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<h1><a class="anchor" name="scache">Sample Cache </a></h1><h2><a class="anchor" name="overv_sec">
Overview</a></h2>
The sample cache provides a simple way of overcoming high network latencies and reducing bandwidth. Instead of streaming a sound precisely when it should be played, it is stored on the server and only the command to start playing it needs to be sent.<h2><a class="anchor" name="create_sec">
Creating</a></h2>
To create a sample, the normal stream API is used (see <a class="el" href="streams.html">Audio Streams</a>). The function <a class="el" href="scache_8h.html#4725d83c96ddb3a4c67954bf5ec3a8c1" title="Make this stream a sample upload stream.">pa_stream_connect_upload()</a> will make sure the stream is stored as a sample on the server.<p>
To complete the upload, <a class="el" href="scache_8h.html#892d5d35de5ec726b8fa151abd87b92b" title="Finish the sample upload, the stream name will become the sample name.">pa_stream_finish_upload()</a> is called and the sample will receive the same name as the stream. If the upload should be aborted, simply call <a class="el" href="stream_8h.html#a4e0c83264f3935911e6b30e6f8ef2b1" title="Disconnect a stream from a source/sink.">pa_stream_disconnect()</a>.<h2><a class="anchor" name="play_sec">
Playing samples</a></h2>
To play back a sample, simply call <a class="el" href="scache_8h.html#db1bf81ecef03f8bae77e5e3ab30464f" title="Play a sample from the sample cache to the specified device.">pa_context_play_sample()</a>:<p>
<div class="fragment"><pre class="fragment"> <a class="code" href="operation_8h.html#5614a07f2e7a129e4cb16596ed452a0c" title="An asynchronous operation object.">pa_operation</a> *o;
o = <a class="code" href="scache_8h.html#db1bf81ecef03f8bae77e5e3ab30464f" title="Play a sample from the sample cache to the specified device.">pa_context_play_sample</a>(my_context,
<span class="stringliteral">"sample2"</span>, <span class="comment">// Name of my sample</span>
NULL, <span class="comment">// Use default sink</span>
<a class="code" href="volume_8h.html#ded56902e68e0f8ab576339bde55960e" title="Normal volume (100%, 0 dB).">PA_VOLUME_NORM</a>, <span class="comment">// Full volume</span>
NULL, <span class="comment">// Don't need a callback</span>
NULL
);
<span class="keywordflow">if</span> (o)
<a class="code" href="operation_8h.html#8d2ef9bb2ff961ee31675882bf125227" title="Decrease the reference count by one.">pa_operation_unref</a>(o);
</pre></div><h2><a class="anchor" name="rem_sec">
Removing samples</a></h2>
When a sample is no longer needed, it should be removed on the server to save resources. The sample is deleted using <a class="el" href="scache_8h.html#8c5e594fd912cd5badab7804eae22ba9" title="Remove a sample from the sample cache.">pa_context_remove_sample()</a>. </div>
<hr size="1"><address style="text-align: right;"><small>Generated on Wed Sep 2 04:18:20 2009 for PulseAudio by
<a href="http://www.doxygen.org/index.html">
<img src="doxygen.png" alt="doxygen" align="middle" border="0"></a> 1.5.8 </small></address>
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