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Side by Side Diff: media/cast/common/clock_drift_smoother.cc

Issue 638123004: Type conversion fixes, media/ edition. (Closed) Base URL: https://chromium.googlesource.com/chromium/src.git@master
Patch Set: Fix test Created 6 years, 2 months ago
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1 // Copyright 2014 The Chromium Authors. All rights reserved. 1 // Copyright 2014 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be 2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file. 3 // found in the LICENSE file.
4 4
5 #include "media/cast/common/clock_drift_smoother.h" 5 #include "media/cast/common/clock_drift_smoother.h"
6 6
7 #include "base/logging.h" 7 #include "base/logging.h"
8 8
9 namespace media { 9 namespace media {
10 namespace cast { 10 namespace cast {
11 11
12 ClockDriftSmoother::ClockDriftSmoother(base::TimeDelta time_constant) 12 ClockDriftSmoother::ClockDriftSmoother(base::TimeDelta time_constant)
13 : time_constant_(time_constant), 13 : time_constant_(time_constant),
14 estimate_us_(0.0) { 14 estimate_us_(0.0) {
15 DCHECK(time_constant_ > base::TimeDelta()); 15 DCHECK(time_constant_ > base::TimeDelta());
16 } 16 }
17 17
18 ClockDriftSmoother::~ClockDriftSmoother() {} 18 ClockDriftSmoother::~ClockDriftSmoother() {}
19 19
20 base::TimeDelta ClockDriftSmoother::Current() const { 20 base::TimeDelta ClockDriftSmoother::Current() const {
21 DCHECK(!last_update_time_.is_null()); 21 DCHECK(!last_update_time_.is_null());
22 return base::TimeDelta::FromMicroseconds( 22 return base::TimeDelta::FromMicroseconds(
23 static_cast<int64>(estimate_us_ + 0.5)); // Round to nearest microsecond. 23 static_cast<int64>(estimate_us_ + 0.5)); // Round to nearest microsecond.
24 } 24 }
25 25
26 void ClockDriftSmoother::Reset(base::TimeTicks now, 26 void ClockDriftSmoother::Reset(base::TimeTicks now,
27 base::TimeDelta measured_offset) { 27 base::TimeDelta measured_offset) {
28 DCHECK(!now.is_null()); 28 DCHECK(!now.is_null());
29 last_update_time_ = now; 29 last_update_time_ = now;
30 estimate_us_ = measured_offset.InMicroseconds(); 30 estimate_us_ = static_cast<double>(measured_offset.InMicroseconds());
31 } 31 }
32 32
33 void ClockDriftSmoother::Update(base::TimeTicks now, 33 void ClockDriftSmoother::Update(base::TimeTicks now,
34 base::TimeDelta measured_offset) { 34 base::TimeDelta measured_offset) {
35 DCHECK(!now.is_null()); 35 DCHECK(!now.is_null());
36 if (last_update_time_.is_null()) { 36 if (last_update_time_.is_null()) {
37 Reset(now, measured_offset); 37 Reset(now, measured_offset);
38 } else if (now < last_update_time_) { 38 } else if (now < last_update_time_) {
39 // |now| is not monotonically non-decreasing. 39 // |now| is not monotonically non-decreasing.
40 NOTREACHED(); 40 NOTREACHED();
41 } else { 41 } else {
42 const double elapsed_us = (now - last_update_time_).InMicroseconds(); 42 const double elapsed_us =
43 static_cast<double>((now - last_update_time_).InMicroseconds());
43 last_update_time_ = now; 44 last_update_time_ = now;
44 const double weight = 45 const double weight =
45 elapsed_us / (elapsed_us + time_constant_.InMicroseconds()); 46 elapsed_us / (elapsed_us + time_constant_.InMicroseconds());
46 estimate_us_ = weight * measured_offset.InMicroseconds() + 47 estimate_us_ = weight * measured_offset.InMicroseconds() +
47 (1.0 - weight) * estimate_us_; 48 (1.0 - weight) * estimate_us_;
48 } 49 }
49 } 50 }
50 51
51 // static 52 // static
52 base::TimeDelta ClockDriftSmoother::GetDefaultTimeConstant() { 53 base::TimeDelta ClockDriftSmoother::GetDefaultTimeConstant() {
53 static const int kDefaultTimeConstantInSeconds = 30; 54 static const int kDefaultTimeConstantInSeconds = 30;
54 return base::TimeDelta::FromSeconds(kDefaultTimeConstantInSeconds); 55 return base::TimeDelta::FromSeconds(kDefaultTimeConstantInSeconds);
55 } 56 }
56 57
57 } // namespace cast 58 } // namespace cast
58 } // namespace media 59 } // namespace media
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