content/browser/media/audio_stream_monitor.cc

   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 "content/browser/media/audio_stream_monitor.h"
   6
   7 #include "base/bind.h"
   8 #include "base/bind_helpers.h"
   9 #include "content/browser/web_contents/web_contents_impl.h"
  10 #include "content/public/browser/browser_thread.h"
  11 #include "content/public/browser/invalidate_type.h"
  12 #include "content/public/browser/render_frame_host.h"
  13
  14 namespace content {
  15
  16 namespace {
  17
  18 AudioStreamMonitor* AudioStreamMonitorFromRenderFrame(int render_process_id,
  19                                                       int render_frame_id) {
  20   DCHECK_CURRENTLY_ON(BrowserThread::UI);
  21   WebContentsImpl* const web_contents =
  22       static_cast<WebContentsImpl*>(WebContents::FromRenderFrameHost(
  23           RenderFrameHost::FromID(render_process_id, render_frame_id)));
  24   return web_contents ? web_contents->audio_stream_monitor() : NULL;
  25 }
  26
  27 }  // namespace
  28
  29 AudioStreamMonitor::AudioStreamMonitor(WebContents* contents)
  30     : web_contents_(contents),
  31       clock_(&default_tick_clock_),
  32       was_recently_audible_(false) {
  33   DCHECK(web_contents_);
  34 }
  35
  36 AudioStreamMonitor::~AudioStreamMonitor() {}
  37
  38 bool AudioStreamMonitor::WasRecentlyAudible() const {
  39   DCHECK(thread_checker_.CalledOnValidThread());
  40   return was_recently_audible_;
  41 }
  42
  43 // static
  44 void AudioStreamMonitor::StartMonitoringStream(
  45     int render_process_id,
  46     int render_frame_id,
  47     int stream_id,
  48     const ReadPowerAndClipCallback& read_power_callback) {
  49   if (!monitoring_available())
  50     return;
  51   BrowserThread::PostTask(BrowserThread::UI,
  52                           FROM_HERE,
  53                           base::Bind(&StartMonitoringHelper,
  54                                      render_process_id,
  55                                      render_frame_id,
  56                                      stream_id,
  57                                      read_power_callback));
  58 }
  59
  60 // static
  61 void AudioStreamMonitor::StopMonitoringStream(int render_process_id,
  62                                               int render_frame_id,
  63                                               int stream_id) {
  64   if (!monitoring_available())
  65     return;
  66   BrowserThread::PostTask(BrowserThread::UI,
  67                           FROM_HERE,
  68                           base::Bind(&StopMonitoringHelper,
  69                                      render_process_id,
  70                                      render_frame_id,
  71                                      stream_id));
  72 }
  73
  74 // static
  75 void AudioStreamMonitor::StartMonitoringHelper(
  76     int render_process_id,
  77     int render_frame_id,
  78     int stream_id,
  79     const ReadPowerAndClipCallback& read_power_callback) {
  80   DCHECK_CURRENTLY_ON(BrowserThread::UI);
  81   AudioStreamMonitor* const monitor =
  82       AudioStreamMonitorFromRenderFrame(render_process_id, render_frame_id);
  83   if (monitor) {
  84     monitor->StartMonitoringStreamOnUIThread(
  85         render_process_id, stream_id, read_power_callback);
  86   }
  87 }
  88
  89 // static
  90 void AudioStreamMonitor::StopMonitoringHelper(int render_process_id,
  91                                               int render_frame_id,
  92                                               int stream_id) {
  93   DCHECK_CURRENTLY_ON(BrowserThread::UI);
  94   AudioStreamMonitor* const monitor =
  95       AudioStreamMonitorFromRenderFrame(render_process_id, render_frame_id);
  96   if (monitor)
  97     monitor->StopMonitoringStreamOnUIThread(render_process_id, stream_id);
  98 }
  99
 100 void AudioStreamMonitor::StartMonitoringStreamOnUIThread(
 101     int render_process_id,
 102     int stream_id,
 103     const ReadPowerAndClipCallback& read_power_callback) {
 104   DCHECK(thread_checker_.CalledOnValidThread());
 105   DCHECK(!read_power_callback.is_null());
 106   poll_callbacks_[StreamID(render_process_id, stream_id)] = read_power_callback;
 107   if (!poll_timer_.IsRunning()) {
 108     poll_timer_.Start(
 109         FROM_HERE,
 110         base::TimeDelta::FromSeconds(1) / kPowerMeasurementsPerSecond,
 111         base::Bind(&AudioStreamMonitor::Poll, base::Unretained(this)));
 112   }
 113 }
 114
 115 void AudioStreamMonitor::StopMonitoringStreamOnUIThread(int render_process_id,
 116                                                         int stream_id) {
 117   DCHECK(thread_checker_.CalledOnValidThread());
 118   poll_callbacks_.erase(StreamID(render_process_id, stream_id));
 119   if (poll_callbacks_.empty())
 120     poll_timer_.Stop();
 121 }
 122
 123 void AudioStreamMonitor::Poll() {
 124   for (StreamPollCallbackMap::const_iterator it = poll_callbacks_.begin();
 125        it != poll_callbacks_.end();
 126        ++it) {
 127     // TODO(miu): A new UI for delivering specific power level and clipping
 128     // information is still in the works.  For now, we throw away all
 129     // information except for "is it audible?"
 130     const float power_dbfs = it->second.Run().first;
 131     const float kSilenceThresholdDBFS = -72.24719896f;
 132     if (power_dbfs >= kSilenceThresholdDBFS) {
 133       last_blurt_time_ = clock_->NowTicks();
 134       MaybeToggle();
 135       break;  // No need to poll remaining streams.
 136     }
 137   }
 138 }
 139
 140 void AudioStreamMonitor::MaybeToggle() {
 141   const bool indicator_was_on = was_recently_audible_;
 142   const base::TimeTicks off_time =
 143       last_blurt_time_ + base::TimeDelta::FromMilliseconds(kHoldOnMilliseconds);
 144   const base::TimeTicks now = clock_->NowTicks();
 145   const bool should_indicator_be_on = now < off_time;
 146
 147   if (should_indicator_be_on != indicator_was_on) {
 148     was_recently_audible_ = should_indicator_be_on;
 149     web_contents_->NotifyNavigationStateChanged(INVALIDATE_TYPE_TAB);
 150   }
 151
 152   if (!should_indicator_be_on) {
 153     off_timer_.Stop();
 154   } else if (!off_timer_.IsRunning()) {
 155     off_timer_.Start(
 156         FROM_HERE,
 157         off_time - now,
 158         base::Bind(&AudioStreamMonitor::MaybeToggle, base::Unretained(this)));
 159   }
 160 }
 161
 162 }  // namespace content