<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html> <html lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <!-- qaudioinput.cpp --> <title>QAudioInput Class | Qt Multimedia 5.12.2</title> <link rel="stylesheet" type="text/css" href="style/offline-simple.css" /> <script type="text/javascript"> document.getElementsByTagName("link").item(0).setAttribute("href", "style/offline.css"); // loading style sheet breaks anchors that were jumped to before // so force jumping to anchor again setTimeout(function() { var anchor = location.hash; // need to jump to different anchor first (e.g. none) location.hash = "#"; setTimeout(function() { location.hash = anchor; }, 0); }, 0); </script> </head> <body> <div class="header" id="qtdocheader"> <div class="main"> <div class="main-rounded"> <div class="navigationbar"> <table><tr> <td >Qt 5.12</td><td ><a href="qtmultimedia-index.html">Qt Multimedia</a></td><td ><a href="qtmultimedia-modules.html">C++ Classes</a></td><td >QAudioInput</td></tr></table><table class="buildversion"><tr> <td id="buildversion" width="100%" align="right"><a href="qtmultimedia-index.html">Qt 5.12.2 Reference Documentation</a></td> </tr></table> </div> </div> <div class="content"> <div class="line"> <div class="content mainContent"> <div class="sidebar"> <div class="toc"> <h3><a name="toc">Contents</a></h3> <ul> <li class="level1"><a href="#public-functions">Public Functions</a></li> <li class="level1"><a href="#signals">Signals</a></li> <li class="level1"><a href="#static-public-members">Static Public Members</a></li> <li class="level1"><a href="#details">Detailed Description</a></li> </ul> </div> <div class="sidebar-content" id="sidebar-content"></div></div> <h1 class="title">QAudioInput Class</h1> <!-- $$$QAudioInput-brief --> <p>The <a href="qaudioinput.html">QAudioInput</a> class provides an interface for receiving audio data from an audio input device. <a href="#details">More...</a></p> <!-- @@@QAudioInput --> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> Header:</td><td class="memItemRight bottomAlign"> <span class="preprocessor">#include <QAudioInput></span> </td></tr><tr><td class="memItemLeft rightAlign topAlign"> qmake:</td><td class="memItemRight bottomAlign"> QT += multimedia</td></tr></table></div><ul> <li><a href="qaudioinput-members.html">List of all members, including inherited members</a></li> </ul> <a name="public-functions"></a> <h2 id="public-functions">Public Functions</h2> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b><a href="qaudioinput.html#QAudioInput">QAudioInput</a></b>(const QAudioFormat &<i>format</i> = QAudioFormat(), QObject *<i>parent</i> = nullptr)</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b><a href="qaudioinput.html#QAudioInput-1">QAudioInput</a></b>(const QAudioDeviceInfo &<i>audioDevice</i>, const QAudioFormat &<i>format</i> = QAudioFormat(), QObject *<i>parent</i> = nullptr)</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> virtual </td><td class="memItemRight bottomAlign"><b><a href="qaudioinput.html#dtor.QAudioInput">~QAudioInput</a></b>()</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> int </td><td class="memItemRight bottomAlign"><b><a href="qaudioinput.html#bufferSize">bufferSize</a></b>() const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> int </td><td class="memItemRight bottomAlign"><b><a href="qaudioinput.html#bytesReady">bytesReady</a></b>() const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> qint64 </td><td class="memItemRight bottomAlign"><b><a href="qaudioinput.html#elapsedUSecs">elapsedUSecs</a></b>() const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> QAudio::Error </td><td class="memItemRight bottomAlign"><b><a href="qaudioinput.html#error">error</a></b>() const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> QAudioFormat </td><td class="memItemRight bottomAlign"><b><a href="qaudioinput.html#format">format</a></b>() const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> int </td><td class="memItemRight bottomAlign"><b><a