1 /*

     2 * Copyright (c) 2004-2006 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:    Provides a comfort noise generator class

    15 *

    16 */

    17 

    18 

    19 

    20 

    21 #ifndef MCCCNGENERATOR_H

    22 #define MCCCNGENERATOR_H

    23 

    24 #include <e32base.h>

    25 #include <mmf/common/mmfutilities.h>

    26 

    27 // FORWARD DECLARATIONS

    28 class CMMFDevSound;

    29 class CErrorConcealmentIntfc;

    30 

    31 /**

    32 * MCC Comfort noise generator

    33 *

    34 * @lib MMccJitterBuffer.lib

    35 * @since Series 60 3.0

    36 */

    37 NONSHARABLE_CLASS( CMccCnGenerator ) : public CBase

    38     {

    39     public:  // Constructors and destructor 

    40         

    41         /**

    42         * Two phased constructor

    43         */

    44         static CMccCnGenerator* NewL( const TFourCC& aAudioType, 

    45                 CMMFDevSound& aDevSound );

    46 

    47         /**

    48         * Destructor

    49         */

    50         virtual ~CMccCnGenerator();

    51 

    52     public: // New functions

    53 

    54         /**

    55         * Generates an SID packet to given buffer

    56         * @since Series 60 3.0

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

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

    59         * @return void

    60         */

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

    62         

    63         /**

    64         * Jitterbuffer has noted that frames were missing, so error concealment

    65         * needs to be done to some frames. This function calls the error 

    66         * concealment interface's error concealment function.

    67         * @since Series 60 3.0

    68         * @param None

    69         * @return void

    70         */

    71         void ConcealErrorForNextFrame() const;

    72         

    73         /**

    74         * Returns the current DTX status

    75         * @since Series 60 3.0

    76         * @param None

    77         * @return TBool ETrue if DTX period ongoing

    78         */

    79         inline TBool DtxPeriodStatus() const

    80             {

    81             return ( iDtxPeriodStarted );

    82             }

    83         

    84         /**

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

    86         * @since Series 60 3.0

    87         * @param aData Buffer containing the data

    88         * @return void

    89         */

    90         void DoDtxDecision( const TDesC8& aData );

    91         

    92         /**

    93         * Check if the given databuffer is a SID frame for current codec

    94         * @since Series 60 3.0

    95         * @param aData Buffer containing the data

    96         * @return TBool ETrue if the aBuffer is a SID for current codec

    97         */

    98         TBool IsSidBuffer( const TDesC8& aData ) const;

    99 

   100     private: // New functions

   101 

   102         /**

   103         * Generates an AMR CN packet into aPayload

   104         * @since Series 60 3.0

   105         * @param aPayload

   106         * @return void

   107         */

   108         void GenerateAmrNoDataPacket( TDes8& aPayload ) const;

   109         

   110         /**

   111         * Generates an VoIP NO_DATA frame into aPayload

   112         * @since Series 60 3.0

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

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

   115         * @return void

   116         */

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

   118 

   119     private: //Constructors

   120 

   121         /**

   122         * C++ default constructor.

   123         */

   124         CMccCnGenerator( const TFourCC& aAudioType, CMMFDevSound& aDevSound );

   125 

   126         /**

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

   128         */

   129         void ConstructL();

   130            

   131     private:    // Data

   132                 

   133         // Audio type

   134         TFourCC iAudioType;

   135         

   136         // Sound device for Error Concealment IF creation

   137         CMMFDevSound& iDevSound;

   138         

   139         // Error concealment interface

   140         CErrorConcealmentIntfc* iErrorConcealer;

   141         

   142         // Generated CN frames

   143         TInt iGeneratedCnFrames;

   144         

   145         // DTX period started

   146         TBool iDtxPeriodStarted;

   147       

   148     private:    // Friend classes

   149     

   150     // Friend class for EUNIT tests

   151     #ifdef TEST_EUNIT

   152         friend class UT_CMccCnGenerator;

   153     #endif

   154     };

   155 

   156 #endif  // MCCCNGENERATOR_H