legato 0.0.9

Legato is a WIP audiograph and DSL for quickly developing audio applications
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
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160

use crate::{
    context::AudioContext,
    math::fast_tanh_vf32,
    node::{Inputs, Node},
    ports::{PortBuilder, Ports},
    simd::{LANES, Vf32},
};

#[derive(Clone)]
pub struct ApplyOp {
    val: f32,
    apply_op: fn(Vf32, Vf32) -> Vf32,
    ports: Ports,
    chans: usize,
}

impl ApplyOp {
    /// Here, we typically pass in chans = 1 for binary two channel operations.
    /// For instance, multiply two streams by each other.
    ///
    /// However, we can also pass in multiple channels that are operated against
    /// the current val, which is convenient for say mc gain
    pub fn new(val: f32, chans: usize, apply_op: fn(Vf32, Vf32) -> Vf32) -> Self {
        Self {
            val,
            apply_op,
            chans,
            ports: PortBuilder::default()
                .audio_in(1)
                .audio_in_named(&["val"])
                .audio_out(1)
                .build(),
        }
    }
    fn process_no_input_val(&mut self, ai: &Inputs, ao: &mut [&mut [f32]]) {
        let chunk_size = LANES;

        let val = Vf32::splat(self.val);

        for (in_channel, out_channel) in ai.iter().zip(ao.iter_mut()) {
            for (in_chunk, out_chunk) in in_channel
                .unwrap()
                .chunks_exact(chunk_size)
                .zip(out_channel.chunks_exact_mut(chunk_size))
            {
                let result = (self.apply_op)(Vf32::from_slice(in_chunk), val);
                out_chunk.copy_from_slice(result.as_array());
            }
        }
    }
    fn process_with_input_val(&mut self, val: &[f32], ai: &Inputs, ao: &mut [&mut [f32]]) {
        let audio_inputs = &ai[0..self.chans];

        for (in_chan, out_chan) in audio_inputs.iter().zip(ao) {
            for ((in_chunk, out_chunk), val_chunk) in in_chan
                .unwrap()
                .chunks_exact(LANES)
                .zip(out_chan.chunks_exact_mut(LANES))
                .zip(val.chunks_exact(LANES))
            {
                let result =
                    (self.apply_op)(Vf32::from_slice(in_chunk), Vf32::from_slice(val_chunk));
                out_chunk.copy_from_slice(result.as_array());
            }
        }
    }
}

impl Node for ApplyOp {
    fn process(&mut self, _: &mut AudioContext, ai: &Inputs, ao: &mut [&mut [f32]]) {
        let val_idx = self.ports.audio_in.len() - 1;
        let val_chan = ai[val_idx];

        match val_chan {
            Some(inner) => self.process_with_input_val(inner, ai, ao),
            None => self.process_no_input_val(ai, ao),
        }
    }
    fn ports(&self) -> &Ports {
        &self.ports
    }
}

fn add(a: Vf32, b: Vf32) -> Vf32 {
    a + b
}

fn subtract(a: Vf32, b: Vf32) -> Vf32 {
    a - b
}

fn mult(a: Vf32, b: Vf32) -> Vf32 {
    a * b
}

fn gain(a: Vf32, b: Vf32) -> Vf32 {
    // Fast soft clip
    fast_tanh_vf32(a * b)
}

fn div(a: Vf32, b: Vf32) -> Vf32 {
    a / b
}

pub enum ApplyOpKind {
    Add,
    Subtract,
    Mult,
    Div,
    Gain,
}

pub fn mult_node_factory(val: f32, chans: usize, op_kind: ApplyOpKind) -> ApplyOp {
    let op = match op_kind {
        ApplyOpKind::Add => add,
        ApplyOpKind::Subtract => subtract,
        ApplyOpKind::Mult => mult,
        ApplyOpKind::Gain => gain,
        ApplyOpKind::Div => div,
    };
    ApplyOp::new(val, chans, op)
}

#[cfg(test)]
mod test {
    use crate::{
        config::{BlockSize, Config},
        context::AudioContext,
        node::Node,
        nodes::audio::ops::{ApplyOpKind, mult_node_factory},
    };

    #[test]
    fn sanity_add_inverse() {
        const BLOCK_SIZE: usize = 64;

        let buf_one = vec![-1.0; BLOCK_SIZE];
        let buf_two_val = vec![1.0; BLOCK_SIZE];

        let mut node = mult_node_factory(1.0, 1, ApplyOpKind::Add);

        let config = Config::new(48_000, BlockSize::Block64, 2, 4);

        let mut ctx = AudioContext::new(config);

        let inputs = [Some(buf_one.as_slice()), Some(buf_two_val.as_slice())];

        let mut output_one = [42.0; BLOCK_SIZE];

        let mut outputs = [output_one.as_mut_slice()];

        node.process(&mut ctx, &inputs, &mut outputs);

        for chan in outputs.iter() {
            for sample in chan.iter() {
                assert!(sample.abs() < 1e-6);
            }
        }
    }
}