Merge pull request #51 from phip1611/dev

Release v1.3

.editorconfig

@@ -9,6 +9,10 @@ insert_final_newline = true
 indent_style = space
 indent_size = 4
 trim_trailing_whitespace = true
+max_line_length = 80
+
+[*.nix]
+indent_size = 2
 
 [*.yml]
 indent_size = 2

.github/workflows/rust.yml

@@ -14,7 +14,7 @@ jobs:
         rust:
           - stable
           - nightly
-          - 1.56.1
+          - 1.61.0 # MSRV
     steps:
       - uses: actions/checkout@v2
       # Important preparation step: override the latest default Rust version in GitHub CI
@@ -39,6 +39,9 @@ jobs:
       - run: cargo test --all-targets --no-default-features --features "microfft-complex"
       - run: cargo test --all-targets --no-default-features --features "microfft-real"
 
+      # run benchmark: right now, there is no reporting or so from the results
+      - run: cargo bench
+
       # test `no_std`-build with all features/fft implementations
       - run: rustup target add thumbv7em-none-eabihf
       - run: cargo check --target thumbv7em-none-eabihf --no-default-features --features "microfft-complex"
@@ -55,7 +58,7 @@ jobs:
     strategy:
       matrix:
         rust:
-          - stable
+          - 1.61.0 # MSRV
     steps:
       - uses: actions/checkout@v2
       # Important preparation step: override the latest default Rust version in GitHub CI

CHANGELOG.md

@@ -1,5 +1,20 @@
 # Changelog
 
+## 1.3.0 (2022-12-XX)
+- dependency updates
+- MSRV is now `1.61.0`
+- `FrequencySpectrum::apply_scaling_fn` now requires a reference to `&mut self`:
+  This is breaking but only for a small percentage of users. Performance is
+  slightly improved as less heap allocations are required.
+- `FrequencySpectrum` is now `Send` and interior mutability is dropped:
+  You can wrap the struct in a `Mutex` or similar types now!
+- `FrequencySpectrum::to_map` doesn't  has the `scaling_fn` parameter anymore.
+  This is breaking but only for a small percentage of users.
+- `FrequencySpectrum::to_mel_map` added for getting the spectrum in the
+  [mel](https://en.wikipedia.org/wiki/Mel_scale) scale.
+-
+- small internal code quality and performance improvements
+
 ## 1.2.6 (2022-07-20)
 - fixed wrong scaling in `scaling::divide_by_N_sqrt` (<https://github.com/phip1611/spectrum-analyzer/issues/41>)
 

Cargo.toml

@@ -1,10 +1,10 @@
 [package]
 name = "spectrum-analyzer"
 description = """
-A simple and fast `no_std` library to get the frequency spectrum of a digital signal (e.g. audio) using FFT.
-It follows the KISS principle and consists of simple building blocks/optional features.
+An easy to use and fast `no_std` library (with `alloc`) to get the frequency
+spectrum of a digital signal (e.g. audio) using FFT.
 """
-version = "1.2.6"
+version = "1.3.0"
 authors = ["Philipp Schuster <phip1611@gmail.com>"]
 edition = "2021"
 keywords = ["fft", "spectrum", "frequencies", "audio", "dsp"]
@@ -20,6 +20,10 @@ exclude = [
     ".github"
 ]
 
+[[bench]]
+name = "fft_spectrum_bench"
+harness = false
+
 [features]
 # by default we use microfft-real: it's the fastest and totally fit's our needs.
 # As of version 0.5.0 there is no advantage by using other implementations.
@@ -47,12 +51,14 @@ minimp3 = "0.5"
 # visualize spectrum in tests and examples
 audio-visualizer = "0.3"
 # get audio input in examples
-cpal = "0.13"
+cpal = "0.15.0"
 # audio data buffering
-ringbuffer = "0.8" # REQUIRES Rust Stable 1.55 because it uses "ringbuffer v0.8"
+ringbuffer = "0.12.0"
 rand = "0.8" # for benchmark
 # exit in examples
 ctrlc = "3.2"
+# for benchmark
+criterion = "0.4"
 
 
 # otherwise FFT and other code is too slow

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2021 Philipp Schuster
+Copyright (c) 2023 Philipp Schuster
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -1,25 +1,21 @@
 # Rust: library for frequency spectrum analysis using FFT
-A simple and fast `no_std` library to get the frequency spectrum of a digital signal (e.g. audio) using FFT.
-It follows the KISS principle and consists of simple building blocks/optional features. In short, this is 
-a convenient wrapper around several FFT implementations which you can choose from during compilation time
-via Cargo features.
+An easy to use and fast `no_std` library (with `alloc`) to get the frequency
+spectrum of a digital signal (e.g. audio) using FFT.
 
