Modifies AudioInputCallback::OnData and use media::AudioBus instead of plain byte vector

media/audio/audio_input_device.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/audio/audio_input_device.h"
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/time/time.h"
@@ skipping 279 matching lines @@
   uint8* ptr = static_cast<uint8*>(shared_memory_.memory());
   ptr += current_segment_id_ * segment_length_;
   AudioInputBuffer* buffer = reinterpret_cast<AudioInputBuffer*>(ptr);
   // Usually this will be equal but in the case of low sample rate (e.g. 8kHz,
   // the buffer may be bigger (on mac at least)).
   DCHECK_GE(buffer->params.size,
             segment_length_ - sizeof(AudioInputBufferParameters));
   double volume = buffer->params.volume;
   bool key_pressed = buffer->params.key_pressed;
 
+  // Create audio bus wrapping existing block of shared memory.

[henrika (OOO until Aug 14), 2014/06/04 11:58:50]

...and here.

+  scoped_ptr<AudioBus> audio_bus =
+      AudioBus::WrapMemory(audio_parameters_, &buffer->audio[0]);
+
+  // Deliver captured data to the client in floating point format
+  // and update the audio-delay measurement.
   int audio_delay_milliseconds = pending_data / bytes_per_ms_;
-  int16* memory = reinterpret_cast<int16*>(&buffer->audio[0]);
-  const int bytes_per_sample = sizeof(memory[0]);
+  capture_callback_->Capture(
+      audio_bus.get(), audio_delay_milliseconds, volume, key_pressed);
 
   if (++current_segment_id_ >= total_segments_)
     current_segment_id_ = 0;
-
-  // Deinterleave each channel and convert to 32-bit floating-point
-  // with nominal range -1.0 -> +1.0.
-  audio_bus_->FromInterleaved(memory, audio_bus_->frames(), bytes_per_sample);
-
-  // Deliver captured data to the client in floating point format
-  // and update the audio-delay measurement.
-  capture_callback_->Capture(
-      audio_bus_.get(), audio_delay_milliseconds, volume, key_pressed);
 }
 
 }  // namespace media