audio 0.2.1

A crate for working with audio in Rust
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
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
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177

/// Note: most of these tests are duplicated doc tests, but they're here so that
/// we can run them through miri and get a good idea of the soundness of our
/// implementations.
use audio_core::{InterleavedBufMut, ResizableBuf};

#[test]
fn test_init() {
    let mut buf = crate::buf::Interleaved::<f32>::with_topology(2, 4);

    for (c, s) in buf
        .get_mut(0)
        .unwrap()
        .iter_mut()
        .zip(&[1.0, 2.0, 3.0, 4.0])
    {
        *c = *s;
    }

    for (c, s) in buf
        .get_mut(1)
        .unwrap()
        .iter_mut()
        .zip(&[5.0, 6.0, 7.0, 8.0])
    {
        *c = *s;
    }

    assert_eq!(buf.as_slice(), &[1.0, 5.0, 2.0, 6.0, 3.0, 7.0, 4.0, 8.0]);
}

#[test]
fn test_complicated() {
    let mut buf = crate::buf::Interleaved::<f32>::with_topology(2, 4);

    let mut it = buf.iter_channels_mut();

    let mut left_chan = it.next().unwrap();
    let mut right_chan = it.next().unwrap();

    let left = left_chan.iter_mut().collect::<Vec<_>>();
    let right = right_chan.iter_mut().collect::<Vec<_>>();

    for (c, f) in left.into_iter().zip(&[1.0, 2.0, 3.0, 4.0]) {
        *c = *f;
    }

    for (c, f) in right.into_iter().zip(&[5.0, 6.0, 7.0, 8.0]) {
        *c = *f;
    }

    assert_eq!(buf.as_slice(), &[1.0, 5.0, 2.0, 6.0, 3.0, 7.0, 4.0, 8.0]);
}

#[test]
fn test_iter() {
    let mut buf = crate::buf::Interleaved::<f32>::with_topology(2, 4);

    let mut it = buf.iter_channels_mut();

    for (c, f) in it.next().unwrap().iter_mut().zip(&[1.0, 2.0, 3.0, 4.0]) {
        *c = *f;
    }

    for (c, f) in it.next().unwrap().iter_mut().zip(&[5.0, 6.0, 7.0, 8.0]) {
        *c = *f;
    }

    let channels = buf.iter_channels().collect::<Vec<_>>();
    let left = channels[0].iter().collect::<Vec<_>>();
    let right = channels[1].iter().collect::<Vec<_>>();
    let left2 = channels[0].iter().collect::<Vec<_>>();
    let right2 = channels[1].iter().collect::<Vec<_>>();

    assert_eq!(left, &[1.0, 2.0, 3.0, 4.0]);
    assert_eq!(right, &[5.0, 6.0, 7.0, 8.0]);
    assert_eq!(left2, &[1.0, 2.0, 3.0, 4.0]);
    assert_eq!(right2, &[5.0, 6.0, 7.0, 8.0]);
}

#[test]
fn test_iter_mut() {
    let mut buf = crate::buf::Interleaved::<f32>::with_topology(2, 4);

    let mut it = buf.iter_channels_mut();

    for (c, f) in it.next().unwrap().iter_mut().zip(&[1.0, 2.0, 3.0, 4.0]) {
        *c = *f;
    }

    for (c, f) in it.next().unwrap().iter_mut().zip(&[5.0, 6.0, 7.0, 8.0]) {
        *c = *f;
    }

    let mut it = buf.iter_channels_mut();

    let mut left = it.next().unwrap();
    let mut right = it.next().unwrap();

    let left = left.iter_mut().collect::<Vec<_>>();
    let right = right.iter_mut().collect::<Vec<_>>();

    assert_eq!(left, &[&mut 1.0, &mut 2.0, &mut 3.0, &mut 4.0]);
    assert_eq!(right, &[&mut 5.0, &mut 6.0, &mut 7.0, &mut 8.0]);
}

#[test]
fn test_resize() {
    let mut buf = crate::buf::Interleaved::<f32>::new();

    assert_eq!(buf.channels(), 0);
    assert_eq!(buf.frames(), 0);

    buf.resize_channels(4);
    buf.resize_frames(256);

    assert_eq!(buf.channels(), 4);
    assert_eq!(buf.frames(), 256);

    {
        let mut chan = buf.get_mut(1).unwrap();

        assert_eq!(chan.get(127), Some(0.0));
        *chan.get_mut(127).unwrap() = 42.0;
        assert_eq!(chan.get(127), Some(42.0));
    }

    buf.resize_frames(128);
    assert_eq!(buf.sample(1, 127), Some(42.0));

    buf.resize_frames(256);
    assert_eq!(buf.sample(1, 127), Some(42.0));

    buf.resize_channels(2);
    assert_eq!(buf.sample(1, 127), Some(42.0));

    buf.resize_frames(64);
    assert_eq!(buf.sample(1, 127), None);
}

// Miri: Grabbing a mutable pointer out of a slice has many potential issues.
// This tests basic soundness of the process.

#[test]
fn test_as_interleaved_mut_ptr() {
    use std::ptr;

    unsafe fn fill_with_ones(buf: ptr::NonNull<i16>, len: usize) -> (usize, usize) {
        let buf = std::slice::from_raw_parts_mut(buf.as_ptr(), len);

        for (o, b) in buf.iter_mut().zip(std::iter::repeat(1)) {
            *o = b;
        }

        (2, len / 2)
    }

    fn test(mut buf: impl ResizableBuf + InterleavedBufMut<Sample = i16>) {
        assert!(buf.try_reserve(16));
        // Note: call fills the buf with ones.
        // Safety: We've initialized exactly 16 frames before calling this
        // function.
        let (channels, frames) = unsafe { fill_with_ones(buf.as_interleaved_mut_ptr(), 16) };
        buf.resize_topology(channels, frames);
    }

    let mut buf = crate::buf::Interleaved::new();
    test(&mut buf);

    assert_eq! {
        buf.get_channel(0).unwrap().iter().collect::<Vec<_>>(),
        &[1, 1, 1, 1, 1, 1, 1, 1],
    };
    assert_eq! {
        buf.get_channel(1).unwrap().iter().collect::<Vec<_>>(),
        &[1, 1, 1, 1, 1, 1, 1, 1],
    };
}