/*

* Copyright (c) 2009 Aricent and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the License "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:

* Aricent - initial contribution.

*

* Contributors:

*

* Description:

* Contains base class for process engine (CBaseEngine) and an abstract class

* (MProcessEngineObserver) which has callback methods to indicate events like

* completion of encoding, processing of a command etc.

*

*/

#ifndef ARIBASEENGINE_H

#define ARIBASEENGINE_H

#include <E32base.h>

#include "aribasecodec.h"

/**

 * An abstract class which contains call back functions to be derived and

 * implemented by any module wishing to use the process engine.

 */

class MProcessEngineObserver

	{

	public:

		/**

		 * From MProcessEngineObserver

		 * The function is a callback to indicate the input buffer is consumed

		 * @param aInp

		 *    Pointer to the input picture that has been processed

		 * @param aError

		 *   Error code returned by process engine

		 * @return error value

		 */

		virtual TInt InputBufferConsumed( TAny* aInp, TInt aError ) = 0;

		/**

		 * From MProcessEngineObserver

		 * The function is a callback to indicate the output buffer is ready

		 * @param aOup

		 *    Pointer to the output picture that has been processed

		 * @param aError

		 *   Error code returned by process engine

		 * @return error value

		 */

		virtual TInt OutputBufferReady( TAny* aOup, TInt aError  ) = 0;

		/**

		 * From MProcessEngineObserver

		 * The function indicates to hwdevice that process engine has finished

		 * with the processing of command requested by hwdevice

		 * @param aCmd

		 *    Command that has been processed by process engine

		 * @param aCmdData

		 *   Pointer to command data that has been processed by process engine

		 * @param aError

		 *   Error code corresponding to the command

		 */

		virtual void CommandProcessed( TInt aCmd, TAny* aCmdData,

														TInt aError ) = 0;

		/**

		 * From CMMFVideoEncodeHwDevice

		 * The function indicates to hwdevice that process engine has met with 

		 * an unrecoverable error during its processing

		 * @param aError

		 *    The fatal error code

		 */

		virtual	void FatalErrorFromProcessEngine( TInt aError ) = 0;

	};

	/**

	 * Base class for base process engine. This calls creates class

	 * CAriH264encHwDeviceImpl which derives this class & provides

	 * implementation for pure virtual functions present in this class.

	 */

class CBaseEngine

	{

	public:

	/**

	 * Enumeration to be used to set priority of an command

	 */

	enum TCmdPriority

		{

		ENormalPriority  = 0,

		EStandardPriority = 1,

		EHighPriority = 2,

		EVeryHighPriority = 3

		};

	/**

	 * Two-phased constructor.

	 * @param aObserver

	 *    Pointer to observer to the process engine - HwDevice

	 * @param aCodec

	 *    Pointer to wrapper

	 * @param aInPlaceProcessing

	 *

	 * @param aProcessingAutomatic

	 *

	 * @return pointer to an instance of CBaseProcessEngine

	 */

	IMPORT_C static CBaseEngine* NewL( MProcessEngineObserver* aObserver,

			MBaseCodec* aCodec,

			TBool aInPlaceProcessing,

			TBool aProcessingAutomatic = ETrue );

	/**> Destructor */

	virtual ~CBaseEngine ()

		{

		}

	public:

	/**

	 * Adds an input buffer to the Q

	 * @param aBuffer

	 * 	  Pointer to an input buffer.

	 * @return symbian wide error code

	 */

	virtual TInt AddInput( TAny* aBuffer ) = 0;

	/**

	 * Adds an output buffer to the Q

	 * @param aBuffer

	 * 	  Pointer to an output buffer.

	 * @return symbian wide error code

	 */

	virtual TInt AddOutput( TAny* aBuffer ) = 0;

	/**

	 * Starts the processing

	 * @return symbian wide error code, KErrNone on success

	 */

	virtual TInt Start() = 0;

	/**

	 * Stops the processing

	 * @return symbian wide error code, KErrNone on success

	 */

	virtual TInt Stop() = 0;

	/**

	 * Processes the commands

	 * @param aPriority

	 * 	  Priority of the encode command object

	 */

	virtual void DoProcessL( TInt aPriority ) = 0;

	/**

	 * Adds a new command to the priority queue of commands

	 * @param aPriority

	 * 	  Priority of the command object

	 * @param aCmd

	 * 	  The command

	 * @param aCmdData

	 * 	  Command specific data

	 */

	virtual void AddCommandL( TInt aPriority, TInt aCmd, TAny* aCmdData ) = 0;

	/**

	 * Resets the processing engine and flushes all the pending input and

	 * output buffers.

	 * Calls InputBufferConsumed and OutputBufferReady to give pending

	 * input & output buffers with aError = KErrCancel.

	 */

	virtual void Reset() = 0;

	/**

	 * Returns a output buffer back to the HwDevice

	 */

	virtual void ReturnOutputBuffers() = 0;

	/**

	 * Gets the number of input buffers

	 * @return returns the number of input buffers in process engine q

	 */

	virtual TInt NumInputBuffers() = 0;

	/**

	 * Gets the number of output buffers

	 * @return returns the number of output buffers in process engine q

	 */

	virtual TInt NumOutputBuffers() = 0;

	/**

	 * Returns whether processing of an input buffer is going on or else

	 * @return ETrue if processing in on going, else EFalse

	 */

	virtual TBool IsProcessing() = 0;

	/**

	 * Returns input buffer back to the HwDevice

	 */

	virtual void ReturnInputBuffers() = 0;

	/**

	 * Returns all the input pictures added previously.

	 */

	virtual void ReturnInput() = 0;

	public:

	/**

	 * Called by MBaseCodec when processing is complete

	 * @param aInpBuf

	 * 	  The input buffer sent for processing

	 * @param aOutBuf

	 *    The output buffer

	 * @param aState

	 *    The result of processing

	 * @param aError

	 *    Error value returned from DoProcessL

	 */

	virtual void ProcessingComplete( TAny *aInpBuf, TAny* aOutBuf,

					MBaseCodec::TCodecState aState, TInt aError ) = 0;

	/**

	 * Called by MBaseCodec when processing of commmands is complete

	 * @param aCommand

	 * 	  The command which has been processed

	 * @param aCmdData

	 *    Command specific data

	 * @param aState

	 *    The result of processing

	 * @param aError

	 * 	  Result of processing command

	 */

	virtual void ProcessingCommandComplete( TInt aCommand, TAny* aCmdData,

															TInt aError ) = 0;

	/**

	 * Returns the 1st buffer from the output buffer queue

	 * @return returns pointer to the fetched output buffer

	 */

	virtual TAny* FetchOutputBuffer() = 0;

	};

#endif //ARIBASEENGINE_H