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<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="functions.html"><font color="#004faf">All Functions</font></a> · <a href="overviews.html"><font color="#004faf">Overviews</font></a></td></tr></table><h1 class="title">QAudioDeviceInfo Class Reference<br /><span class="small-subtitle">[<a href="qtmultimedia.html">QtMultimedia</a> module]</span>
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<p>The QAudioDeviceInfo class provides an interface to query audio devices and their functionality. <a href="#details">More...</a></p>
<pre> #include <QAudioDeviceInfo></pre><p><b>This class is not part of the Qt GUI Framework Edition.</b></p>
<p>This class was introduced in Qt 4.6.</p>
<ul>
<li><a href="qaudiodeviceinfo-members.html">List of all members, including inherited members</a></li>
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<a name="public-functions"></a>
<h2>Public Functions</h2>
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<tr><td class="memItemLeft" align="right" valign="top"></td><td class="memItemRight" valign="bottom"><b><a href="qaudiodeviceinfo.html#QAudioDeviceInfo">QAudioDeviceInfo</a></b> ()</td></tr>
<tr><td class="memItemLeft" align="right" valign="top"></td><td class="memItemRight" valign="bottom"><b><a href="qaudiodeviceinfo.html#QAudioDeviceInfo-2">QAudioDeviceInfo</a></b> ( const QAudioDeviceInfo & <i>other</i> )</td></tr>
<tr><td class="memItemLeft" align="right" valign="top"></td><td class="memItemRight" valign="bottom"><b><a href="qaudiodeviceinfo.html#dtor.QAudioDeviceInfo">~QAudioDeviceInfo</a></b> ()</td></tr>
<tr><td class="memItemLeft" align="right" valign="top">QString </td><td class="memItemRight" valign="bottom"><b><a href="qaudiodeviceinfo.html#deviceName">deviceName</a></b> () const</td></tr>
<tr><td class="memItemLeft" align="right" valign="top">bool </td><td class="memItemRight" valign="bottom"><b><a href="qaudiodeviceinfo.html#isFormatSupported">isFormatSupported</a></b> ( const QAudioFormat & <i>settings</i> ) const</td></tr>
<tr><td class="memItemLeft" align="right" valign="top">bool </td><td class="memItemRight" valign="bottom"><b><a href="qaudiodeviceinfo.html#isNull">isNull</a></b> () const</td></tr>
<tr><td class="memItemLeft" align="right" valign="top">QAudioFormat </td><td class="memItemRight" valign="bottom"><b><a href="qaudiodeviceinfo.html#nearestFormat">nearestFormat</a></b> ( const QAudioFormat & <i>settings</i> ) const</td></tr>
<tr><td class="memItemLeft" align="right" valign="top">QAudioFormat </td><td class="memItemRight" valign="bottom"><b><a href="qaudiodeviceinfo.html#preferredFormat">preferredFormat</a></b> () const</td></tr>
<tr><td class="memItemLeft" align="right" valign="top">QList<QAudioFormat::Endian> </td><td class="memItemRight" valign="bottom"><b><a href="qaudiodeviceinfo.html#supportedByteOrders">supportedByteOrders</a></b> () const</td></tr>
<tr><td class="memItemLeft" align="right" valign="top">QList<int> </td><td class="memItemRight" valign="bottom"><b><a href="qaudiodeviceinfo.html#supportedChannels">supportedChannels</a></b> () const</td></tr>
<tr><td class="memItemLeft" align="right" valign="top">QStringList </td><td class="memItemRight" valign="bottom"><b><a href="qaudiodeviceinfo.html#supportedCodecs">supportedCodecs</a></b> () const</td></tr>
<tr><td class="memItemLeft" align="right" valign="top">QList<int> </td><td class="memItemRight" valign="bottom"><b><a href="qaudiodeviceinfo.html#supportedFrequencies">supportedFrequencies</a></b> () const</td></tr>
<tr><td class="memItemLeft" align="right" valign="top">QList<int> </td><td class="memItemRight" valign="bottom"><b><a href="qaudiodeviceinfo.html#supportedSampleSizes">supportedSampleSizes</a></b> () const</td></tr>