-**I'm not an expert on digital signal processing. Code contributions are highly welcome! 🙂**
-
-The **MSRV** (minimum supported Rust version) is 1.56.1 stable, because this crate uses
-Rust edition 2021.
+The **MSRV** (minimum supported Rust version) is `1.61.0`.
 
 ## I want to understand how FFT can be used to get a spectrum
 Please see file [/EDUCATIONAL.md](/EDUCATIONAL.md).
 
 ## How to use (including `no_std`-environments)
-Most tips and comments are located inside the code, so please check out the repository on
-Github! Anyway, the most basic usage looks like this:
+Most tips and comments are located inside the code, so please check out the
+repository on GitHub! Anyway, the most basic usage looks like this:
 
 ### FFT implementation as compile time configuration via Cargo features
-By default this crate uses the `real`-module from the great `microfft`-crate. It's the fastest implementation
-and as of version `v0.5.0` there should be no valid reason why you should ever change this. The multiple features
-are there mainly for educational reasons and to support me while programming/testing.
+By default, this crate uses the `real`-module from the great `microfft`-crate.
+It's the fastest implementation and as of version `v0.5.0` there should be no
+valid reason why you should ever change this. The multiple features are there
+mainly for educational reasons and to support me during programming/testing.
 
 ### Cargo.toml
 ```toml
@@ -68,7 +64,6 @@ fn main() {
 ## Performance
 *Measurements taken on i7-1165G7 @ 2.80GHz (Single-threaded) with optimized build*
 
-
 | Operation                                              | Time   |
 | ------------------------------------------------------ | ------:|
 | Hann Window with 4096 samples                          | ≈68µs  |
@@ -78,8 +73,8 @@ fn main() {
 | FFT (`microfft/complex`) to spectrum with 4096 samples | ≈250µs |
 
 ## Example Visualizations
-In the following examples you can see a basic visualization of the spectrum from `0 to 4000Hz` for 
-a layered signal of sine waves of `50`, `1000`, and `3777Hz` @ `44100Hz` sampling rate. The peaks for the 
+In the following examples you can see a basic visualization of the spectrum from `0 to 4000Hz` for
+a layered signal of sine waves of `50`, `1000`, and `3777Hz` @ `44100Hz` sampling rate. The peaks for the
 given frequencies are clearly visible. Each calculation was done with `2048` samples, i.e. ≈46ms of audio signal.
 
 **The noise (wrong peaks) also comes from clipping of the added sine waves!**
@@ -89,34 +84,38 @@ Peaks (50, 1000, 3777 Hz) are clearly visible but also some noise.
 ![Visualization of spectrum 0-4000Hz of layered sine signal (50, 1000, 3777 Hz)) with no window function.](res/spectrum_sine_waves_50_1000_3777hz--no-window.png "Peaks (50, 1000, 3777 Hz) are clearly visible but also some noise.")
 
 ### Spectrum with *Hann window function* on samples before FFT
-Peaks (50, 1000, 3777 Hz) are clearly visible and Hann window reduces noise a little bit. Because this example has few noise, you don't see much difference.
+Peaks (50, 1000, 3777 Hz) are clearly visible and Hann window reduces noise a
+little. Because this example has few noise, you don't see much difference.
 ![Visualization of spectrum 0-4000Hz of layered sine signal (50, 1000, 3777 Hz)) with Hann window function.](res/spectrum_sine_waves_50_1000_3777hz--hann-window.png "Peaks (50, 1000, 3777 Hz) are clearly visible and Hann window reduces noise a little bit. Because this example has few noise, you don't see much difference.")
 
 ### Spectrum with *Hamming window function* on samples before FFT
-Peaks (50, 1000, 3777 Hz) are clearly visible and Hamming window reduces noise a little bit. Because this example has few noise, you don't see much difference.
+Peaks (50, 1000, 3777 Hz) are clearly visible and Hamming window reduces noise a
+little. Because this example has few noise, you don't see much difference.
