crap delay test

Makefile

@@ -7,7 +7,7 @@ FULLNAME = ${DISTNAME}-${VERSION}
 
 BOTH = crap_eq_const
 LADSPA_ONLY = crap_eq crap_noise
-VST_ONLY =
+VST_ONLY = crap_delay_test
 LADSPA = ${BOTH:=-ladspa} ${LADSPA_ONLY:=-ladspa}
 VST = ${BOTH:=-vst} ${VST_ONLY:=-vst}
 PLUGINS = ${LADSPA} ${VST}

README.md

@@ -25,6 +25,12 @@ __crap\_noise (0xEC57A71C)__
 
 white noise generator. loud, full-range, 0dBFS. don't say i didn't warn you.
 
+### crap delay test
+
+__crap\_delay\_test (0xDEDEDEDE)__
+
+experimentation with delay compensation and EQ oversampling, not for use.
+
 ## build notes
 
 `make` it.

crap_delay_test.h

@@ -0,0 +1,132 @@
+#define BIQUAD_DOUBLE
+#include "crap_util.h"
+
+typedef unsigned long ulong;
+
+#define ID 0xDEDEDEDE
+#define LABEL "crap_delay_test"
+#define NAME "crap sample delay test"
+#define AUTHOR "Connor Olding"
+#define COPYRIGHT "MIT"
+#define PARAMETERS 0
+#define DELAY
+
+static ulong global_delay = 2;
+static double oversample = 4;
+
+// taps. coefficients via:
+// http://vladgsound.wordpress.com/2013/06/01/iir-based-eq-and-distortions/
+#define UP 19
+#define DOWN 5
+
+typedef struct {
+	double up[UP], down[DOWN];
+	biquad filter;
+} channel;
+
+typedef struct {
+	channel c[2];
+} personal;
+
+static double
+fir_up(double *x, double s)
+{
+	x[0] = s;
+	s = 0.021484375000000000*x[18]
+	  + 0.026041666666666668*x[17]
+	  - 0.017578125000000000*x[16]
+	  - 0.062499999999999972*x[15] // uh
+	  - 0.18457031250000000 *x[14]
+	  - 0.18229166666666666 *x[13]
+	  + 0.14355468750000000 *x[12]
+	  + 0.56250000000000000 *x[11]
+	  + 1.0371093750000000  *x[10]
+	  + 1.3125000000000000  *x[9]
+	  + 1.0371093750000000  *x[8]
+	  + 0.56250000000000000 *x[7]
+	  + 0.14355468750000000 *x[6]
+	  - 0.18229166666666666 *x[5]
+	  - 0.18457031250000000 *x[4]
+	  - 0.062499999999999993*x[3] // uh
+	  - 0.017578125000000000*x[2]
+	  + 0.026041666666666668*x[1]
+	  + 0.021484375000000000*x[0];
+	for (int i = UP - 1; i > 0; i--)
+		x[i] = x[i - 1];
+	return s;
+}
+
+static double
+fir_down(double *x, double s)
+{
+	x[0] = s;
+	s = 0.077777777777777779*x[4]
+	  + 0.35555555555555557 *x[3]
+	  + 0.13333333333333333 *x[2]
+	  + 0.35555555555555557 *x[1]
+	  + 0.077777777777777779*x[0];
+	for (int i = DOWN - 1; i > 0; i--)
+		x[i] = x[i - 1];
+	return s;
+}
+
+static double
+process_one(channel *c, double s)
+{
+	s =    fir_down(c->down, biquad_run(&c->filter, fir_up(c->up, s)));
+	       fir_down(c->down, biquad_run(&c->filter, fir_up(c->up, 0)));
+	       fir_down(c->down, biquad_run(&c->filter, fir_up(c->up, 0)));
+	       fir_down(c->down, biquad_run(&c->filter, fir_up(c->up, 0)));
+	return s;
+}
+
+static void
+process(personal *data,
+    float *in_L, float *in_R,
+    float *out_L, float *out_R,
+    ulong count) {
+	for (ulong pos = 0; pos < count; pos++) {
+		out_L[pos] = process_one(&data->c[0], in_L[pos]);
+		out_R[pos] = process_one(&data->c[1], in_R[pos]);
+	}
+}
+
+static void
+process_double(personal *data,
+    double *in_L, double *in_R,
+    double *out_L, double *out_R,
+    ulong count) {
+	for (ulong pos = 0; pos < count; pos++) {
+		out_L[pos] = process_one(&data->c[0], in_L[pos]);
+		out_R[pos] = process_one(&data->c[1], in_R[pos]);
+	}
+}
+
+static void
+construct(personal *data) {
+}
+
+static void
+destruct(personal *data) {
+}
+
+static void
+resume(personal *data) {
+}
+
+static void
+pause(personal *data) {
+}
+
+static void
+adjust(personal *data, ulong fs) {
+	for (int k = 0; k < 2; k++) {
+		channel *c = &data->c[k];
+		for (int i = 0; i < UP; i++)
+			c->up[i] = 0;
+		for (int i = 0; i < DOWN; i++)
+			c->down[i] = 0;
+		c->filter = biquad_gen(0, 16630, 10, 1, fs*oversample);
+		biquad_init(&c->filter);
+	}
+}

template-vst.cpp

@@ -104,6 +104,9 @@ void
 plugin::setSampleRate(float fs) {
 	AudioEffectX::setSampleRate(fs);
 	::adjust(&data, (unsigned long) fs);
+	#ifdef DELAY
+	setInitialDelay(global_delay);
+	#endif
 }
 
 bool