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<div class="section" id="module-sunaudiodev">
<h1>40.1. <tt class="xref docutils literal"><span class="pre">sunaudiodev</span></tt> — Access to Sun audio hardware<a class="headerlink" href="#module-sunaudiodev" title="Permalink to this headline">¶</a></h1>
<p><em>Platforms: </em>SunOS</p>
<p class="deprecated">
<span class="versionmodified">Deprecated since version 2.6: </span>The <tt class="xref docutils literal"><span class="pre">sunaudiodev</span></tt> module has been deprecated for removal in Python 3.0.</p>
<p id="index-632">This module allows you to access the Sun audio interface. The Sun audio hardware
is capable of recording and playing back audio data in u-LAW format with a
sample rate of 8K per second. A full description can be found in the
<em>audio(7I)</em> manual page.</p>
<p id="index-633">The module <tt class="xref docutils literal"><span class="pre">SUNAUDIODEV</span></tt> defines constants which may be used with this
module.</p>
<p>This module defines the following variables and functions:</p>
<dl class="exception">
<dt id="sunaudiodev.error">
<em class="property">exception </em><tt class="descclassname">sunaudiodev.</tt><tt class="descname">error</tt><a class="headerlink" href="#sunaudiodev.error" title="Permalink to this definition">¶</a></dt>
<dd>This exception is raised on all errors. The argument is a string describing what
went wrong.</dd></dl>
<dl class="function">
<dt id="sunaudiodev.open">
<tt class="descclassname">sunaudiodev.</tt><tt class="descname">open</tt><big>(</big><em>mode</em><big>)</big><a class="headerlink" href="#sunaudiodev.open" title="Permalink to this definition">¶</a></dt>
<dd><p>This function opens the audio device and returns a Sun audio device object. This
object can then be used to do I/O on. The <em>mode</em> parameter is one of <tt class="docutils literal"><span class="pre">'r'</span></tt> for
record-only access, <tt class="docutils literal"><span class="pre">'w'</span></tt> for play-only access, <tt class="docutils literal"><span class="pre">'rw'</span></tt> for both and
<tt class="docutils literal"><span class="pre">'control'</span></tt> for access to the control device. Since only one process is
allowed to have the recorder or player open at the same time it is a good idea
to open the device only for the activity needed. See <em>audio(7I)</em> for
details.</p>
<p>As per the manpage, this module first looks in the environment variable
<tt class="docutils literal"><span class="pre">AUDIODEV</span></tt> for the base audio device filename. If not found, it falls back to
<tt class="docutils literal"><span class="pre">/dev/audio</span></tt>. The control device is calculated by appending “ctl” to the
base audio device.</p>
</dd></dl>
<div class="section" id="audio-device-objects">
<span id="id1"></span><h2>40.1.1. Audio Device Objects<a class="headerlink" href="#audio-device-objects" title="Permalink to this headline">¶</a></h2>
<p>The audio device objects are returned by <a title="sunaudiodev.open" class="reference internal" href="#sunaudiodev.open"><tt class="xref docutils literal"><span class="pre">open()</span></tt></a> define the following
methods (except <tt class="docutils literal"><span class="pre">control</span></tt> objects which only provide <tt class="xref docutils literal"><span class="pre">getinfo()</span></tt>,
<tt class="xref docutils literal"><span class="pre">setinfo()</span></tt>, <tt class="xref docutils literal"><span class="pre">fileno()</span></tt>, and <tt class="xref docutils literal"><span class="pre">drain()</span></tt>):</p>
<dl class="method">
<dt>
<tt class="descname">audio device.close()</tt></dt>
<dd>This method explicitly closes the device. It is useful in situations where
deleting the object does not immediately close it since there are other
references to it. A closed device should not be used again.</dd></dl>
<dl class="method">
<dt>
<tt class="descname">audio device.fileno()</tt></dt>
<dd>Returns the file descriptor associated with the device. This can be used to set
up <tt class="docutils literal"><span class="pre">SIGPOLL</span></tt> notification, as described below.</dd></dl>
<dl class="method">
<dt>
<tt class="descname">audio device.drain()</tt></dt>
<dd>This method waits until all pending output is processed and then returns.
Calling this method is often not necessary: destroying the object will
automatically close the audio device and this will do an implicit drain.</dd></dl>
<dl class="method">
<dt>
<tt class="descname">audio device.flush()</tt></dt>
<dd>This method discards all pending output. It can be used avoid the slow response
to a user’s stop request (due to buffering of up to one second of sound).</dd></dl>
<dl class="method">
<dt>
<tt class="descname">audio device.getinfo()</tt></dt>
<dd>This method retrieves status information like input and output volume, etc. and
returns it in the form of an audio status object. This object has no methods but
it contains a number of attributes describing the current device status. The
names and meanings of the attributes are described in <tt class="docutils literal"><span class="pre"><sun/audioio.h></span></tt> and in
the <em>audio(7I)</em> manual page. Member names are slightly different from
their C counterparts: a status object is only a single structure. Members of the
<tt class="xref docutils literal"><span class="pre">play</span></tt> substructure have <tt class="docutils literal"><span class="pre">o_</span></tt> prepended to their name and members of
the <tt class="xref docutils literal"><span class="pre">record</span></tt> structure have <tt class="docutils literal"><span class="pre">i_</span></tt>. So, the C member
<tt class="xref docutils literal"><span class="pre">play.sample_rate</span></tt> is accessed as <tt class="xref docutils literal"><span class="pre">o_sample_rate</span></tt>,
<tt class="xref docutils literal"><span class="pre">record.gain</span></tt> as <tt class="xref docutils literal"><span class="pre">i_gain</span></tt> and <tt class="xref docutils literal"><span class="pre">monitor_gain</span></tt> plainly as
<tt class="xref docutils literal"><span class="pre">monitor_gain</span></tt>.</dd></dl>
<dl class="method">
<dt>
<tt class="descname">audio device.ibufcount()</tt></dt>
<dd>This method returns the number of samples that are buffered on the recording
side, i.e. the program will not block on a <tt class="xref docutils literal"><span class="pre">read()</span></tt> call of so many samples.</dd></dl>
<dl class="method">
<dt>
<tt class="descname">audio device.obufcount()</tt></dt>
<dd>This method returns the number of samples buffered on the playback side.