href="qaudioinput.html#notifyInterval">notifyInterval</a></b>() const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> int </td><td class="memItemRight bottomAlign"><b><a href="qaudioinput.html#periodSize">periodSize</a></b>() const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> qint64 </td><td class="memItemRight bottomAlign"><b><a href="qaudioinput.html#processedUSecs">processedUSecs</a></b>() const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="qaudioinput.html#reset">reset</a></b>()</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="qaudioinput.html#resume">resume</a></b>()</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="qaudioinput.html#setBufferSize">setBufferSize</a></b>(int <i>value</i>)</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="qaudioinput.html#setNotifyInterval">setNotifyInterval</a></b>(int <i>ms</i>)</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="qaudioinput.html#setVolume">setVolume</a></b>(qreal <i>volume</i>)</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="qaudioinput.html#start">start</a></b>(QIODevice *<i>device</i>)</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> QIODevice *</td><td class="memItemRight bottomAlign"><b><a href="qaudioinput.html#start-1">start</a></b>()</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> QAudio::State </td><td class="memItemRight bottomAlign"><b><a href="qaudioinput.html#state">state</a></b>() const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="qaudioinput.html#stop">stop</a></b>()</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="qaudioinput.html#suspend">suspend</a></b>()</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> qreal </td><td class="memItemRight bottomAlign"><b><a href="qaudioinput.html#volume">volume</a></b>() const</td></tr> </table></div> <a name="signals"></a> <h2 id="signals">Signals</h2> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="qaudioinput.html#notify">notify</a></b>()</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="qaudioinput.html#stateChanged">stateChanged</a></b>(QAudio::State <i>state</i>)</td></tr> </table></div> <a name="static-public-members"></a> <h2 id="static-public-members">Static Public Members</h2> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> const QMetaObject </td><td class="memItemRight bottomAlign"><b><a href="qaudioinput.html#staticMetaObject-var">staticMetaObject</a></b></td></tr> </table></div> <a name="details"></a> <!-- $$$QAudioInput-description --> <div class="descr"> <h2 id="details">Detailed Description</h2> <p>The <a href="qaudioinput.html">QAudioInput</a> class provides an interface for receiving audio data from an audio input device.</p> <p>You can construct an audio input with the system's <a href="qaudiodeviceinfo.html#defaultInputDevice">default audio input device</a>. It is also possible to create <a href="qaudioinput.html">QAudioInput</a> with a specific <a href="qaudiodeviceinfo.html">QAudioDeviceInfo</a>. When you create the audio input, you should also send in the <a href="qaudioformat.html">QAudioFormat</a> to be used for the recording (see the <a href="qaudioformat.html">QAudioFormat</a> class description for details).</p> <p>To record to a file:</p> <p><a href="qaudioinput.html">QAudioInput</a> lets you record audio with an audio input device. The default constructor of this class will use the systems default audio device, but you can also specify a <a href="qaudiodeviceinfo.html">QAudioDeviceInfo</a> for a specific device. You also need to pass in the <a href="qaudioformat.html">QAudioFormat</a> in which you wish to record.</p> <p>Starting up the <a href="qaudioinput.html">QAudioInput</a> is simply a matter of calling <a href="qaudioinput.html#start-1">start</a>() with a QIODevice opened for writing. For instance, to record to a file, you can:</p> <pre class="cpp"> <span class="type">QFile</span> destinationFile; <span class="comment">// Class member</span> <span class="type"><a href="qaudioinput.html#QAudioInput">QAudioInput</a></span><span class="operator">*</span> audio; <span class="comment">// Class member</span> { destinationFile<span class="operator">.