include/media/IAudioTrack.h

/*
 * 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_IAUDIOTRACK_H
#define ANDROID_IAUDIOTRACK_H

#include <stdint.h>
#include <sys/types.h>

#include <utils/RefBase.h>
#include <utils/Errors.h>
#include <binder/IInterface.h>
#include <binder/IMemory.h>
#include <utils/LinearTransform.h>

namespace android {

// ----------------------------------------------------------------------------

class IAudioTrack : public IInterface
{
public: 
    DECLARE_META_INTERFACE(AudioTrack);

    /* After it's created the track is not active. Call start() to
     * make it active. If set, the callback will start being called.
     */
    virtual status_t    start() = 0;

    /* Stop a track. If set, the callback will cease being called and
     * obtainBuffer will return an error. Buffers that are already released 
     * will be processed, unless flush() is called.
     */
    virtual void        stop() = 0;

    /* flush a stopped track. All pending buffers are discarded.
     * This function has no effect if the track is not stoped.
     */
    virtual void        flush() = 0;

    /* mute or unmutes this track.
     * While mutted, the callback, if set, is still called.
     */
    virtual void        mute(bool) = 0;
    
    /* Pause a track. If set, the callback will cease being called and
     * obtainBuffer will return an error. Buffers that are already released 
     * will be processed, unless flush() is called.
     */
    virtual void        pause() = 0;

    /* Attach track auxiliary output to specified effect. Use effectId = 0
     * to detach track from effect.
     */
    virtual status_t    attachAuxEffect(int effectId) = 0;

    /* get this tracks control block */
    virtual sp<IMemory> getCblk() const = 0;    

    /* Allocate a shared memory buffer suitable for holding timed audio
       samples */
    virtual status_t    allocateTimedBuffer(size_t size,
                                            sp<IMemory>* buffer) = 0;

    /* Queue a buffer obtained via allocateTimedBuffer for playback at the given
       timestamp */
    virtual status_t    queueTimedBuffer(const sp<IMemory>& buffer,
                                         int64_t pts) = 0;

    /* Define the linear transform that will be applied to the timestamps
       given to queueTimedBuffer (which are expressed in media time).
       Target specifies whether this transform converts media time to local time
       or Tungsten time. The values for target are defined in AudioTrack.h */
    virtual status_t    setMediaTimeTransform(const LinearTransform& xform,
                                              int target) = 0;
};

// ----------------------------------------------------------------------------

class BnAudioTrack : public BnInterface<IAudioTrack>
{
public:
    virtual status_t    onTransact( uint32_t code,
                                    const Parcel& data,
                                    Parcel* reply,
                                    uint32_t flags = 0);
};

// ----------------------------------------------------------------------------

}; // namespace android

#endif // ANDROID_IAUDIOTRACK_H