Unfortunately, this number cannot be used to determine a number of samples that
can be written without blocking since the kernel output queue length seems to be
variable.</dd></dl>
<dl class="method">
<dt>
<tt class="descname">audio device.read(size)</tt></dt>
<dd>This method reads <em>size</em> samples from the audio input and returns them as a
Python string. The function blocks until enough data is available.</dd></dl>
<dl class="method">
<dt>
<tt class="descname">audio device.setinfo(status)</tt></dt>
<dd>This method sets the audio device status parameters. The <em>status</em> parameter is
an device status object as returned by <tt class="xref docutils literal"><span class="pre">getinfo()</span></tt> and possibly modified by
the program.</dd></dl>
<dl class="method">
<dt>
<tt class="descname">audio device.write(samples)</tt></dt>
<dd>Write is passed a Python string containing audio samples to be played. If there
is enough buffer space free it will immediately return, otherwise it will block.</dd></dl>
<p>The audio device supports asynchronous notification of various events, through
the SIGPOLL signal. Here’s an example of how you might enable this in Python:</p>
<div class="highlight-python"><div class="highlight"><pre><span class="k">def</span> <span class="nf">handle_sigpoll</span><span class="p">(</span><span class="n">signum</span><span class="p">,</span> <span class="n">frame</span><span class="p">):</span>
<span class="k">print</span> <span class="s">'I got a SIGPOLL update'</span>
<span class="kn">import</span> <span class="nn">fcntl</span><span class="o">,</span> <span class="nn">signal</span><span class="o">,</span> <span class="nn">STROPTS</span>
<span class="n">signal</span><span class="o">.</span><span class="n">signal</span><span class="p">(</span><span class="n">signal</span><span class="o">.</span><span class="n">SIGPOLL</span><span class="p">,</span> <span class="n">handle_sigpoll</span><span class="p">)</span>
<span class="n">fcntl</span><span class="o">.</span><span class="n">ioctl</span><span class="p">(</span><span class="n">audio_obj</span><span class="o">.</span><span class="n">fileno</span><span class="p">(),</span> <span class="n">STROPTS</span><span class="o">.</span><span class="n">I_SETSIG</span><span class="p">,</span> <span class="n">STROPTS</span><span class="o">.</span><span class="n">S_MSG</span><span class="p">)</span>
</pre></div>
</div>
</div>
</div>
<div class="section" id="module-SUNAUDIODEV">
<h1>40.2. <tt class="xref docutils literal"><span class="pre">SUNAUDIODEV</span></tt> — Constants used with <tt class="xref docutils literal"><span class="pre">sunaudiodev</span></tt><a class="headerlink" href="#module-SUNAUDIODEV" title="Permalink to this headline">¶</a></h1>
<p><em>Platforms: </em>SunOS</p>
<p class="deprecated">
<span class="versionmodified">Deprecated since version 2.6: </span>The <tt class="xref docutils literal"><span class="pre">SUNAUDIODEV</span></tt> module has been deprecated for removal in Python 3.0.</p>
<p id="index-634">This is a companion module to <tt class="xref docutils literal"><span class="pre">sunaudiodev</span></tt> which defines useful symbolic
constants like <tt class="xref docutils literal"><span class="pre">MIN_GAIN</span></tt>, <tt class="xref docutils literal"><span class="pre">MAX_GAIN</span></tt>, <tt class="xref docutils literal"><span class="pre">SPEAKER</span></tt>, etc. The
names of the constants are the same names as used in the C include file
<tt class="docutils literal"><span class="pre"><sun/audioio.h></span></tt>, with the leading string <tt class="docutils literal"><span class="pre">AUDIO_</span></tt> stripped.</p>
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<h3><a href="../contents.html">Table Of Contents</a></h3>
<ul>
<li><a class="reference external" href="#">40.1. <tt class="docutils literal"><span class="pre">sunaudiodev</span></tt> — Access to Sun audio hardware</a><ul>
<li><a class="reference external" href="#audio-device-objects">40.1.1. Audio Device Objects</a></li>
</ul>
</li>
<li><a class="reference external" href="#module-SUNAUDIODEV">40.2. <tt class="docutils literal"><span class="pre">SUNAUDIODEV</span></tt> — Constants used with <tt class="docutils literal"><span class="pre">sunaudiodev</span></tt></a></li>
</ul>
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