<?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"/>
    <code><![CDATA[
      #include <string.h>

      #include <fftw3.h>

      typedef fftwf_plan fft_plan;
      typedef float fftw_real;
      #define local_malloc(s) fftwf_malloc(s)
      #define local_free(s) fftwf_free(s)

      #include "ladspa-util.h"

      #define MAX_FFT_LENGTH 16384
      #define SEG_LENGTH     128

      #define IMP_LENGTH(a) (sizeof(a) / sizeof(float))

      #define MK_IMP(i) impulse2freq(c, i, IMP_LENGTH(i), impulse_freq[c]); c++

      inline void impulse2freq(int id, float *imp, unsigned int length, fftw_real *out);

      #include "impulses/all.h"

      fft_plan plan_rc[IMPULSES],
               plan_cr[IMPULSES];

      static fftw_real *real_in, *real_out, *comp_in, *comp_out;

      unsigned int fft_length[IMPULSES];

      inline void impulse2freq(int id, float *imp, unsigned int length, fftw_real *out)
      {
        fftw_real impulse_time[MAX_FFT_LENGTH];
#ifdef FFTW3
	fft_plan tmp_plan;
#endif
        unsigned int i, fftl = 128;

	while (fftl < length+SEG_LENGTH) {
		fftl *= 2;
	}

	fft_length[id] = fftl;
#ifdef FFTW3
	plan_rc[id] = fftwf_plan_r2r_1d(fftl, real_in, comp_out, FFTW_R2HC, FFTW_MEASURE);
	plan_cr[id] = fftwf_plan_r2r_1d(fftl, comp_in, real_out, FFTW_HC2R, FFTW_MEASURE);
	tmp_plan = fftwf_plan_r2r_1d(fftl, impulse_time, out, FFTW_R2HC, FFTW_MEASURE);
#else
        plan_rc[id] = rfftw_create_plan(fftl, FFTW_REAL_TO_COMPLEX, FFTW_ESTIMATE);
        plan_cr[id] = rfftw_create_plan(fftl, FFTW_COMPLEX_TO_REAL, FFTW_ESTIMATE);
#endif

        for (i=0; i<length; i++) {
          impulse_time[i] = imp[i];
        }
        for (; i<fftl; i++) {
          impulse_time[i] = 0.0f;
        }
#ifdef FFTW3
	fftwf_execute(tmp_plan);
	fftwf_destroy_plan(tmp_plan);
#else
        rfftw_one(plan_rc[id], impulse_time, out);
#endif
      }
        
    ]]></code>
  </global>

  <plugin label="imp" id="1199" class="SpectralPlugin">
    <name>Impulse convolver</name>
    <p><![CDATA[
    This is a convolver for a set of fairly short impulses.

    The set of impulses has to be compiled in, they are:

    \begin{tabular}{|r|l|}
    \hline
    Id & Impulse \\
    \hline \hline
    1 & Unit impulse (identity) \\
    2 & My flat (light natural reverb) \\
    3 & Yamaha Marshall stack simulator \\
    4 & Fender 68 Vibrolux (SM57 on axis) \\
    5 & Fender 68 Vibrolux (SM57 off axis) \\
    6 & Fender 68 Vibrolux (Audio-technica AT4050) \\
    7 & Fender 68 Vibrolux (Neumann U87) \\
    8 & Fender Bassman (SM57 on axis) \\
    9 & Fender Bassman (SM57 off axis) \\
    10 & Fender Bassman (Audio-technica AT4050) \\
    11 & Fender Bassman (Neumann U87) \\
    12 & Fender Superchamp (SM57 on axis) \\
    13 & Fender Superchamp (SM57 off axis) \\
    14 & Fender Superchamp (Audio-technica AT4050) \\
    15 & Fender Superchamp (Neumann U87) \\
    16 & Marshall JCM2000 (SM57 on axis) \\
    17 & Marshall JCM2000 (SM57 off axis) \\
    18 & Marshall Plexi (SM57 on axis) \\
    19 & Marshall Plexi (SM57 off axis) \\
    20 & Matchless Chieftan (SM57 on axis) \\
    21 & Matchless Chieftan (SM57 off axis) \\
    \hline
    \end{tabular}

    The first three were quickly grabbed by me using jack_impulse_grabber, and the others we collected by someone else, but unfortunately I've lost his email address and can't find him on the web :(
    ]]></p>

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

      impulse_freq = local_malloc(IMPULSES * sizeof(fftw_real *));
      for (i=0; i<IMPULSES; i++) {
        impulse_freq[i] = local_malloc(MAX_FFT_LENGTH * sizeof(fftw_real));
      }

      block_time = local_malloc(MAX_FFT_LENGTH * sizeof(fftw_real));
      block_freq = local_malloc(MAX_FFT_LENGTH * sizeof(fftw_real));
      op = local_malloc(MAX_FFT_LENGTH * sizeof(fftw_real));
      overlap = local_malloc(MAX_FFT_LENGTH * sizeof(float));
      opc = local_malloc(SEG_LENGTH * sizeof(LADSPA_Data));

