chestercs
/
detectSoundlevel-spike


			
				
					
						
						
							123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734735736737738739740741742743744745746747748749750751752753754755756757758759760761762763764765766767768769770771772773774775776777778779780781782783784785786787788789790791792793794795796797798799800801802803804805806807808809810811812813814815816817818819820821822823824825826827828829830831832833834835836837838839840841842843844845846847848849850851852853854855856857858859860861862863864865866867868869870871872873874875876877878879880881882883884885886887888889890
							<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <meta name="Generator" content="XN-Docs v2.03 (http://ccgi.inspiration3.plus.com/ahk/xn-docs/)" />
    <title>Vista Audio Control Function Reference</title>
    <style type="text/css" media="all">
/*<![CDATA[*/
html {
	color: #333;
	background: #fff;
	font: .9em Calibri, Arial, Helvetica, sans-serif;
}
body { margin: 0em;  min-width: 600px; }
h1 {
	margin: 0em;
	color: #fff;
	background: #333;
	padding: .2em .5em;
	border-bottom: 1px solid #000;
}
h1 a {
	color: #fff !important;
	background: inherit;
	text-decoration: none;
}
h2 { border-bottom: 1px solid #ddd; }
h3.command {
	background: #09c;
	padding: .7em;
	color: #fff;
	cursor: help;
	letter-spacing: .1em;
	font: bold 1.2em "Courier New", Courier, monospace;
}
a { color: #06c; }
a:hover { color: #936; }
table { font-size: 1em; }
p.descr {
	margin: 1.5em;
	line-height: 1.5;
}
span.sub {
	color: #666;
	background: inherit;
}
p.descr span.sub:before { content: ">> "; }
table.params span.sub {
	font-size: .75em;
	margin-right: .5em;
}
div#contents {
	width: 200px;
	float: right;
	border-left: 1px dashed #ddd;
	margin-top: 2em;
	overflow: auto;
	padding: 10px;
}
div#contents div { margin-left: 1em; }
div#contents ul {
	list-style: square;
	padding-left: 1em;
}
div#contents *:first-child { margin-top: 0em; }
div#page {
  position: relative;
  margin-left: 0px;
  margin-right: 230px;
	width: auto;
}
div#page > div:not(:target) { display: none; }
div#page > div:target { display: block; }
div.method {
	background: #fefefe;
	border: 1px solid #eee;
	margin-bottom: 2em;
	margin-left: 0.5em;
	padding: 1em;
}
div.method *:first-child { margin-top: 0em; }
div#end {
	font-size: .9em;
	margin-top: 1em;
	border-top: 1px solid #000;
	padding: 1em;
	color: #fff;
	background: #666;
}
div#end a { color: #fff; }
span.vers {
	font-size: .6em;
	color: #ccc;
	padding-left: .3em;
}
table.params {
	font-size: 1em;
	margin-left: 3em;
}
table.params th {
	text-align: left;
	background: #eee;
	padding: .2em;
}
table.params td {
	vertical-align: top;
	padding: .2em 1em .2em .5em;
	background: #fff;
	border: 1px solid #f3f3f3;
}
table.params td:first-child { background: #f3f3f3 !important; }
table.params tr.returns td { background: #f3f3f3; }
table.params tr.returns td:first-child { background: #fff !important; }
table.dataset { margin-left: 3em; }
table.dataset th {
	background: #eee;
	text-align: left;
	padding: .2em;
}
table.dataset td {
	vertical-align: top;
	padding: .2em 1em .2em .5em;
}
pre.code {
	padding: 1em;
	font-size: 1em;
	border: 1px dotted #999;
	background: #fff;
	margin-left: 2em;
	overflow: auto;
}
kbd { font: 1em "Courier New", Courier, monospace; }
code, pre.code { font: .9em "Courier New", Courier, monospace; }
pre.code em, code em {
	color: #060;
	font-style: normal;
	font-weight: bold;
}
pre.code kbd, code kbd {
	color: #c00;
	font-weight: normal;
}
pre.code var, code var {
	font-style: normal;
	font-weight: bold;
	color: #f80;
}
pre.code var.prc, code var.prc {
	font-weight: normal;
	color: #f00;
	font-style: italic;
}
pre.code strong, code strong { color: #039; }
pre.code strong.res, code strong.res { color: #800000; }
@media print {
	* {
		background: none !important;
		color: #000 !important;
	}
	p.descr span.sub, div#contents { display: none; }
	div#page { width: 100%; }
	div#page > div:not(:target) { display: block; }
	table.params, pre.code { margin: 0em; }
	div.method {
		border: none;
		margin: 1em 0em;
		padding: 0em;
	}
	pre.code { overflow: visible; }
}
/*]]>*/
    </style>
    <script type="text/javascript">
/*<![CDATA[*/
function tabsetup() {
var a = document.getElementById('contents').getElementsByTagName('a'), i;
	tabswitch(window.location.hash);
	for (i in a) { a[i].onclick = tabswitch; }
}
