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<?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 <steve@plugin.org.uk>"/>
<meta name="copyright" value="GPL"/>
<code>
#include "ladspa-util.h"
#define BASE_BUFFER 8 // Base buffer length (s)
</code>
</global>
<plugin label="fadDelay" id="1192" class="DelayPlugin">
<name>Fractionally Addressed Delay Line</name>
<p>A fixed ring buffer delay implementation. Has different dynamics to a normal delay, more suitable for certain things.</p>
<p>Changes in delay length are generally more pleasing, but delays >2s long have reduced sound quality.</p>
<callback event="instantiate"><![CDATA[
unsigned int min_bs;
sample_rate = s_rate;
min_bs = BASE_BUFFER * s_rate;
for (buffer_size = 4096; buffer_size < min_bs;
buffer_size *= 2);
buffer = calloc(buffer_size, sizeof(LADSPA_Data));
buffer_mask = buffer_size - 1;
phase = 0;
last_phase = 0;
last_in = 0.0f;
]]></callback>
<callback event="activate">
int i;
for (i = 0; i < buffer_size; i++) {
buffer[i] = 0;
}
phase = 0;
last_phase = 0;
last_in = 0.0f;
sample_rate = sample_rate;
</callback>
<callback event="cleanup">
free(plugin_data->buffer);
</callback>
<callback event="run"><![CDATA[
long int pos;
float increment = (float)buffer_size / ((float)sample_rate *
f_max(fabs(delay), 0.01));
float lin_int, lin_inc;
int track;
int fph;
LADSPA_Data out;
const float fb = DB_CO(fb_db);
for (pos = 0; pos < sample_count; pos++) {
fph = f_round(floor(phase));
last_phase = fph;
lin_int = phase - (float)fph;
out = LIN_INTERP(lin_int, buffer[(fph+1) & buffer_mask],
buffer[(fph+2) & buffer_mask]);
phase += increment;
lin_inc = 1.0f / (floor(phase) - last_phase + 1);
lin_inc = lin_inc > 1.0f ? 1.0f : lin_inc;
lin_int = 0.0f;
for (track = last_phase; track < phase; track++) {
lin_int += lin_inc;
buffer[track % buffer_size] = out * fb +
LIN_INTERP(lin_int, last_in, input[pos]);
}
last_in = input[pos];
buffer_write(output[pos], out);
if (phase >= buffer_size) {
phase -= buffer_size;
}
}
// Store current phase in instance
plugin_data->phase = phase;
plugin_data->last_phase = last_phase;
plugin_data->last_in = last_in;
]]></callback>
<port label="delay" dir="input" type="control" hint="default_1">
<name>Delay (seconds)</name>
<p>The neutral delay time is 2 seconds. Times above 2 seconds will have reduced quality and times below will have increased CPU usage.</p>
<range min="0.1" max="10"/>
</port>
<port label="fb_db" dir="input" type="control" hint="default_0">
<name>Feedback (dB)</name>
<range min="-70" max="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="buffer" type="LADSPA_Data *"/>
<instance-data label="phase" type="float"/>
<instance-data label="last_phase" type="int"/>
<instance-data label="last_in" type="LADSPA_Data"/>
<instance-data label="buffer_size" type="unsigned long"/>
<instance-data label="buffer_mask" type="unsigned long"/>
<instance-data label="sample_rate" type="long"/>
</plugin>
</ladspa>
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