/*

 * Copyright (c) 2009 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: Telephony Multimedia Service

 *

 */

#ifndef __AMRCODEC_H__

#define __AMRCODEC_H__

// INCLUDES

#include <E32Base.h>

// FORWARD DECLARATIONS

class CAmrToPcmDecoderImpl;

class CPcmToAmrEncoderImpl;

// CLASS DECLARATION

/**

*    TAmrDecParams

*    AMR decoding parameters.

*/

class TAmrDecParams

    {

public:

    /**

    * Default constructor.

    */

    inline TAmrDecParams();

public:

    // error concealment level (0 none, 1 default)

    TInt iConcealment;

    };

TAmrDecParams::TAmrDecParams() :

iConcealment(1) {}

/**

*    TAmrEncParams

*    AMR encoding parameters.

*/

class TAmrEncParams

    {

public:

    /**

    * Default constructor.

    */

    inline TAmrEncParams();

public:

    // encoding mode 0-7 (0=MR475,1=MR515,...,7=MR122, default 7)

    TInt iMode;

    // DTX flag (TRUE or default FALSE)

    TInt iDTX;

    };

TAmrEncParams::TAmrEncParams() :

iMode(7), iDTX(0) {}

// CLASS DEFINITIONS

/**

*    TAmrFrameInfo

*    AMR frame info struct.

*/

class TAmrFrameInfo

    {

public:

    /**

    * Default constructor.

    */

    TAmrFrameInfo() {};

public:

    /**

    * Returns the size of smallest AMR audio frame, i.e., the size of one DTX

    * frame. NO DATA frames (size 1 byte) are not taken into account here.

    *

    * @since ?Series60_version

    * @param none

    * @return TInt

    */

    IMPORT_C static TInt MinFrameSize();

    /**

    * Returns the size of biggest AMR audio frame, i.e., the size of one EFR

    * frame.

    *

    * @since ?Series60_version

    * @param none

    * @return TInt

    */

    IMPORT_C static TInt MaxFrameSize();

    /**

    * Returns the maximum number of samples per one audio channel in one

    * AMR audio frame.

    *

    * @since ?Series60_version

    * @param none

    * @return TInt

    */

    IMPORT_C static TInt MaxFrameSamples();

    /**

    * Returns the maximum number audio channels in one frame.

    *

    * @since ?Series60_version

    * @param none

    * @return TInt

    */

    IMPORT_C static TInt MaxChannels();

    /**

    * Returns the size of one AMR frame header. The header must include

    * all bits needed for determining the actual frame length.

    *

    * @since ?Series60_version

    * @param none

    * @return TInt Size of AMR frame header

    */

    IMPORT_C static TInt FrameHeaderSize();

    /**

    * Returns the size of frame described by given coding parameters. The only

    * parameter used in calculation is the coding mode (iMode).

    *

    * @since ?Series60_version

    * @param none

    * @return TInt AMR frame size

    */

    IMPORT_C static TInt FrameSize(const TAmrFrameInfo& aInfo);

public:

    TInt iMode;            // encoding mode

    TInt iBitrate;         // bitrate (kbit/s)

    TInt iSamplingRate;    // sampling frequency (Hz)

    TInt iChannels;        // number of channels

    TInt iFrameSize;       // encoded size (bytes)

    TInt iFrameSamples;    // decoded size (samples per channel)

public:

    TInt iSamplingRateOut; // sampling frequency after conversion (Hz)

    TInt iChannelsOut;     // number of audio channels after conversion (1 or 2)

    TInt iFrameSamplesOut; // decoded size after conversion (samples per channel)

    };

/**

*    CAmrToPcmDecoder

*    Low level AMR decoding API.

*/

class CAmrToPcmDecoder : public CBase

    {

protected:

    /**

    * Default constructor.

    */

    IMPORT_C CAmrToPcmDecoder();

    /**

    * 2nd phase constructor. Constructs the decoder.

    */

    IMPORT_C void ConstructL();

public:

    /**

    * Two-phased constructor. First allocates and constructs decoder 

    * and then resets it according to the given configuration.

    *

    * @since ?Series60_version

    * @param aConf Decoder configuration params

    * @return CAmrToPcmDecoder* Pointer to constructed decoder

    */

    IMPORT_C static CAmrToPcmDecoder* NewL(const TAmrDecParams& aConf);

    /**

    * Destructor

    */

    IMPORT_C virtual ~CAmrToPcmDecoder();

    /**

    * Initializes decoder and resets it into the default decoding state.

    *

    * @since ?Series60_version

    * @param none

    * @return void

    */

    IMPORT_C void Reset();

    /**

    * Initializes decoder and resets it according to the given configuration.

    *

    * @since ?Series60_version

    * @param aConf Decoder configuration params

    * @return void

    */

    IMPORT_C void Reset(const TAmrDecParams& aConf);

    /**

    * Calculates the frame size and returns information about the frame which

    * starts from the beginning of aBuf. Returns 0, if the frame bit syntax is

    * incorrect or not enough bits are available for calculating the frame size

    * and the frame parameters (aBufLen < TAmrCodecParams::FrameHeaderSize).

    *

    * The frame parameters returned via aInfo are: mode, sampling frequency,

    * number of channels, frame size (same as return value) and number of

    * samples in this frame. See also TMdaRawAmrAudioCodec class.