function tabswitch(e) {
	var d = document.getElementById('page').getElementsByTagName('div'),
		h = typeof(e) == 'string' ? e : this.hash, id = h ? h.slice(1) : '', i;
	for (i = 0; i < d.length; i++) { if (d[i].className == 'method') { d[i].style.display = 'none'; } }
	if (id) { document.getElementById(id).style.display = 'block'; }
}
if (window.attachEvent) { window.attachEvent('onload', tabsetup); }
/*]]>*/
    </script>
  </head>
  <body>
    <h1>
      <a href="http://www.autohotkey.com/forum/topic23792.html">Vista Audio Control Function Reference</a><span class="vers"> (version 2.3)</span>
    </h1>
    <div id="contents">
      <div>
        <h4>Master Controls</h4>
        <ul>
          <li>
            <a href="#VA_GetMasterVolume">VA_GetMasterVolume</a>
          </li>
          <li>
            <a href="#VA_SetMasterVolume">VA_SetMasterVolume</a>
          </li>
          <li>
            <a href="#VA_GetMasterChannelCount">VA_GetMasterChannelCount</a>
          </li>
          <li>
            <a href="#VA_GetMasterMute">VA_GetMasterMute</a>
          </li>
          <li>
            <a href="#VA_SetMasterMute">VA_SetMasterMute</a>
          </li>
        </ul>
        <h4>Subunit Controls</h4>
        <ul>
          <li>
            <a href="#VA_GetVolume">VA_GetVolume</a>
          </li>
          <li>
            <a href="#VA_SetVolume">VA_SetVolume</a>
          </li>
          <li>
            <a href="#VA_GetChannelCount">VA_GetChannelCount</a>
          </li>
          <li>
            <a href="#VA_GetMute">VA_GetMute</a>
          </li>
          <li>
            <a href="#VA_SetMute">VA_SetMute</a>
          </li>
        </ul>
        <h4>Advanced</h4>
        <ul>
          <li>
            <a href="#VA_GetAudioEndpointVolume">VA_GetAudioEndpointVolume</a>
          </li>
          <li>
            <a href="#VA_GetAudioMeter">VA_GetAudioMeter</a>
          </li>
          <li>
            <a href="#VA_GetDevice">VA_GetDevice</a>
          </li>
          <li>
            <a href="#VA_GetDeviceName">VA_GetDeviceName</a>
          </li>
          <li>
            <a href="#VA_GetDevicePeriod">VA_GetDevicePeriod</a>
          </li>
          <li>
            <a href="#VA_GetDeviceSubunit">VA_GetDeviceSubunit</a>
          </li>
          <li>
            <a href="#VA_EnumSubunits">VA_EnumSubunits</a>
          </li>
          <li>
            <a href="#VA_EnumSubunitsEx">VA_EnumSubunitsEx</a>
          </li>
          <li>
            <a href="#VA_FindSubunit">VA_FindSubunit</a>
          </li>
          <li>
            <a href="#VA_SetDefaultEndpoint">VA_SetDefaultEndpoint</a>
          </li>
          <li>
            <a href="#VA_dB2Scalar">VA_dB2Scalar</a>
          </li>
          <li>
            <a href="#VA_Scalar2dB">VA_Scalar2dB</a>
          </li>
        </ul>
        <h4>Other</h4>
        <ul>
          <li>
            <a href="#Interface%20Functions">Interface Functions</a>
          </li>
        </ul>
      </div>
    </div>
    <p class="descr"><br /><span class="sub">Browse through the topics in the contents list to the right.</span></p>
    <div id="page">
      <div class="method" id="VA_GetMasterVolume">
        <h2>VA_GetMasterVolume</h2>
        <p>Gets the master volume level of an audio endpoint device.</p>
        <h3 class="command">VA_GetMasterVolume(channel, device_desc)</h3>
        <h4>Parameters</h4>
        <table class="params">
          <tr class="returns">
            <td>
              <em>Returns</em>
            </td>
            <td>A value between 0.0 and 100.0, inclusive.</td>
          </tr>
          <tr>
            <td>channel</td>
            <td><span class="sub">(optional)</span>The one-based index of the channel to retrieve.</td>
          </tr>
          <tr>
            <td>device_desc</td>
            <td><span class="sub">(optional)</span>See <a href="#VA_GetDevice">VA_GetDevice</a>. Defaults to "playback".</td>
          </tr>
        </table>
        <h4>Remarks</h4>
        <p>Volume levels returned by this function follow the same curve as the Windows Vista Sound Mixer.</p>
        <h4>Example</h4>
        <pre class="code"><em>; Get the master volume of the default playback device.</em>
volume := <strong>VA_GetMasterVolume</strong>()

<em>; Get the volume of the first and second channels.</em>
volume1 := <strong>VA_GetMasterVolume</strong>(1)
