diff -r 89d6a7a84779 -r 25a17d01db0c Symbian3/PDK/Source/GUID-73B853D5-13E6-54E7-AA8B-C41EEDB5EA7F.dita
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Symbian3/PDK/Source/GUID-73B853D5-13E6-54E7-AA8B-C41EEDB5EA7F.dita	Fri Jan 22 18:26:19 2010 +0000
@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (c) 2007-2010 Nokia Corporation 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:
+    Nokia Corporation - initial contribution.
+Contributors: 
+-->
+<!DOCTYPE concept
+  PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
+<concept id="GUID-73B853D5-13E6-54E7-AA8B-C41EEDB5EA7F" xml:lang="en"><title> RMdaDevSound-Based
+Driver Migration</title><shortdesc>Explains how to convert an <codeph>RMdaDevSound</codeph> -based
+sound driver to the current Sound Driver architecture. </shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>
+<p>Symbian converted the PDD of the <codeph>RMdaDevSound</codeph> based driver
+to an <xref href="GUID-B0118EDD-2B08-353E-BE92-2DC75E5622B3.dita"><apiname>RSoundSc</apiname></xref> version of the PDD. The same procedure was
+used for this on all three platforms. </p>
+<p>PDDs for the <codeph>RMdaDevSound</codeph> based driver have a significant
+amount of code that is dedicated to creating and managing a circular buffer, <codeph>DSoundBuffer</codeph>,
+for storing playback or record audio. In the <xref href="GUID-B0118EDD-2B08-353E-BE92-2DC75E5622B3.dita"><apiname>RSoundSc</apiname></xref> version
+of the driver, this is taken care of by the shared chunk and this code can
+be discarded. </p>
+<p>For the remaining PDD code, although the LDD to PDD interface for the <codeph>RMdaDevSound</codeph> based
+version is similar to the <xref href="GUID-B0118EDD-2B08-353E-BE92-2DC75E5622B3.dita"><apiname>RSoundSc</apiname></xref> version, it is best
+to start by taking a copy of the template port as described in <xref href="GUID-C6ABE2CA-901E-55F1-9837-7018A1612BCF.dita">Set
+Up</xref> , then fill in the sections marked TODO in the template code by
+cutting and pasting the relevant code coming from a single function, this
+is often called the same in each version of the driver. </p>
+<p>One complication comes if the <xref href="GUID-B0118EDD-2B08-353E-BE92-2DC75E5622B3.dita"><apiname>RSoundSc</apiname></xref> version is to
+support both record and playback driver channels, as this requires some of
+the functionality to be moved to the shared PDD factory object. </p>
+</conbody></concept>
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