 ![Visualization of spectrum 0-4000Hz of layered sine signal (50, 1000, 3777 Hz)) with Hamming window function.](res/spectrum_sine_waves_50_1000_3777hz--hamming-window.png "Peaks (50, 1000, 3777 Hz) are clearly visible and Hamming window reduces noise a little bit. Because this example has few noise, you don't see much difference.")
 
 ## Live Audio + Spectrum Visualization
-Execute example `$ cargo run --release --example live-visualization`. It will show you
-how you can visualize audio data in realtime + the current spectrum.
+Execute example `$ cargo run --release --example live-visualization`. It will
+show you how you can visualize audio data in realtime + the current spectrum.
 
 ![Example visualization of real-time audio + spectrum analysis](res/live_demo_spectrum_green_day_holiday.gif "Example visualization of real-time audio + spectrum analysis")
 
 ## Building and Executing Tests
-To execute tests you need the package `libfreetype6-dev` (on Ubuntu/Debian). This is required because
-not all tests are "automatic unit tests" but also tests that you need to check visually, by looking at the
-generated diagram of the spectrum.
+To execute tests you need the package `libfreetype6-dev` (on Ubuntu/Debian).
+This is required because not all tests are "automatic unit tests" but also tests
+that you need to check visually, by looking at the generated diagram of the
+spectrum.
 
 ## Trivia / FAQ
 ### Why f64 and no f32?
-I tested f64 but the additional accuracy doesn't pay out the ~40% calculation overhead (on x86_64).
+I tested f64 but the additional accuracy doesn't pay out the ~40% calculation
+overhead (on x86_64).
 ### What can I do against the noise?
-Apply a window function, like Hann window or Hamming window. But I'm not an expert on this.
+Apply a window function, like Hann window or Hamming window.
 
 ## Good resources with more information
-- Interpreting FFT Results: https://www.gaussianwaves.com/2015/11/interpreting-fft-results-complex-dft-frequency-bins-and-fftshift/
-- FFT basic concepts: https://www.youtube.com/watch?v=z7X6jgFnB6Y
-- „The Fundamentals of FFT-Based Signal Analysis and Measurement“ https://www.sjsu.edu/people/burford.furman/docs/me120/FFT_tutorial_NI.pdf
-- Fast Fourier Transforms (FFTs) and Windowing: https://www.youtube.com/watch?v=dCeHOf4cJE0
+- Interpreting FFT Results: <https://www.gaussianwaves.com/2015/11/interpreting-fft-results-complex-dft-frequency-bins-and-fftshift/>
+- FFT basic concepts: <https://www.youtube.com/watch?v=z7X6jgFnB6Y>
+- „The Fundamentals of FFT-Based Signal Analysis and Measurement“ <https://www.sjsu.edu/people/burford.furman/docs/me120/FFT_tutorial_NI.pdf>
+- Fast Fourier Transforms (FFTs) and Windowing: <https://www.youtube.com/watch?v=dCeHOf4cJE0>
 
-Also check out my blog post! https://phip1611.de/2021/03/programmierung-und-skripte/frequency-spectrum-analysis-with-fft-in-rust/
+Also check out my [blog post](https://phip1611.de/2021/03/programmierung-und-skripte/frequency-spectrum-analysis-with-fft-in-rust/).

benches/fft_spectrum_bench.rs

@@ -0,0 +1,57 @@
+use criterion::{black_box, criterion_group, criterion_main, Criterion};
+use spectrum_analyzer::{
+    samples_fft_to_spectrum, scaling, windows, FrequencyLimit, FrequencySpectrum,
+};
+
+fn spectrum_without_scaling(samples: &[f32]) -> FrequencySpectrum {
+    samples_fft_to_spectrum(samples, 44100, FrequencyLimit::All, None).unwrap()
+}
+
+fn spectrum_with_scaling(samples: &[f32]) -> FrequencySpectrum {
+    samples_fft_to_spectrum(
+        samples,
+        44100,
+        FrequencyLimit::All,
+        Some(&scaling::divide_by_N_sqrt),
+    )
+    .unwrap()
+}
+
+fn spectrum_with_multiple_scaling(samples: &[f32]) -> FrequencySpectrum {
+    let mut spectrum = spectrum_with_scaling(samples);
+
+    let mut working_buffer = vec![(0.0.into(), 0.0.into()); spectrum.data().len()];
+
+    spectrum
+        .apply_scaling_fn(&scaling::divide_by_N_sqrt, &mut working_buffer)