volume2 := <strong>VA_GetMasterVolume</strong>(2)

<em>; Get the master volume of a device by name.</em>
lineout_volume := <strong>VA_GetMasterVolume</strong>(<kbd>""</kbd>, <kbd>"Line Out"</kbd>)

<em>; Get the master volume of the default recording device.</em>
recording_volume := <strong>VA_GetMasterVolume</strong>(<kbd>""</kbd>, <kbd>"capture"</kbd>)

<strong>MsgBox</strong>, % <kbd>"Playback volume:`t"</kbd> volume
        . <kbd>"`n  Channel 1:`t"</kbd> volume1
        . <kbd>"`n  Channel 2:`t"</kbd> volume2
        . <kbd>"`nLine Out volume:`t"</kbd> lineout_volume
        . <kbd>"`nRecording volume:`t"</kbd> recording_volume
        </pre>
      </div>
      <div class="method" id="VA_SetMasterVolume">
        <h2>VA_SetMasterVolume</h2>
        <p>Sets the master volume level of an audio endpoint device.</p>
        <h3 class="command">VA_SetMasterVolume(vol, channel, device_desc)</h3>
        <h4>Parameters</h4>
        <table class="params">
          <tr>
            <td>vol</td>
            <td>A value between 0.0 and 100.0, inclusive.</td>
          </tr>
          <tr>
            <td>channel</td>
            <td><span class="sub">(optional)</span>The one-based index of the channel to adjust.</td>
          </tr>
          <tr>
            <td>device_desc</td>
            <td><span class="sub">(optional)</span>See <a href="#VA_GetDevice">VA_GetDevice</a>. Defaults to "playback".</td>
          </tr>
        </table>
        <h4>Remarks</h4>
        <p>Volume levels set by this function follow the same curve as the Windows Vista Sound Mixer.</p>
      </div>
      <div class="method" id="VA_GetMasterChannelCount">
        <h2>VA_GetMasterChannelCount</h2>
        <p>Gets the number of channels an audio endpoint device has.</p>
        <h3 class="command">VA_GetMasterChannelCount(device_desc)</h3>
        <h4>Parameters</h4>
        <table class="params">
          <tr>
            <td>device_desc</td>
            <td><span class="sub">(optional)</span>See <a href="#VA_GetDevice">VA_GetDevice</a>. Defaults to "playback".</td>
          </tr>
        </table>
        <h4>Example</h4>
        <pre class="code"><strong>Loop</strong> % <strong>VA_GetMasterChannelCount</strong>()
    Message .= <kbd>"Channel "</kbd> <strong class="res">A_Index</strong> <kbd>": "</kbd> <strong>VA_GetMasterVolume</strong>(<strong class="res">A_Index</strong>) <kbd>"`n"</kbd>
<strong>MsgBox</strong> %Message%</pre>
      </div>
      <div class="method" id="VA_GetMasterMute">
        <h2>VA_GetMasterMute</h2>
        <p>Gets the mute status of an audio endpoint device.</p>
        <h3 class="command">VA_GetMasterMute(device_desc)</h3>
        <h4>Parameters</h4>
        <table class="params">
          <tr class="returns">
            <td>
              <em>Returns</em>
            </td>
            <td>True if the audio endpoint device is muted, otherwise false.</td>
          </tr>
          <tr>
            <td>device_desc</td>
            <td><span class="sub">(optional)</span>See <a href="#VA_GetDevice">VA_GetDevice</a>. Defaults to "playback".</td>
          </tr>
        </table>
      </div>
      <div class="method" id="VA_SetMasterMute">
        <h2>VA_SetMasterMute</h2>
        <p>Mutes or un-mutes an audio endpoint device.</p>
        <h3 class="command">VA_SetMasterMute(mute, device_desc)</h3>
        <h4>Parameters</h4>
        <table class="params">
          <tr>
            <td>mute</td>
            <td>True to mute; false to un-mute.</td>
          </tr>
          <tr>
            <td>device_desc</td>
            <td><span class="sub">(optional)</span>See <a href="#VA_GetDevice">VA_GetDevice</a>. Defaults to "playback".</td>
          </tr>
        </table>
      </div>
      <div class="method" id="VA_GetVolume">
        <h2>VA_GetVolume</h2>
        <p>Gets the volume level of a subunit.</p>
        <h3 class="command">VA_GetVolume(subunit_desc, channel, device_desc)</h3>
        <h4>Parameters</h4>
        <table class="params">
          <tr class="returns">
            <td>
              <em>Returns</em>
            </td>
            <td>A value between 0.0 and 100.0, inclusive.</td>
          </tr>
          <tr>
            <td>subunit_desc</td>
            <td><span class="sub">(optional)</span>See <a href="#VA_FindSubunit">VA_FindSubunit</a>. Defaults to "1".</td>
          </tr>
