feat: add faustlpf example

Shows how to use DSP code in C generated from FAUST code

Signed-off-by: Christopher Arndt <chris@chrisarndt.de>
This commit is contained in:
Christopher Arndt 2024-09-29 13:47:26 +02:00
parent eb814d16c3
commit 521fefc531
7 changed files with 604 additions and 0 deletions

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@prefix bufs: <http://lv2plug.in/ns/ext/buf-size#> .
@prefix doap: <http://usefulinc.com/ns/doap#> .
@prefix foaf: <http://xmlns.com/foaf/0.1/> .
@prefix lv2: <http://lv2plug.in/ns/lv2core#> .
@prefix opts: <http://lv2plug.in/ns/ext/options#> .
@prefix params: <http://lv2plug.in/ns/ext/parameters#> .
@prefix props: <http://lv2plug.in/ns/ext/port-props#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix units: <http://lv2plug.in/ns/extensions/units#> .
<urn:nymph:examples:faustlpf>
a lv2:Plugin , lv2:FilterPlugin , doap:Project ;
lv2:optionalFeature lv2:hardRTCapable , bufs:boundedBlockLength , opts:options ;
opts:supportedOption bufs:nominalBlockLength ,
bufs:maxBlockLength ,
params:sampleRate ;
lv2:port [
a lv2:InputPort, lv2:AudioPort ;
lv2:index 0 ;
lv2:name "Audio In" ;
lv2:symbol "in" ;
],
[
a lv2:OutputPort, lv2:AudioPort ;
lv2:index 1 ;
lv2:name "Audio Out" ;
lv2:symbol "out" ;
],
[
a lv2:InputPort, lv2:ControlPort ;
lv2:index 2 ;
lv2:name "Cutoff" ;
lv2:symbol "cutoff" ;
lv2:default 15000.0 ;
lv2:minimum 16.0 ;
lv2:maximum 15000.0 ;
lv2:portProperty props:logarithmic ;
units:unit units:hz ;
];
rdfs:comment """
A 2-pole lowpass filter from the FAUST standard library.
""" ;
doap:name "nymph faust LPF" ;
doap:license <https://spdx.org/licenses/MIT> ;
doap:maintainer [
foaf:name "Christopher Arndt" ;
foaf:mbox <mailto:info@chrisarndt.de> ;
foaf:homepage <https://gitlab.com/SpotlightKid/nymph> ;
] ;
lv2:microVersion 0 ;
lv2:minorVersion 1 .

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@prefix lv2: <http://lv2plug.in/ns/lv2core#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
<urn:nymph:examples:faustlpf>
a lv2:Plugin ;
lv2:binary <libfaustlpf.so> ;
rdfs:seeAlso <faustlpf.ttl> .

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## A FAUST standard library 2-pole lowpass filter LV2 plugin
import nymph
type
SampleBuffer = UncheckedArray[cfloat]
{.emit: "#include \"lpf.h\"".}
type
faustlpf {.importc, header: "lpf.h".}= object
fHslider0: cfloat
proc newfaustlpf(): ptr faustlpf {.importc.}
proc deletefaustlpf(dsp: ptr faustlpf) {.importc.}
proc initfaustlpf(dsp: ptr faustlpf, sample_rate: cint) {.importc.}
proc instanceClearfaustlpf(dsp: ptr faustlpf) {.importc.}
#proc getNumInputsmydsp(dsp: ptr faustlpf): cint {.importc.}
#proc getNumOutputsmydsp(dsp: ptr faustlpf): cint {.importc.}
#proc getSampleRatefaustlpf(dsp: ptr faustlpf): cint {.importc.}
proc computefaustlpf(dsp: ptr faustlpf, count: cint, inputs, outputs: ptr ptr SampleBuffer) {.importc.}
type
PluginPort {.pure.} = enum
Input, Output, Frequency
FaustLPFPlugin = object
input: ptr SampleBuffer
