1<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "https://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 2<html xmlns="http://www.w3.org/1999/xhtml"> 3<head> 4<meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/> 5<meta http-equiv="X-UA-Compatible" content="IE=9"/> 6<meta name="generator" content="Doxygen 1.8.15"/> 7<meta name="viewport" content="width=device-width, initial-scale=1"/> 8<title>Oboe: oboe::AudioStreamDataCallback Class Reference</title> 9<link href="tabs.css" rel="stylesheet" type="text/css"/> 10<script type="text/javascript" src="jquery.js"></script> 11<script type="text/javascript" src="dynsections.js"></script> 12<link href="search/search.css" rel="stylesheet" type="text/css"/> 13<script type="text/javascript" src="search/searchdata.js"></script> 14<script type="text/javascript" src="search/search.js"></script> 15<link href="doxygen.css" rel="stylesheet" type="text/css" /> 16</head> 17<body> 18<div id="top"><!-- do not remove this div, it is closed by doxygen! --> 19<div id="titlearea"> 20<table cellspacing="0" cellpadding="0"> 21 <tbody> 22 <tr style="height: 56px;"> 23 <td id="projectalign" style="padding-left: 0.5em;"> 24 <div id="projectname">Oboe 25  <span id="projectnumber">1.5</span> 26 </div> 27 <div id="projectbrief">A library for creating real-time audio apps on Android</div> 28 </td> 29 </tr> 30 </tbody> 31</table> 32</div> 33<!-- end header part --> 34<!-- Generated by Doxygen 1.8.15 --> 35<script type="text/javascript"> 36/* @license magnet:?xt=urn:btih:cf05388f2679ee054f2beb29a391d25f4e673ac3&dn=gpl-2.0.txt GPL-v2 */ 37var searchBox = new SearchBox("searchBox", "search",false,'Search'); 38/* @license-end */ 39</script> 40<script type="text/javascript" src="menudata.js"></script> 41<script type="text/javascript" src="menu.js"></script> 42<script type="text/javascript"> 43/* @license magnet:?xt=urn:btih:cf05388f2679ee054f2beb29a391d25f4e673ac3&dn=gpl-2.0.txt GPL-v2 */ 44$(function() { 45 initMenu('',true,false,'search.php','Search'); 46 $(document).ready(function() { init_search(); }); 47}); 48/* @license-end */</script> 49<div id="main-nav"></div> 50<!-- window showing the filter options --> 51<div id="MSearchSelectWindow" 52 onmouseover="return searchBox.OnSearchSelectShow()" 53 onmouseout="return searchBox.OnSearchSelectHide()" 54 onkeydown="return searchBox.OnSearchSelectKey(event)"> 55</div> 56 57<!-- iframe showing the search results (closed by default) --> 58<div id="MSearchResultsWindow"> 59<iframe src="javascript:void(0)" frameborder="0" 60 name="MSearchResults" id="MSearchResults"> 61</iframe> 62</div> 63 64<div id="nav-path" class="navpath"> 65 <ul> 66<li class="navelem"><a class="el" href="namespaceoboe.html">oboe</a></li><li class="navelem"><a class="el" href="classoboe_1_1_audio_stream_data_callback.html">AudioStreamDataCallback</a></li> </ul> 67</div> 68</div><!-- top --> 69<div class="header"> 70 <div class="summary"> 71<a href="#pub-methods">Public Member Functions</a> | 72<a href="classoboe_1_1_audio_stream_data_callback-members.html">List of all members</a> </div> 73 <div class="headertitle"> 74<div class="title">oboe::AudioStreamDataCallback Class Reference<span class="mlabels"><span class="mlabel">abstract</span></span></div> </div> 75</div><!--header--> 76<div class="contents"> 77 78<p><code>#include <<a class="el" href="_audio_stream_callback_8h_source.html">AudioStreamCallback.h</a>></code></p> 79<div class="dynheader"> 80Inheritance diagram for oboe::AudioStreamDataCallback:</div> 81<div class="dyncontent"> 82 <div class="center"> 83 <img src="classoboe_1_1_audio_stream_data_callback.png" usemap="#oboe::AudioStreamDataCallback_map" alt=""/> 84 <map id="oboe::AudioStreamDataCallback_map" name="oboe::AudioStreamDataCallback_map"> 85<area href="classoboe_1_1_audio_stream_callback.html" alt="oboe::AudioStreamCallback" shape="rect" coords="0,56,193,80"/> 86<area href="classoboe_1_1_stabilized_callback.html" alt="oboe::StabilizedCallback" shape="rect" coords="0,112,193,136"/> 87 </map> 88</div></div> 89<table class="memberdecls"> 90<tr class="heading"><td colspan="2"><h2 class="groupheader"><a name="pub-methods"></a> 91Public Member Functions</h2></td></tr> 92<tr class="memitem:ad8a3a9f609df5fd3a5d885cbe1b2204d"><td class="memItemLeft" align="right" valign="top">virtual <a class="el" href="namespaceoboe.html#af85fc9910a287df6c5df0ed396bb75cd">DataCallbackResult</a> </td><td class="memItemRight" valign="bottom"><a class="el" href="classoboe_1_1_audio_stream_data_callback.html#ad8a3a9f609df5fd3a5d885cbe1b2204d">onAudioReady</a> (<a class="el" href="classoboe_1_1_audio_stream.html">AudioStream</a> *audioStream, void *audioData, int32_t numFrames)=0</td></tr> 93<tr class="separator:ad8a3a9f609df5fd3a5d885cbe1b2204d"><td class="memSeparator" colspan="2"> </td></tr> 94</table> 95<a name="details" id="details"></a><h2 