Upstream: Media implementation for Android.

media/audio/android/audio_track_output_android.h

+// Copyright (c) 2011 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_AUDIO_TRACK_OUTPUT_ANDROID_H_
+#define MEDIA_AUDIO_AUDIO_TRACK_OUTPUT_ANDROID_H_
+
+#include <jni.h>
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/timer.h"
+#include "media/audio/audio_io.h"
+#include "media/audio/audio_parameters.h"
+
+class AudioManagerAndroid;
+
+// Implements PCM audio output support for Android using the AudioTrack API.
+class AudioTrackOutputStream : public AudioOutputStream {
+ public:
+  enum Status {
+    IDLE,
+    OPENED,
+    PLAYING,
+    INVALID
+  };
+
+  class StreamBuffer {
+   public:
+    explicit StreamBuffer(uint32 buffer_size);
+
+    uint32 ReadStream(uint8* dest, uint32 max_size);
+    void ResetBuffer(uint32 data_size);
+    uint8* GetWritableBuffer();
+    const uint8* ReadBuffer();
+    void AdvancePosition(uint32 advance);
+
+    uint32 buffer_size() { return buffer_size_; }
+    uint32 data_len() { return data_size_ - current_; }
+
+   private:
+    scoped_array<uint8> buffer_;
+    uint32 buffer_size_;
+    uint32 data_size_;
+    uint32 current_;
+  };
+
+  AudioTrackOutputStream(AudioManagerAndroid* manager,
+                         const AudioParameters& params);
+
+  virtual ~AudioTrackOutputStream();
+
+  // 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;
+
+  static AudioOutputStream* MakeStream(AudioManagerAndroid* manager,
+                                       const AudioParameters& params);
+
+ private:
+  // Helper methods to invoke Java methods on |j_audio_track_|.
+  void CallVoidMethod(std::string method_name);
+
+  // Get the value of static field.
+  jint GetStaticIntField(std::string class_name, std::string field_name);
+
+  // Feed more data to AudioTrack.
+  void FillAudioBufferTask();
+
+  AudioSourceCallback* source_callback_;
+  AudioManagerAndroid* manager_;
+  AudioParameters params_;
+  scoped_ptr<StreamBuffer> data_buffer_;
+  Status status_;
+  double volume_;
+  int buffer_size_;
+
+  // Java AudioTrack class and instance.
+  jclass j_class_;
+  jobject j_audio_track_;
+
+  base::RepeatingTimer<AudioTrackOutputStream> timer_;
+
+  DISALLOW_COPY_AND_ASSIGN(AudioTrackOutputStream);
+};
+
+#endif  // MEDIA_AUDIO_AUDIO_TRACK_OUTPUT_ANDROID_H_