          <tr>
            <td>channel</td>
            <td><span class="sub">(optional)</span>The one-based index of the channel to retrieve.</td>
          </tr>
          <tr>
            <td>device_desc</td>
            <td><span class="sub">(optional)</span>See <a href="#VA_GetDevice">VA_GetDevice</a>. Defaults to "playback".</td>
          </tr>
        </table>
        <h4>Remarks</h4>
        <p>Volume levels returned by this function follow the same curve as the Sound applet in Control Panel, not the Sound Mixer.</p>
        <h4>Example</h4>
        <pre class="code"><em>; Note that subunit names are audio driver-specific.</em>
<em>; The following will match "Line", "Line In", "Line Volume", etc.</em>
linein_feedback := <strong>VA_GetVolume</strong>(<kbd>"Line"</kbd>)
mic_feedback := <strong>VA_GetVolume</strong>(<kbd>"Mic"</kbd>, <kbd>""</kbd>, <kbd>"Line Out"</kbd>)
<strong>MsgBox</strong>, % <kbd>"Line In feedback through default playback device: "</kbd> linein_feedback
        . <kbd>"`nMicrophone feedback through Line Out: "</kbd> mic_feedback
        . <kbd>"`n(Note: these may be muted.)"</kbd></pre>
      </div>
      <div class="method" id="VA_SetVolume">
        <h2>VA_SetVolume</h2>
        <p>Sets the volume level of a subunit.</p>
        <h3 class="command">VA_SetVolume(vol, subunit_desc, channel, device_desc)</h3>
        <h4>Parameters</h4>
        <table class="params">
          <tr>
            <td>vol</td>
            <td>A value between 0.0 and 100.0, inclusive.</td>
          </tr>
          <tr>
            <td>subunit_desc</td>
            <td><span class="sub">(optional)</span>See <a href="#VA_FindSubunit">VA_FindSubunit</a>. Defaults to "1".</td>
          </tr>
          <tr>
            <td>channel</td>
            <td><span class="sub">(optional)</span>The one-based index of the channel to retrieve.</td>
          </tr>
          <tr>
            <td>device_desc</td>
            <td><span class="sub">(optional)</span>See <a href="#VA_GetDevice">VA_GetDevice</a>. Defaults to "playback".</td>
          </tr>
        </table>
        <h4>Remarks</h4>
        <p>Volume levels set by this function follow the same curve as the Sound applet in Control Panel, not the Sound Mixer.</p>
      </div>
      <div class="method" id="VA_GetChannelCount">
        <h2>VA_GetChannelCount</h2>
        <p>Gets the number of channels a subunit has.</p>
        <h3 class="command">VA_GetChannelCount(subunit_desc, device_desc)</h3>
        <h4>Parameters</h4>
        <table class="params">
          <tr>
            <td>subunit_desc</td>
            <td><span class="sub">(optional)</span>See <a href="#VA_FindSubunit">VA_FindSubunit</a>. Defaults to "1".</td>
          </tr>
          <tr>
            <td>device_desc</td>
            <td><span class="sub">(optional)</span>See <a href="#VA_GetDevice">VA_GetDevice</a>. Defaults to "playback".</td>
          </tr>
        </table>
      </div>
      <div class="method" id="VA_GetMute">
        <h2>VA_GetMute</h2>
        <p>Gets the mute status of a subunit.</p>
        <h3 class="command">VA_GetMute(subunit_desc, device_desc)</h3>
        <h4>Parameters</h4>
        <table class="params">
          <tr class="returns">
            <td>
              <em>Returns</em>
            </td>
            <td>True if the subunit is muted, otherwise false.</td>
          </tr>
          <tr>
            <td>subunit_desc</td>
            <td><span class="sub">(optional)</span>See <a href="#VA_FindSubunit">VA_FindSubunit</a>. Defaults to "1".</td>
          </tr>
          <tr>
            <td>device_desc</td>
            <td><span class="sub">(optional)</span>See <a href="#VA_GetDevice">VA_GetDevice</a>. Defaults to "playback".</td>
          </tr>
        </table>
      </div>
      <div class="method" id="VA_SetMute">
        <h2>VA_SetMute</h2>
        <p>Mutes or un-mutes a subunit.</p>
        <h3 class="command">VA_SetMute(mute, subunit_desc, device_desc)</h3>
        <h4>Parameters</h4>
        <table class="params">
          <tr>
            <td>mute</td>
            <td>True to mute; false to un-mute.</td>
          </tr>
          <tr>
            <td>subunit_desc</td>
            <td><span class="sub">(optional)</span>See <a href="#VA_FindSubunit">VA_FindSubunit</a>. Defaults to "1".</td>
          </tr>
          <tr>
            <td>device_desc</td>
