ruffbox_synth 0.14.0

A beatbox-oriented synthesizer library.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90

use crate::building_blocks::convolver::block_convolver::BlockConvolver;
use rubato::{FftFixedIn, Resampler};

// 4x128 points @ 44100kHz, raw f32 ...
const DEFAULT_FILTER: &[u8] = include_bytes!("../../../binaural_filter/default.raw");

/**
 * a simple first-order convolution binauralizer
 */
pub struct BinauralizerO1<const BUFSIZE: usize, const NCHAN: usize> {
    left: Vec<BlockConvolver<BUFSIZE>>,
    right: Vec<BlockConvolver<BUFSIZE>>,
}

impl<const BUFSIZE: usize, const NCHAN: usize> BinauralizerO1<BUFSIZE, NCHAN> {
    pub fn default_filter(samplerate: f32) -> Self {
        let mut ir: Vec<f32> = DEFAULT_FILTER
            .chunks(4)
            .map(|b| f32::from_le_bytes(b.try_into().unwrap()))
            .collect();

        debug_assert!(ir.len() == 1024);

        // lower gain a little
        for s in ir.iter_mut() {
            *s *= 0.45;
        }

        let mut ir_proc: Vec<(Vec<f32>, Vec<f32>)> = vec![
            (ir[0..128].to_vec(), ir[512..640].to_vec()),
            (ir[128..256].to_vec(), ir[640..768].to_vec()),
            (ir[256..384].to_vec(), ir[768..896].to_vec()),
            (ir[384..512].to_vec(), ir[896..1024].to_vec()),
        ];

        if samplerate != 44100.0 {
            for i in 0..4 {
                let (l, r) = ir_proc.get(i).unwrap();
                let mut resampler_l =
                    FftFixedIn::<f32>::new(44100, samplerate as usize, 128, 1, 1).unwrap();
                let mut resampler_r =
                    FftFixedIn::<f32>::new(44100, samplerate as usize, 128, 1, 1).unwrap();
                let l_resampled = resampler_l.process(&[l], None).unwrap();
                let r_resampled = resampler_r.process(&[r], None).unwrap();
                ir_proc[i] = (l_resampled[0].clone(), r_resampled[0].clone());
            }
        }

        BinauralizerO1::from_ir(ir_proc)
    }

    // initialize with unit IRs
    pub fn from_ir(ir: Vec<(Vec<f32>, Vec<f32>)>) -> Self {
        let mut left = Vec::new();
        let mut right = Vec::new();

        for i in ir.iter().take(4) {
            left.push(BlockConvolver::<BUFSIZE>::from_ir(&i.0));
            right.push(BlockConvolver::<BUFSIZE>::from_ir(&i.1))
        }

        BinauralizerO1 { left, right }
    }

    pub fn binauralize(&mut self, input: [[f32; BUFSIZE]; NCHAN]) -> [[f32; BUFSIZE]; 2] {
        let mut bin_block = [[0.0; BUFSIZE]; 2];

        // only handle o1 for now ...
        for (ach, i) in input.iter().enumerate().take(4) {
            let lch = self.left[ach].convolve(*i);
            let rch = self.right[ach].convolve(*i);
            for fr in 0..BUFSIZE {
                bin_block[0][fr] += lch[fr];
                bin_block[1][fr] += rch[fr];
            }
        }

        bin_block
    }
}

#[cfg(test)]
mod tests {
    // Note this useful idiom: importing names from outer (for mod tests) scope.
    use super::*;
    #[test]
    fn test_load() {
        let _bin = BinauralizerO1::<128, 4>::default_filter(44100.0);
    }
}