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<?xml version="1.0" encoding="iso-8859-1"?>
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<html><head><title>QAudioDeviceInfo Class Reference</title><style>h3.fn,span.fn { margin-left: 1cm; text-indent: -1cm }
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</style></head><body><table border="0" cellpadding="0" cellspacing="0" width="100%"><tr /><td align="left" valign="top" width="32"><img align="left" border="0" height="32" src="images/rb-logo.png" width="32" /></td><td width="1">  </td><td class="postheader" valign="center"><a href="index.html"><font color="#004faf">Home</font></a> · <a href="classes.html"><font color="#004faf">All Classes</font></a> · <a href="modules.html"><font color="#004faf">Modules</font></a></td></table><h1 align="center">QAudioDeviceInfo Class Reference<br /><sup><sup>[<a href="qtmultimedia.html">QtMultimedia</a> module]</sup></sup></h1><p>The QAudioDeviceInfo class provides an interface to query audio
devices and their functionality. <a href="#details">More...</a></p>
<h3>Methods</h3><ul><li><div class="fn" /><b><a href="qaudiodeviceinfo.html#QAudioDeviceInfo">__init__</a></b> (<i>self</i>)</li><li><div class="fn" /><b><a href="qaudiodeviceinfo.html#QAudioDeviceInfo-2">__init__</a></b> (<i>self</i>, QAudioDeviceInfo <i>other</i>)</li><li><div class="fn" />QString <b><a href="qaudiodeviceinfo.html#deviceName">deviceName</a></b> (<i>self</i>)</li><li><div class="fn" />bool <b><a href="qaudiodeviceinfo.html#isFormatSupported">isFormatSupported</a></b> (<i>self</i>, QAudioFormat <i>format</i>)</li><li><div class="fn" />bool <b><a href="qaudiodeviceinfo.html#isNull">isNull</a></b> (<i>self</i>)</li><li><div class="fn" />QAudioFormat <b><a href="qaudiodeviceinfo.html#nearestFormat">nearestFormat</a></b> (<i>self</i>, QAudioFormat <i>format</i>)</li><li><div class="fn" />QAudioFormat <b><a href="qaudiodeviceinfo.html#preferredFormat">preferredFormat</a></b> (<i>self</i>)</li><li><div class="fn" />unknown-type <b><a href="qaudiodeviceinfo.html#supportedByteOrders">supportedByteOrders</a></b> (<i>self</i>)</li><li><div class="fn" />unknown-type <b><a href="qaudiodeviceinfo.html#supportedChannelCounts">supportedChannelCounts</a></b> (<i>self</i>)</li><li><div class="fn" />unknown-type <b><a href="qaudiodeviceinfo.html#supportedChannels">supportedChannels</a></b> (<i>self</i>)</li><li><div class="fn" />QStringList <b><a href="qaudiodeviceinfo.html#supportedCodecs">supportedCodecs</a></b> (<i>self</i>)</li><li><div class="fn" />unknown-type <b><a href="qaudiodeviceinfo.html#supportedFrequencies">supportedFrequencies</a></b> (<i>self</i>)</li><li><div class="fn" />unknown-type <b><a href="qaudiodeviceinfo.html#supportedSampleRates">supportedSampleRates</a></b> (<i>self</i>)</li><li><div class="fn" />unknown-type <b><a href="qaudiodeviceinfo.html#supportedSampleSizes">supportedSampleSizes</a></b> (<i>self</i>)</li><li><div class="fn" />unknown-type <b><a href="qaudiodeviceinfo.html#supportedSampleTypes">supportedSampleTypes</a></b> (<i>self</i>)</li></ul><h3>Static Methods</h3><ul><li><div class="fn" />unknown-type <b><a href="qaudiodeviceinfo.html#availableDevices">availableDevices</a></b> (QAudio.Mode <i>mode</i>)</li><li><div class="fn" />QAudioDeviceInfo <b><a href="qaudiodeviceinfo.html#defaultInputDevice">defaultInputDevice</a></b> ()</li><li><div class="fn" />QAudioDeviceInfo <b><a href="qaudiodeviceinfo.html#defaultOutputDevice">defaultOutputDevice</a></b> ()</li></ul><a name="details" /><hr /><h2>Detailed Description</h2><p>The QAudioDeviceInfo class provides an interface to query audio
devices and their functionality.</p>
<p>QAudioDeviceInfo lets you query for audio devices--such as sound
cards and USB headsets--that are currently available on the system.
