1 /*

     2 * Copyright (c) 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:    PayloadFormat plugin capable to read RTP payload containing

    15 *                Amr audio.

    16 *

    17 */

    18 

    19 

    20 

    21 

    22 // INCLUDE FILES

    23 #include "amrpayloadheader.h"

    24 #include "streamformatter.h"

    25 

    26 // CONSTANTS

    27 

    28 

    29 // ============================= LOCAL FUNCTIONS ===============================

    30 

    31 // ============================ MEMBER FUNCTIONS ===============================

    32 

    33 // ---------------------------------------------------------------------------

    34 // CAmrPayloadHeader::CAmrPayloadHeader

    35 // C++ default constructor can NOT contain any code, that

    36 // might leave.

    37 // ---------------------------------------------------------------------------

    38 //

    39 CAmrPayloadHeader::CAmrPayloadHeader() :iCmr( EAmrModeReqNone )

    40     {

    41     DP_AMR_ENCODE( "CAmrPayloadHeader::CAmrPayloadHeader" );        

    42     }

    43 

    44 

    45 // ---------------------------------------------------------------------------

    46 // CAmrPayloadHeader::NewL

    47 // Two-phased constructor.

    48 // ---------------------------------------------------------------------------

    49 //

    50 CAmrPayloadHeader* CAmrPayloadHeader::NewL()

    51     {

    52     DP_AMR_ENCODE( "CAmrPayloadHeader::NewL" );

    53     

    54     CAmrPayloadHeader* self = new( ELeave ) CAmrPayloadHeader( );

    55     

    56     return self;

    57     }

    58 

    59 

    60 // Destructor

    61 CAmrPayloadHeader::~CAmrPayloadHeader()

    62     {

    63     DP_AMR_ENCODE( "CAmrPayloadHeader::~CAmrPayloadHeader" );

    64     }

    65 

    66 

    67 // ---------------------------------------------------------------------------

    68 // CAmrPayloadHeader::Encode

    69 // Encode the payload header fields into a given buffer at the given position.

    70 // ---------------------------------------------------------------------------

    71 //

    72 void CAmrPayloadHeader::Encode( TUint8* aBuffer,

    73         TInt& aByteIndex, TInt& aBitIndex )

    74     {

    75     DP_AMR_ENCODE( "CAmrPayloadHeader::Encode" );

    76         

    77     TStreamEncoder encoder;

    78     encoder.Initialize( aBuffer, aByteIndex, aBitIndex );

    79     

    80     //In bandwidth-efficient mode, the payload header simply consists of a

    81     //4 bit codec mode request:

    82     //  0 1 2 3

    83     // +-+-+-+-+

    84     // |  CMR  |

    85     // +-+-+-+-+

    86     encoder.Encode( iCmr, KCMRFieldBits );

    87 

    88     // Update Byte and Bit positions

    89     aByteIndex = encoder.ByteIndex( ); 

    90     aBitIndex = encoder.BitIndex( );

    91     }

    92 

    93 

    94 // ---------------------------------------------------------------------------

    95 // CAmrPayloadHeader::Decode

    96 // Decode the payload header from a given buffer at the given position.

    97 // ---------------------------------------------------------------------------

    98 //

    99 void CAmrPayloadHeader::Decode( const TUint8* aBuffer,

   100         TInt& aByteIndex, TInt& aBitIndex )

   101     {

   102     DP_AMR_ENCODE( "CAmrPayloadHeader::Decode" );

   103     

   104     TStreamDecoder decoder;

   105     decoder.Initialize( aBuffer, aByteIndex, aBitIndex );

   106     iCmr = TAmrModeRequest( decoder.Decode( KCMRFieldBits ) );

   107 

   108     // Update Byte and Bit positions

   109     aByteIndex = decoder.ByteIndex( );

   110     aBitIndex = decoder.BitIndex( );

   111     }

   112