diff --git a/include/media/AudioTrack.h b/include/media/AudioTrack.h
new file mode 100644
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--- /dev/null
+++ b/include/media/AudioTrack.h
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+/*
+ * Copyright (C) 2007 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_AUDIOTRACK_H
+#define ANDROID_AUDIOTRACK_H
+
+#include <stdint.h>
+#include <sys/types.h>
+
+#include <media/IAudioFlinger.h>
+#include <media/IAudioTrack.h>
+#include <media/AudioSystem.h>
+
+#include <utils/RefBase.h>
+#include <utils/Errors.h>
+#include <utils/IInterface.h>
+#include <utils/IMemory.h>
+#include <utils/threads.h>
+
+
+namespace android {
+
+// ----------------------------------------------------------------------------
+
+class audio_track_cblk_t;
+
+// ----------------------------------------------------------------------------
+
+class AudioTrack
+{
+public:
+    enum channel_index {
+        MONO   = 0,
+        LEFT   = 0,
+        RIGHT  = 1
+    };
+
+    /* Events used by AudioTrack callback function (audio_track_cblk_t).
+     */
+    enum event_type {
+        EVENT_MORE_DATA = 0,        // Request to write more data to PCM buffer.
+        EVENT_UNDERRUN = 1,         // PCM buffer underrun occured.
+        EVENT_LOOP_END = 2,         // Sample loop end was reached; playback restarted from loop start if loop count was not 0.
+        EVENT_MARKER = 3,           // Playback head is at the specified marker position (See setMarkerPosition()).
+        EVENT_NEW_POS = 4,          // Playback head is at a new position (See setPositionUpdatePeriod()).
+        EVENT_BUFFER_END = 5        // Playback head is at the end of the buffer.
+    };
+
+    /* Create Buffer on the stack and pass it to obtainBuffer()
+     * and releaseBuffer().
+     */
+
+    class Buffer
+    {
+    public:
+        enum {
+            MUTE    = 0x00000001
+        };
+        uint32_t    flags;
+        int         channelCount;
+        int         format;
+        size_t      frameCount;
+        size_t      size;
+        union {
+            void*       raw;
+            short*      i16;
+            int8_t*     i8;
+        };
+    };
+
+
+    /* As a convenience, if a callback is supplied, a handler thread
+     * is automatically created with the appropriate priority. This thread
+     * invokes the callback when a new buffer becomes availlable or an underrun condition occurs.
+     * Parameters:
+     *
+     * event:   type of event notified (see enum AudioTrack::event_type).
+     * user:    Pointer to context for use by the callback receiver.
+     * info:    Pointer to optional parameter according to event type:
+     *          - EVENT_MORE_DATA: pointer to AudioTrack::Buffer struct. The callback must not write
+     *          more bytes than indicated by 'size' field and update 'size' if less bytes are
+     *          written.
+     *          - EVENT_UNDERRUN: unused.
+     *          - EVENT_LOOP_END: pointer to an int indicating the number of loops remaining.
+     *          - EVENT_MARKER: pointer to an uin32_t containing the marker position in frames.
+     *          - EVENT_NEW_POS: pointer to an uin32_t containing the new position in frames.
+     *          - EVENT_BUFFER_END: unused.
+     */
+
+    typedef void (*callback_t)(int event, void* user, void *info);
+
+    /* Constructs an uninitialized AudioTrack. No connection with
+     * AudioFlinger takes place.
+     */
+                        AudioTrack();
+
+    /* Creates an audio track and registers it with AudioFlinger.
+     * Once created, the track needs to be started before it can be used.
+     * Unspecified values are set to the audio hardware's current
+     * values.
+     *
+     * Parameters:
+     *
+     * streamType:         Select the type of audio stream this track is attached to
+     *                     (e.g. AudioSystem::MUSIC).
+     * sampleRate:         Track sampling rate in Hz.
+     * format:             PCM sample format (e.g AudioSystem::PCM_16_BIT for signed
+     *                     16 bits per sample).
+     * channelCount:       Number of PCM channels (e.g 2 for stereo).
+     * frameCount:         Total size of track PCM buffer in frames. This defines the
+     *                     latency of the track.
+     * flags:              Reserved for future use.
+     * cbf:                Callback function. If not null, this function is called periodically
+     *                     to request new PCM data.
+     * notificationFrames: The callback function is called each time notificationFrames PCM
+     *                     frames have been comsumed from track input buffer.
+     * user                Context for use by the callback receiver.
+     */
+
+                        AudioTrack( int streamType,
+                                    uint32_t sampleRate  = 0,
+                                    int format           = 0,
+                                    int channelCount     = 0,
+                                    int frameCount       = 0,
+                                    uint32_t flags       = 0,
+                                    callback_t cbf       = 0,
+                                    void* user           = 0,
+                                    int notificationFrames = 0);
+
+    /* Creates an audio track and registers it with AudioFlinger. With this constructor,
+     * The PCM data to be rendered by AudioTrack is passed in a shared memory buffer
+     * identified by the argument sharedBuffer. This prototype is for static buffer playback.
+     * PCM data must be present into memory before the AudioTrack is started.
