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1 <?xml version="1.0" encoding="utf-8"?> |
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2 <!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. --> |
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3 <!-- This component and the accompanying materials are made available under the terms of the License |
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4 "Eclipse Public License v1.0" which accompanies this distribution, |
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5 and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". --> |
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6 <!-- Initial Contributors: |
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7 Nokia Corporation - initial contribution. |
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8 Contributors: |
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9 --> |
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10 <!DOCTYPE concept |
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11 PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd"> |
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12 <concept id="GUID-1499E635-B6E3-51A0-AE38-ADF99FF86CD6" xml:lang="en"><title>Sound |
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13 Driver LDD Overview</title><shortdesc>Describes the sound driver LDD part of the sound driver framework. </shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody> |
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14 <section id="GUID-0A84C890-65DD-46AE-BC8E-9020996D2899"><title>Purpose</title> <p>The sound driver provides the conduit by |
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15 which Symbian platform can access the audio hardware and hence create sounds: |
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16 for example multi-media applications and ring tones. </p> </section> |
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17 <section id="GUID-2EBA51DD-5599-419C-A251-AB509CE3D407"><title>Required background</title> <p>Since audio hardware is rather |
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18 complex, the reader of this document needs to know what is meant by: </p> <ul> |
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19 <li id="GUID-43DF6FEB-6045-559A-97BC-1C0C20DE1AED"><p>Audio channels </p> </li> |
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20 <li id="GUID-62FD63A2-2901-579E-A33B-D227C5543DDE"><p>Codec </p> </li> |
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21 </ul> </section> |
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22 <section id="GUID-00AD36A1-D39D-4F7F-B1A5-F4DB10487718"><title>Key concepts and terms</title> <dl> |
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23 <dlentry> |
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24 <dt>Codec</dt> |
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25 <dd><p>Stands for COmpressor-DECompressor and refers to the algorithm used |
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26 to compress and decompress the audio data stream. </p> </dd> |
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27 </dlentry> |
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28 </dl> </section> |
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29 <section id="GUID-018D8B6C-D05C-474E-90A2-2B482636CA82"><title>Architecture</title> <p>The LDD for the sound driver sits |
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30 below the <xref href="GUID-6FBFA078-8253-3E24-B1F8-5F75E86C3066.dita"><apiname>RBusLogicalChannel</apiname></xref> and the <xref href="GUID-B0118EDD-2B08-353E-BE92-2DC75E5622B3.dita"><apiname>RSoundSc</apiname></xref> classes. </p> <p>The |
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31 communication between the driver and the application on the user-side is handled |
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32 by class <xref href="GUID-B0118EDD-2B08-353E-BE92-2DC75E5622B3.dita"><apiname>RSoundSc</apiname></xref>. </p> </section> |
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33 <section id="GUID-8E0A77A7-4514-44CA-A1B0-F26B7614E2FE"><title>APIs</title> <table id="GUID-56059B35-9466-5067-B136-9AC1D15D33AC"> |
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34 <tgroup cols="2"><colspec colname="col0"/><colspec colname="col1"/> |
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35 <thead> |
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36 <row> |
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37 <entry>API</entry> |
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38 <entry>Description</entry> |
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39 </row> |
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40 </thead> |
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41 <tbody> |
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42 <row> |
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43 <entry><p> <xref href="GUID-5807543D-A30F-3EB9-8F28-91A623B0D484.dita"><apiname>DSoundScLdd</apiname></xref> </p> </entry> |
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44 <entry><p>Defines each logical channel. One instance of this class is created |
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45 for each driver channel opened. </p> </entry> |
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46 </row> |
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47 </tbody> |
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48 </tgroup> |
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49 </table> </section> |
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50 <section id="GUID-6B257FE9-F036-4808-A1A0-186964B25608"><title>Typical uses</title> <p>The sound driver is used whenever |
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51 audio operations are required: for example MP3 player, having a phone call |
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52 and ring tones. </p> <ul> |
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53 <li id="GUID-931CC604-0C09-5990-9DDF-88AEA1086EFE"><p>MP3 player </p> </li> |
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54 <li id="GUID-8680BFA5-52DE-58A3-88D1-24810DBA0BF5"><p>Multi-media </p> </li> |
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55 </ul> </section> |
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56 </conbody><related-links> |
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57 <link href="GUID-E2641957-8163-5EF4-B282-FC3FD9CA75A6.dita"><linktext>Sound Driver |
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58 Technology</linktext></link> |
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59 </related-links></concept> |