From ad4f87e0ebfd361c69c7ba9adc29292305f21f7c Mon Sep 17 00:00:00 2001 From: skal Date: Tue, 27 Jan 2026 22:16:23 +0100 Subject: feat(audio): Implement real-time spectrogram synthesizer Adds a multi-voice, real-time audio synthesis engine that generates sound from spectrogram data using an Inverse Discrete Cosine Transform (IDCT). Key features: - A thread-safe, double-buffered system for dynamically updating spectrograms in real-time without interrupting audio playback. - Core DSP components: FDCT, IDCT, and Hamming window functions. - A simple sequencer in the main loop to demonstrate scripted audio events and dynamic updates. - Unit tests for the new synth engine and Hamming window, integrated with CTest. - A file documenting the build process, features, and how to run tests. --- src/tests/test_window.cpp | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) create mode 100644 src/tests/test_window.cpp (limited to 'src/tests/test_window.cpp') diff --git a/src/tests/test_window.cpp b/src/tests/test_window.cpp new file mode 100644 index 0000000..1667dab --- /dev/null +++ b/src/tests/test_window.cpp @@ -0,0 +1,34 @@ +#include "audio/window.h" +#include +#include +#include + +// A simple floating point comparison with a tolerance +bool is_close(float a, float b, float epsilon = 1e-6f) { + return fabsf(a - b) < epsilon; +} + +int main() { + float window[WINDOW_SIZE]; + hamming_window_512(window); + + // Test 1: Window should start and end at the same small value + assert(is_close(window[0], 0.08f)); + assert(is_close(window[WINDOW_SIZE - 1], 0.08f)); + printf("Test 1 passed: Window start and end values are correct.\n"); + + // Test 2: Window should be symmetric + for (int i = 0; i < WINDOW_SIZE / 2; ++i) { + assert(is_close(window[i], window[WINDOW_SIZE - 1 - i])); + } + printf("Test 2 passed: Window is symmetric.\n"); + + // Test 3: The two middle points of the even-sized window should be equal and the peak. + assert(is_close(window[WINDOW_SIZE / 2 - 1], window[WINDOW_SIZE / 2])); + assert(window[WINDOW_SIZE / 2] > window[WINDOW_SIZE / 2 - 2]); // Should be greater than neighbors + printf("Test 3 passed: Window peak is correct for even size.\n"); + + printf("All tests passed for Hamming window!\n"); + + return 0; +} -- cgit v1.2.3