1 <?xml version="1.0" encoding="utf-8"?>

     2 <!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. -->

     3 <!-- This component and the accompanying materials are made available under the terms of the License 

     4 "Eclipse Public License v1.0" which accompanies this distribution, 

     5 and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". -->

     6 <!-- Initial Contributors:

     7     Nokia Corporation - initial contribution.

     8 Contributors: 

     9 -->

    10 <!DOCTYPE concept

    11   PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">

    12 <concept id="GUID-73B853D5-13E6-54E7-AA8B-C41EEDB5EA7F" xml:lang="en"><title> RMdaDevSound-Based

    13 Driver Migration</title><shortdesc>Explains how to convert an <codeph>RMdaDevSound</codeph> -based

    14 sound driver to the current Sound Driver architecture. </shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

    15 <p>Symbian converted the PDD of the <codeph>RMdaDevSound</codeph> based driver

    16 to an <xref href="GUID-B0118EDD-2B08-353E-BE92-2DC75E5622B3.dita"><apiname>RSoundSc</apiname></xref> version of the PDD. The same procedure was

    17 used for this on all three platforms. </p>

    18 <p>PDDs for the <codeph>RMdaDevSound</codeph> based driver have a significant

    19 amount of code that is dedicated to creating and managing a circular buffer, <codeph>DSoundBuffer</codeph>,

    20 for storing playback or record audio. In the <xref href="GUID-B0118EDD-2B08-353E-BE92-2DC75E5622B3.dita"><apiname>RSoundSc</apiname></xref> version

    21 of the driver, this is taken care of by the shared chunk and this code can

    22 be discarded. </p>

    23 <p>For the remaining PDD code, although the LDD to PDD interface for the <codeph>RMdaDevSound</codeph> based

    24 version is similar to the <xref href="GUID-B0118EDD-2B08-353E-BE92-2DC75E5622B3.dita"><apiname>RSoundSc</apiname></xref> version, it is best

    25 to start by taking a copy of the template port as described in <xref href="GUID-C6ABE2CA-901E-55F1-9837-7018A1612BCF.dita">Set

    26 Up</xref> , then fill in the sections marked TODO in the template code by

    27 cutting and pasting the relevant code coming from a single function, this

    28 is often called the same in each version of the driver. </p>

    29 <p>One complication comes if the <xref href="GUID-B0118EDD-2B08-353E-BE92-2DC75E5622B3.dita"><apiname>RSoundSc</apiname></xref> version is to

    30 support both record and playback driver channels, as this requires some of

    31 the functionality to be moved to the shared PDD factory object. </p>

    32 </conbody></concept>