sl@0: /*
sl@0: * Copyright (c) 2006-2009 Nokia Corporation and/or its subsidiary(-ies).
sl@0: * All rights reserved.
sl@0: * This component and the accompanying materials are made available
sl@0: * under the terms of "Eclipse Public License v1.0"
sl@0: * which accompanies this distribution, and is available
sl@0: * at the URL "http://www.eclipse.org/legal/epl-v10.html".
sl@0: *
sl@0: * Initial Contributors:
sl@0: * Nokia Corporation - initial contribution.
sl@0: *
sl@0: * Contributors:
sl@0: *
sl@0: * Description:
sl@0: *
sl@0: */
sl@0: 
sl@0: 
sl@0: 
sl@0: 
sl@0: /**
sl@0:  @file
sl@0:  @publishedPartner
sl@0:  @released
sl@0: */
sl@0: 
sl@0: #ifndef MAUDIOCODEC_H
sl@0: #define MAUDIOCODEC_H
sl@0: 
sl@0: #include <a3f/a3fbase.h>
sl@0: #include <a3f/maudioprocessingunit.h>
sl@0: #include <a3f/maudiocodecobserver.h>
sl@0: 
sl@0: 
sl@0: /**
sl@0:  * A generic abstract interface for codecs.
sl@0:  *
sl@0:  * The client must add a codec to a stream for operation.
sl@0:  * The codec can only be added to a stream when the codec is in uninitialized state.
sl@0:  * The codec can only be removed from a stream when the codec is in uninitialized or dead states.
sl@0:  */
sl@0: class MAudioCodec
sl@0: 	{
sl@0: 	public:
sl@0: 	
sl@0: 	/**
sl@0: 	 * Sets the codec format.
sl@0: 	 *
sl@0: 	 * For encoders this sets the output format.
sl@0: 	 * For decoders this configures the input format.
sl@0: 	 * Format must be set before the codec can transfer to initialized state.
sl@0: 	 *
sl@0: 	 * @param aFormat codec format.
sl@0: 	 * @return An error code. KErrNone on success, otherwise one of the system wide error codes.
sl@0: 	 */
sl@0: 	virtual TInt SetFormat(TUid aFormat)=0;
sl@0: 
sl@0: 	/**
sl@0: 	* Sets the sample rate in samples/sec.
sl@0: 	*
sl@0: 	* sets the sample rate of the encoded data,
sl@0: 	* and says nothing about the sample rate used on the output device
sl@0: 	* or whether re-sampling is required that is up to the adaptation.
sl@0: 	* the result of the operation is returned by MAudioCodecObserver::SampleRateSet().
sl@0: 	*
sl@0: 	* @param aSampleRate sample rate to be used, in samples/sec.
sl@0: 	* @return An error code. KErrNone on success, otherwise one of the system wide error codes.
sl@0: 	*/
sl@0: 	virtual TInt SetSampleRate(TInt aSampleRate)=0;
sl@0: 
sl@0: 	/**
sl@0: 	* Sets the mode, e.g. mono/stereo. 
sl@0: 	* The result of the operation is returned by MAudioCodecObserver::ModeSet().
sl@0: 	*
sl@0: 	* @param aMode uid stating the mode.
sl@0: 	* @return An error code. KErrNone on success, otherwise one of the system wide error codes.
sl@0: 	*/
sl@0: 	virtual TInt SetMode(TUid aMode)=0;
sl@0: 
sl@0: 	/**
sl@0: 	* This returns a list of supported sample rates. The list need just include those of the standard list 
sl@0: 	* that are supported. Includes rates supported by sample rate conversion. 
sl@0: 	* GetSupportedSampleRatesComplete() callback shows result.
sl@0: 	* TODO Need to document that the implementation is responsible for calling Reset() on aSupportedRates.
sl@0: 	*
sl@0: 	* @param aSupportedRates array that is populated with the supported rates list.
sl@0: 	* @return An error code. KErrNone on success, otherwise one of the system wide error codes.
sl@0: 	*/
sl@0: 	virtual TInt GetSupportedSamplesRates(RArray<TInt>& aSupportedRates)=0;
sl@0: 
sl@0: 	/**
sl@0: 	* This returns a list of supported sample modes. The list corresponds to the current configuration 
sl@0: 	* and support may include the use of mono/stereo conversion etc. 
sl@0: 	* GetSupportedModesComplete() callback shows result.
sl@0: 	* TODO Need to document that the implementation is responsible for calling Reset() on aSupportedModes.
sl@0: 	*
sl@0: 	* @param aSupportedModes array that is populated with the supported modes list.
sl@0: 	* @return An error code. KErrNone on success, otherwise one of the system wide error codes.
sl@0: 	*/
sl@0: 	virtual TInt GetSupportedModes(RArray<TUid>& aSupportedModes)=0;
sl@0: 
sl@0: 	/**
sl@0: 	* Registers an audio codec observer.
sl@0: 	*
sl@0: 	* Note that this function is meant for clients of the Audio codec. 
sl@0: 	* The client should unregister using UnregisterAudioCodecObserver() when applicable
sl@0: 	*
sl@0: 	* @param aObserver reference to the observer to register.
sl@0: 	* @return an error code. KErrNone if successful.
sl@0: 	*				KErrAlreadyExists if the client is already registered.
sl@0: 	*				KErrOutOfMemory in case of memory exhaustion.
sl@0: 	*/
sl@0: 	virtual TInt RegisterAudioCodecObserver(MAudioCodecObserver& aObserver)=0;
sl@0: 
sl@0: 	/**
sl@0: 	* Unregisters an audio codec observer.
sl@0: 	*
sl@0: 	* @param aObserver reference to the observer to unregister.
sl@0: 	* @return an error code.  KErrNone if successful.
sl@0: 	* 						KErrNotFound if the client has not been registered as observer.
sl@0: 	*/
sl@0: 	virtual void UnregisterAudioCodecObserver(MAudioCodecObserver& aObserver)=0;
sl@0: 
sl@0: 	};
sl@0: 
sl@0: #endif // MAUDIOCODEC_H