diff --git a/services/audioflinger/AudioStreamOut.h b/services/audioflinger/AudioStreamOut.h
new file mode 100644
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+++ b/services/audioflinger/AudioStreamOut.h
@@ -0,0 +1,83 @@
+/*
+**
+** Copyright 2015, The Android Open Source Project
+**
+** Licensed under the Apache License, Version 2.0 (the "License");
+** you may not use this file except in compliance with the License.
+** You may obtain a copy of the License at
+**
+**     http://www.apache.org/licenses/LICENSE-2.0
+**
+** Unless required by applicable law or agreed to in writing, software
+** distributed under the License is distributed on an "AS IS" BASIS,
+** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+** See the License for the specific language governing permissions and
+** limitations under the License.
+*/
+
+#ifndef ANDROID_AUDIO_STREAM_OUT_H
+#define ANDROID_AUDIO_STREAM_OUT_H
+
+#include <stdint.h>
+#include <sys/types.h>
+
+#include <system/audio.h>
+
+#include "AudioStreamOut.h"
+
+namespace android {
+
+class AudioHwDevice;
+
+/**
+ * Managed access to a HAL output stream.
+ */
+class AudioStreamOut {
+public:
+// AudioStreamOut is immutable, so its fields are const.
+// For emphasis, we could also make all pointers to them be "const *",
+// but that would clutter the code unnecessarily.
+    AudioHwDevice * const audioHwDev;
+    audio_stream_out_t *stream;
+    const audio_output_flags_t flags;
+
+    audio_hw_device_t *hwDev() const;
+
+    AudioStreamOut(AudioHwDevice *dev, audio_output_flags_t flags);
+
+    virtual status_t open(
+            audio_io_handle_t handle,
+            audio_devices_t devices,
+            struct audio_config *config,
+            const char *address);
+
+    virtual ~AudioStreamOut() { }
+
+    virtual status_t getRenderPosition(uint32_t *frames);
+
+    virtual status_t getPresentationPosition(uint64_t *frames, struct timespec *timestamp);
+
+    /**
+    * Write audio buffer to driver. Returns number of bytes written, or a
+    * negative status_t. If at least one frame was written successfully prior to the error,
+    * it is suggested that the driver return that successful (short) byte count
+    * and then return an error in the subsequent call.
+    *
+    * If set_callback() has previously been called to enable non-blocking mode
+    * the write() is not allowed to block. It must write only the number of
+    * bytes that currently fit in the driver/hardware buffer and then return
+    * this byte count. If this is less than the requested write size the
+    * callback function must be called when more space is available in the
+    * driver/hardware buffer.
+    */
+    virtual ssize_t write(const void *buffer, size_t bytes);
+
+    virtual size_t getFrameSize();
+
+    virtual status_t flush();
+    virtual status_t standby();
+};
+
+} // namespace android
+
+#endif // ANDROID_AUDIO_STREAM_OUT_H