<tr><td class="memItemLeft" align="right" valign="top">QList<QAudioFormat::SampleType> </td><td class="memItemRight" valign="bottom"><b><a href="qaudiodeviceinfo.html#supportedSampleTypes">supportedSampleTypes</a></b> () const</td></tr>
<tr><td class="memItemLeft" align="right" valign="top">QAudioDeviceInfo & </td><td class="memItemRight" valign="bottom"><b><a href="qaudiodeviceinfo.html#operator-eq">operator=</a></b> ( const QAudioDeviceInfo & <i>other</i> )</td></tr>
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<a name="static-public-members"></a>
<h2>Static Public Members</h2>
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<tr><td class="memItemLeft" align="right" valign="top">QList<QAudioDeviceInfo> </td><td class="memItemRight" valign="bottom"><b><a href="qaudiodeviceinfo.html#availableDevices">availableDevices</a></b> ( QAudio::Mode <i>mode</i> )</td></tr>
<tr><td class="memItemLeft" align="right" valign="top">QAudioDeviceInfo </td><td class="memItemRight" valign="bottom"><b><a href="qaudiodeviceinfo.html#defaultInputDevice">defaultInputDevice</a></b> ()</td></tr>
<tr><td class="memItemLeft" align="right" valign="top">QAudioDeviceInfo </td><td class="memItemRight" valign="bottom"><b><a href="qaudiodeviceinfo.html#defaultOutputDevice">defaultOutputDevice</a></b> ()</td></tr>
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<a name="details"></a>
<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#supportedChannels">supportedChannels</a>(), <a href="qaudiodeviceinfo.html#supportedCodecs">supportedCodecs</a>(), <a href="qaudiodeviceinfo.html#supportedFrequencies">supportedFrequencies</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> QAudioFormat format;
format.setFrequency(44100);
...
format.setSampleType(QAudioFormat::SignedInt);
QAudioDeviceInfo info(QAudioDeviceInfo::defaultOutputDevice());
if (!info.isFormatSupported(format))
format = info.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> foreach(const QAudioDeviceInfo &deviceInfo, QAudioDeviceInfo::availableDevices(QAudio::AudioOutput))
qDebug() << "Device name: " << deviceInfo.deviceName();</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>
<p>See also <a href="qaudiooutput.html">QAudioOutput</a> and <a href="qaudioinput.html">QAudioInput</a>.</p>
<hr />
<h2>Member Function Documentation</h2>
<a name="//apple_ref/cpp/instm/QAudioDeviceInfo/QAudioDeviceInfo"></a>
<h3 class="fn"><a name="QAudioDeviceInfo"></a>QAudioDeviceInfo::QAudioDeviceInfo ()</h3>
<p>Constructs an empty <a href="qaudiodeviceinfo.html">QAudioDeviceInfo</a> object.</p>
<h3 class="fn"><a name="QAudioDeviceInfo-2"></a>QAudioDeviceInfo::QAudioDeviceInfo ( const QAudioDeviceInfo & <i>other</i> )</h3>
<p>Constructs a copy of <i>other</i>.</p>
<a name="//apple_ref/cpp/instm/QAudioDeviceInfo/~QAudioDeviceInfo"></a>
<h3 class="fn"><a name="dtor.QAudioDeviceInfo"></a>QAudioDeviceInfo::~QAudioDeviceInfo ()</h3>
<p>Destroy this audio device info.</p>
<a name="//apple_ref/cpp/clm/QAudioDeviceInfo/availableDevices"></a>
<h3 class="fn"><a name="availableDevices"></a><a href="qlist.html">QList</a><QAudioDeviceInfo> QAudioDeviceInfo::availableDevices ( <a href="qaudio.html#Mode-enum">QAudio::Mode</a> <i>mode</i> ) <tt> [static]</tt></h3>
<p>Returns a list of audio devices that support <i>mode</i>.</p>
<a name="//apple_ref/cpp/clm/QAudioDeviceInfo/defaultInputDevice"></a>
<h3 class="fn"><a name="defaultInputDevice"></a>QAudioDeviceInfo QAudioDeviceInfo::defaultInputDevice () <tt> [static]</tt></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>
<a name="//apple_ref/cpp/clm/QAudioDeviceInfo/defaultOutputDevice"></a>
