diff -r 000000000000 -r bde4ae8d615e os/mm/devsound/a3facf/inc/maudiostream.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/os/mm/devsound/a3facf/inc/maudiostream.h Fri Jun 15 03:10:57 2012 +0200 @@ -0,0 +1,327 @@ +/* +* Copyright (c) 2007-2009 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: +* +*/ + + + + +/** + @file + @publishedPartner + @released +*/ + +#ifndef MAUDIOSTREAM_H +#define MAUDIOSTREAM_H + +#include +#include +#include +#include + +class MAudioStreamObserver; +class MAudioCodecObserver; +class MAudioCodec; +class MAudioProcessingUnit; + +/** + * this is the main control interface for the state of a processing unit chain. + * + * An AudioStream object binds together audio components processing the same data. + * An AudioStrem executes the audio processing states as requested by the client. The processing units + * attached to a stream will follow the state of the stream. + * + * The possible states of an AudioStream object are: + * EUninitialized: The state which the chain is in initially. + * The logical chain can be constructed. + * The settings in the logical chain cannot be related to the adaptation because no adaptation has been selected yet. + * + * EInitialized: this state is set after a successful initialization request. + * EIdle: All the chain resources are allocated, however, no processing time + * (other than expended to put the chain into EIdle state) is consumed in this phase. + * EPrimed: As per EIdle, but the stream can consume processing time, by filling its buffers. + * EActive: The chain has all the resources as per EIdle and EPrimed but also has started to + * process the actions requested by the client. + * EDead: The stream can no longer function due to fatal error. + * The logical chain still exists, but any physical resources should be reclaimed by the adaptation. + * + * The MAudioStreamObserver includes completion callbacks for many of the methods of MAudioStream. + * The protocol is such that when an asynchronous method is called and KErrNone is returned, + * then the call will be followed by a corresponding callback. if the returned error code from + * the asynchronous function is other than KErrNone, then a callback will not be made as + * a result of that method call. The callbacks will always occur out-of-context. + * Note that many of the functions will also require a context commit for the actual processing to take place. + */ +class MAudioStream + { +public: + /** + * Registers an audio stream observer. + * + * Note that this function is meant for clients of the Audio Stream. + * The client should unregister using UnregisterAudioStreamObserver() when applicable. + * + * @param aObserver reference to the observer to register. + * @return an error code. KErrNone if successful. + * KErrAlreadyExists if the client is already registered. + * KErrOutOfMemory in case of memory exhaustion. + */ + virtual TInt RegisterAudioStreamObserver(MAudioStreamObserver& aObserver)=0; + + /** + * Unregisters an audio stream observer. + * + * @param aObserver reference to the observer to unregister. + * @return an error code. KErrNone if successful. KErrNotFound if the client has not been registered as observer. + */ + virtual void UnregisterAudioStreamObserver(MAudioStreamObserver& aObserver)=0; + + + /** + * Sets the type of audio being processed in this context. + * + * The audio type settings are used by the resource control subsystem when it arbitrates between multiple clients + * trying to access the same resource. Additionally it may impact the availability of certain audio features for the client. + * It may also have an effect on other aspects, including, but not limited to routing and automatically applied effects. + * The audio types available for the client may be limited by the platform security capabilities, vendorId etc of the client application. + * + * @param aAudioTypeSettings defines the settings associated with this stream. + * @return an error code. KErrNone if successful, otherwise one of the system wide error codes. + */ + virtual TInt SetAudioType(const TAudioTypeSettings& aAudioTypeSettings)=0; + + /** + * Fetch the type of audio being processed in this stream. + * + * @param aAudioTypeSettings On return contains the audio type of this stream. + */ + virtual void GetAudioType(TAudioTypeSettings& aAudioTypeSettings) const = 0; + + /** + * Requests a transition to the EInitialized state. + * + * this function is asynchronous, and its successful return merely issues a request which is acted upon on Commit(), + * and while will lead to a StateEvent() callback. this function is only allowed while the stream is in EUninitialized state. + * A call in any other state will cause an error code of KErrNotReady to be returned. + * + * @return an error code. if KErrNone, the state transition has been requested, + * and there will be a StateEvent() callback following Commit(). + * On error, there is no request made: KErrNotReady states the stream if not in valid current state, + * otherwise one of the system-wide error codes. + */ + virtual TInt