Adding input and output audio backend to Android.

media/audio/android/opensles_output.h

+// 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.
+
+#ifndef MEDIA_AUDIO_ANDROID_OPENSLES_OUTPUT_H_
+#define MEDIA_AUDIO_ANDROID_OPENSLES_OUTPUT_H_
+
+#include <vector>
+
+#include "base/compiler_specific.h"
+#include "media/audio/android/opensles_util.h"
+#include "media/audio/audio_io.h"
+#include "media/audio/audio_parameters.h"
+#include <SLES/OpenSLES_Android.h>
+
+class AudioManagerAndroid;
+
+// Implements PCM audio output support for Android using the OpenSLES API.
+class OpenSLESOutputStream : public AudioOutputStream {
+ public:
+  static const int kNumOfQueuesInBuffer = 2;
+
+  OpenSLESOutputStream(AudioManagerAndroid* manager,
+                       const AudioParameters& params);
+
+  virtual ~OpenSLESOutputStream();
+
+  // Implementation of AudioOutputStream.
+  virtual bool Open() OVERRIDE;
+  virtual void Close() OVERRIDE;
+  virtual void Start(AudioSourceCallback* callback) OVERRIDE;
+  virtual void Stop() OVERRIDE;
+  virtual void SetVolume(double volume) OVERRIDE;
+  virtual void GetVolume(double* volume) OVERRIDE;
+
+ private:
+  bool CreatePlayer();
+
+  static void SimpleBufferQueueCallback(
+      SLAndroidSimpleBufferQueueItf buffer_queue, void* instance);
+
+  void FillBufferQueue();
+
+  // If OpenSLES reports an error this function handles it and passes it to
+  // the attached AudioOutputCallback::OnError().
+  void HandleError(SLresult error);
+
+  AudioManagerAndroid* audio_manager_;
+
+  AudioSourceCallback* callback_;
+
+  // Shared engine interfaces for the app.
+  media::ScopedSLObjectItf engine_object_;
+  media::ScopedSLObjectItf player_object_;
+  media::ScopedSLObjectItf output_mixer_;
+
+  SLPlayItf player_;
+
+  // Buffer queue recorder interface.
+  SLAndroidSimpleBufferQueueItf simple_buffer_queue_;
+
+  SLDataFormat_PCM format_;
+
+  // Audio buffer arrays that are allocated in the constructor.
+  uint8* audio_data_[kNumOfQueuesInBuffer];
+
+  int active_queue_;
+  size_t buffer_size_bytes_;
+
+  bool started_;
+
+  // Volume level from 0 to 1.
+  float volume_;
+
+  DISALLOW_COPY_AND_ASSIGN(OpenSLESOutputStream);
+};
+
+#endif  // MEDIA_AUDIO_ANDROID_OPENSLES_INPUT_H_