class="groupheader">Detailed Description</h2> 96<div class="textblock"><p><a class="el" href="classoboe_1_1_audio_stream_data_callback.html">AudioStreamDataCallback</a> defines a callback interface for moving data to/from an audio stream using <code>onAudioReady</code> 2) being alerted when a stream has an error using <code>onError*</code> methods</p> 97<p>It is used with <a class="el" href="classoboe_1_1_audio_stream_builder.html#acad307720e0f370267b4e2f9a626ae70">AudioStreamBuilder::setDataCallback()</a>. </p> 98</div><h2 class="groupheader">Member Function Documentation</h2> 99<a id="ad8a3a9f609df5fd3a5d885cbe1b2204d"></a> 100<h2 class="memtitle"><span class="permalink"><a href="#ad8a3a9f609df5fd3a5d885cbe1b2204d">◆ </a></span>onAudioReady()</h2> 101 102<div class="memitem"> 103<div class="memproto"> 104<table class="mlabels"> 105 <tr> 106 <td class="mlabels-left"> 107 <table class="memname"> 108 <tr> 109 <td class="memname">virtual <a class="el" href="namespaceoboe.html#af85fc9910a287df6c5df0ed396bb75cd">DataCallbackResult</a> oboe::AudioStreamDataCallback::onAudioReady </td> 110 <td>(</td> 111 <td class="paramtype"><a class="el" href="classoboe_1_1_audio_stream.html">AudioStream</a> * </td> 112 <td class="paramname"><em>audioStream</em>, </td> 113 </tr> 114 <tr> 115 <td class="paramkey"></td> 116 <td></td> 117 <td class="paramtype">void * </td> 118 <td class="paramname"><em>audioData</em>, </td> 119 </tr> 120 <tr> 121 <td class="paramkey"></td> 122 <td></td> 123 <td class="paramtype">int32_t </td> 124 <td class="paramname"><em>numFrames</em> </td> 125 </tr> 126 <tr> 127 <td></td> 128 <td>)</td> 129 <td></td><td></td> 130 </tr> 131 </table> 132 </td> 133 <td class="mlabels-right"> 134<span class="mlabels"><span class="mlabel">pure virtual</span></span> </td> 135 </tr> 136</table> 137</div><div class="memdoc"> 138<p>A buffer is ready for processing.</p> 139<p>For an output stream, this function should render and write numFrames of data in the stream's current data format to the audioData buffer.</p> 140<p>For an input stream, this function should read and process numFrames of data from the audioData buffer.</p> 141<p>The audio data is passed through the buffer. So do NOT call read() or write() on the stream that is making the callback.</p> 142<p>Note that numFrames can vary unless <a class="el" href="classoboe_1_1_audio_stream_builder.html#a3f397821f61eabaeedaf31064c859a54">AudioStreamBuilder::setFramesPerCallback()</a> is called.</p> 143<p>Also note that this callback function should be considered a "real-time" function. It must not do anything that could cause an unbounded delay because that can cause the audio to glitch or pop.</p> 144<p>These are things the function should NOT do: </p><ul> 145<li> 146allocate memory using, for example, malloc() or new </li> 147<li> 148any file operations such as opening, closing, reading or writing </li> 149<li> 150any network operations such as streaming </li> 151<li> 152use any mutexes or other synchronization primitives </li> 153<li> 154sleep </li> 155<li> 156oboeStream->stop(), pause(), flush() or close() </li> 157<li> 158oboeStream->read() </li> 159<li> 160oboeStream->write() </li> 161</ul> 162<p>The following are OK to call from the data callback: </p><ul> 163<li> 164oboeStream->get*() </li> 165<li> 166<a class="el" href="namespaceoboe.html#af65aaea3c5d82eee6906664d61c094b3">oboe::convertToText()</a> </li> 167<li> 168oboeStream->setBufferSizeInFrames() </li> 169</ul> 170<p>If you need to move data, eg. MIDI commands, in or out of the callback function then we recommend the use of non-blocking techniques such as an atomic FIFO.</p> 171<dl class="params"><dt>Parameters</dt><dd> 172 <table class="params"> 173 <tr><td class="paramname">audioStream</td><td>pointer to the associated stream </td></tr> 174 <tr><td class="paramname">audioData</td><td>buffer containing input data or a place to put output data </td></tr> 175 <tr><td class="paramname">numFrames</td><td>number of frames to be processed </td></tr> 176 </table> 177 </dd> 178</dl> 179<dl class="section return"><dt>Returns</dt><dd>DataCallbackResult::Continue or DataCallbackResult::Stop </dd></dl> 180 181<p>Implemented in <a class="el" href="classoboe_1_1_stabilized_callback.html#ad447e12ebf732cf151655c1fbaf58a49">oboe::StabilizedCallback</a>.</p> 182 183</div> 184</div> 185<hr/>The documentation for this class was generated from the following file:<ul> 186<li>include/oboe/<a class="el" href="_audio_stream_callback_8h_source.html">AudioStreamCallback.h</a></li> 187</ul> 188</div><!-- contents --> 189<!-- start footer part --> 190<hr class="footer"/><address class="footer"><small> 191Generated by  <a href="http://www.doxygen.org/index.html"> 192<img class="footer" src="doxygen.png" alt="doxygen"/> 193</a> 1.8.15 194</small></address> 195</body> 196</html> 197
