/*

 * Copyright (c) 2008 Nokia Corporation and/or its subsidiary(-ies).

 * All rights reserved.

 * This component and the accompanying materials are made available

 * under the terms of "Eclipse Public License v1.0"

 * which accompanies this distribution, and is available

 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

 *

 * Initial Contributors:

 * Nokia Corporation - initial contribution.

 *

 * Contributors:

 *

 *

 */

// DATA TYPES

// FORWARD DECLARATIONS

class CMccCnGenerator;

class CVoIPJitterBufferImpl;

class TVoIPJBConfig;

class MJitterBufferObserver;

// CLASS DECLARATION

/**

 *  Jitter buffer.

 *

 *  @lib VoIPJitterBuffer.lib

 */

class CVoIPJitterBuffer : public CActive

    {

private:

    /**

     * Jitter buffer states

     */

    enum TJBState

        {

        EJBufStopped,

        EJBufPlaying,

        EJBufPaused

        };

    /**

     * Transition states during JB playback

     */

    enum TJBTransitionState

        {

        EWait,

        EEmptyData

        };

public:

    // Constructors and destructor

    /**

     * Two-phased constructor.

     */

    IMPORT_C static CVoIPJitterBuffer* NewL(MJitterBufferObserver* aObserver);

    /**

     * Destructor.

     */

    virtual ~CVoIPJitterBuffer();

public:

    // Methods

    /**

     * SetupL

     * Sets codec information and initializes JB.

     * @param TFourCC - codec's fourcc

     * @param TVoIPJBConfig& - JB configuraion parameters

     * @return void

     */

    IMPORT_C void SetupL(const TFourCC aCodec, const TVoIPJBConfig& aJBConfig);

    /**

     * ResetBuffer

     * Resets JB to its original state with no data.

     * @param TBool - ETrue == tone is to be played

     * @return void

     */

    IMPORT_C void ResetBuffer(TBool aPlayTone = ETrue);

    /**

     * Delay Down

     *

     * @param none

     * @return void

     */

    IMPORT_C void DelayDown();

    /**

     * Delay Up

     *

     * @param none

     * @return void

     */

    IMPORT_C void DelayUp();

    /**

     * Play

     *

     * @param none

     * @return void

     */

    IMPORT_C void Play();

    /**

     * Pause

     *

     * @param none

     * @return void

     */

    IMPORT_C void Pause();

    /**

     * Stop

     *

     * @param none

     * @return void

     */

    IMPORT_C void Stop();

    /**

     * FillBuffer

     * Retrieves next frame from JB queue.

     * @param CMMFBuffer* - buffer to be filled with data from the JB

     * @return TInt

     */

    IMPORT_C TInt FillBuffer(CMMFBuffer* aBuffer);

    /**

     * EmptyBufferL

     * Queues received frame in JB.

     * @param CMMFBuffer* - buffer to be queued in the JB

     * @return TInt

     */

    IMPORT_C TInt EmptyBuffer(CMMFBuffer* aBuffer);

private:

    /**

     * C++ default constructor.

     */

    CVoIPJitterBuffer(MJitterBufferObserver* aObserver);

    /**

     * Symbian 2nd phase constructor.

     */

    void ConstructL();

    /**

     * from CActive

     */

    void DoCancel();

    /**

     * from CActive

     */

    void RunL();

    /**

     * from CActive

     */

    TInt RunError(TInt aError);

private:

    // Internal helper methods

    /**

     * Play current frame from JB.

     * @param none

     * @return void

     */

    void PlayBuffer();

    /**

     * TransitionState

     * @param TJBTransitionState

     * @param TUint32

     * @return void

     */

    void TransitionState(TJBTransitionState aTransitionState,

            TUint32 aStateChangeDelay = 0);

    /**

     * Calculates the time interval at which data rate should be slowed down

     * when subsequent EmptyBufferL calls are coming too fast.

     * @param none

     * @return Suggested delay in microseconds.

     */

    TUint32 DetermineEmptyBufferDelay();

private:

    // Data

    // Jitter buffer Implementation

    CVoIPJitterBufferImpl* iJitterBufferImpl;

    // Pointer to databuffer

    CMMFBuffer* iPlayBuffer;

    // Jitterbuffer state

    TJBState iState;

    // JB Transition State

    TJBTransitionState iTransitionState;

    MJitterBufferObserver* iObserver;

    TFourCC iCodec;

    RTimer iTimer;

    TTime iTmCurrentEmptyBuffer;

    TTime iTmPreviousEmptyBuffer;

    TUint32 iSampleInterval;

    TUint32 iEmptyBufferDelayThreshold;

    // Current request size of the buffer

    TInt iRequestSize;

    };

// End of file