            <td><span class="sub">(optional)</span>See <a href="#VA_GetDevice">VA_GetDevice</a>. Defaults to "playback".</td>
          </tr>
        </table>
      </div>
      <div class="method" id="VA_GetAudioEndpointVolume">
        <h2>VA_GetAudioEndpointVolume</h2>
        <p>Gets a pointer to the <a href="http://msdn2.microsoft.com/en-us/library/aa964574(VS.85).aspx">IAudioEndpointVolume</a> interface of an audio endpoint device.</p>
        <h3 class="command">VA_GetAudioEndpointVolume(device_desc)</h3>
        <h4>Parameters</h4>
        <table class="params">
          <tr>
            <td>device_desc</td>
            <td><span class="sub">(optional)</span>See <a href="#VA_GetDevice">VA_GetDevice</a>. Defaults to "playback".</td>
          </tr>
        </table>
        <h4>Remarks</h4>
        <p>Use <code><strong>ObjRelease</strong>(pointer)</code> to release the interface pointer when it is no longer needed.</p>
      </div>
      <div class="method" id="VA_GetAudioMeter">
        <h2>VA_GetAudioMeter</h2>
        <p>Gets a pointer to the <a href="http://msdn2.microsoft.com/en-us/library/aa964578(VS.85).aspx">IAudioMeterInformation</a> interface of an audio endpoint device.</p>
        <h3 class="command">VA_GetAudioMeter(device_desc)</h3>
        <h4>Parameters</h4>
        <table class="params">
          <tr>
            <td>device_desc</td>
            <td><span class="sub">(optional)</span>See <a href="#VA_GetDevice">VA_GetDevice</a>. Defaults to "playback".</td>
          </tr>
        </table>
        <h4>Remarks</h4>
        <p>Use <code><strong>ObjRelease</strong>(pointer)</code> to release the interface pointer when it is no longer needed.</p>
        <h4>Example</h4>
        <pre class="code"><var class="prc">#SingleInstance</var>, Force
MeterLength =<kbd> 30</kbd>

audioMeter := <strong>VA_GetAudioMeter</strong>()

<strong>VA_IAudioMeterInformation_GetMeteringChannelCount</strong>(audioMeter, channelCount)

<em>; "The peak value for each channel is recorded over one device</em>
<em>;  period and made available during the subsequent device period."</em>
<strong>VA_GetDevicePeriod</strong>(<kbd>"capture"</kbd>, devicePeriod)

<strong>Loop</strong>
{
    <em>; Get the peak value across all channels.</em>
    <strong>VA_IAudioMeterInformation_GetPeakValue</strong>(audioMeter, peakValue)    
    meter := <strong>MakeMeter</strong>(peakValue, MeterLength)
    
    <em>; Get the peak values of all channels.</em>
    <strong>VarSetCapacity</strong>(peakValues, channelCount*4)
    <strong>VA_IAudioMeterInformation_GetChannelsPeakValues</strong>(audioMeter, channelCount, &peakValues)
    <strong>Loop</strong> %channelCount%
        meter .= <kbd>"`n"</kbd> <strong>MakeMeter</strong>(<strong>NumGet</strong>(peakValues, <strong class="res">A_Index</strong>*4-4, <kbd>"float"</kbd>), MeterLength)

    <strong>ToolTip</strong>, %meter%
    <strong>Sleep</strong>, %devicePeriod%
}

<strong>MakeMeter</strong>(fraction, size)
{
    <strong>global</strong> MeterLength
    <strong>Loop</strong> % fraction*size
        meter .= <kbd>"|"</kbd>
    <strong>Loop</strong> % (1-fraction)*size
        meter .= <kbd>"."</kbd>
    meter .= <kbd>"  "</kbd> fraction
    <strong>return</strong> meter
}</pre>
      </div>
      <div class="method" id="VA_GetDevice">
        <h2>VA_GetDevice</h2>
        <p>Gets a pointer to the <a href="http://msdn2.microsoft.com/en-us/library/ms679028(VS.85).aspx">IMMDevice</a> interface of an audio endpoint device.</p>
        <h3 class="command">VA_GetDevice(device_desc)</h3>
        <h4>Parameters</h4>
        <table class="params">
          <tr>
            <td>device_desc</td>
            <td>device_id | device_number | ( friendly_name | 'playback' | 'capture' ) [ ':' index ]</td>
          </tr>
        </table>
        <h4>Remarks</h4>
        <p>Use <code><strong>ObjRelease</strong>(device)</code> to release the interface pointer when it is no longer needed.</p>
        <p>If device_desc is a device pointer returned by a previous call to VA_GetDevice, it is returned as-is.  This behaviour is useful for other functions which accept a device_desc; these functions call VA_GetDevice internally.</p>
        <h4>Examples</h4>
        <pre class="code">device := <strong>VA_GetDevice</strong>(<kbd>"playback"</kbd>)      <em>; default playback device</em>
