1 files changed, 37 insertions, 1 deletions
diff --git a/chromium/third_party/blink/renderer/platform/audio/audio_destination.cc b/chromium/third_party/blink/renderer/platform/audio/audio_destination.cc
index 24e122b12ac..1c98e7ca63f 100644
--- a/chromium/third_party/blink/renderer/platform/audio/audio_destination.cc
+++ b/chromium/third_party/blink/renderer/platform/audio/audio_destination.cc
@@ -36,6 +36,7 @@
 #include "third_party/blink/public/platform/web_audio_latency_hint.h"
 #include "third_party/blink/renderer/platform/audio/audio_utilities.h"
 #include "third_party/blink/renderer/platform/audio/push_pull_fifo.h"
+#include "third_party/blink/renderer/platform/audio/vector_math.h"
 #include "third_party/blink/renderer/platform/cross_thread_functional.h"
 #include "third_party/blink/renderer/platform/histogram.h"
 #include "third_party/blink/renderer/platform/instrumentation/tracing/trace_event.h"
@@ -149,6 +150,23 @@ void AudioDestination::Render(const WebVector<float*>& destination_data,
                    delay_timestamp, "delay (s)", delay);
 }
 
+// Determine if the rendered data is audible.
+static bool IsAudible(const AudioBus* rendered_data) {
+  // Compute the energy in each channel and sum up the energy in each channel
+  // for the total energy.
+  float energy = 0;
+
+  unsigned data_size = rendered_data->length();
+  for (unsigned k = 0; k < rendered_data->NumberOfChannels(); ++k) {
+    const float* data = rendered_data->Channel(k)->Data();
+    float channel_energy;
+    VectorMath::Vsvesq(data, 1, &channel_energy, data_size);
+    energy += channel_energy;
+  }
+
+  return energy > 0;
+}
+
 void AudioDestination::RequestRender(size_t frames_requested,
                                      size_t frames_to_render,
                                      double delay,
@@ -183,8 +201,26 @@ void AudioDestination::RequestRender(size_t frames_requested,
       output_position.position = 0.0;
 
     // Process WebAudio graph and push the rendered output to FIFO.
-    callback_.Render(nullptr, render_bus_.get(),
+    callback_.Render(render_bus_.get(),
                      AudioUtilities::kRenderQuantumFrames, output_position);
+
+    // Detect silence (or not) for MEI
+    bool is_audible = IsAudible(render_bus_.get());
+
+    if (is_audible) {
+      ++total_audible_renders_;
+    }
+
+    if (was_audible_) {
+      if (!is_audible) {
+        was_audible_ = false;
+      }
+    } else {
+      if (is_audible) {
+        was_audible_ = true;
+      }
+    }
+
     fifo_->Push(render_bus_.get());
   }