output: ptr SampleBuffer
freq: ptr cfloat
flt: ptr faustlpf
const
PluginUri = "urn:nymph:examples:faustlpf"
minFreq = 16.0
maxFreq = 15_000.0
proc instantiate(descriptor: ptr Lv2Descriptor; sampleRate: cdouble;
bundlePath: cstring; features: ptr UncheckedArray[ptr Lv2Feature]):
Lv2Handle {.cdecl.} =
try:
let plug = cast[ptr FaustLPFPlugin](createShared(FaustLPFPlugin))
plug.flt = newfaustlpf()
initfaustlpf(plug.flt, sampleRate.cint)
return cast[Lv2Handle](plug)
except OutOfMemDefect:
return nil
proc connectPort(instance: Lv2Handle; port: cuint;
dataLocation: pointer) {.cdecl.} =
let plug = cast[ptr FaustLPFPlugin](instance)
case cast[PluginPort](port)
of PluginPort.Input:
plug.input = cast[ptr SampleBuffer](dataLocation)
of PluginPort.Output:
plug.output = cast[ptr SampleBuffer](dataLocation)
of PluginPort.Frequency:
plug.freq = cast[ptr cfloat](dataLocation)
proc activate(instance: Lv2Handle) {.cdecl.} =
let plug = cast[ptr FaustLPFPlugin](instance)
instanceClearfaustlpf(plug.flt)
proc run(instance: Lv2Handle; nSamples: cuint) {.cdecl.} =
let plug = cast[ptr FaustLPFPlugin](instance)
plug.flt.fHslider0 = plug.freq[].clamp(minFreq, maxFreq)
computefaustlpf(plug.flt, nSamples.cint, addr plug.input, addr plug.output)
proc deactivate(instance: Lv2Handle) {.cdecl.} =
discard
proc cleanup(instance: Lv2Handle) {.cdecl.} =
let plug = cast[ptr FaustLPFPlugin](instance)
deletefaustlpf(plug.flt)
freeShared(plug)
proc extensionData(uri: cstring): pointer {.cdecl.} =
return nil
proc NimMain() {.cdecl, importc.}
proc lv2Descriptor(index: cuint): ptr Lv2Descriptor {.
cdecl, exportc, dynlib, extern: "lv2_descriptor".} =
NimMain()
if index == 0:
result = createShared(Lv2Descriptor)
result.uri = cstring(PluginUri)
result.instantiate = instantiate
result.connectPort = connectPort
result.activate = activate
result.run = run
result.deactivate = deactivate
result.cleanup = cleanup
result.extensionData = extensionData

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examples/lpf.dsp Normal file
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declare name "FaustLPF";
declare author "Christopher Arndt";
declare copyright "Christopher Arndt, 2024";
declare license "MIT";
declare version "0.1.0";
import("stdfaust.lib");
cutoff = hslider("[1] Cutoff [symbol:cutoff] [unit:Hz] [scale:log] [style:knob] [tooltip:Low-pass filter cutoff frequency]",
15000, 16, 15000, 0.1) : si.smoo;
process = fi.lowpass(2, cutoff);

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examples/lpf.h Normal file
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/* ------------------------------------------------------------
author: "Christopher Arndt"
copyright: "Christopher Arndt, 2024"
license: "MIT"
name: "FaustLPF"
version: "0.1.0"
Code generated with Faust 2.74.6 (https://faust.grame.fr)
Compilation options: -a ./examples/minarch.h -lang c -ct 1 -cn faustlpf -es 1 -mcd 16 -mdd 1024 -mdy 33 -single -ftz 0 -vec -lv 0 -vs 32