</span>setFileName(<span class="string">"/tmp/test.raw"</span>); destinationFile<span class="operator">.</span>open( <span class="type">QIODevice</span><span class="operator">::</span>WriteOnly <span class="operator">|</span> <span class="type">QIODevice</span><span class="operator">::</span>Truncate ); <span class="type"><a href="qaudioformat.html">QAudioFormat</a></span> format; <span class="comment">// Set up the desired format, for example:</span> format<span class="operator">.</span>setSampleRate(<span class="number">8000</span>); format<span class="operator">.</span>setChannelCount(<span class="number">1</span>); format<span class="operator">.</span>setSampleSize(<span class="number">8</span>); format<span class="operator">.</span>setCodec(<span class="string">"audio/pcm"</span>); format<span class="operator">.</span>setByteOrder(<span class="type"><a href="qaudioformat.html">QAudioFormat</a></span><span class="operator">::</span>LittleEndian); format<span class="operator">.</span>setSampleType(<span class="type"><a href="qaudioformat.html">QAudioFormat</a></span><span class="operator">::</span>UnSignedInt); <span class="type"><a href="qaudiodeviceinfo.html">QAudioDeviceInfo</a></span> info <span class="operator">=</span> <span class="type"><a href="qaudiodeviceinfo.html">QAudioDeviceInfo</a></span><span class="operator">::</span>defaultInputDevice(); <span class="keyword">if</span> (<span class="operator">!</span>info<span class="operator">.</span>isFormatSupported(format)) { qWarning() <span class="operator"><</span><span class="operator"><</span> <span class="string">"Default format not supported, trying to use the nearest."</span>; format <span class="operator">=</span> info<span class="operator">.</span>nearestFormat(format); } audio <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qaudioinput.html#QAudioInput">QAudioInput</a></span>(format<span class="operator">,</span> <span class="keyword">this</span>); connect(audio<span class="operator">,</span> SIGNAL(stateChanged(<span class="type">QAudio</span><span class="operator">::</span>State))<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(handleStateChanged(<span class="type">QAudio</span><span class="operator">::</span>State))); <span class="type">QTimer</span><span class="operator">::</span>singleShot(<span class="number">3000</span><span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> SLOT(stopRecording())); audio<span class="operator">-</span><span class="operator">></span>start(<span class="operator">&</span>destinationFile); <span class="comment">// Records audio for 3000ms</span> } </pre> <p>This will start recording if the format specified is supported by the input device (you can check this with <a href="qaudiodeviceinfo.html#isFormatSupported">QAudioDeviceInfo::isFormatSupported</a>(). In case there are any snags, use the <a href="qaudioinput.html#error">error</a>() function to check what went wrong. We stop recording in the <code>stopRecording()</code> slot.</p> <pre class="cpp"> <span class="type">void</span> AudioInputExample<span class="operator">::</span>stopRecording() { audio<span class="operator">-</span><span class="operator">></span>stop(); destinationFile<span class="operator">.</span>close(); <span class="keyword">delete</span> audio; } </pre> <p>At any point in time, <a href="qaudioinput.html">QAudioInput</a> will be in one of four states: active, suspended, stopped, or idle. These states are specified by the <a href="qaudio.html#State-enum">QAudio::State</a> enum. You can request a state change directly through <a href="qaudioinput.html#suspend">suspend</a>(), <a href="qaudioinput.html#resume">resume</a>(), <a href="qaudioinput.html#stop">stop</a>(), <a href="qaudioinput.html#reset">reset</a>(), and <a href="qaudioinput.html#start-1">start</a>(). The current state is reported by <a href="qaudioinput.html#state">state</a>(). <a href="qaudiooutput.html">QAudioOutput</a> will also signal you when the state changes (<a href="qaudioinput.html#stateChanged">stateChanged</a>()).