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
3 // found in the LICENSE file.
4
5 #include "chrome/browser/media/audio_stream_monitor.h"
6
7 #include "base/bind.h"
8 #include "base/bind_helpers.h"
9 #include "content/public/browser/invalidate_type.h"
10 #include "content/public/browser/web_contents.h"
11
12 DEFINE_WEB_CONTENTS_USER_DATA_KEY(AudioStreamMonitor);
13
AudioStreamMonitor(content::WebContents * contents)14 AudioStreamMonitor::AudioStreamMonitor(content::WebContents* contents)
15 : web_contents_(contents),
16 clock_(&default_tick_clock_),
17 was_recently_audible_(false) {
18 DCHECK(web_contents_);
19 }
20
~AudioStreamMonitor()21 AudioStreamMonitor::~AudioStreamMonitor() {}
22
WasRecentlyAudible() const23 bool AudioStreamMonitor::WasRecentlyAudible() const {
24 DCHECK(thread_checker_.CalledOnValidThread());
25 return was_recently_audible_;
26 }
27
StartMonitoringStream(int stream_id,const ReadPowerAndClipCallback & read_power_callback)28 void AudioStreamMonitor::StartMonitoringStream(
29 int stream_id,
30 const ReadPowerAndClipCallback& read_power_callback) {
31 DCHECK(thread_checker_.CalledOnValidThread());
32 DCHECK(!read_power_callback.is_null());
33 poll_callbacks_[stream_id] = read_power_callback;
34 if (!poll_timer_.IsRunning()) {
35 poll_timer_.Start(
36 FROM_HERE,
37 base::TimeDelta::FromSeconds(1) / kPowerMeasurementsPerSecond,
38 base::Bind(&AudioStreamMonitor::Poll, base::Unretained(this)));
39 }
40 }
41
StopMonitoringStream(int stream_id)42 void AudioStreamMonitor::StopMonitoringStream(int stream_id) {
43 DCHECK(thread_checker_.CalledOnValidThread());
44 poll_callbacks_.erase(stream_id);
45 if (poll_callbacks_.empty())
46 poll_timer_.Stop();
47 }
48
Poll()49 void AudioStreamMonitor::Poll() {
50 for (StreamPollCallbackMap::const_iterator it = poll_callbacks_.begin();
51 it != poll_callbacks_.end();
52 ++it) {
53 // TODO(miu): A new UI for delivering specific power level and clipping
54 // information is still in the works. For now, we throw away all
55 // information except for "is it audible?"
56 const float power_dbfs = it->second.Run().first;
57 const float kSilenceThresholdDBFS = -72.24719896f;
58 if (power_dbfs >= kSilenceThresholdDBFS) {
59 last_blurt_time_ = clock_->NowTicks();
60 MaybeToggle();
61 break; // No need to poll remaining streams.
62 }
63 }
64 }
65
MaybeToggle()66 void AudioStreamMonitor::MaybeToggle() {
67 const bool indicator_was_on = was_recently_audible_;
68 const base::TimeTicks off_time =
69 last_blurt_time_ + base::TimeDelta::FromMilliseconds(kHoldOnMilliseconds);
70 const base::TimeTicks now = clock_->NowTicks();
71 const bool should_indicator_be_on = now < off_time;
72
73 if (should_indicator_be_on != indicator_was_on) {
74 was_recently_audible_ = should_indicator_be_on;
75 web_contents_->NotifyNavigationStateChanged(content::INVALIDATE_TYPE_TAB);
76 }
77
78 if (!should_indicator_be_on) {
79 off_timer_.Stop();
80 } else if (!off_timer_.IsRunning()) {
81 off_timer_.Start(
82 FROM_HERE,
83 off_time - now,
84 base::Bind(&AudioStreamMonitor::MaybeToggle, base::Unretained(this)));
85 }
86 }
87