+     * The Write() and Flush() methods are not supported in this case.
+     * It is recommented to pass a callback function to be notified of playback end by an
+     * EVENT_UNDERRUN event.
+     */
+
+                        AudioTrack( int streamType,
+                                    uint32_t sampleRate = 0,
+                                    int format          = 0,
+                                    int channelCount    = 0,
+                                    const sp<IMemory>& sharedBuffer = 0,
+                                    uint32_t flags      = 0,
+                                    callback_t cbf      = 0,
+                                    void* user          = 0,
+                                    int notificationFrames = 0);
+
+    /* Terminates the AudioTrack and unregisters it from AudioFlinger.
+     * Also destroys all resources assotiated with the AudioTrack.
+     */
+                        ~AudioTrack();
+
+
+    /* Initialize an uninitialized AudioTrack.
+     * Returned status (from utils/Errors.h) can be:
+     *  - NO_ERROR: successful intialization
+     *  - INVALID_OPERATION: AudioTrack is already intitialized
+     *  - BAD_VALUE: invalid parameter (channelCount, format, sampleRate...)
+     *  - NO_INIT: audio server or audio hardware not initialized
+     * */
+            status_t    set(int streamType      =-1,
+                            uint32_t sampleRate = 0,
+                            int format          = 0,
+                            int channelCount    = 0,
+                            int frameCount      = 0,
+                            uint32_t flags      = 0,
+                            callback_t cbf      = 0,
+                            void* user          = 0,
+                            int notificationFrames = 0,
+                            const sp<IMemory>& sharedBuffer = 0,
+                            bool threadCanCallJava = false);
+
+
+    /* Result of constructing the AudioTrack. This must be checked
+     * before using any AudioTrack API (except for set()), using
+     * an uninitialized AudioTrack produces undefined results.
+     * See set() method above for possible return codes.
+     */
+            status_t    initCheck() const;
+
+    /* Returns this track's latency in milliseconds.
+     * This includes the latency due to AudioTrack buffer size, AudioMixer (if any)
+     * and audio hardware driver.
+     */
+            uint32_t     latency() const;
+
+    /* getters, see constructor */
+
+            int         streamType() const;
+            uint32_t    sampleRate() const;
+            int         format() const;
+            int         channelCount() const;
+            uint32_t    frameCount() const;
+            int         frameSize() const;
+            sp<IMemory>& sharedBuffer();
+
+
+    /* After it's created the track is not active. Call start() to
+     * make it active. If set, the callback will start being called.
+     */
+            void        start();
+
+    /* Stop a track. If set, the callback will cease being called and
+     * obtainBuffer returns STOPPED. Note that obtainBuffer() still works
+     * and will fill up buffers until the pool is exhausted.
+     */
+            void        stop();
+            bool        stopped() const;
+
+    /* flush a stopped track. All pending buffers are discarded.
+     * This function has no effect if the track is not stoped.
+     */
+            void        flush();
+
+    /* Pause a track. If set, the callback will cease being called and
+     * obtainBuffer returns STOPPED. Note that obtainBuffer() still works
+     * and will fill up buffers until the pool is exhausted.
+     */
+            void        pause();
+
+    /* mute or unmutes this track.
+     * While mutted, the callback, if set, is still called.
+     */
+            void        mute(bool);
+            bool        muted() const;
+
+
+    /* set volume for this track, mostly used for games' sound effects
+     */
+            void        setVolume(float left, float right);
+            void        getVolume(float* left, float* right);
+
+    /* set sample rate for this track, mostly used for games' sound effects
+     */
+            void        setSampleRate(int sampleRate);
+            uint32_t    getSampleRate();
+
+    /* Enables looping and sets the start and end points of looping.
+     *
+     * Parameters:
+     *
+     * loopStart:   loop start expressed as the number of PCM frames played since AudioTrack start.
+     * loopEnd:     loop end expressed as the number of PCM frames played since AudioTrack start.
+     * loopCount:   number of loops to execute. Calling setLoop() with loopCount == 0 cancels any pending or
+     *          active loop. loopCount = -1 means infinite looping.
+     *
+     * For proper operation the following condition must be respected:
+     *          (loopEnd-loopStart) <= framecount()
+     */
+            status_t    setLoop(uint32_t loopStart, uint32_t loopEnd, int loopCount);
+            status_t    getLoop(uint32_t *loopStart, uint32_t *loopEnd, int *loopCount);
+
+
+    /* Sets marker position. When playback reaches the number of frames specified, a callback with event 
+     * type EVENT_MARKER is called. Calling setMarkerPosition with marker == 0 cancels marker notification 
+     * callback. 
+     * If the AudioTrack has been opened with no callback function associated, the operation will fail.
+     *
+     * Parameters:
+     *
+     * marker:   marker position expressed in frames.
+     *
+     * Returned status (from utils/Errors.h) can be:
+     *  - NO_ERROR: successful operation
+     *  - INVALID_OPERATION: the AudioTrack has no callback installed.
+     */
+            status_t    setMarkerPosition(uint32_t marker);
+            status_t    getMarkerPosition(uint32_t *marker);
+
+
+    /* Sets position update period. Every time the number of frames specified has been played, 
+     * a callback with event type EVENT_NEW_POS is called. 