Initialize()=0; + + /** + * Requests a transition to the EIdle state. + * + * this function is asynchronous, and its successful return merely issues a request which is acted upon on Commit(), + * and while will lead to a StateEvent() callback. this function is only allowed while the stream is in EInitialized state. + * A call in any other state will cause an error code of KErrNotReady to be returned + * + * The resources must be released using Unload() when they are no longer needed. + * Note that it is recommended that the resources are not kept reserved for long periods of inactivity, + * since it may prevent other audio streams from becoming active by stealing resources they need to use + * + * @return An error code. if KErrNone, the state transition has been requested, + * and there will be a StateEvent() callback following Commit(). + * On error, there is no request made: KErrNotReady states the stream if not in valid current state, + * otherwise one of the system-wide error codes. + */ + virtual TInt Load()=0; + + /** + * Starts the audio processing. this function is only allowed while the stream is in EIdle or EPrimed states. + * + * The start-up procedures include requesting permission for audio processing from audio policy. + * + * @return an error code. A call in any state different to EIdle or EPrimed will cause an error code of KErrNotReady. + * if permission to start is denied by audio policy, a state change back to EPrimed will occur with error code KErrAccessDenied + */ + virtual TInt Activate()=0; + + /** + * Requests a transition to the Idle state – stopping the ongoing operation. + * + * this function is asynchronous, and its successful return merely issues a request which is acted upon on Commit(), + * and while will lead to a StateEvent() callback this function is only allowed while the stream is either Active or Primed. + * A call in any other state will cause an error code of KErrNotReady to be returned. + * @return An error code. if KErrNone, the state transition has been requested, and there will be a StateEvent() callback + * following Commit(). On error, there is no request made: KErrNotReady states the stream if not in valid current state, + * otherwise one of the system-wide error codes + */ + virtual TInt Stop()=0; + + /** + * Prepares the audio stream for releasing the resources reserved for it and for the processing units attached to the stream. + * + * this function is only allowed while the stream is EIdle state. + * A call in any other state will cause an error code of KErrNotReady to be returned. + * + * During this call the stream will query all attached processing units whether they are ready to unload. + * if a processing unit indicates that it is not ready to uninitialize, then an error code other than KErrNone will be returned. + * Provided that this call succeeds, the actual unloading process will begins once Commit() is called for the context of this stream. + * + * @return An error code. KErrNone if successful. + * KErrNotReady if called while the stream is not in correct state. + * Other system wide error codes are also possible. + */ + virtual TInt Unload()=0; + + /** + * Requests a transition to the Unitialized state – returning the stream to its initial state. + * + * this function is asynchronous, and its successful return merely issues a request which is acted upon on Commit(), + * and while will lead to a StateEvent() callback. this function is only allowed while the stream is in Initialized state. + * A call in any other state will cause an error code of KErrNotReady to be returned. + * + * @return an error code. if KErrNone, the state transition has been requested, and there will be a StateEvent() callback + * following Commit(). On error, there is no request made: KErrNotReady states the stream if not in valid current state, + * otherwise one of the system-wide error codes. + */ + virtual TInt Uninitialize()=0; + + /** + * Requests a transition to the EPrime state. + * + * this function is asynchronous, and its successful return merely issues a request which is acted upon on Commit(), + * and while will lead to a StateEvent() callback. this function is only allowed while the stream is in EActive + * (semantics of Prime in EActive– go into a buffering pause) or EIdle state (semantics of Prime in EIdle – start to buffer). + * A call in any other state will cause an error code of KErrNotReady to be returned. Not all streams support Prime. + * + * @return an error code. if KErrNone, the state transition has been requested, and there will be a StateEvent() callback + * following Commit(). On error, there is no request made: KErrNotReady states the stream if not in valid current state, + * otherwise one of the system-wide error codes + */ + virtual TInt Prime()=0; + + + /** + * Empty any buffers that have been filled. + * + * Reclain any outstanding buffers from the client, if required. + * this function is only allowed while the stream is in Idle state. this is an asynchronous operation. + * if the call returns KErrNone it merely indicates a flush has been requested and there