--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/mmlibs/mmfw/src/server/BaseClasses/Mmfcodec.cpp Thu Oct 07 22:34:12 2010 +0100
@@ -0,0 +1,222 @@
+// Copyright (c) 2002-2009 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:
+//
+
+
+#include <mmf/server/mmfcodec.h>
+#include "MmfUtilities.h"
+#include <mmf/common/mmfcontrollerpluginresolver.h>
+#include <ecom/ecom.h>
+#include <mm/mmpluginutils.h>
+
+_LIT8( KEmptyFourCCString, " , " ) ;
+_LIT( KNullString, "" ) ;
+
+static const TUid KUidMmfPluginInterfaceCodec = {KMmfUidPluginInterfaceCodec};
+
+/**
+Creates a CMMFCodec object with match parameter in addition to the source and
+destination fourCC codes (for instance a manufacturer's name).
+
+Will attempt match without extra match string if no match.
+
+Will Leave if no match on 4CC codes (KErrNotFound).
+
+Used where there may be multiple codecs that perform the same conversion to ensure the controller
+uses the codec specified by aPreferredSupplier.
+
+@param aSrcDataType
+ The source data type.
+@param aDstDataType
+ The destination data type.
+@param aPreferredSupplier
+ Additional resolution criteria when searching for plug in codec. If this is provided, the
+ list of matching plugins will be further searched for the latest version of a plugin
+ supplied by supplier named. Note that the display name field is parsed for a match.
+
+@return An instantiated CMMFCodec derived obeject from an ECOM plugin DLL.
+*/
+EXPORT_C CMMFCodec* CMMFCodec::NewL(const TFourCC& aSrcDataType, const TFourCC& aDstDataType, const TDesC& aPreferredSupplier)
+ {
+
+ // Create a match string using the two FourCC codes.
+ TBufC8<9> fourCCString( KEmptyFourCCString ) ;
+ TPtr8 fourCCPtr = fourCCString.Des() ;
+ TPtr8 fourCCPtr1( &fourCCPtr[0], 4 ) ;
+ TPtr8 fourCCPtr2( &fourCCPtr[5], 4 ) ;
+ aSrcDataType.FourCC( &fourCCPtr1 ) ;
+ aDstDataType.FourCC( &fourCCPtr2 ) ;
+
+ // Do a list implementations here.
+
+ RImplInfoPtrArray plugInArray; // Array to return matching decoders in
+ CleanupResetAndDestroyPushL(plugInArray);
+
+ MmPluginUtils::FindImplementationsL(KUidMmfPluginInterfaceCodec, plugInArray, fourCCPtr);
+
+ if (plugInArray.Count() == 0)
+ {
+ User::Leave(KErrNotSupported);
+ }
+
+ TUid chosenUid = {0};
+
+ if ( plugInArray.Count() == 1 )
+ {
+ chosenUid = plugInArray[0]->ImplementationUid() ;
+ }
+ else
+ {
+ // Use the preferred supplier to select a codec.
+ SelectByPreference( plugInArray, aPreferredSupplier ) ;
+ for ( TInt ii = 0 ; ii < plugInArray.Count() ; ii++ )
+ {
+ if ( !(plugInArray[ii]->Disabled()) )
+ {
+ // we've found our plugin...
+ chosenUid = plugInArray[ii]->ImplementationUid() ;
+ break ;
+ }
+ }
+ }
+
+ //Instantiate the chosen one
+ CMMFCodec* theChosenOne = REINTERPRET_CAST( CMMFCodec*,
+ REComSession::CreateImplementationL( chosenUid, _FOFF( CMMFCodec, iDtor_ID_Key ) ) ) ;
+
+ CleanupStack::PopAndDestroy() ; // pluginArray
+
+ return theChosenOne ;
+ }
+
+/**
+Creates a CMMFCodec object with known fourCC codes for source and destination.
+The first matching plug-in will be used.
+
+The FourCC codes are the same codes as those specified in the resource file and are used to identify
+the datatype. ECom scans the registry to find a codec that is registered in its resource file as
+being able to convert between the source data type and the destination data type as specified by
+their FourCC codes. If a match is found then an instantiation of the appropriate CMMFCodec is made.
