working on finally fixed interpolation functions in the delay line and the sampler
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Weird Constructor
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1fbc6741cb
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1ee4af6cd1
3 changed files with 213 additions and 11 deletions
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@ -892,7 +892,6 @@ fn fclampc<F: Flt>(x: F, mi: f64, mx: f64) -> F {
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x.max(f(mi)).min(f(mx))
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}
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/// Hermite / Cubic interpolation of a buffer full of samples at the given _index_.
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/// _len_ is the buffer length to consider and wrap the index into. And _fract_ is the
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/// fractional part of the index.
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@ -913,6 +912,7 @@ fn fclampc<F: Flt>(x: F, mi: f64, mx: f64) -> F {
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///```
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#[inline]
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pub fn cubic_interpolate<F: Flt>(data: &[F], len: usize, index: usize, fract: F) -> F {
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let index = index + len;
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// Hermite interpolation, take from
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// https://github.com/eric-wood/delay/blob/main/src/delay.rs#L52
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//
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@ -1031,11 +1031,21 @@ impl<F: Flt> DelayBuffer<F> {
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let offs = s_offs.floor().to_usize().unwrap_or(0) % len;
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let fract = s_offs.fract();
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let i = (self.wr + len) - offs;
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// one extra offset, because feed() advances self.wr to the next writing position!
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let i = (self.wr + len) - (offs + 1);
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let x0 = data[i % len];
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let x1 = data[(i - 1) % len];
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x0 + fract * (x1 - x0)
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let res = x0 + fract * (x1 - x0);
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//d// eprintln!(
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//d// "INTERP: {:6.4} x0={:6.4} x1={:6.4} fract={:6.4} => {:6.4}",
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//d// s_offs.to_f64().unwrap_or(0.0),
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//d// x0.to_f64().unwrap(),
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//d// x1.to_f64().unwrap(),
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//d// fract.to_f64().unwrap(),
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//d// res.to_f64().unwrap(),
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//d// );
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res
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}
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/// Fetch a sample from the delay buffer at the given time.
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@ -1057,23 +1067,33 @@ impl<F: Flt> DelayBuffer<F> {
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let offs = s_offs.floor().to_usize().unwrap_or(0) % len;
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let fract = s_offs.fract();
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let i = (self.wr + len) - offs;
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cubic_interpolate(data, len, i, f::<F>(1.0) - fract)
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let i = (self.wr + len) - (offs + 2);
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let res = cubic_interpolate(data, len, i, f::<F>(1.0) - fract);
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// eprintln!(
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// "cubic at={} ({:6.4}) res={:6.4}",
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// i % len,
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// s_offs.to_f64().unwrap(),
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// res.to_f64().unwrap()
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// );
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res
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}
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#[inline]
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pub fn nearest_at(&self, delay_time_ms: F) -> F {
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let len = self.data.len();
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let offs = ((delay_time_ms * self.srate) / f(1000.0)).floor().to_usize().unwrap_or(0) % len;
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let idx = ((self.wr + len) - offs) % len;
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// (offs + 1) one extra offset, because feed() advances
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// self.wr to the next writing position!
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let idx = ((self.wr + len) - (offs + 1)) % len;
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self.data[idx]
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}
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#[inline]
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pub fn at(&self, delay_sample_count: usize) -> F {
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let len = self.data.len();
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let idx = ((self.wr + len) - delay_sample_count) % len;
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// (delay_sample_count + 1) one extra offset, because feed() advances self.wr to
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// the next writing position!
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let idx = ((self.wr + len) - (delay_sample_count + 1)) % len;
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self.data[idx]
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}
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}
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@ -148,8 +148,8 @@ impl Sampl {
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return 0.0;
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}
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let j = self.phase.floor() as usize % sd_len;
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let i = ((sd_len - 1) - j) + sd_len;
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let j = self.phase.floor() as usize;
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let i = ((sd_len - 1) - j);
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let f = self.phase.fract();
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self.phase = j as f64 + f + sr_factor * speed;
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@ -165,7 +165,7 @@ impl Sampl {
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return 0.0;
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}
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let i = self.phase.floor() as usize + sd_len;
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let i = self.phase.floor() as usize;
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let f = self.phase.fract();
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self.phase = (i % sd_len) as f64 + f + sr_factor * speed;
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182
tests/delay_buffer.rs
Normal file
182
tests/delay_buffer.rs
Normal file
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@ -0,0 +1,182 @@
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// Copyright (c) 2021 Weird Constructor <weirdconstructor@gmail.com>
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// This file is a part of HexoDSP. Released under GPL-3.0-or-later.
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// See README.md and COPYING for details.
