Moved AudioUtil static functions to AudioManager interfaces

media/audio/ios/audio_manager_ios.mm

 // Copyright 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/ios/audio_manager_ios.h"
 
 #import <AudioToolbox/AudioToolbox.h>
 #import <AVFoundation/AVFoundation.h>
 
 #include "base/sys_info.h"
+#include "media/audio/audio_parameters.h"
 #include "media/audio/fake_audio_input_stream.h"
 #include "media/audio/ios/audio_session_util_ios.h"
 #include "media/audio/mac/audio_input_mac.h"
+#include "media/base/channel_layout.h"
 #include "media/base/limits.h"
 
 namespace media {
 
 enum { kMaxInputChannels = 2 };
 
 AudioManagerIOS::AudioManagerIOS() {
 }
 
 AudioManagerIOS::~AudioManagerIOS() {
@@ skipping 16 matching lines @@
   if (error != kAudioSessionNoError)
     return false;
   UInt32 audio_input_is_available = false;
   DCHECK(property_size == sizeof(audio_input_is_available));
   error = AudioSessionGetProperty(kAudioSessionProperty_AudioInputAvailable,
                                   &property_size,
                                   &audio_input_is_available);
   return error == kAudioSessionNoError ? audio_input_is_available : false;
 }
 
+AudioParameters AudioManagerIOS::GetInputStreamParameters(
+    const std::string& device_id) {
+  // TODO(xians): figure out the right input sample rate and buffer size to
+  // achieve the best audio performance for iOS devices.
+  // TODO(xians): query the native channel layout for the specific device.
+  static const int kDefaultSampleRate = 48000;
+  static const int kDefaultBufferSize = 2048;
+  return AudioParameters(
+      AudioParameters::AUDIO_PCM_LOW_LATENCY, CHANNEL_LAYOUT_STEREO,
+      kDefaultSampleRate, 16, kDefaultBufferSize);
+}
+
 AudioOutputStream* AudioManagerIOS::MakeAudioOutputStream(
     const AudioParameters& params) {
   NOTIMPLEMENTED();  // Only input is supported on iOS.
   return NULL;
 }
 
 AudioInputStream* AudioManagerIOS::MakeAudioInputStream(
     const AudioParameters& params, const std::string& device_id) {
   // Current line of iOS devices has only one audio input.
   // Ignore the device_id (unittest uses a test value in it).
@@ skipping 23 matching lines @@
       const AudioParameters& params, const std::string& device_id) {
   return MakeAudioInputStream(params, device_id);
 }
 
 AudioInputStream* AudioManagerIOS::MakeLowLatencyInputStream(
       const AudioParameters& params, const std::string& device_id) {
   NOTIMPLEMENTED();  // Only linear audio input is supported on iOS.
   return MakeAudioInputStream(params, device_id);
 }
 
+
+AudioParameters AudioManagerIOS::GetPreferredOutputStreamParameters(
+    const AudioParameters& input_params) {
+  // TODO(xians): handle the case when input_params is valid.
+  // TODO(xians): figure out the right output sample rate and sample rate to
+  // achieve the best audio performance for iOS devices.
+  static const int kDefaultSampleRate = 48000;
+  static const int kDefaultBufferSize = 2048;
+  if (input_params.IsValid()) {
+    NOTREACHED();
+  }
+  return AudioParameters(
+      AudioParameters::AUDIO_PCM_LOW_LATENCY, CHANNEL_LAYOUT_STEREO,
+      kDefaultSampleRate, 16, kDefaultBufferSize);
+}
+
 // Called by the stream when it has been released by calling Close().
 void AudioManagerIOS::ReleaseOutputStream(AudioOutputStream* stream) {
   NOTIMPLEMENTED();  // Only input is supported on iOS.
 }
 
 // Called by the stream when it has been released by calling Close().
 void AudioManagerIOS::ReleaseInputStream(AudioInputStream* stream) {
   delete stream;
 }
 
 // static
 AudioManager* CreateAudioManager() {
   return new AudioManagerIOS();
 }
 
 }  // namespace media