/*

* Copyright (c) 2005 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:  ?Description

*

*/

#ifndef __BTAUDIOSTREAMINPUTBASE_H__

#define __BTAUDIOSTREAMINPUTBASE_H__

#include <e32base.h>

#include <e32std.h>

#include <mmf/common/mmfutilities.h> 

/**

 *  Observer interface for receiving the audio data buffers. 

 *

 *  This class defines an observer interface to be implemented by the 

 *  class that is going to receive the audio data. 

 *

 *  @lib btaudioadaptation.lib 

 *  @since S60 v3.1

 */

class MBTAudioStreamObserver 

{

public: 

    /**

     * Method for receiving audio data and an associated timestamp. 

     *

     * @since S60 v3.1 

     * @param aBuffer the audio data frames from the encoder. 

     * @param aTimestamp the timestamp of the first audio frame in the aBuffer 

     * @return a Symbian OS wide error code. 

     */

	virtual TInt Receive(const TDesC8& aBuffer, TTimeIntervalMicroSeconds aTimestamp) = 0;

    /**

     * Method for receiving audio data. 

     *

     * @since S60 v3.1 

     * @param aBuffer the audio data frames from the encoder. 

     * @return a Symbian OS wide error code. 

     */

	virtual TInt Receive(const TDesC8& aBuffer) = 0;

}; 

/**

 *  Observer interface for receiving the audio adaptation errors. 

 *

 *  This class defines an observer interface to be implemented by the 

 *  class that is going to receive the errors that have occurred in 

 *  BT Audio Adaptation or in the audio subsystem. 

 *

 *  To be implemented by a class who uses this adaptation class. 

 *  @lib btaudioadaptation.lib 

 *  @since S60 v3.1

 */

class MBTAudioErrorObserver 

{

public: 

    /**

 		 *  Method for receiving the errors. 

     *

     * @since S60 v3.1 

     * @param aError a Symbian OS wide error code. 

     * @return a Symbian OS wide error code. 

     */

	virtual TInt Error(const TInt aError) = 0;

}; 

/**

 *  This class specifies the interface for receiving audio data from audio subsystem. 

 *

 *  This class contains the interface definition. It can't be instantiated directly, 

 *  but instead the implementation is done in the class inherited from this class. 

 *  

 *  Also, the factory method for the base class must be implemented by the 

 *  implementator of this interface. 

 *

 *  @lib btaudioadaptation.lib

 *  @since S60 v3.1 

 */

class CBTAudioStreamInputBase : public CBase

{

public: 

    IMPORT_C static CBTAudioStreamInputBase* NewL( MBTAudioStreamObserver &aStreamObserver, MBTAudioErrorObserver &aErrorObserver );

    /**

     * This method is for connecting to the audio subsystem. 

     *

     * See BT Audio Adaptation API and BT Audio Adaptation Design specifications 

     * for detailed explanation. 

     *

     * @since S60 v3.1

     * @param void. 

     * @return a Symbian OS wide error code. 

     */

    virtual TInt Connect() = 0;

    /**

     * This method is for disconnecting from the audio subsystem. 

     *

     * See BT Audio Adaptation API and BT Audio Adaptation Design specifications 

     * for detailed explanation. 

     *

     * @since S60 v3.1

     * @param void. 

     * @return void

     */

    virtual void Disconnect() = 0;

    /**

     * This method is for passing the custom interfaces that are 

     * needed sometimes for configuring the hardware encoder. 

     *

     * See BT Audio Adaptation API and BT Audio Adaptation Design specifications 

     * for detailed explanation. 

     *

     * @since S60 v3.1

     * @param aInterfaceId specifies the id of custom interface that the client 

     *        wants to get. 

     * @return  A pointer to the requested interface. Client must cast it into a correct class. 

     */

    virtual TAny *EncoderInterface(TUid aInterfaceId) = 0;

    /**

     * This method is for choosing the encoder for the audio data. 

     *

     * See BT Audio Adaptation API and BT Audio Adaptation Design specifications 

     * for detailed explanation. 

     *

     * @since S60 v3.1

     * @param aDesiredFourCC specifies the encoder that the client wants to use. 

     * @return a Symbian OS wide error code. 

     */

    virtual TInt SetFormat(TFourCC aDesiredFourCC) = 0; 

    /**

     * This method is for starting the recording from the audio subsystem. 

     *

     * See BT Audio Adaptation API and BT Audio Adaptation Design specifications 

     * for detailed explanation. 

     *

     * @since S60 v3.1

     * @param void. 

     * @return a Symbian OS wide error code. 

     */

    virtual TInt Start() = 0;

    /**

     * This method is for stopping the recording from the audio subsystem. 

     *

     * See BT Audio Adaptation API and BT Audio Adaptation Design specifications 

     * for detailed explanation. 

     *

     * @since S60 v3.1

     * @param void. 

     * @return a Symbian OS wide error code. 

     */

    virtual void Stop() = 0;

    /**

	 * This method is called when the client has processed the buffer it got 

	 * from the Receive method. 

	 * 

     * See BT Audio Adaptation API and BT Audio Adaptation Design specifications 

     * for detailed explanation. 

     *

     * @since S60 v3.1

     * @param aBuffer refers to the buffer that was received earlier in the Receive method. 

     * @return  void

     */

    virtual void BufferEmptied( const TDesC8 &aBuffer ) = 0;

}; 

#endif