Adding input and output audio backend to Android.

media/audio/audio_util.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.
 
 // Software adjust volume of samples, allows each audio stream its own
 // volume without impacting master volume for chrome and other applications.
 
 // Implemented as templates to allow 8, 16 and 32 bit implementations.
 // 8 bit is unsigned and biased by 128.
 
@@ skipping 287 matching lines @@
           volume);
       break;
     default:
       NOTREACHED() << "Illegal bytes per sample";
       break;
   }
 }
 
 int GetAudioHardwareSampleRate() {
 #if defined(OS_MACOSX)
-    // Hardware sample-rate on the Mac can be configured, so we must query.
-    return AUAudioOutputStream::HardwareSampleRate();
+  // Hardware sample-rate on the Mac can be configured, so we must query.
+  return AUAudioOutputStream::HardwareSampleRate();
 #elif defined(OS_WIN)
   if (!IsWASAPISupported()) {
     // Fall back to Windows Wave implementation on Windows XP or lower
     // and use 48kHz as default input sample rate.
     return 48000;
   }
 
   // Hardware sample-rate on Windows can be configured, so we must query.
   // TODO(henrika): improve possibility to specify audio endpoint.
   // Use the default device (same as for Wave) for now to be compatible.
   return WASAPIAudioOutputStream::HardwareSampleRate(eConsole);
+#elif defined(OS_ANDROID)
+  return 16000;
 #else
     // Hardware for Linux is nearly always 48KHz.
     // TODO(crogers) : return correct value in rare non-48KHz cases.
     return 48000;
 #endif
 }
 
 int GetAudioInputHardwareSampleRate(const std::string& device_id) {
   // TODO(henrika): add support for device selection on all platforms.
   // Only exists on Windows today.
 #if defined(OS_MACOSX)
   return AUAudioInputStream::HardwareSampleRate();
 #elif defined(OS_WIN)
   if (!IsWASAPISupported()) {
     return 48000;
   }
   return WASAPIAudioInputStream::HardwareSampleRate(device_id);
+#elif defined(OS_ANDROID)
+  return 16000;
 #else
   return 48000;
 #endif
 }
 
 size_t GetAudioHardwareBufferSize() {
   // The sizes here were determined by experimentation and are roughly
   // the lowest value (for low latency) that still allowed glitch-free
   // audio under high loads.
   //
@@ skipping 95 matching lines @@
 
 bool IsWASAPISupported() {
   // Note: that function correctly returns that Windows Server 2003 does not
   // support WASAPI.
   return base::win::GetVersion() >= base::win::VERSION_VISTA;
 }
 
 #endif
 
 }  // namespace media