</p> <p><a href="qaudioinput.html">QAudioInput</a> provides several ways of measuring the time that has passed since the <a href="qaudioinput.html#start-1">start</a>() of the recording. The <code>processedUSecs()</code> function returns the length of the stream in microseconds written, i.e., it leaves out the times the audio input was suspended or idle. The <a href="qaudioinput.html#elapsedUSecs">elapsedUSecs</a>() function returns the time elapsed since <a href="qaudioinput.html#start-1">start</a>() was called regardless of which states the <a href="qaudioinput.html">QAudioInput</a> has been in.</p> <p>If an error should occur, you can fetch its reason with <a href="qaudioinput.html#error">error</a>(). The possible error reasons are described by the <a href="qaudio.html#Error-enum">QAudio::Error</a> enum. The <a href="qaudioinput.html">QAudioInput</a> will enter the <a href="qaudio.html#State-enum">StoppedState</a> when an error is encountered. Connect to the <a href="qaudioinput.html#stateChanged">stateChanged</a>() signal to handle the error:</p> <pre class="cpp"> <span class="type">void</span> AudioInputExample<span class="operator">::</span>handleStateChanged(<span class="type">QAudio</span><span class="operator">::</span>State newState) { <span class="keyword">switch</span> (newState) { <span class="keyword">case</span> <span class="type">QAudio</span><span class="operator">::</span>StoppedState: <span class="keyword">if</span> (audio<span class="operator">-</span><span class="operator">></span>error() <span class="operator">!</span><span class="operator">=</span> <span class="type">QAudio</span><span class="operator">::</span>NoError) { <span class="comment">// Error handling</span> } <span class="keyword">else</span> { <span class="comment">// Finished recording</span> } <span class="keyword">break</span>; <span class="keyword">case</span> <span class="type">QAudio</span><span class="operator">::</span>ActiveState: <span class="comment">// Started recording - read from IO device</span> <span class="keyword">break</span>; <span class="keyword">default</span>: <span class="comment">// ... other cases as appropriate</span> <span class="keyword">break</span>; } } </pre> </div> <p><b>See also </b><a href="qaudiooutput.html">QAudioOutput</a> and <a href="qaudiodeviceinfo.html">QAudioDeviceInfo</a>.</p> <!-- @@@QAudioInput --> <div class="func"> <h2>Member Function Documentation</h2> <!-- $$$QAudioInput[overload1]$$$QAudioInputconstQAudioFormat&QObject* --> <h3 class="fn" id="QAudioInput"><a name="QAudioInput"></a>QAudioInput::<span class="name">QAudioInput</span>(const <span class="type"><a href="qaudioformat.html">QAudioFormat</a></span> &<i>format</i> = QAudioFormat(), <span class="type">QObject</span> *<i>parent</i> = nullptr)</h3> <p>Construct a new audio input and attach it to <i>parent</i>. The default audio input device is used with the output <i>format</i> parameters.</p> <!-- @@@QAudioInput --> <!-- $$$QAudioInput$$$QAudioInputconstQAudioDeviceInfo&constQAudioFormat&QObject* --> <h3 class="fn" id="QAudioInput-1"><a name="QAudioInput-1"></a>QAudioInput::<span class="name">QAudioInput</span>(const <span class="type"><a href="qaudiodeviceinfo.html">QAudioDeviceInfo</a></span> &<i>audioDevice</i>, const <span class="type"><a href="qaudioformat.html">QAudioFormat</a></span> &<i>format</i> = QAudioFormat(), <span class="type">QObject</span> *<i>parent</i> = nullptr)</h3> <p>Construct a new audio input and attach it to <i>parent</i>. The device referenced by <i>audioDevice</i> is used with the input <i>format</i> parameters.</p> <!-- @@@QAudioInput --> <!-- $$$~QAudioInput[overload1]$$$~QAudioInput --> <h3 class="fn" id="dtor.QAudioInput"><a name="dtor.QAudioInput"></a><code>[virtual] </code>QAudioInput::<span class="name">~QAudioInput</span>()</h3> <p>Destroy this audio input.</p> <!-- @@@~QAudioInput --> <!