<h1><a class="anchor" id="apinotes">API Notes </a></h1><p><a class="el" href="classRtAudio.html" title="Realtime audio i/o C++ classes.">RtAudio</a> is designed to provide a common API across the various supported operating systems and audio libraries. Despite that, some issues should be mentioned with regard to each.</p>
<h2><a class="anchor" id="linux">
Linux:</a></h2>
-<p><a class="el" href="classRtAudio.html" title="Realtime audio i/o C++ classes.">RtAudio</a> for Linux was developed under Redhat distributions 7.0 - Fedora.
Three different audio APIs are supported on Linux platforms: <a href="http://www.opensound.com/oss.html">OSS</a> (versions >= 4.0), <a href="http://www.alsa-project.org/">ALSA</a>, and <a href="http://jackit.sourceforge.net/">Jack</a>. Note that <a class="el" href="classRtAudio.html" title="Realtime audio i/o C++ classes.">RtAudio</a> now only supports the newer version 4.0 OSS API. The ALSA API is now part of the Linux kernel and offers significantly better functionality than the OSS API. <a class="el" href="classRtAudio.html" title="Realtime audio i/o C++ classes.">RtAudio</a> provides support for the 1.0 and higher versions of ALSA. Jack is a low-latency audio server written primarily for the GNU/Linux operating system. It can connect a number of different applications to an audio device, as well as allow them to share audio between themselves. Input/output latency on the order of 15 milliseconds can typically be achieved using any of the Linux APIs by fine-tuning the <a class="el" href="classRtAudio.html" title="Realtime audio i/o C++ classes.">RtAudio</a> buffer parameters (without kernel modifications). Latencies on the order of 5 milliseconds or less can be achieved using a low-latency kernel patch and increasing FIFO scheduling priority. The pthread library, which is used for callback functionality, is a standard component of all Linux distributions.</p>
+<p><a class="el" href="classRtAudio.html" title="Realtime audio i/o C++ classes.">RtAudio</a> for Linux was developed under Redhat distributions 7.0 - Fedora.
Four different audio APIs are supported on Linux platforms: <a href="http://www.opensound.com/oss.html">OSS</a> (versions >= 4.0), <a href="http://www.alsa-project.org/">ALSA</a>, <a href="http://jackit.sourceforge.net/">Jack</a>, and <a href="http://www.freedesktop.org/wiki/Software/PulseAudio">PulseAudio</a>. Note that <a class="el" href="classRtAudio.html" title="Realtime audio i/o C++ classes.">RtAudio</a> now only supports the newer version 4.0 OSS API. The ALSA API is now part of the Linux kernel and offers significantly better functionality than the OSS API. <a class="el" href="classRtAudio.html" title="Realtime audio i/o C++ classes.">RtAudio</a> provides support for the 1.0 and higher versions of ALSA. Jack is a low-latency audio server written primarily for the GNU/Linux operating system. It can connect a number of different applications to an audio device, as well as allow them to share audio between themselves. Input/output latency on the order of 15 milliseconds can typically be achieved using any of the Linux APIs by fine-tuning the <a class="el" href="classRtAudio.html" title="Realtime audio i/o C++ classes.">RtAudio</a> buffer parameters (without kernel modifications). Latencies on the order of 5 milliseconds or less can be achieved using a low-latency kernel patch and increasing FIFO scheduling priority. The pthread library, which is used for callback functionality, is a standard component of all Linux distributions.</p>
<p>The ALSA library includes OSS emulation support. That means that you can run programs compiled for the OSS API even when using the ALSA drivers and library. It should be noted however that OSS emulation under ALSA is not perfect. Specifically, channel number queries seem to consistently produce invalid results. While OSS emulation is successful for the majority of <a class="el" href="classRtAudio.html" title="Realtime audio i/o C++ classes.">RtAudio</a> tests, it is recommended that the native ALSA implementation of <a class="el" href="classRtAudio.html" title="Realtime audio i/o C++ classes.">RtAudio</a> be used on systems which have ALSA drivers installed.</p>
<p>The ALSA implementation of <a class="el" href="classRtAudio.html" title="Realtime audio i/o C++ classes.">RtAudio</a> makes no use of the ALSA "plug" interface. All necessary data format conversions, channel compensation, de-interleaving, and byte-swapping is handled by internal <a class="el" href="classRtAudio.html" title="Realtime audio i/o C++ classes.">RtAudio</a> routines.</p>
-<p>At the moment, only one <a class="el" href="classRtAudio.html" title="Realtime audio i/o C++ classes.">RtAudio</a> instance can be connected to the Jack server.</p>
<h2><a class="anchor" id="macosx">
Macintosh OS-X (CoreAudio and Jack):</a></h2>
<p>The Apple CoreAudio API is designed to use a separate callback procedure for each of its audio devices. A single <a class="el" href="classRtAudio.html" title="Realtime audio i/o C++ classes.">RtAudio</a> duplex stream using two different devices is supported, though it cannot be guaranteed to always behave correctly because we cannot synchronize these two callbacks. The <em>numberOfBuffers</em> parameter to the <a class="el" href="classRtAudio.html#afacc99740fa4c5606fb35467cdea6da8" title="A public function for opening a stream with the specified parameters.">RtAudio::openStream()</a> function has no affect in this implementation.</p>
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