+If a match is not found this function leaves with KErrNotFound. If more than one codec is present
+with the same fourCC match codes then the one that is instantiated is indeterminate. If there is
+likely to be any ambiguity due to more than one codec that performs the same conversion being
+present, then a preferred supplier should be specified.
+
+@param aSrcDataType
+ The source data type.
+@param aDstDataType
+ The destination data type.
+
+@return An instantiated CMMFCodec derived obeject from an ECOM plugin DLL.
+*/
+EXPORT_C CMMFCodec* CMMFCodec::NewL(const TFourCC& aSrcDataType, const TFourCC& aDstDataType )
+ {
+ // Create a match string using the two FourCC codes.
+ return NewL( aSrcDataType, aDstDataType, KNullString ) ;
+
+ }
+
+
+// local function to disable items which do not match the preferred supplier.
+// Note that at least one enabled item is returned (if there was an enabled item to begin with) which
+// may not match the preferred supplier.
+/**
+Selects a codec according to the specified preference.
+
+@param aPlugInArray
+ On return, array of plugins.
+@param aPreferredSupplier
+ Search criteria, a supplier's name for example.
+*/
+void CMMFCodec::SelectByPreference( RImplInfoPtrArray& aPlugInArray, const TDesC& aPreferredSupplier )
+ {
+ // Use the Disabled flag to eliminated all currently enabled matches that
+ // do not match the preferred supplier.
+ TInt firstEnabled = -1 ; // to ensure that we return something valid
+ TInt matchCount = 0 ;
+ for ( TInt ii = 0 ; ii < aPlugInArray.Count() ; ii++ )
+ {
+ if ( !( aPlugInArray[ii]->Disabled() ) )
+ {
+ if ( firstEnabled == -1 )
+ firstEnabled = ii ;
+ if ( aPlugInArray[ii]->DisplayName().FindF( aPreferredSupplier ) == KErrNotFound )
+ aPlugInArray[ii]->SetDisabled( ETrue ) ;
+ else
+ matchCount++ ;
+ }
+ }
+
+ // If there are no matches then re-enable the first enabled
+ if ( matchCount == 0 )
+ aPlugInArray[firstEnabled]->SetDisabled( EFalse ) ;
+ else if ( matchCount > 1 )
+ {
+ // find the latest version from more than one match
+ TInt highestVersionIndex = -1 ;
+ for ( TInt ii = 0 ; ii < aPlugInArray.Count() ; ii++ )
+ {
+ if ( !( aPlugInArray[ii]->Disabled() ) ) // only interested in enabled elements
+ {
+ if ( highestVersionIndex == -1 )
+ { // first match. Store this. Keep it enabled
+ highestVersionIndex = ii ;
+ }
+ else if ( aPlugInArray[ii]->Version() > aPlugInArray[highestVersionIndex]->Version() )
+ { // a new leader. Disable the previous leader. Keep this one.
+ aPlugInArray[highestVersionIndex]->SetDisabled( ETrue ) ;
+ highestVersionIndex = ii ;
+ }
+ else // we already have a higher version.
+ aPlugInArray[ii]->SetDisabled( ETrue ) ;
+ }
+ }
+ }
+ }
+
+
+/**
+Creates a CMMFCodec object with a known UID.
+
+Will Leave if the plug in is not found (KErrNotFound).
+
+@param aUid
+ The UID of a plugin implementation.
+
+@return An instantiated CMMFCodec derived obeject from an ECOM plugin DLL.
+*/
+EXPORT_C CMMFCodec* CMMFCodec::NewL(TUid aUid)
+ {
+ return REINTERPRET_CAST(CMMFCodec*, REComSession::CreateImplementationL(aUid,
+ _FOFF(CMMFCodec,iDtor_ID_Key)));
+ }
+
+/**
+@internalComponent
+
+Gets a pointer to the extension specified by an identifier. The extension can be either an
+interface or function. If the extension is not supported NULL value is given and returns
+KErrExtensionNotSupported.
+
+@param aExtensionId
+ Extension identifier.
+@param aExtPtr
+ Pointer to get the extension.
+@return If successful returns KErrNone otherwise KErrExtensionNotSupported.
+*/
+TInt CMMFCodec::ExtensionInterface(TUint aExtensionId, TAny*& aExtPtr)
+ {
+ return Extension_(aExtensionId, aExtPtr, NULL);
+ }
+