      /* transform the impulses */
      real_in = block_time;
      comp_out = block_freq;
      comp_in = block_freq;
      real_out = op;
      mk_imps(impulse_freq);

      in_ptr = 0;
      out_ptr = 0;
      count = 0;
    ]]></callback>

    <callback event="activate"><![CDATA[
      memset(block_time, 0, MAX_FFT_LENGTH * sizeof(fftw_real));
      memset(block_freq, 0, MAX_FFT_LENGTH * sizeof(fftw_real));
      memset(op, 0, MAX_FFT_LENGTH * sizeof(fftw_real));
      memset(overlap, 0, (MAX_FFT_LENGTH - SEG_LENGTH) * sizeof(float));
      memset(opc, 0, SEG_LENGTH * sizeof(LADSPA_Data));

      in_ptr = 0;
      out_ptr = 0;
      count = 0;
    ]]></callback>

    <callback event="cleanup"><![CDATA[
      local_free(plugin_data->block_time);
      local_free(plugin_data->block_freq);
      local_free(plugin_data->op);
      local_free(plugin_data->overlap);
      local_free(plugin_data->opc);
    ]]></callback>

    <callback event="run"><![CDATA[
      unsigned long i, pos, ipos, limit;
      unsigned int im;
      unsigned int len;
      fftw_real tmp;
      fftw_real *imp_freq;
      float coef;

      im = f_round(impulse) - 1;
      if (im >= IMPULSES) {
        im = 0;
      }

      coef = pow(10.0f, gain * 0.05f) / (float)fft_length[im];

      imp_freq = impulse_freq[im];

      for (pos = 0; pos < sample_count; pos += SEG_LENGTH) {
        limit = pos + SEG_LENGTH;

        for (ipos = pos; ipos < sample_count && ipos<limit; ipos++) {
          block_time[in_ptr++] = input[ipos];

          if (in_ptr == SEG_LENGTH) {
#ifdef FFTW3
	    fftwf_execute(plan_rc[im]);
#else
            rfftw_one(plan_rc[im], block_time, block_freq);
#endif
 
            len = fft_length[im];
            for (i=1; i<fft_length[im]/2; i++) {
	      len--;
              tmp = block_freq[i] * imp_freq[i] -
               block_freq[len] * imp_freq[len];
              block_freq[len] =
               block_freq[i] * imp_freq[len] +
               block_freq[len] * imp_freq[i];
              block_freq[i] = tmp;
            }

            block_freq[0] = imp_freq[0] * block_freq[0];
            block_freq[fft_length[im]/2] = imp_freq[fft_length[im]/2] * block_freq[fft_length[im]/2];

#ifdef FFTW3
	    fftwf_execute(plan_cr[im]);
#else
            rfftw_one(plan_cr[im], block_freq, op);
#endif

            for (i=0; i<fft_length[im]-SEG_LENGTH; i++) {
              op[i] += overlap[i];
            }
            for (i=SEG_LENGTH; i<fft_length[im]; i++) {
              overlap[i-SEG_LENGTH] = op[i];
            }

            in_ptr = 0;
	    if (count == 0 && high_lat < 1.0f) {
	      count = 1;
	      plugin_data->count = 1;
	      out_ptr = 0;
	    }
          }
        }

        for (ipos = pos; ipos < sample_count && ipos<limit; ipos++) {
          buffer_write(output[ipos], opc[out_ptr++] * coef);
          if (out_ptr == SEG_LENGTH) {
            for (i=0; i<SEG_LENGTH; i++) {
              opc[i] = op[i];
            }
            out_ptr = 0;
          }
        }
      }

      plugin_data->in_ptr = in_ptr;
      plugin_data->out_ptr = out_ptr;

      *(plugin_data->latency) = SEG_LENGTH;
    ]]></callback>

    <port label="impulse" dir="input" type="control" hint="integer,default_1">
      <name>Impulse ID</name>
      <p>Selects the impulse to convolve with. New impulses have to be compiled in.</p>
      <range min="1" max="21"/>
    </port>

    <port label="high_lat" dir="input" type="control" hint="integer,default_0">
      <name>High latency mode</name>
      <p>If you are running with blocks that are not whole powers of two long, or you are hearing distortion, try changing this to 1.</p>
      <range min="0" max="1"/>
    </port>

    <port label="gain" dir="input" type="control" hint="default_0">
      <name>Gain (dB)</name>
      <p>Controls the gain of the output signal in dB's.</p>
      <range min="-90" max="+24"/>
    </port>

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

    <port label="output" dir="output" type="audio">
      <name>Output</name>
    </port>

    <port label="latency" dir="output" type="control">
      <name>latency</name>
    </port>

    <instance-data label="impulse_freq" type="fftw_real **" />
    <instance-data label="block_time" type="fftw_real *" />
    <instance-data label="block_freq" type="fftw_real *" />
    <instance-data label="op" type="fftw_real *" />
    <instance-data label="opc" type="LADSPA_Data *" />
    <instance-data label="overlap" type="LADSPA_Data *" />
    <instance-data label="in_ptr" type="unsigned long" />
    <instance-data label="out_ptr" type="unsigned long" />
    <instance-data label="count" type="unsigned int" />
  </plugin>
</ladspa>