------------------------------------------------------------ */
#ifndef __faustlpf_H__
#define __faustlpf_H__
/******************* BEGIN minarch.h ****************/
/************************************************************************
FAUST Architecture File for generating a very minimal C interface
************************************************************************/
#include <math.h>
#include <stdio.h>
#include "faust/gui/CInterface.h"
#define max(a,b) ((a < b) ? b : a)
#define min(a,b) ((a < b) ? a : b)
/******************************************************************************
VECTOR INTRINSICS
*******************************************************************************/
/**************************BEGIN USER SECTION **************************/
#ifndef FAUSTFLOAT
#define FAUSTFLOAT float
#endif
#ifdef __cplusplus
extern "C" {
#endif
#if defined(_WIN32)
#define RESTRICT __restrict
#else
#define RESTRICT __restrict__
#endif
#include <math.h>
#include <stdint.h>
#include <stdlib.h>
static float faustlpf_faustpower2_f(float value) {
return value * value;
}
#ifndef FAUSTCLASS
#define FAUSTCLASS faustlpf
#endif
#ifdef __APPLE__
#define exp10f __exp10f
#define exp10 __exp10
#endif
typedef struct {
int fSampleRate;
float fConst0;
float fConst1;
float fConst2;
FAUSTFLOAT fHslider0;
float fRec1_perm[4];
float fConst3;
float fRec0_perm[4];
} faustlpf;
faustlpf* newfaustlpf() {
faustlpf* dsp = (faustlpf*)calloc(1, sizeof(faustlpf));
return dsp;
}
void deletefaustlpf(faustlpf* dsp) {
free(dsp);
}
void metadatafaustlpf(MetaGlue* m) {
m->declare(m->metaInterface, "author", "Christopher Arndt");
m->declare(m->metaInterface, "compile_options", "-a ./examples/minarch.h -lang c -ct 1 -cn faustlpf -es 1 -mcd 16 -mdd 1024 -mdy 33 -single -ftz 0 -vec -lv 0 -vs 32");
m->declare(m->metaInterface, "copyright", "Christopher Arndt, 2024");
m->declare(m->metaInterface, "filename", "lpf.dsp");
m->declare(m->metaInterface, "filters.lib/fir:author", "Julius O. Smith III");
m->declare(m->metaInterface, "filters.lib/fir:copyright", "Copyright (C) 2003-2019 by Julius O. Smith III <jos@ccrma.stanford.edu>");
m->declare(m->metaInterface, "filters.lib/fir:license", "MIT-style STK-4.3 license");
m->declare(m->metaInterface, "filters.lib/iir:author", "Julius O. Smith III");
m->declare(m->metaInterface, "filters.lib/iir:copyright", "Copyright (C) 2003-2019 by Julius O. Smith III <jos@ccrma.stanford.edu>");
m->declare(m->metaInterface, "filters.lib/iir:license", "MIT-style STK-4.3 license");
m->declare(m->metaInterface, "filters.lib/lowpass0_highpass1", "Copyright (C) 2003-2019 by Julius O. Smith III <jos@ccrma.stanford.edu>");
m->declare(m->metaInterface, "filters.lib/lowpass0_highpass1:author", "Julius O. Smith III");
m->declare(m->metaInterface, "filters.lib/lowpass:author", "Julius O. Smith III");
m->declare(m->metaInterface, "filters.lib/lowpass:copyright", "Copyright (C) 2003-2019 by Julius O. Smith III <jos@ccrma.stanford.edu>");