will be a subsequent FlushComplete() callback. + * Note that this does not relate to the Commit() cycle, and is not considered transactional. + * + * @return a system wide error code. KErrNone if successful. + * KErrNotReady if called while the stream is not in correct state. Other system wide error codes are also possible. + */ + virtual TInt Flush()=0; + + /** + * Adds an audio source to this stream. + * + * A stream cannot operate before a source has been set. + * The source must be removed from the stream before the sink or the stream is destroyed. + * The source can only be set while the stream is in uninitialized state. + * this is an asynchronous call and the completion will be indicated to the + * client via a callback in the stream observer interface. + * + * @param aSource the audio source for this stream. + * @return an error code. KErrNone if successful, there will be a subsequent callback on MAudioStreamObserver::AddProcessingUnitComplete(). + * KErrInUse a source has already been set fot this stream. + * KErrNotReady the stream is not in correct state. + */ + virtual TInt AddSource(MAudioProcessingUnit* aSource)=0; + + /** + * Adds sink for this stream. + * + * Stream cannot operate before source and sink have been set. + * The sink must be removed from the stream before it is destroyed. + * The sink can only be set while the stream is in uninitialized state. + * this is an asynchronous call and the completion will be indicated to the + * client via a callback in the stream observer interface. + * + * @param aSink the sink for this stream + * @return an error code. KErrNone if successful, there will be a subsequent callback on MAudioStreamObserver::AddProcessingUnitComplete(). + * KErrInUse a sink has already been set fot this stream. + * KErrNotReady the stream is not in correct state, + */ + virtual TInt AddSink(MAudioProcessingUnit* aSink)=0; + + /** + * Adds an codec for this stream. + * + * The codec must be removed from the stream before the codec or the stream + * is deleted. The codec can only be set while the stream is in uninitialized state. + * this is an asynchronous call and the completion will be indicated to + * the client via a callback in the stream observer interface. + * + * @param aCodec the codec for this stream + * @return an error code. KErrNone if successful, there will be a subsequent callback on MAudioStreamObserver::AddProcessingUnitComplete(). + * KErrInUse a codec has already been set fot this stream. + * KErrNotReady the stream is not in correct state. + */ + virtual TInt AddAudioCodec(MAudioProcessingUnit* aCodec)=0; + + /** + * Adds an audio processing unit to this stream. + * + * The processing unit must be removed from the stream before the processing unit or the stream is removed from the context. + * The supplied component must implement the AudioGainControl feature. + * + * @param aGainControl the gain control to add to this stream. + * @return KErrNone if succesful returned, there will be a subsequent callback on MAudioStreamObserver::AddProcessingUnitComplete(). + * KErrInUse a gain control has already been set fot this stream. + * KErrNotReady the stream is not in correct state. + */ + virtual TInt AddGainControl(MAudioProcessingUnit* aGainControl)=0; + + /** + * Removes any audio processing unit from this stream, whether it has been added by AddSource(), AddSink(), AddCodec() or AddGainControl(). + * this is an asynchronous function, on successful call there will be a subsequent RemoveProcessingUnitComplete() callback. + * @param aProcessingUnit the processing unit to remove. + * @return a system wide error code, KErrNone if successful, or the processing unit had not been added to the stream. + * KErrNotReady the decoder is not in correct state. Other system wide error codes are also possible. + */ + virtual TInt RemoveProcessingUnit(MAudioProcessingUnit* aProcessingUnit)=0; + + /** + * Resets the duration counter. + * + * Used to differentiate between when a stream has been momentarily interrupted and when + * a different conceptual use-case is underway. Defined for EIdle. + */ + virtual TInt ResetStreamTime()=0; + + /** + * Returns the duration of audio that has been processed from the hardware device perspective. + * The time is reset when the MAudioStream object transfers from Initialized state to Idle. + * as a result of calling Load(). It can be reset at other times using ResetStreamTime(). + */ + virtual TInt GetStreamTime(TTimeIntervalMicroSeconds& aStreamTime)=0; + + /** + * A mechanism to obtain additional control APIs on the stream. + * + * These can be used to extend the basic play/record, pause, stop with future use-cases such as seek play. + * + * @param aType Uid that denotes the type of the interface. + * @return the pointer to the specified interface, or NULL if it does not exist. Must be cast to correct type by the user.. + */ + virtual TAny* Interface(TUid aType)=0; + + /** + * Returns the component instance id. + * + * @return component instance id. + */ + virtual TAudioStreamId InstanceId() const =0; + + }; + +#endif // MAUDIOSTREAM_H