<h3 class="fn"><a name="defaultOutputDevice"></a>QAudioDeviceInfo QAudioDeviceInfo::defaultOutputDevice () <tt> [static]</tt></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>
<a name="//apple_ref/cpp/instm/QAudioDeviceInfo/deviceName"></a>
<h3 class="fn"><a name="deviceName"></a><a href="qstring.html">QString</a> QAudioDeviceInfo::deviceName () const</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>
<a name="//apple_ref/cpp/instm/QAudioDeviceInfo/isFormatSupported"></a>
<h3 class="fn"><a name="isFormatSupported"></a>bool QAudioDeviceInfo::isFormatSupported ( const <a href="qaudioformat.html">QAudioFormat</a> & <i>settings</i> ) const</h3>
<p>Returns true if <i>settings</i> are supported by the audio device of this <a href="qaudiodeviceinfo.html">QAudioDeviceInfo</a>.</p>
<a name="//apple_ref/cpp/instm/QAudioDeviceInfo/isNull"></a>
<h3 class="fn"><a name="isNull"></a>bool QAudioDeviceInfo::isNull () const</h3>
<p>Returns whether this <a href="qaudiodeviceinfo.html">QAudioDeviceInfo</a> object holds a device definition.</p>
<a name="//apple_ref/cpp/instm/QAudioDeviceInfo/nearestFormat"></a>
<h3 class="fn"><a name="nearestFormat"></a><a href="qaudioformat.html">QAudioFormat</a> QAudioDeviceInfo::nearestFormat ( const <a href="qaudioformat.html">QAudioFormat</a> & <i>settings</i> ) const</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>
<a name="//apple_ref/cpp/instm/QAudioDeviceInfo/preferredFormat"></a>
<h3 class="fn"><a name="preferredFormat"></a><a href="qaudioformat.html">QAudioFormat</a> QAudioDeviceInfo::preferredFormat () const</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>
<a name="//apple_ref/cpp/instm/QAudioDeviceInfo/supportedByteOrders"></a>
<h3 class="fn"><a name="supportedByteOrders"></a><a href="qlist.html">QList</a><<a href="qaudioformat.html#Endian-enum">QAudioFormat::Endian</a>> QAudioDeviceInfo::supportedByteOrders () const</h3>
<p>Returns a list of supported byte orders.</p>
<a name="//apple_ref/cpp/instm/QAudioDeviceInfo/supportedChannels"></a>
<h3 class="fn"><a name="supportedChannels"></a><a href="qlist.html">QList</a><int> QAudioDeviceInfo::supportedChannels () const</h3>
<p>Returns a list of supported channels.</p>
<a name="//apple_ref/cpp/instm/QAudioDeviceInfo/supportedCodecs"></a>
<h3 class="fn"><a name="supportedCodecs"></a><a href="qstringlist.html">QStringList</a> QAudioDeviceInfo::supportedCodecs () const</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>
<a name="//apple_ref/cpp/instm/QAudioDeviceInfo/supportedFrequencies"></a>
<h3 class="fn"><a name="supportedFrequencies"></a><a href="qlist.html">QList</a><int> QAudioDeviceInfo::supportedFrequencies () const</h3>
<p>Returns a list of supported frequencies.</p>
<a name="//apple_ref/cpp/instm/QAudioDeviceInfo/supportedSampleSizes"></a>
<h3 class="fn"><a name="supportedSampleSizes"></a><a href="qlist.html">QList</a><int> QAudioDeviceInfo::supportedSampleSizes () const</h3>
<p>Returns a list of supported sample sizes.</p>
<a name="//apple_ref/cpp/instm/QAudioDeviceInfo/supportedSampleTypes"></a>
<h3 class="fn"><a name="supportedSampleTypes"></a><a href="qlist.html">QList</a><<a href="qaudioformat.html#SampleType-enum">QAudioFormat::SampleType</a>> QAudioDeviceInfo::supportedSampleTypes () const</h3>
<p>Returns a list of supported sample types.</p>
<a name="//apple_ref/cpp/instm/QAudioDeviceInfo/operator="></a>
<h3 class="fn"><a name="operator-eq"></a>QAudioDeviceInfo & QAudioDeviceInfo::operator= ( const QAudioDeviceInfo & <i>other</i> )</h3>
<p>Sets the <a href="qaudiodeviceinfo.html">QAudioDeviceInfo</a> object to be equal to <i>other</i>.</p>
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