m->declare(m->metaInterface, "filters.lib/lowpass:license", "MIT-style STK-4.3 license");
m->declare(m->metaInterface, "filters.lib/name", "Faust Filters Library");
m->declare(m->metaInterface, "filters.lib/tf2:author", "Julius O. Smith III");
m->declare(m->metaInterface, "filters.lib/tf2:copyright", "Copyright (C) 2003-2019 by Julius O. Smith III <jos@ccrma.stanford.edu>");
m->declare(m->metaInterface, "filters.lib/tf2:license", "MIT-style STK-4.3 license");
m->declare(m->metaInterface, "filters.lib/tf2s:author", "Julius O. Smith III");
m->declare(m->metaInterface, "filters.lib/tf2s:copyright", "Copyright (C) 2003-2019 by Julius O. Smith III <jos@ccrma.stanford.edu>");
m->declare(m->metaInterface, "filters.lib/tf2s:license", "MIT-style STK-4.3 license");
m->declare(m->metaInterface, "filters.lib/version", "1.3.0");
m->declare(m->metaInterface, "license", "MIT");
m->declare(m->metaInterface, "maths.lib/author", "GRAME");
m->declare(m->metaInterface, "maths.lib/copyright", "GRAME");
m->declare(m->metaInterface, "maths.lib/license", "LGPL with exception");
m->declare(m->metaInterface, "maths.lib/name", "Faust Math Library");
m->declare(m->metaInterface, "maths.lib/version", "2.8.0");
m->declare(m->metaInterface, "name", "FaustLPF");
m->declare(m->metaInterface, "platform.lib/name", "Generic Platform Library");
m->declare(m->metaInterface, "platform.lib/version", "1.3.0");
m->declare(m->metaInterface, "signals.lib/name", "Faust Signal Routing Library");
m->declare(m->metaInterface, "signals.lib/version", "1.5.0");
m->declare(m->metaInterface, "version", "0.1.0");
}
int getSampleRatefaustlpf(faustlpf* RESTRICT dsp) {
return dsp->fSampleRate;
}
int getNumInputsfaustlpf(faustlpf* RESTRICT dsp) {
return 1;
}
int getNumOutputsfaustlpf(faustlpf* RESTRICT dsp) {
return 1;
}
void classInitfaustlpf(int sample_rate) {
}
void instanceResetUserInterfacefaustlpf(faustlpf* dsp) {
dsp->fHslider0 = (FAUSTFLOAT)(1.5e+04f);
}
void instanceClearfaustlpf(faustlpf* dsp) {
/* C99 loop */
{
int l0;
for (l0 = 0; l0 < 4; l0 = l0 + 1) {
dsp->fRec1_perm[l0] = 0.0f;
}
}
/* C99 loop */
{
int l1;
for (l1 = 0; l1 < 4; l1 = l1 + 1) {
dsp->fRec0_perm[l1] = 0.0f;
}
}
}
void instanceConstantsfaustlpf(faustlpf* dsp, int sample_rate) {
dsp->fSampleRate = sample_rate;
dsp->fConst0 = fminf(1.92e+05f, fmaxf(1.0f, (float)(dsp->fSampleRate)));
dsp->fConst1 = 44.1f / dsp->fConst0;
dsp->fConst2 = 1.0f - dsp->fConst1;
dsp->fConst3 = 3.1415927f / dsp->fConst0;
}
void instanceInitfaustlpf(faustlpf* dsp, int sample_rate) {
instanceConstantsfaustlpf(dsp, sample_rate);
instanceResetUserInterfacefaustlpf(dsp);
instanceClearfaustlpf(dsp);
}
void initfaustlpf(faustlpf* dsp, int sample_rate) {
classInitfaustlpf(sample_rate);
instanceInitfaustlpf(dsp, sample_rate);
}
void buildUserInterfacefaustlpf(faustlpf* dsp, UIGlue* ui_interface) {
ui_interface->openVerticalBox(ui_interface->uiInterface, "FaustLPF");
ui_interface->declare(ui_interface->uiInterface, &dsp->fHslider0, "1", "");
