_blocks.size() == 1) {
// No aggregation needed.
return report_blocks[0];
}
// Fraction lost since previous report block.
aggregate.fractionLost =
FractionLost(num_lost_sequence_numbers, num_sequence_numbers);
aggregate.jitter = static_cast<uint32_t>(
(aggregate.jitter + report_blocks.size() / 2) / report_blocks.size());
return aggregate;
}
void ReportBlockStats::StoreAndAddPacketIncrement(
const RTCPReportBlock& report_block,
uint32_t* num_sequence_numbers,
uint32_t* num_lost_sequence_numbers) {
// Get diff with previous report block.
ReportBlockMap::iterator prev_report_block = prev_report_blocks_.find(
report_block.sourceSSRC);
if (prev_report_block != prev_report_blocks_.end()) {
int seq_num_diff = report_block.extendedHighSeqNum -
prev_report_block->second.extendedHighSeqNum;
int cum_loss_diff = report_block.cumulativeLost -
prev_report_block->second.cumulativeLost;
if (seq_num_diff >= 0 && cum_loss_diff >= 0) {
*num_sequence_numbers += seq_num_diff;
*num_lost_sequence_numbers += cum_loss_diff;
// Update total number of packets/lost packets.
num_sequence_numbers_ += seq_num_diff;
num_lost_sequence_numbers_ += cum_loss_diff;
}
}
// Store current report block.
prev_report_blocks_[report_block.sourceSSRC] = report_block;
}
int ReportBlockStats::FractionLostInPercent() const {
if (num_sequence_numbers_ == 0) {
return -1;
}
return FractionLost(
num_lost_sequence_numbers_, num_sequence_numbers_) * 100 / 255;
}
} // namespace webrtc
|
