1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>snd_pcm_add_chmap_ctls</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="ch02.html#idp1093485324" title="PCM Core"><link rel="prev" href="API-snd-pcm-period-elapsed.html" title="snd_pcm_period_elapsed"><link rel="next" href="API-snd-pcm-stream-lock.html" title="snd_pcm_stream_lock"></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_pcm_add_chmap_ctls</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API-snd-pcm-period-elapsed.html">Prev</a>&#160;</td><th width="60%" align="center">PCM Core</th><td width="20%" align="right">&#160;<a accesskey="n" href="API-snd-pcm-stream-lock.html">Next</a></td></tr></table><hr></div><div class="refentry"><a name="API-snd-pcm-add-chmap-ctls"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>snd_pcm_add_chmap_ctls &#8212; 
2     create channel-mapping control elements
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_pcm_add_chmap_ctls </b>(</code></td><td>struct snd_pcm * <var class="pdparam">pcm</var>, </td></tr><tr><td>&#160;</td><td>int <var class="pdparam">stream</var>, </td></tr><tr><td>&#160;</td><td>const struct snd_pcm_chmap_elem * <var class="pdparam">chmap</var>, </td></tr><tr><td>&#160;</td><td>int <var class="pdparam">max_channels</var>, </td></tr><tr><td>&#160;</td><td>unsigned long <var class="pdparam">private_value</var>, </td></tr><tr><td>&#160;</td><td>struct snd_pcm_chmap ** <var class="pdparam">info_ret</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer">&#160;</div></div></div><div class="refsect1"><a name="idp1093790612"></a><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>pcm</code></em></span></dt><dd><p>
4     the assigned PCM instance
5    </p></dd><dt><span class="term"><em class="parameter"><code>stream</code></em></span></dt><dd><p>
6     stream direction
7    </p></dd><dt><span class="term"><em class="parameter"><code>chmap</code></em></span></dt><dd><p>
8     channel map elements (for query)
9    </p></dd><dt><span class="term"><em class="parameter"><code>max_channels</code></em></span></dt><dd><p>
10     the max number of channels for the stream
11    </p></dd><dt><span class="term"><em class="parameter"><code>private_value</code></em></span></dt><dd><p>
12     the value passed to each kcontrol's private_value field
13    </p></dd><dt><span class="term"><em class="parameter"><code>info_ret</code></em></span></dt><dd><p>
14     store struct snd_pcm_chmap instance if non-NULL
15    </p></dd></dl></div></div><div class="refsect1"><a name="idp1093797196"></a><h2>Description</h2><p>
16   Create channel-mapping control elements assigned to the given PCM stream(s).
17</p></div><div class="refsect1"><a name="idp1093797860"></a><h2>Return</h2><p>
18   Zero if successful, or a negative error value.
19</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-pcm-period-elapsed.html">Prev</a>&#160;</td><td width="20%" align="center"><a accesskey="u" href="ch02.html#idp1093485324">Up</a></td><td width="40%" align="right">&#160;<a accesskey="n" href="API-snd-pcm-stream-lock.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span class="phrase">snd_pcm_period_elapsed</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_pcm_stream_lock</span></td></tr></table></div></body></html>
20