/*

* 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:

*

* Description:  Jitter buffer for Audio frames.

*  Interface   : VoIPJitterBuffer.lib

*

*/

#ifndef __VOIPJITTERBUFFERIMPL_H

#define __VOIPJITTERBUFFERIMPL_H

//  INCLUDES

#include <voipjitterbufferintfc.h>

// FORWARD DECLARATIONS

class CVoIPCNGenerator;

class MJitterBufferObserver;

// CLASS DECLARATION

/**

 *  Jitter buffer element including packet received.

 *

 *  @lib VoIPJitterBuffer.lib

 *  @since Series 60 5.0

 */

class TJitterBufferElement

    {

public: // Constructor

    inline TJitterBufferElement() : iDataFrame(NULL),

                                    iSequenceNumber(-1),

                                    iTimeStamp(-1) {}

public: // Methods

    /**

     * Compares two elements based on their sequence number

     * @since Series 60 5.0

     * @param aElem1 First element

     * @param aElem2 Second element

     * @return TInt

     */

    static TInt CompareSeqNum(const TJitterBufferElement& aElem1,

                              const TJitterBufferElement& aElem2);

    /**

     * Compares two elements based on their stamps

     * @since Series 60 5.0

     * @param aElem1 First element

     * @param aElem2 Second element

     * @return TInt

     */

    static TInt CompareStamp(const TJitterBufferElement& aElem1,

                             const TJitterBufferElement& aElem2);

public: // Data members

    // Data

    CMMFDataBuffer* iDataFrame;

    // Data packet number

    TInt64 iSequenceNumber;

    // Time stamp

    TInt64 iTimeStamp;

    };

/**

 *  Jitter buffer.

 *

 *  @lib VoIPJitterBuffer.lib

 *  @since Series 60 5.0

 */

class CVoIPJitterBufferImpl : public CBase

    {

public: // Constructors and destructor

    /**

     * Two-phased constructor.

     */

    static CVoIPJitterBufferImpl* NewL(MJitterBufferObserver* aObserver);

    /**

     * Destructor.

     */

    virtual ~CVoIPJitterBufferImpl();

public: // Methods

    /**

     * Setup jitterbuffer

     * @since Series 60 5.0

     * @param parameters

     * @return void

     */

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

    /**

     * Reset buffer

     * @since Series 60 5.0

     * @param aPlayTone ETrue, if tone is to played

     * @return void

     */

    void ResetBuffer(TBool aPlayTone = ETrue);

    /**

     * Add DataFrame to buffer

     * @since Series 60 5.0

     * @param aBuffer Buffer to read data from

     * @return void

     */

    TInt AddDataFrame(CMMFBuffer* aDataBuffer);

    /**

     * Get DataFrame from buffer

     * @since Series 60 5.0

     * @param aBuffer Buffer to write data to

     * @return TInt

     */

    TInt GetDataFrame(CMMFBuffer* aBuffer);

    /**

     * Get Current Codec

     * @since Series 60 5.0

     * @param None

     * @return TFourCC

     */

    TFourCC CurrentCodec() const;

    /**

     * Delay Up

     * @since Series 60 5.0

     * @param None

     * @return void

     */

    void DelayUpL();

    /**

     * Decreases jitter buffer delay

     * @since Series 60 5.0

     * @param None

     * @return void

     */

    void DelayDownL();

    /**

     * ?Description

     * @since Series 60 5.0

     * @param None

     * @return TTimeIntervalMicroSeconds32

     */

    TTimeIntervalMicroSeconds32 CalculateDelay() const;

    /**

     * Get the length of jitter buffer, in terms of number of packets.

     * @since Series 60 5.0

     * @param none

     * @return buffer lenght.

     */

    TInt BufferLength() const;

    /**

     * Get number of packets that are currently inside the buffer.

     * @since Series 60 5.0

     * @param none

     * @return Number of packet in buffer.