The audio devices available are dependent on the platform or audio
plugins installed.</p>
<p>You can also query each device for the formats it supports. A
format in this context is a set consisting of a specific byte
order, channel, codec, frequency, sample rate, and sample type. A
format is represented by the <a href="qaudioformat.html">QAudioFormat</a> class.</p>
<p>The values supported by the the device for each of these
parameters can be fetched with <a href="qaudiodeviceinfo.html#supportedByteOrders">supportedByteOrders</a>(),
<a href="qaudiodeviceinfo.html#supportedChannelCounts">supportedChannelCounts</a>(),
<a href="qaudiodeviceinfo.html#supportedCodecs">supportedCodecs</a>(),
<a href="qaudiodeviceinfo.html#supportedSampleRates">supportedSampleRates</a>(),
<a href="qaudiodeviceinfo.html#supportedSampleSizes">supportedSampleSizes</a>(),
and <a href="qaudiodeviceinfo.html#supportedSampleTypes">supportedSampleTypes</a>().
The combinations supported are dependent on the platform, audio
plugins installed and the audio device capabilities. If you need a
specific format, you can check if the device supports it with
<a href="qaudiodeviceinfo.html#isFormatSupported">isFormatSupported</a>(),
or fetch a supported format that is as close as possible to the
format with <a href="qaudiodeviceinfo.html#nearestFormat">nearestFormat</a>(). For
instance:</p>
<pre class="cpp">
<span class="type"><a href="qaudioformat.html">QAudioFormat</a></span> format;
format<span class="operator">.</span>setFrequency(<span class="number">44100</span>);
...
format<span class="operator">.</span>setSampleType(<span class="type"><a href="qaudioformat.html">QAudioFormat</a></span><span class="operator">.</span>SignedInt);
<span class="type">QAudioDeviceInfo</span> info(<span class="type">QAudioDeviceInfo</span><span class="operator">.</span>defaultOutputDevice());
<span class="keyword">if</span> (<span class="operator">!</span>info<span class="operator">.</span>isFormatSupported(format))
format <span class="operator">=</span> info<span class="operator">.</span>nearestFormat(format);
</pre>
<p>A QAudioDeviceInfo is used by Qt to construct classes that
communicate with the device--such as <a href="qaudioinput.html">QAudioInput</a>, and <a href="qaudiooutput.html">QAudioOutput</a>. The static functions <a href="qaudiodeviceinfo.html#defaultInputDevice">defaultInputDevice</a>(),
<a href="qaudiodeviceinfo.html#defaultOutputDevice">defaultOutputDevice</a>(),
and <a href="qaudiodeviceinfo.html#availableDevices">availableDevices</a>() let
you get a list of all available devices. Devices are fetch
according to the value of mode this is specified by the <a href="qaudio.html#Mode-enum">QAudio.Mode</a> enum. The QAudioDeviceInfo
returned are only valid for the <a href="qaudio.html#Mode-enum">QAudio.Mode</a>.</p>
<p>For instance:</p>
<pre class="cpp">
<a href="qtcore.html#foreach">foreach</a>(<span class="keyword">const</span> <span class="type">QAudioDeviceInfo</span> <span class="operator">&</span>deviceInfo<span class="operator">,</span> <span class="type">QAudioDeviceInfo</span><span class="operator">.</span>availableDevices(<span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">.</span>AudioOutput))
<a href="qtcore.html#qDebug">qDebug</a>() <span class="operator"><</span><span class="operator"><</span> <span class="string">"Device name: "</span> <span class="operator"><</span><span class="operator"><</span> deviceInfo<span class="operator">.</span><a href="qaudiodeviceinfo.html#deviceName">deviceName</a>();
</pre>
<p>In this code sample, we loop through all devices that are able
to output sound, i.e., play an audio stream in a supported format.
