divider_1186.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="divider" id="1186" class="GeneratorPlugin">
		<name>Audio Divider (Suboctave Generator)</name>
		<p>Reduces the period of the signal by the factor given, and makes it a square wave in the process. Has some amplitude tracking capability, but not really useful on complex signals.</p>

		<callback event="instantiate"><![CDATA[
out = 1.0f;
amp = 0.0f;
count = 0.0f;
lamp = 0.0f;
last = 0.0f;
zeroxs = 0;
		]]></callback>

		<callback event="run"><![CDATA[
/* Integer version of denominator */
int den = (int)denominator;

unsigned long pos;

for (pos = 0; pos < sample_count; pos++) {
	count += 1.0f;
	if ((input[pos] > 0.0f && last <= 0.0f) ||
	 (input[pos] < 0.0f && last >= 0.0)) {
		zeroxs++;
		if (den == 1) {
			out = out > 0.0f ? -1.0f : 1.0f;
			lamp = amp / count;
			zeroxs = 0;
			count = 0;
			amp = 0;
		}
	}
	amp += fabs(input[pos]);
	if (den > 1 && (zeroxs % den) == den-1) {
		out = out > 0.0f ? -1.0f : 1.0f;
		lamp = amp / count;
		zeroxs = 0;
		count = 0;
		amp = 0;
	}
	last = input[pos];
	buffer_write(output[pos], out * lamp);
}

plugin_data->last = last;
plugin_data->amp = amp;
plugin_data->lamp = lamp;
plugin_data->zeroxs = zeroxs;
plugin_data->count = count;
plugin_data->out = out;
		]]></callback>

		<port label="denominator" dir="input" type="control" hint="integer,default_1">
			<name>Denominator</name>
			<range min="1" max="8"/>
			<p>The factor the incoming frequency will be divided by.</p>
		</port>

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

		<port label="output" dir="output" type="audio">
			<name>Output</name>
			<range min="-1" max="+1"/>
		</port>

		<!-- Last input value, to find 0 crossings -->
		<instance-data label="last" type="LADSPA_Data"/>

		<!-- Current amplitude sum (well, amp of last half cycle) -->
		<instance-data label="amp" type="LADSPA_Data"/>

		<!-- Average last amplitude (well, amp of last half cycle) -->
		<instance-data label="lamp" type="LADSPA_Data"/>

		<!-- Count of zero xings to make divider -->
		<instance-data label="zeroxs" type="int"/>

		<!-- Count of number of samples since x -->
		<instance-data label="count" type="float"/>

		<!-- Current output value -->
		<instance-data label="out" type="LADSPA_Data"/>
	</plugin>
</ladspa>