device := <strong>VA_GetDevice</strong>(<kbd>"playback:1"</kbd>)    <em>; first playback device</em>
device := <strong>VA_GetDevice</strong>(<kbd>"nvidia:2"</kbd>)      <em>; second device whose name contains "nvidia"</em>
device := <strong>VA_GetDevice</strong>(3)               <em>; third device</em></pre>
        <pre class="code"><strong>VA_IMMDevice_GetId</strong>(device, device_id)   <em>; get a device id from a device pointer</em>
<em>;...</em>
device := <strong>VA_GetDevice</strong>(device_id)       <em>; get a device pointer from an id</em></pre>
      </div>
      <div class="method" id="VA_GetDeviceName">
        <h2>VA_GetDeviceName</h2>
        <p>Gets the friendly name of an audio endpoint device.</p>
        <h3 class="command">VA_GetDeviceName(device)</h3>
        <h4>Parameters</h4>
        <table class="params">
          <tr>
            <td>device</td>
            <td>A pointer to an <a href="http://msdn2.microsoft.com/en-us/library/ms679028(VS.85).aspx">IMMDevice</a> interface.</td>
          </tr>
        </table>
      </div>
      <div class="method" id="VA_GetDevicePeriod">
        <h2>VA_GetDevicePeriod</h2>
        <p>Retrieves the length of the periodic interval separating successive processing passes by the audio engine.</p>
        <h3 class="command">VA_GetDevicePeriod(device_desc, default_period, minimum_period)</h3>
        <h4>Parameters</h4>
        <table class="params">
          <tr class="returns">
            <td>
              <em>Returns</em>
            </td>
            <td>True on success, otherwise false.</td>
          </tr>
          <tr>
            <td>device_desc</td>
            <td>See <a href="#VA_GetDevice">VA_GetDevice</a>.</td>
          </tr>
          <tr>
            <td>default_period</td>
            <td><span class="sub">(out)</span> The default interval, in milliseconds.</td>
          </tr>
          <tr>
            <td>minimum_period</td>
            <td><span class="sub">(out)</span> The minimum interval, in milliseconds.</td>
          </tr>
        </table>
      </div>
      <div class="method" id="VA_GetDeviceSubunit">
        <h2>VA_GetDeviceSubunit</h2>
        <p>Finds a subunit of a device, given a device description.</p>
        <h3 class="command">VA_GetDeviceSubunit(device_desc, subunit_desc, subunit_iid)</h3>
        <h4>Parameters</h4>
        <table class="params">
          <tr class="returns">
            <td>
              <em>Returns</em>
            </td>
            <td>A pointer to the requested interface of a matching subunit, or 0 if none were found.</td>
          </tr>
          <tr>
            <td>device_desc</td>
            <td>See <a href="#VA_GetDevice">VA_GetDevice</a>.</td>
          </tr>
          <tr>
            <td>subunit_desc</td>
            <td>See <a href="#VA_FindSubunit">VA_FindSubunit</a> (target_desc).</td>
          </tr>
          <tr>
            <td>subunit_iid</td>
            <td>See <a href="#VA_FindSubunit">VA_FindSubunit</a> (target_iid).</td>
          </tr>
        </table>
        <h4>Remarks</h4>
        <p>See <a href="#VA_FindSubunit">VA_FindSubunit</a>.</p>
      </div>
      <div class="method" id="VA_EnumSubunits">
        <h2>VA_EnumSubunits</h2>
        <p>Enumerates matching subunits of a device.</p>
        <h3 class="command">VA_EnumSubunits(device, callback, target_name, target_iid)</h3>
        <h4>Parameters</h4>
        <table class="params">
          <tr class="returns">
            <td>
              <em>Returns</em>
            </td>
            <td>See <a href="#VA_EnumSubunitsEx">VA_EnumSubunitsEx</a>.</td>
          </tr>
          <tr>
            <td>device</td>
            <td>A pointer to an <a href="http://msdn2.microsoft.com/en-us/library/ms679028(VS.85).aspx">IMMDevice</a> interface.</td>
          </tr>
          <tr>
            <td>callback</td>
            <td>A callback accepting two parameters: part, interface.</td>
          </tr>
          <tr>
            <td>target_name</td>
            <td><span class="sub">(optional)</span>The full or partial friendly name of a subunit or subunits.</td>
          </tr>
          <tr>
            <td>target_iid</td>
            <td><span class="sub">(optional)</span>The ID of an interface which matching subunits must support.</td>
          </tr>
        </table>
        <h4>Remarks</h4>
        <p>See <a href="#VA_EnumSubunitsEx">VA_EnumSubunitsEx</a>.</p>