     */

    TInt PacketCount() const;

    /**

     * Fills the given event with statistics of the jitterbuffer

     * @since Series 60 5.0

     * @param aEvent Event into which set the statistics

     * @return void

     */

    void GenerateStatistics(/*TJBStats& aStats*/) const;

private:

    /**

     * C++ default constructor.

     */

    CVoIPJitterBufferImpl(MJitterBufferObserver* aObserver);

    /**

     * By default Symbian 2nd phase constructor is private.

     */

    void ConstructL();

private: // New functions

    /**

     * Is sequence number wrapped around TUint16 65535->0

     * @since Series 60 5.0

     * @param TInt aSeqNum1 is oldest packet sequence number in buffer

     * @param TInt aSeqNum2 is new element sequence number to buffer

     * @return detect the wrap-around condition.

     */

    TBool IsSeqNumWrappedAround(TInt64 aSeqNum1, TInt64 aSeqNum2) const;

    /**

     * Find Largest SequenceNumber

     * @since Series 60 5.0

     * @param None

     * @return TUint Largest sequence number

     */

    TUint FindLargestSeqNum();

    /**

     * Inserts a databuffer into the jitter buffer

     * @since Series 60 5.0

     * @param aBuffer Buffer containing the data

     * @param aLargestSeqNum Largest sequence number returned by

     *                       FindLargestSeqNum()

     * @return void

     */

    void InsertBufferElement(const TDesC8& aBuffer, TInt64 aLargestSeqNum);

    /**

     * Is jitter buffer full?

     * @since Series 60 5.0

     * @param none

     * @return True if full.

     */

    TBool IsFull() const;

    /**

     * Is jitter buffer empty?

     * @since Series 60 5.0

     * @param none

     * @return True if empty.

     */

    TBool IsEmpty() const;

    /**

     * CheckThresholdBufferLength

     * @since Series 60 5.0

     * @param none

     * @return void

     */

    void CheckThresholdBufferLength(TInt& aBufferLength,

                                    const TInt aTreshhold) const;

private: // Data

    // Playout thresholds

    TInt iCurrentPlayThreshold;

    TInt iOriginalPlayThreshold;

    // Buffer length

    TInt iBufferLength;

    // Jitter buffer array (queue)

    RArray<TJitterBufferElement> iBuffer;

    // Instance of comfort noise generator

    CVoIPCNGenerator* iCNGenerator;

    // Frame SequenceNumber

    TInt64 iCurrentSeqNum;

    // Sequence number of previously played frame

    TInt64 iLastPlayedSeqNum;

    TInt64 iLargestSeqNum;

    // Jitter buffer sorting objects

    TLinearOrder<TJitterBufferElement> iBufStampSorter;

    TLinearOrder<TJitterBufferElement> iBufSequenceSorter;

    // JB configuration parameters

    TVoIPJBConfig iJBConfig;

    // Codec frame size

    TInt  iFrameSize;

    // Encoded frame sample interval

    TInt  iSampleInterval;

    // Increment in frame sequence number

    TUint iSeqNumIncrement;

    TBool iIsWrappedAround;

    MJitterBufferObserver* iObserver;

    CMMFDataBuffer* iDataBuffer;

// These are mainly for statistical purpose

    // Number of frames totally lost

    TUint iFramesLost;

    // Number of frames received

    TUint iFramesReceived;

    // Number of frames removed by adaptation or because of overflows

    TUint iFramesRemoved;

    // Number of frames played

    TUint iFramesPlayed;

    // Number of frames arrived late

    TUint iNumOfLateFrames;

    // Number of packets in buffer

    TInt iPacketsInBuffer;

    // Buffer overflow counter

    TUint iOverflowCounter;

    // Jitter buffer inctivity time

    TInt  iInactivityTime;

// These are for tone playback

    TInt  iPlayToneInterval;

    TTime iTonePlayTime;

    TInt  iSampleRate;

    TBool iPlay;

    };

#endif  //__VOIPJITTERBUFFERIMPL_H

// End of file