1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>snd_ctl_add_slave</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="index.html" title="The ALSA Driver API"><link rel="up" href="ch03s03.html" title="Virtual Master Control API"><link rel="prev" href="API-snd-ctl-sync-vmaster.html" title="snd_ctl_sync_vmaster"><link rel="next" href="API-snd-ctl-add-slave-uncached.html" title="snd_ctl_add_slave_uncached"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center"><span class="phrase">snd_ctl_add_slave</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API-snd-ctl-sync-vmaster.html">Prev</a>&#160;</td><th width="60%" align="center">Virtual Master Control API</th><td width="20%" align="right">&#160;<a accesskey="n" href="API-snd-ctl-add-slave-uncached.html">Next</a></td></tr></table><hr></div><div class="refentry"><a name="API-snd-ctl-add-slave"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>snd_ctl_add_slave &#8212; 
2  Add a virtual slave control
3 </p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="funcsynopsis"><table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">int <b class="fsfunc">snd_ctl_add_slave </b>(</code></td><td>struct snd_kcontrol * <var class="pdparam">master</var>, </td></tr><tr><td>&#160;</td><td>struct snd_kcontrol * <var class="pdparam">slave</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer">&#160;</div></div></div><div class="refsect1"><a name="idp1094847900"></a><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>master</code></em></span></dt><dd><p>
4     vmaster element
5    </p></dd><dt><span class="term"><em class="parameter"><code>slave</code></em></span></dt><dd><p>
6     slave element to add
7    </p></dd></dl></div></div><div class="refsect1"><a name="idp1094850532"></a><h2>Description</h2><p>
8   Add a virtual slave control to the given master element created via
9   <code class="function">snd_ctl_create_virtual_master</code> beforehand.
10   </p><p>
11
12   All slaves must be the same type (returning the same information
13   via info callback).  The function doesn't check it, so it's your
14   responsibility.
15   </p><p>
16
17   Also, some additional limitations:
18   at most two channels,
19   logarithmic volume control (dB level) thus no linear volume,
20   master can only attenuate the volume without gain
21</p></div><div class="refsect1"><a name="idp1094852212"></a><h2>Return</h2><p>
22   Zero if successful or a negative error code.
23</p></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="API-snd-ctl-sync-vmaster.html">Prev</a>&#160;</td><td width="20%" align="center"><a accesskey="u" href="ch03s03.html">Up</a></td><td width="40%" align="right">&#160;<a accesskey="n" href="API-snd-ctl-add-slave-uncached.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span class="phrase">snd_ctl_sync_vmaster</span>&#160;</td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top">&#160;<span class="phrase">snd_ctl_add_slave_uncached</span></td></tr></table></div></body></html>
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