      </div>
      <div class="method" id="VA_EnumSubunitsEx">
        <h2>VA_EnumSubunitsEx</h2>
        <p>Enumerates matching subunits of a part (subunit or connector).</p>
        <h3 class="command">VA_EnumSubunitsEx(part, data_flow, callback, target_name, target_iid)</h3>
        <h4>Parameters</h4>
        <table class="params">
          <tr class="returns">
            <td>
              <em>Returns</em>
            </td>
            <td>See Remarks.</td>
          </tr>
          <tr>
            <td>part</td>
            <td>A pointer to an <a href="http://msdn2.microsoft.com/en-us/library/ms679050(VS.85).aspx">IPart</a> interface.</td>
          </tr>
          <tr>
            <td>data_flow</td>
            <td>0 to enumerate incoming parts; 1 to enumerate outgoing parts.</td>
          </tr>
          <tr>
            <td>callback</td>
            <td>A callback accepting two parameters: part, interface.</td>
          </tr>
          <tr>
            <td>target_name</td>
            <td><span class="sub">(optional)</span>The full or partial friendly name of a subunit or subunits.</td>
          </tr>
          <tr>
            <td>target_iid</td>
            <td><span class="sub">(optional)</span>The ID of an interface which matching subunits must support.</td>
          </tr>
        </table>
        <h4>Remarks</h4>
        <p>The callback is called once for each matching subunit. The callback's first parameter is a pointer to the subunit (<a href="http://msdn2.microsoft.com/en-us/library/ms679050(VS.85).aspx">IPart</a>), while the second        parameter is a pointer to the required interface (or 0 if target_iid was omitted.) If the callback returns a non-zero value, enumeration is        halted and the value is passed on to the caller.</p>
      </div>
      <div class="method" id="VA_FindSubunit">
        <h2>VA_FindSubunit</h2>
        <p>Finds a subunit of a device, given a device pointer.</p>
        <h3 class="command">VA_FindSubunit(device, target_desc, target_iid)</h3>
        <h4>Parameters</h4>
        <table class="params">
          <tr class="returns">
            <td>
              <em>Returns</em>
            </td>
            <td>If a matching subunit is found, the return value is a pointer to the requested interface. Otherwise, the return value is 0.</td>
          </tr>
          <tr>
            <td>device</td>
            <td>A pointer to an <a href="http://msdn2.microsoft.com/en-us/library/ms679028(VS.85).aspx">IMMDevice</a> interface.</td>
          </tr>
          <tr>
            <td>target_desc</td>
            <td>friendly_name | index | friendly_name:index</td>
          </tr>
          <tr>
            <td>target_iid</td>
            <td>An interface ID.</td>
          </tr>
        </table>
        <h4>Remarks</h4>
        <p>VA_FindSubunit requires a valid interface identifier. To retrieve a subunit by name alone, use <a href="#VA_EnumSubunits">VA_EnumSubunits</a> or <a href="#VA_EnumSubunitsEx">VA_EnumSubunitsEx</a>.</p>
      </div>
      <div class="method" id="VA_SetDefaultEndpoint">
        <p>Sets the default audio endpoint for a given role.  Requires v2.3 or later.</p>
        <h3 class="command">VA_SetDefaultEndpoint(device_desc, role)</h3>
        <h4>Parameters</h4>
        <table class="params">
          <tr class="returns">
            <td>
              <em>Returns</em>
            </td>
            <td></td>
          </tr>
          <tr>
            <td>device_desc</td>
            <td>See <a href="#VA_GetDevice">VA_GetDevice</a>.</td>
          </tr>
          <tr>
            <td>role</td>
            <td>One of the following integer values:<br>
            <strong>0</strong>: eConsole - what Windows calls the "Default Device".<br>
            <strong>1</strong>: eMultimedia<br>
            <strong>2</strong>: eCommunications - what Windows calls the "Default Communication Device".</td>
          </tr>
        </table>
        <h4>Remarks</h4>
        <p>This function relies on undocumented interfaces and therefore isn't guaranteed to work.</p>
      </div>
      <div class="method" id="VA_dB2Scalar">
        <h2>VA_dB2Scalar</h2>
        <p>Converts a decibel value to a scalar value.</p>
        <h3 class="command">VA_dB2Scalar(dB, min_dB, max_dB)</h3>
        <h4>Parameters</h4>
        <table class="params">
