Create iOS Audio Manager implementation.

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.
+
+#import <AudioToolbox/AudioToolbox.h>
+
+#include "base/sys_info.h"
+#include "media/audio/fake_audio_input_stream.h"
+#include "media/audio/mac/audio_input_mac.h"
+#include "media/audio/ios/audio_manager_ios.h"

[DaleCurtis, 2012/09/07 11:31:12]

Should be first header; above everything.

[blundell, 2012/09/07 12:35:39]

Done.

+#include "media/base/limits.h"
+
+namespace media {
+
+static const int kMaxInputChannels = 2;

[stuartmorgan, 2012/09/07 11:09:26]

remove static, and put in an anonymous namespace.

[DaleCurtis, 2012/09/07 11:31:12]

Better, just make it an enum { kMaxInputChannels = 2 }

[blundell, 2012/09/07 12:35:39]

Done.

[blundell, 2012/09/07 12:35:39]

Done.

+
+bool AudioManagerIOS::isAudioSessionInitialized_ = false;
+
+AudioManagerIOS::AudioManagerIOS() {
+}
+
+AudioManagerIOS::~AudioManagerIOS() {
+  Shutdown();
+}
+
+bool AudioManagerIOS::HasAudioOutputDevices() {
+  return false;
+}
+
+bool AudioManagerIOS::HasAudioInputDevices() {
+  if (InitAudioSession()) {
+    UInt32 audioInputIsAvailable = false;

[stuartmorgan, 2012/09/07 11:09:26]

All the local variables need style fixing too.

Also, this looks suspiciously like a bool, not a UInt32.

[blundell, 2012/09/07 12:35:39]

Done. This property is actually a 32-bit integer that is interpreted as a
boolean; changing audio_input_is_available to be a boolean causes the result to
not be set correctly. Added some explanation and error-checking code.

+    UInt32 propertySize = sizeof(audioInputIsAvailable);
+    OSStatus error =
+        AudioSessionGetProperty(kAudioSessionProperty_AudioInputAvailable,
+                                &propertySize,
+                                &audioInputIsAvailable);
+    return error == kAudioSessionNoError ? audioInputIsAvailable : false;
+  } else {
+    return false;

[stuartmorgan, 2012/09/07 11:09:26]

Change to:

if (!InitAudioSession())
  return false;
<everything else>

[blundell, 2012/09/07 12:35:39]

Done.

+  }
+}
+
+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).
+  if (!params.IsValid() || (params.channels() > kMaxInputChannels))
+    return NULL;
+
+  if (params.format() == AudioParameters::AUDIO_MOCK) {
+    return FakeAudioInputStream::MakeFakeStream(this, params);
+  } else if (params.format() == AudioParameters::AUDIO_PCM_LINEAR) {
+    return new PCMQueueInAudioInputStream(this, params);
+  }

[stuartmorgan, 2012/09/07 11:09:26]

Remove the {} for both

[blundell, 2012/09/07 12:35:39]

Done.

+  return NULL;
+}
+
+AudioOutputStream* AudioManagerIOS::MakeLinearOutputStream(
+      const AudioParameters& params) {
+  NOTIMPLEMENTED();  // Only input is supported on iOS.
+  return NULL;
+}
+
+AudioOutputStream* AudioManagerIOS::MakeLowLatencyOutputStream(
+      const AudioParameters& params) {
+  NOTIMPLEMENTED();  // Only input is supported on iOS.
+  return NULL;
+}
+
+AudioInputStream* AudioManagerIOS::MakeLinearInputStream(
+      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);
+}
+
+// Called by the stream when it has been released by calling Close().
+void AudioManagerIOS::ReleaseOutputStream(AudioOutputStream* stream) {

[DaleCurtis, 2012/09/07 11:31:12]

Should this have a NOTREACHED() ?

+}
+
+// Called by the stream when it has been released by calling Close().
+void AudioManagerIOS::ReleaseInputStream(AudioInputStream* stream) {
+  delete stream;
+}
+
+bool AudioManagerIOS::InitAudioSession() {
+  if (!isAudioSessionInitialized_) {

[DaleCurtis, 2012/09/07 11:31:12]

Do you expect to retry this call if it fails? Otherwise, just make this a
"static const bool" inside the function so you avoid any races; e.g.,

static bool InitializeAudioSessionInternal() {
...
}

bool AudioManagerIOS::InitAudioSession() {
  static const bool kSessionInitialized = InitializeAudioSessionInternal();
  return kSessionInitialized;
}

This is safe because function level static initialization is guaranteed atomic.

[blundell, 2012/09/07 12:35:39]

Much cleaner, thanks. Done.

On 2012/09/07 11:31:12, DaleCurtis wrote:

+    OSStatus error = AudioSessionInitialize(NULL, NULL, NULL, NULL);
+    isAudioSessionInitialized_ = error == kAudioSessionNoError ||
+        error == kAudioSessionAlreadyInitialized;
+  }
+  return isAudioSessionInitialized_;
+}
+
+// static
+AudioManager* CreateAudioManager() {
+  return new AudioManagerIOS();
+}
+
+}  // namespace media