giant_flange_1437.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><![CDATA[
      #include <sys/types.h>
      #include "ladspa-util.h"

      #define INT_SCALE   16384.0f
      /* INT_SCALE reciprocal includes factor of two scaling */
      #define INT_SCALE_R 0.000030517578125f

      #define MAX_AMP 1.0f
      #define CLIP 0.8f
      #define CLIP_A ((MAX_AMP - CLIP) * (MAX_AMP - CLIP))
      #define CLIP_B (MAX_AMP - 2.0f * CLIP)
    ]]></code>
  </global>

  <plugin label="giantFlange" id="1437" class="FlangerPlugin">
    <name>Giant flange</name>
    <p>This is a fairly normal flanger but with excessively long delay times.
Requested by Patrick Shirkey.</p>
    <p>To cut down the memory requirements the internal delay buffer only has
15bits of resolution, so there is no headroom, if you feed in signals over 0dB
it will clip the output. There is code to soften the effect of the clipping,
but beware of it.</p>

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

      fs = s_rate;
      while (buffer_size < fs * 10.5f) {
	buffer_size *= 2;
      }
      buffer = calloc(buffer_size, sizeof(int16_t));
      buffer_mask = buffer_size - 1;
      buffer_pos = 0;
      x1 = 0.5f;
      y1 = 0.0f;
      x2 = 0.5f;
      y2 = 0.0f;
    ]]></callback>
      
    <callback event="activate"><![CDATA[
      memset(buffer, 0, (buffer_mask + 1) * sizeof(int16_t));
    ]]></callback>

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

    <callback event="run"><![CDATA[
      unsigned long pos;
      const float omega1 = 6.2831852f * (freq1 / fs);
      const float omega2 = 6.2831852f * (freq2 / fs);
      float fb;
      float d1, d2;
      float d1out, d2out;
      float fbs;

      if (feedback > 99.0f) {
	fb = 0.99f;
      } else if (feedback < -99.0f) {
	fb = -0.99f;
      } else {
	fb = feedback * 0.01f;
      }

      if (f_round(deldouble)) {
        const float dr1 = delay1 * fs * 0.25f;
        const float dr2 = delay2 * fs * 0.25f;

      for (pos = 0; pos < sample_count; pos++) {
	/* Write input into delay line */
	buffer[buffer_pos] = f_round(input[pos] * INT_SCALE);

	/* Calcuate delays */
	d1 = (x1 + 1.0f) * dr1;
	d2 = (y2 + 1.0f) * dr2;

	d1out = buffer[(buffer_pos - f_round(d1)) & buffer_mask] * INT_SCALE_R;
	d2out = buffer[(buffer_pos - f_round(d2)) & buffer_mask] * INT_SCALE_R;

	/* Add feedback, must be done afterwards for case where delay = 0 */
	fbs = input[pos] + (d1out + d2out) * fb;
	if(fbs < CLIP && fbs > -CLIP) {
	  buffer[buffer_pos] = fbs * INT_SCALE;
	} else if (fbs > 0.0f) {
	  buffer[buffer_pos] = (MAX_AMP - (CLIP_A / (CLIP_B + fbs))) *
					INT_SCALE;
	} else {
	  buffer[buffer_pos] =  (MAX_AMP - (CLIP_A / (CLIP_B - fbs))) *
					-INT_SCALE;
	}

	/* Write output */
	buffer_write(output[pos], LIN_INTERP(wet, input[pos], d1out + d2out));

	if (pos % 2) {
	  buffer_pos = (buffer_pos + 1) & buffer_mask;
	}

	/* Run LFOs */
	x1 -= omega1 * y1;
	y1 += omega1 * x1;
	x2 -= omega2 * y2;
	y2 += omega2 * x2;
      }
      } else {
        const float dr1 = delay1 * fs * 0.5f;
        const float dr2 = delay2 * fs * 0.5f;

      for (pos = 0; pos < sample_count; pos++) {
	/* Write input into delay line */
	buffer[buffer_pos] = f_round(input[pos] * INT_SCALE);

	/* Calcuate delays */
	d1 = (x1 + 1.0f) * dr1;
	d2 = (y2 + 1.0f) * dr2;

	d1out = buffer[(buffer_pos - f_round(d1)) & buffer_mask] * INT_SCALE_R;
	d2out = buffer[(buffer_pos - f_round(d2)) & buffer_mask] * INT_SCALE_R;

	/* Add feedback, must be done afterwards for case where delay = 0 */
	fbs = input[pos] + (d1out + d2out) * fb;
	if(fbs < CLIP && fbs > -CLIP) {
		buffer[buffer_pos] = fbs * INT_SCALE;
	} else if (fbs > 0.0f) {
		buffer[buffer_pos] = (MAX_AMP - (CLIP_A / (CLIP_B + fbs))) *
					INT_SCALE;
	} else {
		buffer[buffer_pos] =  (MAX_AMP - (CLIP_A / (CLIP_B - fbs))) *
					-INT_SCALE;
	}

	/* Write output */
	buffer_write(output[pos], LIN_INTERP(wet, input[pos], d1out + d2out));

	buffer_pos = (buffer_pos + 1) & buffer_mask;

	/* Run LFOs */
	x1 -= omega1 * y1;
	y1 += omega1 * x1;
	x2 -= omega2 * y2;
	y2 += omega2 * x2;
      }
      }

      plugin_data->x1 = x1;
      plugin_data->y1 = y1;
      plugin_data->x2 = x2;
      plugin_data->y2 = y2;
      plugin_data->buffer_pos = buffer_pos;
    ]]></callback>

    <port label="deldouble" dir="input" type="control" hint="default_0,toggled">
      <name>Double delay</name>
      <p>doubles the length of the delays, this will reduce the sound quality.</p>
    </port>

    <port label="freq1" dir="input" type="control" hint="default_1">
      <name>LFO frequency 1 (Hz)</name>
      <p>The delay of the first LFO in seconds.</p>
      <range min="0" max="30.0"/>
    </port>

    <port label="delay1" dir="input" type="control" hint="default_low">
      <name>Delay 1 range (s)</name>
      <p>The delay range of the first LFO in seconds.</p>
      <range min="0" max="10.5"/>
    </port>

    <port label="freq2" dir="input" type="control" hint="default_1">
      <name>LFO frequency 2 (Hz)</name>
      <p>The delay of the second LFO in seconds.</p>
      <range min="0" max="30.0"/>
    </port>

    <port label="delay2" dir="input" type="control" hint="default_0">
      <name>Delay 2 range (s)</name>
      <p>The delay range of the second LFO in seconds.</p>
      <range min="0" max="10.5"/>
    </port>

    <port label="feedback" dir="input" type="control" hint="default_0">
      <name>Feedback</name>
      <p>The amount of the delays output that is mixed back into the delay.</p>
      <range min="-100" max="100"/>
    </port>

    <port label="wet" dir="input" type="control" hint="default_0">
      <name>Dry/Wet level</name>
      <p>The amounts of the input and effect mixed to produce the output.</p>
      <range min="0" max="1"/>
    </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="int16_t *" />
    <instance-data label="buffer_pos" type="unsigned int" />
    <instance-data label="buffer_mask" type="unsigned int" />
    <instance-data label="fs" type="float" />
    <instance-data label="x1" type="float" />
    <instance-data label="y1" type="float" />
    <instance-data label="x2" type="float" />
    <instance-data label="y2" type="float" />
  </plugin>
</ladspa>