mod_delay_1419.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"/>
    <code>
      #include "ladspa-util.h"
    </code>
  </global>

  <plugin label="modDelay" id="1419" class="DelayPlugin">
    <name>Modulatable delay</name>
    <p>A delay whose tap can be modulated at audio rate.</p>
    <p>Requested by Matthias Nagorni at LinuxTag 2002, in order to make a Leslie simulator.</p>

    <callback event="instantiate"><![CDATA[
      unsigned int size = 32768;

      fs = s_rate;
      while (size < 2.7f * fs) {
	size *= 2;
      }
      buffer = calloc(size, sizeof(LADSPA_Data));
      buffer_mask = size - 1;
      write_ptr = 0;
    ]]></callback>

    <callback event="activate"><![CDATA[
      memset(buffer, 0, buffer_mask + 1);
      write_ptr = 0;
    ]]></callback>

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

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

      for (pos = 0; pos < sample_count; pos++) {
	float tmp;
	const float rpf = modff((base + delay[pos]) * fs, &tmp);
	const int rp = write_ptr - 4 - f_round(tmp);

        buffer[write_ptr++] = input[pos];
	write_ptr &= buffer_mask;

        buffer_write(output[pos], cube_interp(rpf, buffer[(rp - 1) & buffer_mask], buffer[rp & buffer_mask],  buffer[(rp + 1) & buffer_mask], buffer[(rp + 2) & buffer_mask]));
      }
      plugin_data->write_ptr = write_ptr;
    ]]></callback>

    <port label="base" dir="input" type="control" hint="default_maximum">
      <name>Base delay (s)</name>
      <range min="0" max="1"/>
    </port>

    <port label="delay" dir="input" type="audio" hint="default_0">
      <name>Delay (s)</name>
      <range min="0" max="1.7"/>
    </port>

    <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="fs" type="float" />
    <instance-data label="buffer" type="LADSPA_Data *" />
    <instance-data label="buffer_mask" type="unsigned int" />
    <instance-data label="write_ptr" type="unsigned int" />
  </plugin>
</ladspa>