For each device we find, we simply print the <a href="qaudiodeviceinfo.html#deviceName">deviceName</a>().</p>
<hr /><h2>Method Documentation</h2><h3 class="fn"><a name="QAudioDeviceInfo" />QAudioDeviceInfo.__init__ (<i>self</i>)</h3><p>Constructs an empty <a href="qaudiodeviceinfo.html">QAudioDeviceInfo</a> object.</p>
<h3 class="fn"><a name="QAudioDeviceInfo-2" />QAudioDeviceInfo.__init__ (<i>self</i>, <a href="qaudiodeviceinfo.html">QAudioDeviceInfo</a> <i>other</i>)</h3><p>Constructs a copy of <i>other</i>.</p>
<h3 class="fn"><a name="availableDevices" />unknown-type QAudioDeviceInfo.availableDevices (<a href="qaudio.html#Mode-enum">QAudio.Mode</a> <i>mode</i>)</h3><p>Returns a list of audio devices that support <i>mode</i>.</p>
<h3 class="fn"><a name="defaultInputDevice" /><a href="qaudiodeviceinfo.html">QAudioDeviceInfo</a> QAudioDeviceInfo.defaultInputDevice ()</h3><p>Returns the name of the default input audio device. All platform
and audio plugin implementations provide a default audio device to
use.</p>
<h3 class="fn"><a name="defaultOutputDevice" /><a href="qaudiodeviceinfo.html">QAudioDeviceInfo</a> QAudioDeviceInfo.defaultOutputDevice ()</h3><p>Returns the name of the default output audio device. All
platform and audio plugin implementations provide a default audio
device to use.</p>
<h3 class="fn"><a name="deviceName" />QString QAudioDeviceInfo.deviceName (<i>self</i>)</h3><p>Returns human readable name of audio device.</p>
<p>Device names vary depending on platform/audio plugin being
used.</p>
<p>They are a unique string identifiers for the audio device.</p>
<p>eg. default, Intel, U0x46d0x9a4</p>
<h3 class="fn"><a name="isFormatSupported" />bool QAudioDeviceInfo.isFormatSupported (<i>self</i>, <a href="qaudioformat.html">QAudioFormat</a> <i>format</i>)</h3><p>Returns true if <i>settings</i> are supported by the audio
device of this <a href="qaudiodeviceinfo.html">QAudioDeviceInfo</a>.</p>
<h3 class="fn"><a name="isNull" />bool QAudioDeviceInfo.isNull (<i>self</i>)</h3><p>Returns whether this <a href="qaudiodeviceinfo.html">QAudioDeviceInfo</a> object holds a device
definition.</p>
<h3 class="fn"><a name="nearestFormat" /><a href="qaudioformat.html">QAudioFormat</a> QAudioDeviceInfo.nearestFormat (<i>self</i>, <a href="qaudioformat.html">QAudioFormat</a> <i>format</i>)</h3><p>Returns closest <a href="qaudioformat.html">QAudioFormat</a> to
<i>settings</i> that system audio supports.</p>
<p>These settings are provided by the platform/audio plugin being
used.</p>
<p>They also are dependent on the <a href="qaudio.html#Mode-enum">QAudio.Mode</a> being used.</p>
<h3 class="fn"><a name="preferredFormat" /><a href="qaudioformat.html">QAudioFormat</a> QAudioDeviceInfo.preferredFormat (<i>self</i>)</h3><p>Returns <a href="qaudioformat.html">QAudioFormat</a> of default
settings.</p>
<p>These settings are provided by the platform/audio plugin being
used.</p>
<p>They also are dependent on the <a href="qaudio.html#Mode-enum">QAudio.Mode</a> being used.</p>
<p>A typical audio system would provide something like:</p>
<ul>
<li>Input settings: 8000Hz mono 8 bit.</li>
<li>Output settings: 44100Hz stereo 16 bit little endian.</li>
</ul>
<h3 class="fn"><a name="supportedByteOrders" />unknown-type QAudioDeviceInfo.supportedByteOrders (<i>self</i>)</h3><p>Returns a list of supported byte orders.</p>
<h3 class="fn"><a name="supportedChannelCounts" />unknown-type QAudioDeviceInfo.supportedChannelCounts (<i>self</i>)</h3><p>Returns a list of supported channel counts.</p>
<p>This function was introduced in Qt 4.7.</p>
<h3 class="fn"><a name="supportedChannels" />unknown-type QAudioDeviceInfo.supportedChannels (<i>self</i>)</h3><h3 class="fn"><a name="supportedCodecs" />QStringList QAudioDeviceInfo.supportedCodecs (<i>self</i>)</h3><p>Returns a list of supported codecs.</p>
<p>All platform and plugin implementations should provide support
for:</p>
<p>"audio/pcm" - Linear PCM</p>
<p>For writing plugins to support additional codecs refer to:</p>
<p>http://www.iana.org/assignments/media-types/audio/</p>
<h3 class="fn"><a name="supportedFrequencies" />unknown-type QAudioDeviceInfo.supportedFrequencies (<i>self</i>)</h3><h3 class="fn"><a name="supportedSampleRates" />unknown-type QAudioDeviceInfo.supportedSampleRates (<i>self</i>)</h3><p>Returns a list of supported sample rates.</p>
<p>This function was introduced in Qt 4.7.</p>
<h3 class="fn"><a name="supportedSampleSizes" />unknown-type QAudioDeviceInfo.supportedSampleSizes (<i>self</i>)</h3><p>Returns a list of supported sample sizes.</p>
<h3 class="fn"><a name="supportedSampleTypes" />unknown-type QAudioDeviceInfo.supportedSampleTypes (<i>self</i>)</h3><p>Returns a list of supported sample types.</p>
<address><hr /><div align="center"><table border="0" cellspacing="0" width="100%"><tr class="address"><td align="left" width="25%">PyQt 4.12.1 for X11</td><td align="center" width="50%">Copyright © <a href="http://www.riverbankcomputing.com">Riverbank Computing Ltd</a> and <a href="http://www.qt.io">The Qt Company</a> 2015</td><td align="right" width="25%">Qt 4.8.7</td></tr></table></div></address></body></html>
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