          <tr class="returns">
            <td>
              <em>Returns</em>
            </td>
            <td>A value between 0.0 and 1.0.</td>
          </tr>
          <tr>
            <td>dB</td>
            <td>A decibel value.</td>
          </tr>
          <tr>
            <td>min_dB</td>
            <td>Minimum decibel value.</td>
          </tr>
          <tr>
            <td>max_dB</td>
            <td>Maximum decibel value.</td>
          </tr>
        </table>
        <h4>Remarks</h4>
        <p>The returned scalar value is usually consistent with values reported by the Sound applet in Control Panel, but not values reported by the Sound Mixer.</p>
      </div>
      <div class="method" id="VA_Scalar2dB">
        <h2>VA_Scalar2dB</h2>
        <p>Converts a scalar value to a decibel value.</p>
        <h3 class="command">VA_Scalar2dB(s, min_dB, max_dB)</h3>
        <h4>Parameters</h4>
        <table class="params">
          <tr class="returns">
            <td>
              <em>Returns</em>
            </td>
            <td>A decibel value.</td>
          </tr>
          <tr>
            <td>s</td>
            <td>A value between 0.0 and 1.0.</td>
          </tr>
          <tr>
            <td>min_dB</td>
            <td>Minimum decibel value.</td>
          </tr>
          <tr>
            <td>max_dB</td>
            <td>Maximum decibel value.</td>
          </tr>
        </table>
      </div>
      <div class="method" id="Interface Functions">
        <h2>Interface Functions</h2>
        <p>Functions with the naming pattern "VA_I<em>Interface</em>_<em>Function</em>" are direct equivalents of interface functions. These functions are defined under
    INTERFACE WRAPPERS in VA.ahk. For syntax and usage, see <a href="http://msdn2.microsoft.com/en-us/library/ms679156(VS.85).aspx">Core Audio APIs in Windows Vista (Programming Reference)</a>.</p>
        <h3 class="command">VA_I<em>Interface</em>_<em>Function</em></h3>
        <h4>Remarks</h4>
        <p>As of v2.0, interface wrappers for the following interfaces are included:</p>
        <ul>
          <li><a href="http://msdn.microsoft.com/en-us/library/ms679028">IMMDevice</a></li>
          <li><a href="http://msdn.microsoft.com/en-us/library/ms678970">IDeviceTopology</a></li>
          <li><a href="http://msdn.microsoft.com/en-us/library/ms678851">IConnector</a></li>
          <li><a href="http://msdn.microsoft.com/en-us/library/ms679050">IPart</a></li>
          <li><a href="http://msdn.microsoft.com/en-us/library/ms679063">IPartsList</a></li>
          <li><a href="http://msdn.microsoft.com/en-us/library/aa964574">IAudioEndpointVolume</a></li>
          <li><a href="http://msdn.microsoft.com/en-us/library/ms679067">IPerChannelDbLevel</a> (usable with <a href="http://msdn2.microsoft.com/en-us/library/ms678838(VS.85).aspx">IAudioVolumeLevel</a>)</li>
          <li><a href="http://msdn.microsoft.com/en-us/library/ms678773">IAudioMute</a></li>
          <li><a href="http://msdn.microsoft.com/en-us/library/ms678718">IAudioAutoGainControl</a></li>
          <li><a href="http://msdn.microsoft.com/en-us/library/aa964578">IAudioMeterInformation</a></li>
        </ul>
        <p>v2.1:</p>
        <ul>
          <li><a href="http://msdn.microsoft.com/en-us/library/dd370865">IAudioClient</a></li>
          <li><a href="http://msdn.microsoft.com/en-us/library/dd368246">IAudioSessionControl</a></li>
          <li><a href="http://msdn.microsoft.com/en-us/library/dd370948">IAudioSessionManager</a></li>
        </ul>
        <p>v2.1 on Windows 7 or later:</p>
        <ul>
          <li><a href="http://msdn.microsoft.com/en-us/library/dd368248">IAudioSessionControl2</a></li>
          <li><a href="http://msdn.microsoft.com/en-us/library/dd370950">IAudioSessionManager2</a></li>
          <li><a href="http://msdn.microsoft.com/en-us/library/dd368281">IAudioSessionEnumerator</a></li>
        </ul>
        <p>v2.2:</p>
        <ul>
          <li><a href="http://msdn.microsoft.com/en-us/library/dd371399">IMMDeviceEnumerator</a></li>
          <li><a href="http://msdn.microsoft.com/en-us/library/dd371396">IMMDeviceCollection</a></li>
          <li><a href="http://msdn.microsoft.com/en-us/library/dd371098">IControlInterface</a></li>
        </ul>
      </div>
    </div>
    <div style="clear: both;"></div>
    <div id="end">Copyright © Lexikos</div>
  </body>
</html>