dc_remove_1207.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="dcRemove" id="1207" class="HighpassPlugin,UtilityPlugin">
    <name>DC Offset Remover</name>
    <p>Simply removes the DC (0 Hz) component from an audio signal, uses a high pass filter, so has some side effects, but they should be minimal.</p>

    <callback event="activate"><![CDATA[
      itm1 = 0.0f;
      otm1 = 0.0f;
    ]]></callback>

    <callback event="run"><![CDATA[
      unsigned long pos;

      for (pos = 0; pos < sample_count; pos++) {
        otm1 = 0.999f * otm1 + input[pos] - itm1;
	itm1 = input[pos];
        buffer_write(output[pos], otm1);
      }

      plugin_data->itm1 = itm1;
      plugin_data->otm1 = otm1;
    ]]></callback>

    <port label="input" dir="input" type="audio">
      <name>Input</name>
    </port>

    <port label="output" dir="output" type="audio">
      <name>Output</name>
    </port>

    <instance-data label="itm1" type="LADSPA_Data"/>
    <instance-data label="otm1" type="LADSPA_Data"/>
  </plugin>
</ladspa>