ui_interface->declare(ui_interface->uiInterface, &dsp->fHslider0, "scale", "log");
ui_interface->declare(ui_interface->uiInterface, &dsp->fHslider0, "style", "knob");
ui_interface->declare(ui_interface->uiInterface, &dsp->fHslider0, "symbol", "cutoff");
ui_interface->declare(ui_interface->uiInterface, &dsp->fHslider0, "tooltip", "Low-pass filter cutoff frequency");
ui_interface->declare(ui_interface->uiInterface, &dsp->fHslider0, "unit", "Hz");
ui_interface->addHorizontalSlider(ui_interface->uiInterface, "Cutoff", &dsp->fHslider0, (FAUSTFLOAT)1.5e+04f, (FAUSTFLOAT)16.0f, (FAUSTFLOAT)1.5e+04f, (FAUSTFLOAT)0.1f);
ui_interface->closeBox(ui_interface->uiInterface);
}
void computefaustlpf(faustlpf* dsp, int count, FAUSTFLOAT** RESTRICT inputs, FAUSTFLOAT** RESTRICT outputs) {
FAUSTFLOAT* input0_ptr = inputs[0];
FAUSTFLOAT* output0_ptr = outputs[0];
float fSlow0 = dsp->fConst1 * (float)(dsp->fHslider0);
float fRec1_tmp[36];
float* fRec1 = &fRec1_tmp[4];
float fZec0[32];
float fZec1[32];
float fZec2[32];
float fRec0_tmp[36];
float* fRec0 = &fRec0_tmp[4];
int vindex = 0;
/* Main loop */
for (vindex = 0; vindex <= (count - 32); vindex = vindex + 32) {
FAUSTFLOAT* input0 = &input0_ptr[vindex];
FAUSTFLOAT* output0 = &output0_ptr[vindex];
int vsize = 32;
/* Recursive loop 0 */
/* Pre code */
/* C99 loop */
{
int j0;
for (j0 = 0; j0 < 4; j0 = j0 + 1) {
fRec1_tmp[j0] = dsp->fRec1_perm[j0];
}
}
/* Compute code */
/* C99 loop */
{
int i;
for (i = 0; i < vsize; i = i + 1) {
fRec1[i] = fSlow0 + dsp->fConst2 * fRec1[i - 1];
}
}
/* Post code */
/* C99 loop */
{
int j1;
for (j1 = 0; j1 < 4; j1 = j1 + 1) {
dsp->fRec1_perm[j1] = fRec1_tmp[vsize + j1];
}
}
/* Vectorizable loop 1 */
/* Compute code */
/* C99 loop */
{
int i;
for (i = 0; i < vsize; i = i + 1) {
fZec0[i] = tanf(dsp->fConst3 * fRec1[i]);
}
}
/* Vectorizable loop 2 */
/* Compute code */
/* C99 loop */
{
int i;
for (i = 0; i < vsize; i = i + 1) {
fZec1[i] = 1.0f / fZec0[i];
}
}
/* Vectorizable loop 3 */
/* Compute code */
/* C99 loop */
{
int i;
for (i = 0; i < vsize; i = i + 1) {
fZec2[i] = (fZec1[i] + 1.4142135f) / fZec0[i] + 1.0f;
}
}
/* Recursive loop 4 */
/* Pre code */
/* C99 loop */
{
int j2;
for (j2 = 0; j2 < 4; j2 = j2 + 1) {
fRec0_tmp[j2] = dsp->fRec0_perm[j2];
}
}
/* Compute code */
/* C99 loop */
{
int i;
for (i = 0; i < vsize; i = i + 1) {
fRec0[i] = (float)(input0[i]) - (fRec0[i - 2] * ((fZec1[i] + -1.4142135f) / fZec0[i] + 1.0f) + 2.0f * fRec0[i - 1] * (1.0f - 1.0f / faustlpf_faustpower2_f(fZec0[i]))) / fZec2[i];
}
}
/* Post code */
/* C99 loop */
{
int j3;
for (j3 = 0; j3 < 4; j3 = j3 + 1) {
dsp->fRec0_perm[j3] = fRec0_tmp[vsize + j3];
}
}
/* Vectorizable loop 5 */
/* Compute code */
/* C99 loop */
{
int i;
for (i = 0; i < vsize; i = i + 1) {
output0[i] = (FAUSTFLOAT)((fRec0[i - 2] + fRec0[i] + 2.0f * fRec0[i - 1]) / fZec2[i]);
}
}
}
/* Remaining frames */
if (vindex < count) {
FAUSTFLOAT* input0 = &input0_ptr[vindex];
FAUSTFLOAT* output0 = &output0_ptr[vindex];
