chrome/browser/media/audio_stream_indicator.cc

   1 // Copyright (c) 2012 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_indicator.h"
   6
   7 #include <limits>
   8
   9 #include "base/bind.h"
  10 #include "chrome/browser/tab_contents/tab_util.h"
  11 #include "content/public/browser/browser_thread.h"
  12 #include "content/public/browser/invalidate_type.h"
  13 #include "content/public/browser/render_process_host.h"
  14 #include "content/public/browser/render_view_host.h"
  15 #include "content/public/browser/web_contents.h"
  16
  17 using content::BrowserThread;
  18 using content::WebContents;
  19
  20 AudioStreamIndicator::AudioStreamIndicator() {}
  21 AudioStreamIndicator::~AudioStreamIndicator() {}
  22
  23 void AudioStreamIndicator::UpdateWebContentsStatus(
  24     int render_process_id, int render_view_id, int stream_id,
  25     bool is_playing, float power_dbfs, bool clipped) {
  26   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  27
  28   BrowserThread::PostTask(
  29       BrowserThread::UI, FROM_HERE,
  30       base::Bind(&AudioStreamIndicator::UpdateWebContentsStatusOnUIThread, this,
  31                  render_process_id, render_view_id, stream_id,
  32                  is_playing, power_dbfs, clipped));
  33 }
  34
  35 bool AudioStreamIndicator::IsPlayingAudio(const WebContents* contents) {
  36   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  37
  38   // TODO(miu): In order to prevent breaking existing uses of this method, the
  39   // old semantics of "playing AND not silent" have been retained here.  Once
  40   // the tab audio indicator UI switches over to using the new
  41   // GetAudioSignalPower(), this method should really be just "playing."
  42   float level;
  43   bool ignored;
  44   CurrentAudibleLevel(contents, &level, &ignored);
  45   return level > 0.0f;
  46 }
  47
  48 void AudioStreamIndicator::CurrentAudibleLevel(
  49     const content::WebContents* contents, float* level, bool* clipped) {
  50   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  51
  52   float max_power_dbfs = -std::numeric_limits<float>::infinity();
  53   bool has_clipped = false;
  54
  55   // Since a RenderView can have more than one stream playing back, return the
  56   // maximum of the last-reported power levels.  For more information about how
  57   // the power level is measured, see media/audio/audio_power_monitor.h.
  58   const RenderViewId id(contents->GetRenderProcessHost()->GetID(),
  59                         contents->GetRenderViewHost()->GetRoutingID());
  60   RenderViewStreamMap::const_iterator view_it = audio_streams_.find(id);
  61   if (view_it != audio_streams_.end()) {
  62     const StreamPowerLevels& stream_levels = view_it->second;
  63     for (StreamPowerLevels::const_iterator stream_it = stream_levels.begin();
  64          stream_it != stream_levels.end(); ++stream_it) {
  65       if (stream_it->power_dbfs > max_power_dbfs)
  66         max_power_dbfs = stream_it->power_dbfs;
  67       has_clipped |= stream_it->clipped;
  68     }
  69   }
  70
  71   // Map the power into an "audible level" in the range [0.0,1.0].  dBFS values
  72   // are in the range -inf (minimum power) to 0.0 (maximum power).
  73   static const float kSilenceThresholdDBFS = -72.24719896f;
  74   if (max_power_dbfs < kSilenceThresholdDBFS)
  75     *level = 0.0f;
  76   else if (max_power_dbfs > 0.0f)
  77     *level = 1.0f;
  78   else
  79     *level = 1.0f - max_power_dbfs / kSilenceThresholdDBFS;
  80   *clipped = has_clipped;
  81 }
  82
  83 void AudioStreamIndicator::UpdateWebContentsStatusOnUIThread(
  84     int render_process_id, int render_view_id, int stream_id,
  85     bool is_playing, float power_dbfs, bool clipped) {
  86   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  87
  88   const RenderViewId id(render_process_id, render_view_id);
  89   if (is_playing) {
  90     // Find the StreamPowerLevel instance associated with |stream_id|, or
  91     // auto-create a new one.
  92     StreamPowerLevels& stream_levels = audio_streams_[id];
  93     StreamPowerLevels::iterator stream_it;
  94     for (stream_it = stream_levels.begin(); stream_it != stream_levels.end();
  95          ++stream_it) {
  96       if (stream_it->stream_id == stream_id)
  97         break;
  98     }
  99     if (stream_it == stream_levels.end()) {
 100       stream_it = stream_levels.insert(stream_levels.end(), StreamPowerLevel());
 101       stream_it->stream_id = stream_id;
 102     }
 103
 104     // Update power and clip values.
 105     stream_it->power_dbfs = power_dbfs;
 106     stream_it->clipped = clipped;
 107   } else {
 108     // Find and erase the StreamPowerLevel instance associated with |stream_id|.
 109     RenderViewStreamMap::iterator view_it = audio_streams_.find(id);
 110     if (view_it != audio_streams_.end()) {
 111       StreamPowerLevels& stream_levels = view_it->second;
 112       for (StreamPowerLevels::iterator stream_it = stream_levels.begin();
 113            stream_it != stream_levels.end(); ++stream_it) {
 114         if (stream_it->stream_id == stream_id) {
 115           stream_levels.erase(stream_it);
 116           if (stream_levels.empty())
 117             audio_streams_.erase(view_it);
 118           break;
 119         }
 120       }
 121     }
 122   }
 123
 124   // Trigger UI update.
 125   WebContents* web_contents = tab_util::GetWebContentsByID(render_process_id,
 126                                                            render_view_id);
 127   if (web_contents)
 128     web_contents->NotifyNavigationStateChanged(content::INVALIDATE_TYPE_TAB);
 129 }