karaoke_1409.xml

<?xml version="1.0"?>
<!DOCTYPE ladspa SYSTEM "ladspa-swh.dtd">
<?xml-stylesheet href="ladspa.css" type="text/css"?>

<ladspa>
  <global>
    <meta name="maker" value="Steve Harris &lt;steve@plugin.org.uk&gt;"/>
    <meta name="copyright" value="GPL"/>
    <meta name="properties" value="HARD_RT_CAPABLE"/>
  </global>

  <plugin label="karaoke" id="1409" class="UtilityPlugin">
    <name>Karaoke</name>
    <p>Attempts to strip the vocals from a stereo signal.</p>

    <callback event="run"><![CDATA[
      unsigned long pos;
      float coef = pow(10.0f, gain * 0.05f) * 0.5f;
      float m, s;

      for (pos = 0; pos < sample_count; pos++) {
	m = lin[pos] + rin[pos];
	s = lin[pos] - rin[pos];
        buffer_write(lout[pos], m * coef + s * 0.5f);
        buffer_write(rout[pos], m * coef - s * 0.5f);
      }
    ]]></callback>

    <port label="gain" dir="input" type="control" hint="default_0">
      <name>Vocal volume (dB)</name>
      <p>Controls the attenuation of the vocal (centre channel) in dB's.</p>
      <p>The greater the attenuation the greater the loss of stereo field.</p>
      <range min="-70" max="0"/>
    </port>

    <port label="lin" dir="input" type="audio">
      <name>Left in</name>
    </port>

    <port label="rin" dir="input" type="audio">
      <name>Right in</name>
    </port>

    <port label="lout" dir="output" type="audio">
      <name>Left out</name>
    </port>

    <port label="rout" dir="output" type="audio">
      <name>Right out</name>
    </port>
  </plugin>
</ladspa>