-- $$$bufferSize[overload1]$$$bufferSize --> <h3 class="fn" id="bufferSize"><a name="bufferSize"></a><span class="type">int</span> QAudioInput::<span class="name">bufferSize</span>() const</h3> <p>Returns the audio buffer size in bytes.</p> <p>If called before <a href="qaudioinput.html#start-1">start</a>(), returns platform default value. If called before <a href="qaudioinput.html#start-1">start</a>() but <a href="qaudioinput.html#setBufferSize">setBufferSize</a>() was called prior, returns value set by <a href="qaudioinput.html#setBufferSize">setBufferSize</a>(). If called after <a href="qaudioinput.html#start-1">start</a>(), returns the actual buffer size being used. This may not be what was set previously by <a href="qaudioinput.html#setBufferSize">setBufferSize</a>().</p> <p><b>See also </b><a href="qaudioinput.html#setBufferSize">setBufferSize</a>().</p> <!-- @@@bufferSize --> <!-- $$$bytesReady[overload1]$$$bytesReady --> <h3 class="fn" id="bytesReady"><a name="bytesReady"></a><span class="type">int</span> QAudioInput::<span class="name">bytesReady</span>() const</h3> <p>Returns the amount of audio data available to read in bytes.</p> <p>Note: returned value is only valid while in <a href="qaudio.html#State-enum">QAudio::ActiveState</a> or <a href="qaudio.html#State-enum">QAudio::IdleState</a> state, otherwise returns zero.</p> <!-- @@@bytesReady --> <!-- $$$elapsedUSecs[overload1]$$$elapsedUSecs --> <h3 class="fn" id="elapsedUSecs"><a name="elapsedUSecs"></a><span class="type">qint64</span> QAudioInput::<span class="name">elapsedUSecs</span>() const</h3> <p>Returns the microseconds since <a href="qaudioinput.html#start-1">start</a>() was called, including time in Idle and Suspend states.</p> <!-- @@@elapsedUSecs --> <!-- $$$error[overload1]$$$error --> <h3 class="fn" id="error"><a name="error"></a><span class="type"><a href="qaudio.html#Error-enum">QAudio::Error</a></span> QAudioInput::<span class="name">error</span>() const</h3> <p>Returns the error state.</p> <!-- @@@error --> <!-- $$$format[overload1]$$$format --> <h3 class="fn" id="format"><a name="format"></a><span class="type"><a href="qaudioformat.html">QAudioFormat</a></span> QAudioInput::<span class="name">format</span>() const</h3> <p>Returns the <a href="qaudioformat.html">QAudioFormat</a> being used.</p> <!-- @@@format --> <!-- $$$notify[overload1]$$$notify --> <h3 class="fn" id="notify"><a name="notify"></a><code>[signal] </code><span class="type">void</span> QAudioInput::<span class="name">notify</span>()</h3> <!-- @@@notify --> <!-- $$$notifyInterval[overload1]$$$notifyInterval --> <h3 class="fn" id="notifyInterval"><a name="notifyInterval"></a><span class="type">int</span> QAudioInput::<span class="name">notifyInterval</span>() const</h3> <p>Returns the notify interval in milliseconds.</p> <p><b>See also </b><a href="qaudioinput.html#setNotifyInterval">setNotifyInterval</a>().</p> <!-- @@@notifyInterval --> <!-- $$$periodSize[overload1]$$$periodSize --> <h3 class="fn" id="periodSize"><a name="periodSize"></a><span class="type">int</span> QAudioInput::<span class="name">periodSize</span>() const</h3> <p>Returns the period size in bytes.</p> <p>Note: This is the recommended read size in bytes.</p> <!-- @@@periodSize --> <!-- $$$processedUSecs[overload1]$$$processedUSecs --> <h3 class="fn" id="processedUSecs"><a name="processedUSecs"></a><span class="type">qint64</span> QAudioInput::<span class="name">processedUSecs</span>() const</h3> <p>Returns the amount of audio data processed since <a href="qaudioinput.html#start-1">start</a>() was called in microseconds.</p> <!-- @@@processedUSecs --> <!-- $$$reset[overload1]$$$reset --> <h3 class="fn" id="reset"><a name="reset"></a><span class="type">void</span> QAudioInput::<span class="name">reset</span>()</h3> <p>Drops all audio data in the buffers, resets buffers to zero.</p> <!-- @@@reset --> <!-- $$$resume[overload1]$$$resume --> <h3 class="fn" id="resume"><a name="resume"></a><span class="type">void</span> QAudioInput::<span class="name">resume</span>()</h3> <p>Resumes processing audio data after a <a href="qaudioinput.html#suspend">suspend</a>().