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:  Declares class for comfort noise generating utility (CNG)

    15 *

    16 */

    17 

    18 

    19 #ifndef CNGGENERATOR_H

    20 #define CNGGENERATOR_H

    21 

    22 #include <mmfutilities.h>

    23 

    24 // FORWARD DECLARATIONS

    25 class MJitterBufferObserver;

    26 

    27 /**

    28  * Comfort noise generating utility

    29  *

    30  * @lib MMccJitterBuffer.lib

    31  * @since Series 60 5.0

    32  */

    33 NONSHARABLE_CLASS (CVoIPCNGenerator) : public CBase

    34     {

    35 public:  // Constructor and destructor

    36 

    37     /**

    38      * Two phased constructor

    39      */

    40     static CVoIPCNGenerator* NewL(MJitterBufferObserver* iObserver,

    41                                   const TFourCC& aCodec);

    42 

    43     /**

    44      * Destructor

    45      */

    46     virtual ~CVoIPCNGenerator();

    47 

    48 public: // New functions

    49 

    50     /**

    51      * Generates an SID packet to given buffer

    52      * @since Series 60 5.0

    53      * @param aPayload Buffer to be filled with SID data

    54      * @param aRequestSize Amount of data to be generated to buffer.

    55      * @return void

    56      */

    57     void GenerateSidPacket(TDes8& aPayload, TInt aRequestSize);

    58 

    59     /**

    60      * Requests error concealment for the next frame.

    61      * @since Series 60 5.0

    62      * @param None

    63      * @return void

    64      */

    65     void ConcealErrorForNextFrame() const;

    66 

    67     /**

    68      * Returns current DTX status

    69      * @since Series 60 5.0

    70      * @param None

    71      * @return TBool ETrue if DTX period ongoing

    72      */

    73     TBool DtxPeriodStatus() const;

    74 

    75     /**

    76      * Decide whether we are in DTX period or in normal speech period

    77      * @since Series 60 5.0

    78      * @param const TDes8& - Buffer containing data

    79      * @return TInt

    80      */

    81     void DoDtxDecision(const TDes8& aPayload);

    82 

    83     /**

    84      * Checks whether buffer contains SID frame.

    85      * @since Series 60 5.0

    86      * @param const TDes8& - Buffer containing data

    87      * @return TBool - ETrue if buffer contains SID frame

    88      */

    89     TBool IsSidBuffer(const TDes8& aData);

    90         

    91 private: // New functions

    92 

    93     /**

    94      * Generates an AMR CN packet into aPayload

    95      * @since Series 60 5.0

    96      * @param aPayload

    97      * @return void

    98      */

    99     void GenerateAmrNoDataPacket(TDes8& aPayload) const;

   100 

   101     /**

   102      * Generates an VoIP NO_DATA frame into aPayload

   103      * @since Series 60 5.0

   104      * @param aPayload Buffer to be filled with VoIP NO_DATA information

   105      * @param aRequestSize Amount of data to be generated to buffer.

   106      * @return void

   107      */

   108     void GenerateVoIPNoDataPacket(TDes8& aPayload, TInt aRequestSize) const;

   109 

   110 private: //Constructors

   111 

   112     /**

   113      * C++ default constructor.

   114      */

   115     CVoIPCNGenerator(MJitterBufferObserver* iObserver, const TFourCC& aCodec);

   116 

   117     /**

   118      * Symbian 2nd phase constructor.

   119      */

   120     void ConstructL();

   121 

   122 private:    // Data

   123 

   124     // Codec type

   125     TFourCC iCodec;

   126 

   127     // For Error Concealment IF creation

   128     MJitterBufferObserver* iObserver;

   129 

   130     // Generated CN frames

   131     TInt iGeneratedCNFrames;

   132 

   133     // DTX period started

   134     TBool iDtxPeriodStarted;

   135 

   136     };

   137 

   138 #endif  // CNGGENERATOR_H

   139 

   140 

   141 // End of file