1 /*

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

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

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

     6 * which accompanies this distribution, and is available

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

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description:  Jitter buffer for Audio frames.

    15 *  Interface   : VoIPJitterBuffer.lib

    16 *

    17 */

    18 

    19 

    20 

    21 #ifndef __VOIPJITTERBUFFERIMPL_H

    22 #define __VOIPJITTERBUFFERIMPL_H

    23 

    24 //  INCLUDES

    25 #include <voipjitterbufferintfc.h>

    26 

    27 // FORWARD DECLARATIONS

    28 class CVoIPCNGenerator;

    29 class MJitterBufferObserver;

    30 

    31 // CLASS DECLARATION

    32 

    33 /**

    34  *  Jitter buffer element including packet received.

    35  *

    36  *  @lib VoIPJitterBuffer.lib

    37  *  @since Series 60 5.0

    38  */

    39 class TJitterBufferElement

    40     {

    41 public: // Constructor

    42     inline TJitterBufferElement() : iDataFrame(NULL),

    43                                     iSequenceNumber(-1),

    44                                     iTimeStamp(-1) {}

    45 

    46 public: // Methods

    47 

    48     /**

    49      * Compares two elements based on their sequence number

    50      * @since Series 60 5.0

    51      * @param aElem1 First element

    52      * @param aElem2 Second element

    53      * @return TInt

    54      */

    55     static TInt CompareSeqNum(const TJitterBufferElement& aElem1,

    56                               const TJitterBufferElement& aElem2);

    57 

    58     /**

    59      * Compares two elements based on their stamps

    60      * @since Series 60 5.0

    61      * @param aElem1 First element

    62      * @param aElem2 Second element

    63      * @return TInt

    64      */

    65     static TInt CompareStamp(const TJitterBufferElement& aElem1,

    66                              const TJitterBufferElement& aElem2);

    67 

    68 public: // Data members

    69     // Data

    70     CMMFDataBuffer* iDataFrame;

    71 

    72     // Data packet number

    73     TInt64 iSequenceNumber;

    74 

    75     // Time stamp

    76     TInt64 iTimeStamp;

    77 

    78     };

    79 

    80 

    81 /**

    82  *  Jitter buffer.

    83  *

    84  *  @lib VoIPJitterBuffer.lib

    85  *  @since Series 60 5.0

    86  */

    87 class CVoIPJitterBufferImpl : public CBase

    88     {

    89 public: // Constructors and destructor

    90 

    91     /**

    92      * Two-phased constructor.

    93      */

    94     static CVoIPJitterBufferImpl* NewL(MJitterBufferObserver* aObserver);

    95 

    96     /**

    97      * Destructor.

    98      */

    99     virtual ~CVoIPJitterBufferImpl();

   100 

   101 public: // Methods

   102 

   103     /**

   104      * Setup jitterbuffer

   105      * @since Series 60 5.0

   106      * @param parameters

   107      * @return void

   108      */

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

   110 

   111     /**

   112      * Reset buffer

   113      * @since Series 60 5.0

   114      * @param aPlayTone ETrue, if tone is to played

   115      * @return void

   116      */

   117     void ResetBuffer(TBool aPlayTone = ETrue);

   118 

   119     /**

   120      * Add DataFrame to buffer

   121      * @since Series 60 5.0

   122      * @param aBuffer Buffer to read data from

   123      * @return void

   124      */

   125     TInt AddDataFrame(CMMFBuffer* aDataBuffer);

   126 

   127     /**

   128      * Get DataFrame from buffer

   129      * @since Series 60 5.0

   130      * @param aBuffer Buffer to write data to

   131      * @return TInt

   132      */

   133     TInt GetDataFrame(CMMFBuffer* aBuffer);

   134 

   135     /**

   136      * Get Current Codec

   137      * @since Series 60 5.0

   138      * @param None

   139      * @return TFourCC

   140      */

   141     TFourCC CurrentCodec() const;

   142 

   143     /**

   144      * Delay Up

   145      * @since Series 60 5.0

   146      * @param None

   147      * @return void

   148      */

   149     void DelayUpL();

   150 

   151     /**

   152      * Decreases jitter buffer delay

   153      * @since Series 60 5.0

   154      * @param None

   155      * @return void

   156      */

   157     void DelayDownL();

   158 

   159     /**

   160      * ?Description

   161      * @since Series 60 5.0

   162      * @param None

   163      * @return TTimeIntervalMicroSeconds32

   164      */

   165     TTimeIntervalMicroSeconds32 CalculateDelay() const;

   166 

   167     /**

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

   169      * @since Series 60 5.0

   170      * @param none

   171      * @return buffer lenght.