+        .unwrap();
+    spectrum
+        .apply_scaling_fn(&scaling::divide_by_N_sqrt, &mut working_buffer)
+        .unwrap();
+    spectrum
+        .apply_scaling_fn(&scaling::divide_by_N_sqrt, &mut working_buffer)
+        .unwrap();
+    spectrum
+}
+
+fn criterion_benchmark(c: &mut Criterion) {
+    // create 2048 random samples
+    let samples = (0..2048)
+        .map(|_| rand::random::<i16>())
+        .map(|x| x as f32)
+        .collect::<Vec<_>>();
+    let hann_window = windows::hann_window(&samples);
+
+    c.bench_function("spectrum without scaling", |b| {
+        b.iter(|| spectrum_without_scaling(black_box(&hann_window)))
+    });
+    c.bench_function("spectrum with scaling", |b| {
+        b.iter(|| spectrum_without_scaling(black_box(&hann_window)))
+    });
+    c.bench_function("spectrum with multiple scaling steps", |b| {
+        b.iter(|| spectrum_with_multiple_scaling(black_box(&hann_window)))
+    });
+}
+
+criterion_group!(benches, criterion_benchmark);
+criterion_main!(benches);

check-build.sh

@@ -12,6 +12,8 @@ cargo test --all-targets --no-default-features --features "rustfft-complex"
 cargo test --all-targets --no-default-features --features "microfft-complex"
 cargo test --all-targets --no-default-features --features "microfft-real"
 
+cargo bench
+
 cargo fmt -- --check # (--check doesn't change the files)
 
 cargo doc

examples/bench.rs

@@ -1,7 +1,7 @@
 /*
 MIT License
 
-Copyright (c) 2021 Philipp Schuster
+Copyright (c) 2023 Philipp Schuster
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

examples/live-visualization.rs

@@ -1,7 +1,7 @@
 /*
 MIT License
 
-Copyright (c) 2021 Philipp Schuster
+Copyright (c) 2023 Philipp Schuster
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

examples/minimal.rs

@@ -1,7 +1,7 @@
 /*
 MIT License
 
-Copyright (c) 2021 Philipp Schuster
+Copyright (c) 2023 Philipp Schuster
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

examples/mp3-samples.rs

@@ -1,7 +1,7 @@
 /*
 MIT License
 
-Copyright (c) 2021 Philipp Schuster
+Copyright (c) 2023 Philipp Schuster
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
@@ -212,31 +212,31 @@ fn to_spectrum_and_plot(
     }*/
 
     spectrum_static_plotters_png_visualize(
-        &spectrum_no_window.to_map(None),
+        &spectrum_no_window.to_map(),
         TEST_OUT_DIR,
         &format!("{}--no-window.png", filename),
     );
 
     spectrum_static_plotters_png_visualize(
-        &spectrum_hamming_window.to_map(None),
+        &spectrum_hamming_window.to_map(),
         TEST_OUT_DIR,
         &format!("{}--hamming-window.png", filename),
     );
 
     spectrum_static_plotters_png_visualize(
-        &spectrum_hann_window.to_map(None),
+        &spectrum_hann_window.to_map(),
         TEST_OUT_DIR,
         &format!("{}--hann-window.png", filename),
     );
 
     spectrum_static_plotters_png_visualize(
-        &spectrum_blackman_harris_4term_window.to_map(None),
+        &spectrum_blackman_harris_4term_window.to_map(),
         TEST_OUT_DIR,
         &format!("{}--blackman-harris-4-term-window.png", filename),
     );
 
     spectrum_static_plotters_png_visualize(
-        &spectrum_blackman_harris_7term_window.to_map(None),
+        &spectrum_blackman_harris_7term_window.to_map(),
         TEST_OUT_DIR,
         &format!("{}--blackman-harris-7-term-window.png", filename),
     );

shell.nix

@@ -0,0 +1,16 @@
+{ pkgs ? import <nixpkgs> {} }:
+  pkgs.mkShell rec {
+    nativeBuildInputs = with pkgs; [
+      pkg-config
+    ];
+
+    buildInputs = with pkgs; [
+      alsa-lib
+      fontconfig
+      libxkbcommon
+      xorg.libXcursor
+      xorg.libX11
+    ];
+
+  LD_LIBRARY_PATH = "${pkgs.lib.makeLibraryPath buildInputs}";
+}

src/error.rs

@@ -1,7 +1,7 @@
 /*
 MIT License
 
-Copyright (c) 2021 Philipp Schuster
+Copyright (c) 2023 Philipp Schuster
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal