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Merged
wizenink merged 2 commits into from
Dec 21, 2025
Merged

Only check whether fft is power of two when not using rustfft-backend #19

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81cf44f
Only check fft is power of two when not using rustfft-backend
danny900714 Dec 21, 2025
fc3dd1e
Add some tests for microfft
wizenink Dec 21, 2025
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8 changes: 4 additions & 4 deletions src/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -157,7 +157,7 @@ impl<T: Float + FromPrimitive + fmt::Debug> StftConfig<T> {
window: WindowType,
reconstruction_mode: ReconstructionMode,
) -> Result<Self, ConfigError<T>> {
if fft_size == 0 || !fft_size.is_power_of_two() {
if fft_size == 0 || !(cfg!(feature = "rustfft-backend") || fft_size.is_power_of_two()) {
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@gemini-code-assist gemini-code-assist bot Dec 21, 2025

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medium

While logically correct, this condition can be made more readable. By applying De Morgan's law, you can express the logic without negating a grouped expression, which is often easier to reason about. The rewritten form !cfg!(feature = "rustfft-backend") && !fft_size.is_power_of_two() makes it immediately clear that the power-of-two constraint applies only when not using the rustfft-backend.

Suggested change
if fft_size == 0 || !(cfg!(feature = "rustfft-backend") || fft_size.is_power_of_two()) {
if fft_size == 0 || !cfg!(feature = "rustfft-backend") && !fft_size.is_power_of_two() {

return Err(ConfigError::InvalidFftSize);
}
if hop_size == 0 || hop_size > fft_size {
Expand Down Expand Up @@ -361,21 +361,21 @@ fn generate_window<T: Float + FromPrimitive>(window_type: WindowType, size: usiz
let half = T::from(0.5).unwrap();
let one = T::one();
let i_t = T::from(i).unwrap();
let size_t = T::from(size).unwrap(); // Use N, not N-1 for periodic window
let size_t = T::from(size).unwrap(); // Use N, not N-1 for periodic window
half * (one - (two * pi * i_t / size_t).cos())
})
.collect(),
WindowType::Hamming => (0..size)
.map(|i| {
let i_t = T::from(i).unwrap();
let size_t = T::from(size).unwrap(); // Use N, not N-1 for periodic window
let size_t = T::from(size).unwrap(); // Use N, not N-1 for periodic window
T::from(0.54).unwrap() - T::from(0.46).unwrap() * (two * pi * i_t / size_t).cos()
})
.collect(),
WindowType::Blackman => (0..size)
.map(|i| {
let i_t = T::from(i).unwrap();
let size_t = T::from(size).unwrap(); // Use N, not N-1 for periodic window
let size_t = T::from(size).unwrap(); // Use N, not N-1 for periodic window
let angle = two * pi * i_t / size_t;
T::from(0.42).unwrap() - T::from(0.5).unwrap() * angle.cos()
+ T::from(0.08).unwrap() * (two * angle).cos()
Expand Down
34 changes: 25 additions & 9 deletions tests/config_tests.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -21,21 +21,30 @@ fn test_config_invalid_ola() {
assert!(config.is_err())
}

#[cfg(not(feature = "rustfft-backend"))]
#[test]
#[allow(deprecated)]
fn test_config_invalid_fft_size() {
let config = StftConfig::<f32>::new(4095, 1024, WindowType::Hann, ReconstructionMode::Ola);
assert!(matches!(config, Err(_)));
assert!(config.is_err());
}

#[cfg(feature = "rustfft-backend")]
#[test]
#[allow(deprecated)]
fn test_config_fft_size_not_power_of_two() {
let config = StftConfig::<f32>::new(4095, 1024, WindowType::Hann, ReconstructionMode::Ola);
assert!(config.is_ok());
}

#[test]
#[allow(deprecated)]
fn test_config_invalid_hop_size() {
let config = StftConfig::<f32>::new(4096, 0, WindowType::Hann, ReconstructionMode::Ola);
assert!(matches!(config, Err(_)));
assert!(config.is_err());

let config = StftConfig::<f32>::new(4096, 5000, WindowType::Hann, ReconstructionMode::Ola);
assert!(matches!(config, Err(_)));
assert!(config.is_err());
}

// Builder pattern tests
Expand Down Expand Up @@ -75,20 +84,17 @@ fn test_builder_with_reconstruction_mode() {

#[test]
fn test_builder_missing_fft_size() {
let config = StftConfig::<f32>::builder()
.hop_size(1024)
.build();
let config = StftConfig::<f32>::builder().hop_size(1024).build();
assert!(config.is_err());
}

#[test]
fn test_builder_missing_hop_size() {
let config = StftConfig::<f32>::builder()
.fft_size(4096)
.build();
let config = StftConfig::<f32>::builder().fft_size(4096).build();
assert!(config.is_err());
}

#[cfg(not(feature = "rustfft-backend"))]
#[test]
fn test_builder_invalid_fft_size() {
let config = StftConfig::<f32>::builder()
Expand All @@ -98,6 +104,16 @@ fn test_builder_invalid_fft_size() {
assert!(config.is_err());
}

#[cfg(feature = "rustfft-backend")]
#[test]
fn test_builder_fft_size_not_power_of_two() {
let config = StftConfig::<f32>::builder()
.fft_size(4095) // Not a power of 2
.hop_size(1024)
.build();
assert!(config.is_ok());
}

#[test]
fn test_builder_invalid_hop_size() {
let config = StftConfig::<f32>::builder()
Expand Down