samplerate_rs/
converter_type.rs

1use crate::error::{Error, ErrorCode};
2use libsamplerate::*;
3use std::ffi::CStr;
4
5/// A converter type used to distinguish the interpolation function used by libsamplerate.
6/// Has a great impact on quality and performance.
7#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
8pub enum ConverterType {
9    SincBestQuality = SRC_SINC_BEST_QUALITY as isize,
10    SincMediumQuality = SRC_SINC_MEDIUM_QUALITY as isize,
11    SincFastest = SRC_SINC_FASTEST as isize,
12    ZeroOrderHold = SRC_ZERO_ORDER_HOLD as isize,
13    Linear = SRC_LINEAR as isize,
14}
15
16impl ConverterType {
17    /// Create a new `ConverterType` enum from the corresponding integer.
18    pub fn from_int(value: isize) -> Result<ConverterType, Error> {
19        match value {
20            0 => Ok(ConverterType::SincBestQuality),
21            1 => Ok(ConverterType::SincMediumQuality),
22            2 => Ok(ConverterType::SincFastest),
23            3 => Ok(ConverterType::ZeroOrderHold),
24            4 => Ok(ConverterType::Linear),
25            _ => Err(Error::from_code(ErrorCode::BadConverter)),
26        }
27    }
28
29    /// Return a human-readable name for this type of converter.
30    pub fn name(&self) -> &'static str {
31        unsafe { CStr::from_ptr(src_get_name(*self as i32)) }
32            .to_str()
33            .unwrap()
34    }
35
36    /// Return the human-readable description for this type of converter.
37    pub fn description(&self) -> &'static str {
38        unsafe { CStr::from_ptr(src_get_description(*self as i32)) }
39            .to_str()
40            .unwrap()
41    }
42}
43
44#[cfg(test)]
45mod tests {
46    use super::*;
47
48    #[test]
49    fn create_converter_type_from_int() {
50        assert_eq!(
51            ConverterType::from_int(0),
52            Ok(ConverterType::SincBestQuality)
53        );
54        assert_eq!(
55            ConverterType::from_int(1),
56            Ok(ConverterType::SincMediumQuality)
57        );
58        assert_eq!(ConverterType::from_int(2), Ok(ConverterType::SincFastest));
59        assert_eq!(ConverterType::from_int(3), Ok(ConverterType::ZeroOrderHold));
60        assert_eq!(ConverterType::from_int(4), Ok(ConverterType::Linear));
61        assert_eq!(
62            ConverterType::from_int(8),
63            Err(Error::from_code(ErrorCode::BadConverter))
64        );
65    }
66
67    #[test]
68    fn name() {
69        assert_eq!(
70            ConverterType::SincBestQuality.name(),
71            "Best Sinc Interpolator"
72        );
73        assert_eq!(
74            ConverterType::SincMediumQuality.name(),
75            "Medium Sinc Interpolator"
76        );
77        assert_eq!(
78            ConverterType::SincFastest.name(),
79            "Fastest Sinc Interpolator"
80        );
81        assert_eq!(ConverterType::ZeroOrderHold.name(), "ZOH Interpolator");
82        assert_eq!(ConverterType::Linear.name(), "Linear Interpolator");
83    }
84
85    #[test]
86    fn description() {
87        assert_eq!(
88            ConverterType::SincBestQuality.description(),
89            "Band limited sinc interpolation, best quality, 144dB SNR, 96% BW."
90        );
91        assert_eq!(
92            ConverterType::SincMediumQuality.description(),
93            "Band limited sinc interpolation, medium quality, 121dB SNR, 90% BW."
94        );
95        assert_eq!(
96            ConverterType::SincFastest.description(),
97            "Band limited sinc interpolation, fastest, 97dB SNR, 80% BW."
98        );
99        assert_eq!(
100            ConverterType::ZeroOrderHold.description(),
101            "Zero order hold interpolator, very fast, poor quality."
102        );
103        assert_eq!(
104            ConverterType::Linear.description(),
105            "Linear interpolator, very fast, poor quality."
106        );
107    }
108}
samplerate_rs/converter_type.rs

samplerate_rs/
converter_type.rs