    *

    * @since ?Series60_version

    * @param aBuf Pointer to frame buffer

    * @param aBufLen Length of frame buffer

    * @param aInfo Reference to frame parameters

    * @return TInt Length of frame in bytes

    */

    IMPORT_C static TInt FrameInfo(const TUint8* aBuf, TInt aBufLen, TAmrFrameInfo& aInfo);

    /**

    * A variation of the FrameInfo above, which takes into account the

    * decoding switches in calculating iSampligRateOut, iChannelsOut

    * and iFrameSamplesOut.Initializes decoder and resets it according 

    * to the given configuration.

    *

    * @since ?Series60_version

    * @param aBuf Pointer to frame buffer

    * @param aBufLen Length of frame buffer

    * @param aInfo Reference to fram parameters

    * @param aConf Reference to decoding switches

    * @return TInt Length of frame in bytes

    */

    IMPORT_C static TInt FrameInfo(const TUint8* aBuf, TInt aBufLen, TAmrFrameInfo& aInfo, const TAmrDecParams& aConf);

    /**

    * This routine seeks the start position of the next frame and returns

    * the byte position of its header. Returns aBufLen, if no valid frame

    * can not be found (see FrameInfo). The seek progresses from the start

    * of aBuf (0) toward the end of aBuf(aBufLen - 1).

    *    

    * The level of syntax check depends on the number of bits available. At

    * minimum the first frame header bits are checked only, but if more

    * bits are available, they can be used to make the sync seek more robust.

    * For succesful seek the whole frame does not need to exist in aBuf.    

    *

    * @since ?Series60_version

    * @param aBuf Pointer to frame buffer

    * @param aBufLen Length of frame buffer

    * @return TInt Frame position or aBufLen

    */

    IMPORT_C static TInt SeekSync(const TUint8* aBuf, TInt aBufLen);

    /**

    * Decodes one frame.    

    *

    * @since ?Series60_version

    * @param aSrc Pointer to bit stream buffer

    * @param aSrcUsed Number of consumed bytes

    * @param aDst Pointer to PCM buffer

    * @param aDstLen Number of produced bytes

    * @param aMuteFlag If ETrue this frame is muted

    * @return TInt Non-zero if decoding failed

    */

    IMPORT_C TInt Decode(TUint8* aSrc, TInt& aSrcUsed, TUint8* aDst, TInt& aDstLen, TBool aMuteFlag);

    /**

    * Decodes one frame from aSrc to aDst1 and aDst2. NOTE: aDst1 or

    * aDst2 can be NULL and in that case decoding to that buffer is not

    * requested.

    *

    * @since ?Series60_version

    * @param aSrc Pointer to bit stream buffer

    * @param aSrcUsed Number of consumed bytes

    * @param aDst1 Pointer to PCM sample buffer (time domain sample)

    * @param aDst2 Pointer to frequency sample buffer (frequency domain sample)

    * @param aDstLen1 Number of produced bytes in aDst1

    * @param aDstLen2 Number of produced bytes in aDst2

    * @param aMuteFlag If ETrue this frame is muted

    * @return TInt Non-zero if decoding failed

    */

    IMPORT_C TInt Decode(TUint8* aSrc, TInt& aSrcUsed, TUint8* aDst1, TUint8* aDst2, TInt& aDstLen1, TInt& aDstLen2, TInt aMuteFlag);

private:

    CAmrToPcmDecoderImpl* iState;

    };

/**

*    CPcmToAmrEncoder

*    Low level AMR encoding API.

*/

class CPcmToAmrEncoder : public CBase

    {

protected:

    /**

    * Default constructor.

    */

    IMPORT_C CPcmToAmrEncoder();

    /**

    * 2nd phase constructor. Constructs the encoder.

    */

   IMPORT_C void ConstructL();

public:

    /**

    * Two-phased constructor. First allocates and constructs encoder 

    * and then resets it according to the given configuration.

    *

    * @since ?Series60_version

    * @param aConf Encoder configuration params

    * @return CPcmToAmrEncoder* Pointer to constructed encoder

    */

    IMPORT_C static CPcmToAmrEncoder* NewL(const TAmrEncParams& aConf);

    /**

    * Destructor

    */

    IMPORT_C virtual ~CPcmToAmrEncoder();

    /**

    * Initializes encoder and resets encoder state.

    *

    * @since ?Series60_version

    * @param none

    * @return void

    */

    IMPORT_C void Reset();

    /**

    * Initializes encoder and resets it according to the given configuration.

    *

    * @since ?Series60_version

    * @param aConf Encoder configuration params

    * @return void

    */

    IMPORT_C void Reset(const TAmrEncParams& aConf);

    /**

    * Encodes one frame.

    *

    * @since ?Series60_version

    * @param aSrc Pointer to PCM buffer

    * @param aSrcUsed Number of consumed bytes

    * @param aDst Pointer to bit stream buffer

    * @param aDstLen Length of resulting frame

    * @return TInt Non-zero if encoding failed

    */

    IMPORT_C TInt Encode(TUint8* aSrc, TInt& aSrcUsed, TUint8* aDst, TInt& aDstLen);

private:

    CPcmToAmrEncoderImpl* iState;

    };

#endif //__AMRCODEC_H__

//  End of File