--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/multimediacommscontroller/mmccamrpayloadformat/inc/amrpayloaddecoder.h Tue Feb 02 01:04:58 2010 +0200
@@ -0,0 +1,202 @@
+/*
+* Copyright (c) 2004-2006 Nokia Corporation and/or its subsidiary(-ies).
+* All rights reserved.
+* This component and the accompanying materials are made available
+* under the terms of "Eclipse Public License v1.0"
+* which accompanies this distribution, and is available
+* at the URL "http://www.eclipse.org/legal/epl-v10.html".
+*
+* Initial Contributors:
+* Nokia Corporation - initial contribution.
+*
+* Contributors:
+*
+* Description: Formatter classes for decoding of RTP payload format
+* for AMR ( narrow band ) audio codecs.
+*
+*/
+
+
+
+
+#ifndef AMRPAYLOADDECODER_H
+#define AMRPAYLOADDECODER_H
+
+// INCLUDES
+#include <e32std.h>
+#include "amrpayloadformatter.h"
+#include "streamformatter.h"
+
+
+// FORWARD DECLARATIONS
+class CAmrPayloadHeader;
+class CAmrTocEntry;
+class TStreamDecoder;
+
+// CLASS DECLARATION
+
+/**
+* The AMR payload decoder for bandwidth efficient mode.
+*
+* @lib <TBD>
+* @since Series-60 2.1
+*/
+class CAmrPayloadDecoder : public CAmrPayloadFormatter
+ {
+ public: // Constructors and destructor
+
+ /**
+ * Two-phased constructor.
+ */
+ static CAmrPayloadDecoder* NewL( TBool aIsNb );
+
+ /**
+ * Destructor.
+ */
+ virtual ~CAmrPayloadDecoder( );
+
+
+ public: // New functions
+
+ /**
+ * Decode payload data received in the payload buffer.
+ * If AMR FEC is used and redundant frames are discarded, time stamp is
+ * increased to correspond start of remaining frames.
+ *
+ * @since Series 60 3.0
+ * @param aTimeStamp Time stamp from RTP header
+ * @param aTimeStampInc Unit for time stamp incrementing
+ * @return TInt - Number of AMR frames decoded
+ */
+ virtual TInt DecodePayload( TUint32& aTimeStamp,
+ TUint32 aTimeStampInc );
+
+ /**
+ * Get AMR codec mode request ( CMR ) received in the payload.
+ * @since Series-60 2.1
+ * @return TAmrModeRequest - AMR codec mode request ( CMR ) received
+ */
+ TAmrModeRequest ModeRequest() const;
+
+ /**
+ * Get AMR frames decoded from the payload.
+ * Number of frames equals the value returned by `DecodePayload( )' function.
+ * @since Series-60 2.1
+ * @return TAmrFrame[] - Array of AMR frames decoded
+ */
+ TAmrFrame* Frames( );
+
+ protected:
+
+ /**
+ * Constructor.
+ */
+ CAmrPayloadDecoder( TBool aIsNb );
+
+ private:
+
+ /**
+ * By default Symbian 2nd phase constructor is private.
+ */
+ void ConstructL( );
+
+ protected: // Functions
+
+ /**
+ * Decode the AMR payload ( for one RTP packet ) from a given buffer.
+ * Decoded values are returned in `iFrames' array.
+ * @since Series-60 2.1
+ * @param aBuffer - [input] Buffer to decode data from.
+ * @param aBufferSize - [input] Buffer size in bytes.
+ * @return None
+ */
+ void Decode( const TUint8* aBuffer,
+ TInt aBufferSize );
+
+ /**
+ * Decode TOC ( Table of Contents ) entries from a given buffer at the given
+ * position. Decoded information are stored in `iFrames' array.
+ * Byte and bit positions are updated after decoding is done.
+ * @since Series-60 2.1
+ * @param aBuffer - [input] Buffer to decode data from.
+ * @param aBufferSize - [input] Buffer size in bytes.
+ * @param aByteIndex - [input] Starting byte index ( starts from zero ).
+ * [output] Byte index updated after encoding.
+ * @param aBitIndex - [input] Starting bit index ( starts from zero ).
+ * [output] Bit index updated after encoding.
+ * @return Number of TOC entries decoded.
+ */
+ TInt DecodeTableOfContents( const TUint8* aBuffer,
+ TInt aBufferSize,
+ TInt& aByteIndex,
+ TInt& aBitIndex );
+
+ /**
+ * Calculate frames' starting Byte and Bit positions in a given payload buffer
+ * and update `iFrames' array with the frames' positions.
+ * @since Series-60 2.1
+ * @param aBuffer - [input] Payload buffer.
+ * @param aBufferSize - [input] Buffer size in bytes.
+ * @param aFrameCount - [input] Number of frames included in the payload buffer.
+ * @return None
+ */
+ virtual void CalculateFramePosition( const TUint8* aBuffer,
+ TInt aFrameCount );
+
+ protected: // From CAmrPayloadFormatter
+
+ /**
+ * Initializes decoder. Decoder should be initialized when starting
+ * playing.
+ *
+ * @since Series 60 3.0
+ * @param None
+ * @return void
+ */
+ virtual void DoInitialize();
+
+ private: // Functions
+
+ /**
+ * Compares two AMR frames.
+ *
+ * @since Series 60 3.0
+ * @param aBuffer Payload buffer containing one AMR frame
+ * @param aFrameToCmp AMR frame to which compare
+ * @param aBitsToCmp Number of bits to search
+ * @return ETrue if contents are same; otherwise EFalse
+ */
+ TBool CompareBuffers( const TDesC8& aBuffer,
+ const TAmrFrame& aFrameToCmp,
+ TInt aBitsToCmp ) const;
+
+
+
+ protected: // Data
+
+ // Payload decoding
+ // Decoder for payload header
+ CAmrPayloadHeader* iHeaderDecoder;
+
+ // Decoder for TOC entry
+ CAmrTocEntry* iTocEntryDecoder;
+
+ // Frames decoded from received buffer
+ TInt iDecodedFrames;
+
+ // Time stamp to give for next frame being decoded
+ TUint32 iTimeStamp;
+
+ // Unit for time stamp incrementing/decrementing
+ TUint32 iTimeStampInc;
+ private:
+
+ #ifdef TEST_EUNIT
+ friend class UT_CAmrPayloadDecoder;
+ friend class UT_CAmrPayloadFormatRead;
+ #endif
+ };
+
+
+
+#endif // __AMRPAYLOADDECODER_H