1 // Copyright (c) 2003-2009 Nokia Corporation and/or its subsidiary(-ies).

     2 // All rights reserved.

     3 // This component and the accompanying materials are made available

     4 // under the terms of "Eclipse Public License v1.0"

     5 // which accompanies this distribution, and is available

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

     7 //

     8 // Initial Contributors:

     9 // Nokia Corporation - initial contribution.

    10 //

    11 // Contributors:

    12 //

    13 // Description:

    14 //

    15 

    16 #include "mmfpcmS16PcmS8HwDevice.h"

    17 

    18 /**

    19  *

    20  *	Returns the created hw device for passing audio through audio.

    21  *  for the wins implementation this would always be pcm16 although

    22  *  this is effectively a null hw device that will pass any datatype through

    23  *	@return	"CMMFPcm16ToPcmU16BEHwDevice"

    24  *

    25  */

    26 CMMFPcmS16ToPcmS8HwDevice* CMMFPcmS16ToPcmS8HwDevice::NewL()

    27 	{

    28     CMMFPcmS16ToPcmS8HwDevice* self = new (ELeave) CMMFPcmS16ToPcmS8HwDevice();

    29 	CleanupStack::PushL(self);

    30 	self->ConstructL();

    31 	CleanupStack::Pop(self);

    32 	return self;

    33 	}

    34 

    35 /**

    36 *

    37 * ~CMMFPcmS16ToPcmS8HwDevice

    38 */

    39 CMMFPcmS16ToPcmS8HwDevice::~CMMFPcmS16ToPcmS8HwDevice()

    40 	{

    41 	}

    42 

    43 /**

    44 *

    45 * ConstructL

    46 *

    47 */

    48 void CMMFPcmS16ToPcmS8HwDevice::ConstructL()

    49 	{

    50 	iCodec = new (ELeave) CMMFPcmS16ToPcmS8Codec();

    51 	}

    52 

    53 /**

    54 *

    55 * Codec

    56 * @return 'CMMFSwCodec&'

    57 *

    58 */

    59 CMMFSwCodec& CMMFPcmS16ToPcmS8HwDevice::Codec()

    60 	{

    61 	return *iCodec;

    62 	}

    63 

    64 /**

    65 *

    66 * ProcessL

    67 * @param aSrc

    68 * @param aDst

    69 * @param aSamples

    70 *

    71 */

    72 CMMFSwCodec::TCodecProcessResult CMMFPcmS16ToPcmS8Codec::ProcessL(const CMMFBuffer& aSrc, CMMFBuffer& aDst)

    73 	{

    74 	TCodecProcessResult result;

    75 	result.iCodecProcessStatus = TCodecProcessResult::EProcessComplete;

    76 	

    77 	//convert from generic CMMFBuffer to CMMFDataBuffer

    78 	const CMMFDataBuffer* src = STATIC_CAST(const CMMFDataBuffer*, &aSrc);

    79 	CMMFDataBuffer* dst = STATIC_CAST(CMMFDataBuffer*, &aDst);

    80 	

    81 	//[Check Preconditions]

    82 	if( !CheckPreconditions( src, dst ))

    83 		{

    84 		//[ precondition violation ]

    85 		User::Leave( KErrArgument );

    86 		}

    87 	

    88 	//we need to cast away CONST even on the source, as the TClass needs a TUint8*

    89 	TUint8* pSrc = CONST_CAST(TUint8*,src->Data().Ptr());

    90 	TUint8* pDst = CONST_CAST(TUint8*,dst->Data().Ptr());

    91     

    92 	TInt srcUse = src->Data().Length();

    93 	TInt noSamples = srcUse/2;

    94 	

    95 	//compress TWO bytes (16-bit PCM word) into a to 1 byte sample

    96 	iAudioPcmS16ToPcmS8.Convert(pSrc, pDst, noSamples );

    97 	

    98 	result.iCodecProcessStatus = TCodecProcessResult::EProcessComplete;

    99 	result.iSrcBytesProcessed  = srcUse;

   100 	result.iDstBytesAdded      = srcUse/2;

   101 	

   102 	dst->Data().SetLength(result.iDstBytesAdded);

   103 	

   104 	//[ post conditions

   105     // srcbytes/2 == destbytes added

   106 	// pos src == 0

   107 	// pos dest == 0 ]

   108 	__ASSERT_DEBUG( (src->Position() == 0), TMmfAudioCodecPanicsNameSpace::Panic( 	TMmfAudioCodecPanicsNameSpace::EPostConditionViolation ));

   109 	__ASSERT_DEBUG( (dst->Position() == 0), TMmfAudioCodecPanicsNameSpace::Panic( 	TMmfAudioCodecPanicsNameSpace::EPostConditionViolation ));

   110 	__ASSERT_DEBUG( src->Data().Length()/2 == dst->Data().Length(), TMmfAudioCodecPanicsNameSpace::Panic( 	TMmfAudioCodecPanicsNameSpace::EPostConditionViolation ));

   111 	

   112 	return result;

   113 	}

   114 

   115 /**

   116 *

   117 * Preconditions

   118 * This methos tests the preconditions of the ProcessL method

   119 * @return TBool ETrue for sucess and EFalse for failure of the preconditions

   120 *

   121 **/

   122 TBool CMMFPcmS16ToPcmS8Codec::CheckPreconditions( const CMMFDataBuffer* aSrcBuffer, CMMFDataBuffer* aDestBuffer )

   123 	{

   124 	TBool result = EFalse;

   125 	

   126 	if(! aSrcBuffer )

   127 		{

   128 		return result;

   129 		}

   130 	

   131 	if( ! aDestBuffer )

   132 		{

   133 		return result;

   134 		}

   135 	

   136 	// Check position of src and dest are 0

   137 	if( aSrcBuffer->Position() )

   138 		{

   139 		return result;

   140 		}

   141 	

   142 	// Check position of src and dest are 0

   143 	if( aDestBuffer->Position() )

   144 		{

   145 		return result;

   146 		}

   147 	

   148 	// check there are sufficient bytes in the output to consume the input

   149 	if( ( aSrcBuffer->Data().Length()/2 > aDestBuffer->Data().MaxLength() ) &&

   150 		( aSrcBuffer->Data().Length() % 2 == 0 ) ) // must have pcm16 samples on input

   151 		{

   152 		return result;

   153 		}

   154 	

   155 	result = ETrue;  // preconditions have been satisfied

   156 	

   157 	return result;

   158 	}

   159