<?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"/>
    <code>
      #include "util/biquad.h"
    </code>
  </global>

  <plugin label="singlePara" id="1203" class="ParaEQPlugin">
    <name>Single band parametric</name>
    <p>A single band of a parametric filter.</p>

    <callback event="instantiate"><![CDATA[
      fs = (float)s_rate;
      filter = malloc(sizeof(biquad));
      biquad_init(filter);
    ]]></callback>

    <callback event="activate"><![CDATA[
      biquad_init(filter);
    ]]></callback>

    <callback event="cleanup"><![CDATA[
      free(plugin_data->filter);
    ]]></callback>

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

      eq_set_params(filter, fc, gain, bw, fs);

      for (pos = 0; pos < sample_count; pos++) {
	buffer_write(output[pos], biquad_run(filter, input[pos]));
      }
    ]]></callback>

    <port label="gain" dir="input" type="control" hint="default_0">
      <name>Gain (dB)</name>
      <p>The attenuation/gain of the eq.</p>
      <range min="-70" max="+30"/>
    </port>

    <port label="fc" dir="input" type="control" hint="sample_rate,default_440">
      <name>Frequency (Hz)</name>
      <p>The centre frequency (ie. point of most/least attenuation).</p>
      <p>Beware of high values for Frequency and Bandwidth, if the high pitch (Frequency * 2$^{Bandwidth}$) goes over half the sample rate you will get aliasing.</p>
      <p>Note: if your host offers you a frequency range between 0 and 0.4 then it's not rendering the input parameter correctly, the input frequency will actually be that number multiplied by the sample rate (e.g. 44.1kHz).</p>
      <range min="0" max="0.4"/>
    </port>

    <port label="bw" dir="input" type="control" hint="default_1">
      <name>Bandwidth (octaves)</name>
      <p>The pitch difference from the centre before the attenuation has reached half the gain.</p>
      <range min="0" max="4"/>
    </port>

    <port label="input" dir="input" type="audio">
      <name>Input</name>
      <range min="-1.0" max="+1.0"/>
    </port>

    <port label="output" dir="output" type="audio">
      <name>Output</name>
      <range min="-1.0" max="+1.0"/>
    </port>

    <instance-data label="fs" type="float"/>
    <instance-data label="filter" type="biquad *"/>
  </plugin>
</ladspa>