int vsize = count - vindex;
/* Recursive loop 0 */
/* Pre code */
/* C99 loop */
{
int j0;
for (j0 = 0; j0 < 4; j0 = j0 + 1) {
fRec1_tmp[j0] = dsp->fRec1_perm[j0];
}
}
/* Compute code */
/* C99 loop */
{
int i;
for (i = 0; i < vsize; i = i + 1) {
fRec1[i] = fSlow0 + dsp->fConst2 * fRec1[i - 1];
}
}
/* Post code */
/* C99 loop */
{
int j1;
for (j1 = 0; j1 < 4; j1 = j1 + 1) {
dsp->fRec1_perm[j1] = fRec1_tmp[vsize + j1];
}
}
/* Vectorizable loop 1 */
/* Compute code */
/* C99 loop */
{
int i;
for (i = 0; i < vsize; i = i + 1) {
fZec0[i] = tanf(dsp->fConst3 * fRec1[i]);
}
}
/* Vectorizable loop 2 */
/* Compute code */
/* C99 loop */
{
int i;
for (i = 0; i < vsize; i = i + 1) {
fZec1[i] = 1.0f / fZec0[i];
}
}
/* Vectorizable loop 3 */
/* Compute code */
/* C99 loop */
{
int i;
for (i = 0; i < vsize; i = i + 1) {
fZec2[i] = (fZec1[i] + 1.4142135f) / fZec0[i] + 1.0f;
}
}
/* Recursive loop 4 */
/* Pre code */
/* C99 loop */
{
int j2;
for (j2 = 0; j2 < 4; j2 = j2 + 1) {
fRec0_tmp[j2] = dsp->fRec0_perm[j2];
}
}
/* Compute code */
/* C99 loop */
{
int i;
for (i = 0; i < vsize; i = i + 1) {
fRec0[i] = (float)(input0[i]) - (fRec0[i - 2] * ((fZec1[i] + -1.4142135f) / fZec0[i] + 1.0f) + 2.0f * fRec0[i - 1] * (1.0f - 1.0f / faustlpf_faustpower2_f(fZec0[i]))) / fZec2[i];
}
}
/* Post code */
/* C99 loop */
{
int j3;
for (j3 = 0; j3 < 4; j3 = j3 + 1) {
dsp->fRec0_perm[j3] = fRec0_tmp[vsize + j3];
}
}
/* Vectorizable loop 5 */
/* Compute code */
/* C99 loop */
{
int i;
for (i = 0; i < vsize; i = i + 1) {
output0[i] = (FAUSTFLOAT)((fRec0[i - 2] + fRec0[i] + 2.0f * fRec0[i - 1]) / fZec2[i]);
}
}
}
}
#ifdef __cplusplus
}
#endif
/***************************END USER SECTION ***************************/
#endif

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examples/minarch.h Normal file
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/******************* BEGIN minarch.h ****************/
/************************************************************************
FAUST Architecture File for generating a very minimal C interface
************************************************************************/
#include <math.h>
#include <stdio.h>
#include "faust/gui/CInterface.h"
#define max(a,b) ((a < b) ? b : a)
#define min(a,b) ((a < b) ? a : b)
/******************************************************************************
VECTOR INTRINSICS
*******************************************************************************/
<<includeIntrinsic>>
/**************************BEGIN USER SECTION **************************/
<<includeclass>>
/***************************END USER SECTION ***************************/

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@ -25,6 +25,7 @@ type Example = tuple
const examples = to_table({
"amp": "urn:nymph:examples:amp",
"faustlpf": "urn:nymph:examples:faustlpf",
"miditranspose": "urn:nymph:examples:miditranspose",
"multimodefilter": "urn:nymph:examples:multimodefilter",
"tiltfilter": "urn:nymph:examples:tiltfilter",