</p> <p>Sets <a href="qaudioinput.html#error">error</a>() to <a href="qaudio.html#Error-enum">QAudio::NoError</a>. Sets <a href="qaudioinput.html#state">state</a>() to <a href="qaudio.html#State-enum">QAudio::ActiveState</a> if you previously called start(QIODevice*). Sets <a href="qaudioinput.html#state">state</a>() to <a href="qaudio.html#State-enum">QAudio::IdleState</a> if you previously called <a href="qaudioinput.html#start-1">start</a>(). emits <a href="qaudioinput.html#stateChanged">stateChanged</a>() signal.</p> <!-- @@@resume --> <!-- $$$setBufferSize[overload1]$$$setBufferSizeint --> <h3 class="fn" id="setBufferSize"><a name="setBufferSize"></a><span class="type">void</span> QAudioInput::<span class="name">setBufferSize</span>(<span class="type">int</span> <i>value</i>)</h3> <p>Sets the audio buffer size to <i>value</i> bytes.</p> <p>Note: This function can be called anytime before <a href="qaudioinput.html#start-1">start</a>(), calls to this are ignored after <a href="qaudioinput.html#start-1">start</a>(). It should not be assumed that the buffer size set is the actual buffer size used, calling <a href="qaudioinput.html#bufferSize">bufferSize</a>() anytime after <a href="qaudioinput.html#start-1">start</a>() will return the actual buffer size being used.</p> <p><b>See also </b><a href="qaudioinput.html#bufferSize">bufferSize</a>().</p> <!-- @@@setBufferSize --> <!-- $$$setNotifyInterval[overload1]$$$setNotifyIntervalint --> <h3 class="fn" id="setNotifyInterval"><a name="setNotifyInterval"></a><span class="type">void</span> QAudioInput::<span class="name">setNotifyInterval</span>(<span class="type">int</span> <i>ms</i>)</h3> <p>Sets the interval for <a href="qaudioinput.html#notify">notify</a>() signal to be emitted. This is based on the <i>ms</i> of audio data processed not on actual real-time. The minimum resolution of the timer is platform specific and values should be checked with <a href="qaudioinput.html#notifyInterval">notifyInterval</a>() to confirm actual value being used.</p> <p><b>See also </b><a href="qaudioinput.html#notifyInterval">notifyInterval</a>().</p> <!-- @@@setNotifyInterval --> <!-- $$$setVolume[overload1]$$$setVolumeqreal --> <h3 class="fn" id="setVolume"><a name="setVolume"></a><span class="type">void</span> QAudioInput::<span class="name">setVolume</span>(<span class="type">qreal</span> <i>volume</i>)</h3> <p>Sets the input volume to <i>volume</i>.</p> <p>The volume is scaled linearly from <code>0.0</code> (silence) to <code>1.0</code> (full volume). Values outside this range will be clamped.</p> <p>If the device does not support adjusting the input volume then <i>volume</i> will be ignored and the input volume will remain at 1.0.</p> <p>The default volume is <code>1.0</code>.</p> <p>Note: Adjustments to the volume will change the volume of this audio stream, not the global volume.</p> <p><b>See also </b><a href="qaudioinput.html#volume">volume</a>().</p> <!-- @@@setVolume --> <!-- $$$start[overload1]$$$startQIODevice* --> <h3 class="fn" id="start"><a name="start"></a><span class="type">void</span> QAudioInput::<span class="name">start</span>(<span class="type">QIODevice</span> *<i>device</i>)</h3> <p>Starts transferring audio data from the system's audio input to the <i>device</i>. The <i>device</i> must have been opened in the WriteOnly, Append or ReadWrite modes.</p> <p>If the <a href="qaudioinput.html">QAudioInput</a> is able to successfully get audio data, <a href="qaudioinput.html#state">state</a>() returns either <a href="qaudio.html#State-enum">QAudio::ActiveState</a> or <a href="qaudio.html#State-enum">QAudio::IdleState</a>, <a href="qaudioinput.html#error">error</a>() returns <a href="qaudio.html#Error-enum">QAudio::NoError</a> and the <a href="qaudioinput.html#stateChanged">stateChanged</a>() signal is emitted.</p> <p>If a problem occurs during this process, <a href="qaudioinput.html#error">error</a>() returns <a href="qaudio.html#Error-enum">QAudio::OpenError</a>, <a href="qaudioinput.html#state">state</a>() returns <a href="qaudio.html#State-enum">QAudio::StoppedState</a> and the <a href="qaudioinput.html#stateChanged">stateChanged</a>() signal is emitted.