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mod common;
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use common::*;
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#[test]
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fn check_delaybuffer_linear_interpolation() {
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let mut buf = crate::helpers::DelayBuffer::new();
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buf.feed(0.0);
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buf.feed(0.1);
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buf.feed(0.2);
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buf.feed(0.3);
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buf.feed(0.4);
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buf.feed(0.5);
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buf.feed(0.6);
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buf.feed(0.7);
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buf.feed(0.8);
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buf.feed(0.9);
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buf.feed(1.0);
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let mut samples_out = vec![];
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let mut pos = 0.0;
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let pos_inc = 0.5;
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for _ in 0..20 {
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samples_out.push(buf.linear_interpolate_at_s(pos));
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pos += pos_inc;
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}
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assert_vec_feq!(
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samples_out,
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vec![
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1.0, 0.95, 0.9, 0.85, 0.8, 0.75, 0.7, 0.65, 0.6, 0.55, 0.5, 0.45, 0.4, 0.35000002, 0.3,
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0.25, 0.2, 0.15, 0.1, 0.05
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]
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);
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let mut samples_out = vec![];
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let mut pos = 0.0;
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let pos_inc = 0.2;
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for _ in 0..30 {
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samples_out.push(buf.linear_interpolate_at_s(pos));
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pos += pos_inc;
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}
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assert_vec_feq!(
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samples_out,
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vec![
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1.0, 0.98, 0.96, 0.94, 0.91999996, 0.9, 0.88, 0.85999995, 0.84, 0.82, 0.8, 0.78, 0.76,
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0.73999995, 0.71999997, 0.6999999, 0.67999995, 0.65999997, 0.6399999, 0.61999995,
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0.59999996, 0.58, 0.56, 0.54, 0.52000004, 0.50000006, 0.48000008, 0.4600001,
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0.44000012, 0.42000014
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]
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);
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}
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#[test]
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fn check_delaybuffer_nearest() {
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let mut buf = crate::helpers::DelayBuffer::new();
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buf.feed(0.0);
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buf.feed(0.1);
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buf.feed(0.2);
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buf.feed(0.3);
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buf.feed(0.4);
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buf.feed(0.5);
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buf.feed(0.6);
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buf.feed(0.7);
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buf.feed(0.8);
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buf.feed(0.9);
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buf.feed(1.0);
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let mut samples_out = vec![];
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let mut pos = 0.0;
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let pos_inc = 0.5;
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for _ in 0..20 {
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samples_out.push(buf.at(pos as usize));
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pos += pos_inc;
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}
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assert_vec_feq!(
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samples_out,
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vec![
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1.0, 1.0, 0.9, 0.9, 0.8, 0.8, 0.7, 0.7, 0.6, 0.6, 0.5, 0.5, 0.4, 0.4, 0.3, 0.3, 0.2,
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0.2, 0.1, 0.1
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]
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);
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let mut samples_out = vec![];
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let mut pos = 0.0;
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let pos_inc = 0.2;
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for _ in 0..30 {
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samples_out.push(buf.at(pos as usize));
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pos += pos_inc;
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}
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assert_vec_feq!(
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samples_out,
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vec![
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1.0, 1.0, 1.0, 1.0, 1.0, 0.9, 0.9, 0.9, 0.9, 0.9, 0.9, 0.8, 0.8, 0.8, 0.8, 0.7, 0.7,
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0.7, 0.7, 0.7, 0.6, 0.6, 0.6, 0.6, 0.6, 0.5, 0.5, 0.5, 0.5, 0.5
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]
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);
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}
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#[test]
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fn check_cubic_interpolate() {
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use crate::helpers::cubic_interpolate;
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let data = [1.0, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.0];
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let mut samples_out = vec![];
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let mut pos = 0.0_f32;
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let pos_inc = 0.1_f32;
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for _ in 0..30 {
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let i = pos.floor() as usize;
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let f = pos.fract();
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samples_out.push(cubic_interpolate(&data[..], data.len(), i, f));
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pos += pos_inc;
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}
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assert_vec_feq!(
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samples_out,
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vec![
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1.0, 1.03455, 1.0504, 1.05085, 1.0392, 1.01875, 0.99279994, 0.9646499, 0.9375999,
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0.91494995, 0.9, 0.89, 0.87999994, 0.86999995, 0.85999995, 0.84999996, 0.84, 0.83,
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0.82, 0.80999994, 0.8, 0.79, 0.78000003, 0.77000004, 0.76, 0.75, 0.74, 0.73, 0.72,
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0.71000004
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]
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);
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}
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#[test]
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fn check_delaybuffer_cubic_interpolation() {
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let mut buf = crate::helpers::DelayBuffer::new();
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buf.feed(0.0);
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buf.feed(0.1);
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buf.feed(0.2);
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buf.feed(0.3);
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buf.feed(0.4);
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buf.feed(0.5);
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buf.feed(0.6);
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buf.feed(0.7);
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buf.feed(0.8);
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buf.feed(0.9);
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buf.feed(1.0);
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let mut samples_out = vec![];
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let mut pos = 0.0;
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let pos_inc = 0.5;
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for _ in 0..20 {
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samples_out.push(buf.cubic_interpolate_at_s(pos));
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pos += pos_inc;
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}
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assert_vec_feq!(
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samples_out,
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vec![
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1.0, 0.95, 0.9, 0.85, 0.8, 0.75, 0.7, 0.65, 0.6, 0.55, 0.5, 0.45, 0.4, 0.35000002, 0.3,
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0.25, 0.2, 0.15, 0.1, 0.05
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]
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);
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let mut samples_out = vec![];
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let mut pos = 0.0;
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let pos_inc = 0.2;
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for _ in 0..30 {
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samples_out.push(buf.cubic_interpolate_at_s(pos));
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pos += pos_inc;
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}
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assert_vec_feq!(
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samples_out,
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vec![
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1.0, 0.98, 0.96, 0.94, 0.91999996, 0.9, 0.88, 0.85999995, 0.84, 0.82, 0.8, 0.78, 0.76,
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0.73999995, 0.71999997, 0.6999999, 0.67999995, 0.65999997, 0.6399999, 0.61999995,
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0.59999996, 0.58, 0.56, 0.54, 0.52000004, 0.50000006, 0.48000008, 0.4600001,
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0.44000012, 0.42000014
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]
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);
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}
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