/*
* 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