   172      */

   173     TInt BufferLength() const;

   174 

   175     /**

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

   177      * @since Series 60 5.0

   178      * @param none

   179      * @return Number of packet in buffer.

   180      */

   181     TInt PacketCount() const;

   182 

   183     /**

   184      * Fills the given event with statistics of the jitterbuffer

   185      * @since Series 60 5.0

   186      * @param aEvent Event into which set the statistics

   187      * @return void

   188      */

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

   190 

   191 private:

   192 

   193     /**

   194      * C++ default constructor.

   195      */

   196     CVoIPJitterBufferImpl(MJitterBufferObserver* aObserver);

   197 

   198     /**

   199      * By default Symbian 2nd phase constructor is private.

   200      */

   201     void ConstructL();

   202 

   203 private: // New functions

   204 

   205     /**

   206      * Is sequence number wrapped around TUint16 65535->0

   207      * @since Series 60 5.0

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

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

   210      * @return detect the wrap-around condition.

   211      */

   212     TBool IsSeqNumWrappedAround(TInt64 aSeqNum1, TInt64 aSeqNum2) const;

   213 

   214     /**

   215      * Find Largest SequenceNumber

   216      * @since Series 60 5.0

   217      * @param None

   218      * @return TUint Largest sequence number

   219      */

   220     TUint FindLargestSeqNum();

   221 

   222     /**

   223      * Inserts a databuffer into the jitter buffer

   224      * @since Series 60 5.0

   225      * @param aBuffer Buffer containing the data

   226      * @param aLargestSeqNum Largest sequence number returned by

   227      *                       FindLargestSeqNum()

   228      * @return void

   229      */

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

   231 

   232     /**

   233      * Is jitter buffer full?

   234      * @since Series 60 5.0

   235      * @param none

   236      * @return True if full.

   237      */

   238     TBool IsFull() const;

   239 

   240     /**

   241      * Is jitter buffer empty?

   242      * @since Series 60 5.0

   243      * @param none

   244      * @return True if empty.

   245      */

   246     TBool IsEmpty() const;

   247 

   248     /**

   249      * CheckThresholdBufferLength

   250      * @since Series 60 5.0

   251      * @param none

   252      * @return void

   253      */

   254     void CheckThresholdBufferLength(TInt& aBufferLength,

   255                                     const TInt aTreshhold) const;

   256 

   257 private: // Data

   258 

   259     // Playout thresholds

   260     TInt iCurrentPlayThreshold;

   261     TInt iOriginalPlayThreshold;

   262 

   263     // Buffer length

   264     TInt iBufferLength;

   265 

   266     // Jitter buffer array (queue)

   267     RArray<TJitterBufferElement> iBuffer;

   268 

   269     // Instance of comfort noise generator

   270     CVoIPCNGenerator* iCNGenerator;

   271 

   272     // Frame SequenceNumber

   273     TInt64 iCurrentSeqNum;

   274 

   275     // Sequence number of previously played frame

   276     TInt64 iLastPlayedSeqNum;

   277     TInt64 iLargestSeqNum;

   278 

   279     // Jitter buffer sorting objects

   280     TLinearOrder<TJitterBufferElement> iBufStampSorter;

   281     TLinearOrder<TJitterBufferElement> iBufSequenceSorter;

   282 

   283     // JB configuration parameters

   284     TVoIPJBConfig iJBConfig;

   285 

   286     // Codec frame size

   287     TInt  iFrameSize;

   288 

   289     // Encoded frame sample interval

   290     TInt  iSampleInterval;

   291 

   292     // Increment in frame sequence number

   293     TUint iSeqNumIncrement;

   294     

   295     TBool iIsWrappedAround;

   296 

   297     MJitterBufferObserver* iObserver;

   298     CMMFDataBuffer* iDataBuffer;

   299 

   300 // These are mainly for statistical purpose

   301 

   302     // Number of frames totally lost

   303     TUint iFramesLost;

   304 

   305     // Number of frames received

   306     TUint iFramesReceived;

   307 

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

   309     TUint iFramesRemoved;

   310 

   311     // Number of frames played

   312     TUint iFramesPlayed;

   313 

   314     // Number of frames arrived late

   315     TUint iNumOfLateFrames;

   316 

   317     // Number of packets in buffer

   318     TInt iPacketsInBuffer;

   319 

   320     // Buffer overflow counter

   321     TUint iOverflowCounter;

   322 

   323     // Jitter buffer inctivity time

   324     TInt  iInactivityTime;

   325 

   326 // These are for tone playback

   327     TInt  iPlayToneInterval;

   328     TTime iTonePlayTime;

   329     TInt  iSampleRate;

   330     TBool iPlay;

   331 

   332     };

   333 

   334 #endif  //__VOIPJITTERBUFFERIMPL_H

   335 

   336 // End of file