+     * Calling setPositionUpdatePeriod with updatePeriod == 0 cancels new position notification 
+     * callback. 
+     * If the AudioTrack has been opened with no callback function associated, the operation will fail.
+     *
+     * Parameters:
+     *
+     * updatePeriod:  position update notification period expressed in frames.
+     *
+     * Returned status (from utils/Errors.h) can be:
+     *  - NO_ERROR: successful operation
+     *  - INVALID_OPERATION: the AudioTrack has no callback installed.
+     */
+            status_t    setPositionUpdatePeriod(uint32_t updatePeriod);
+            status_t    getPositionUpdatePeriod(uint32_t *updatePeriod);
+
+
+    /* Sets playback head position within AudioTrack buffer. The new position is specified
+     * in number of frames. 
+     * This method must be called with the AudioTrack in paused or stopped state.
+     * Note that the actual position set is <position> modulo the AudioTrack buffer size in frames. 
+     * Therefore using this method makes sense only when playing a "static" audio buffer 
+     * as opposed to streaming.
+     * The getPosition() method on the other hand returns the total number of frames played since
+     * playback start.
+     *
+     * Parameters:
+     *
+     * position:  New playback head position within AudioTrack buffer.
+     *
+     * Returned status (from utils/Errors.h) can be:
+     *  - NO_ERROR: successful operation
+     *  - INVALID_OPERATION: the AudioTrack is not stopped.
+     *  - BAD_VALUE: The specified position is beyond the number of frames present in AudioTrack buffer 
+     */
+            status_t    setPosition(uint32_t position);
+            status_t    getPosition(uint32_t *position);
+
+    /* Forces AudioTrack buffer full condition. When playing a static buffer, this method avoids 
+     * rewriting the buffer before restarting playback after a stop.
+     * This method must be called with the AudioTrack in paused or stopped state.
+     *
+     * Returned status (from utils/Errors.h) can be:
+     *  - NO_ERROR: successful operation
+     *  - INVALID_OPERATION: the AudioTrack is not stopped.
+     */
+            status_t    reload();
+
+    /* obtains a buffer of "frameCount" frames. The buffer must be
+     * filled entirely. If the track is stopped, obtainBuffer() returns
+     * STOPPED instead of NO_ERROR as long as there are buffers availlable,
+     * at which point NO_MORE_BUFFERS is returned.
+     * Buffers will be returned until the pool (buffercount())
+     * is exhausted, at which point obtainBuffer() will either block
+     * or return WOULD_BLOCK depending on the value of the "blocking"
+     * parameter.
+     */
+
+        enum {
+            NO_MORE_BUFFERS = 0x80000001,
+            STOPPED = 1
+        };
+
+            status_t    obtainBuffer(Buffer* audioBuffer, int32_t waitCount);
+            void        releaseBuffer(Buffer* audioBuffer);
+
+
+    /* As a convenience we provide a write() interface to the audio buffer.
+     * This is implemented on top of lockBuffer/unlockBuffer. For best
+     * performance
+     *
+     */
+            ssize_t     write(const void* buffer, size_t size);
+
+    /*
+     * Dumps the state of an audio track.
+     */
+            status_t dump(int fd, const Vector<String16>& args) const;
+
+private:
+    /* copying audio tracks is not allowed */
+                        AudioTrack(const AudioTrack& other);
+            AudioTrack& operator = (const AudioTrack& other);
+
+    /* a small internal class to handle the callback */
+    class AudioTrackThread : public Thread
+    {
+    public:
+        AudioTrackThread(AudioTrack& receiver, bool bCanCallJava = false);
+    private:
+        friend class AudioTrack;
+        virtual bool        threadLoop();
+        virtual status_t    readyToRun();
+        virtual void        onFirstRef();
+        AudioTrack& mReceiver;
+        Mutex       mLock;
+    };
+
+            bool processAudioBuffer(const sp<AudioTrackThread>& thread);
+
+    sp<IAudioFlinger>       mAudioFlinger;
+    sp<IAudioTrack>         mAudioTrack;
+    sp<IMemory>             mCblkMemory;
+    sp<AudioTrackThread>    mAudioTrackThread;
+
+    float                   mVolume[2];
+    uint32_t                mSampleRate;
+    uint32_t                mFrameCount;
+
+    audio_track_cblk_t*     mCblk;
+    uint8_t                 mStreamType;
+    uint8_t                 mFormat;
+    uint8_t                 mChannelCount;
+    uint8_t                 mMuted;
+    status_t                mStatus;
+    uint32_t                mLatency;
+
+    volatile int32_t        mActive;
+
+    callback_t              mCbf;
+    void*                   mUserData;
+    uint32_t                mNotificationFrames;
+    sp<IMemory>             mSharedBuffer;
+    int                     mLoopCount;
+    uint32_t                mRemainingFrames;
+    uint32_t                mMarkerPosition;
+    uint32_t                mNewPosition;
+    uint32_t                mUpdatePeriod;
+};
+
+
+}; // namespace android
+
+#endif // ANDROID_AUDIOTRACK_H