</p> <p><b>See also </b>QIODevice.</p> <!-- @@@start --> <!-- $$$start$$$start --> <h3 class="fn" id="start-1"><a name="start-1"></a><span class="type">QIODevice</span> *QAudioInput::<span class="name">start</span>()</h3> <p>Returns a pointer to the internal QIODevice being used to transfer data from the system's audio input. The device will already be open and read() can read data directly from it.</p> <p><b>Note: </b>The pointer will become invalid after the stream is stopped or if you start another stream.</p><p>If the <a href="qaudioinput.html">QAudioInput</a> is able to access the system's audio device, <a href="qaudioinput.html#state">state</a>() returns <a href="qaudio.html#State-enum">QAudio::IdleState</a>, <a href="qaudioinput.html#error">error</a>() returns <a href="qaudio.html#Error-enum">QAudio::NoError</a> and the <a href="qaudioinput.html#stateChanged">stateChanged</a>() signal is emitted.</p> <p>If a problem occurs during this process, <a href="qaudioinput.html#error">error</a>() returns <a href="qaudio.html#Error-enum">QAudio::OpenError</a>, <a href="qaudioinput.html#state">state</a>() returns <a href="qaudio.html#State-enum">QAudio::StoppedState</a> and the <a href="qaudioinput.html#stateChanged">stateChanged</a>() signal is emitted.</p> <p><b>See also </b>QIODevice.</p> <!-- @@@start --> <!-- $$$state[overload1]$$$state --> <h3 class="fn" id="state"><a name="state"></a><span class="type"><a href="qaudio.html#State-enum">QAudio::State</a></span> QAudioInput::<span class="name">state</span>() const</h3> <p>Returns the state of audio processing.</p> <!-- @@@state --> <!-- $$$stateChanged[overload1]$$$stateChangedQAudio::State --> <h3 class="fn" id="stateChanged"><a name="stateChanged"></a><code>[signal] </code><span class="type">void</span> QAudioInput::<span class="name">stateChanged</span>(<span class="type"><a href="qaudio.html#State-enum">QAudio::State</a></span> <i>state</i>)</h3> <!-- @@@stateChanged --> <!-- $$$stop[overload1]$$$stop --> <h3 class="fn" id="stop"><a name="stop"></a><span class="type">void</span> QAudioInput::<span class="name">stop</span>()</h3> <p>Stops the audio input, detaching from the system resource.</p> <p>Sets <a href="qaudioinput.html#error">error</a>() to <a href="qaudio.html#Error-enum">QAudio::NoError</a>, <a href="qaudioinput.html#state">state</a>() to <a href="qaudio.html#State-enum">QAudio::StoppedState</a> and emit <a href="qaudioinput.html#stateChanged">stateChanged</a>() signal.</p> <!-- @@@stop --> <!-- $$$suspend[overload1]$$$suspend --> <h3 class="fn" id="suspend"><a name="suspend"></a><span class="type">void</span> QAudioInput::<span class="name">suspend</span>()</h3> <p>Stops processing audio data, preserving buffered audio data.</p> <p>Sets <a href="qaudioinput.html#error">error</a>() to <a href="qaudio.html#Error-enum">QAudio::NoError</a>, <a href="qaudioinput.html#state">state</a>() to <a href="qaudio.html#State-enum">QAudio::SuspendedState</a> and emit <a href="qaudioinput.html#stateChanged">stateChanged</a>() signal.</p> <!-- @@@suspend --> <!-- $$$volume[overload1]$$$volume --> <h3 class="fn" id="volume"><a name="volume"></a><span class="type">qreal</span> QAudioInput::<span class="name">volume</span>() const</h3> <p>Returns the input volume.</p> <p>If the device does not support adjusting the input volume the returned value will be 1.0.</p> <p><b>See also </b><a href="qaudioinput.html#setVolume">setVolume</a>().</p> <!-- @@@volume --> </div> </div> </div> </div> </div> </div> <div class="footer"> <p> <acronym title="Copyright">©</acronym> 2019 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners.<br/> The documentation provided herein is licensed under the terms of the <a href="http://www.gnu.org/licenses/fdl.html">GNU Free Documentation License version 1.3</a> as published by the Free Software Foundation.<br/> Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners. </p> </div> </body> </html>