lowpass_iir_1891.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="Alexander Ehlert &lt;mag@glame.de&gt;"/>
		<meta name="copyright" value="GPL"/>
		<meta name="properties" value="HARD_RT_CAPABLE"/>
		<code>
			#include "config.h"
			#include "util/iir.h"
			#include "ladspa-util.h"
                        
		</code>
	</global>

	<plugin label="lowpass_iir" id="1891" class="LowpassPlugin">
		<name>Glame Lowpass Filter</name>
                <p> IIR lowpass filter based using chebishev coefficients. The filter allows you to tweak the number of stages used for
                filtering. Every stage adds two more poles, which leads to a steeper dropoff. More stages need more CPU power. This
                filter was ported from the glame multitrack editor to ladspa.
                </p>

                <callback event="instantiate">
                  sample_rate = s_rate;
                </callback>
		<callback event="run">
                  chebyshev(iirf, gt, 2*CLAMP((int)stages,1,10), IIR_STAGE_LOWPASS, cutoff/(float)sample_rate, 0.5f);
                  iir_process_buffer_ns_5(iirf, gt, input, output, sample_count,RUN_ADDING);
                </callback>

                <callback event="activate">                  
                  gt = init_iir_stage(IIR_STAGE_LOWPASS,10,3,2);
                  iirf = init_iirf_t(gt);
                  chebyshev(iirf, gt, 2*CLAMP(f_round(*(plugin_data->stages)),1,10), IIR_STAGE_LOWPASS, 
                            *(plugin_data->cutoff)/(float)sample_rate, 0.5f);
                </callback>

                <callback event="cleanup">
                  free_iirf_t(plugin_data->iirf, plugin_data->gt);
                  free_iir_stage(plugin_data->gt);
                </callback>

                <port label="cutoff" dir="input" type="control" hint="default_high, sample_rate, logarithmic">
			<name>Cutoff Frequency</name>
 			<range min="0.0001" max="0.45"/>
		</port>
                
                <port label="stages" dir="input" type="control" hint="default_1, integer">
			<name>Stages(2 poles per stage)</name>
			<range min="1.0" max="10.0"/>
		</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="iirf" type="iirf_t*"/>
                <instance-data label="gt" type="iir_stage_t*"/>  
                <instance-data label="sample_rate" type="long"/>           

	</plugin>
</ladspa>