2 files changed, 13 insertions, 4 deletions
diff --git a/Userland/Applications/SoundPlayer/BarsVisualizationWidget.cpp b/Userland/Applications/SoundPlayer/BarsVisualizationWidget.cpp
index 2bfe9fb4e7..810cf783a5 100644
--- a/Userland/Applications/SoundPlayer/BarsVisualizationWidget.cpp
+++ b/Userland/Applications/SoundPlayer/BarsVisualizationWidget.cpp
@@ -7,6 +7,7 @@
 
 #include "BarsVisualizationWidget.h"
 #include <AK/Math.h>
+#include <AK/TypedTransfer.h>
 #include <LibDSP/FFT.h>
 #include <LibDSP/Window.h>
 #include <LibGUI/Event.h>
@@ -22,8 +23,14 @@ void BarsVisualizationWidget::render(GUI::PaintEvent& event, FixedArray<double>
     painter.add_clip_rect(event.rect());
     painter.fill_rect(frame_inner_rect(), Color::Black);
 
-    for (size_t i = 0; i < fft_size; i++)
-        m_fft_samples[i] = samples[i] * m_fft_window[i];
+    // First half of data is from previous iteration, second half is from now.
+    // This gives us fully overlapping windows, which result in more accurate and visually appealing STFT.
+    for (size_t i = 0; i < fft_size / 2; i++)
+        m_fft_samples[i] = m_previous_samples[i] * m_fft_window[i];
+    for (size_t i = 0; i < fft_size / 2; i++)
+        m_fft_samples[i + fft_size / 2] = samples[i] * m_fft_window[i + fft_size / 2];
+
+    AK::TypedTransfer<double>::copy(m_previous_samples.data(), samples.data(), samples.size());
 
     LibDSP::fft(m_fft_samples.span(), false);
 
@@ -74,7 +81,8 @@ BarsVisualizationWidget::BarsVisualizationWidget()
 
     m_fft_window = LibDSP::Window<double>::hann<fft_size>();
 
-    MUST(set_render_sample_count(fft_size));
+    // As we use full-overlapping windows, the passed-in data is only half the size of one FFT operation.
+    MUST(set_render_sample_count(fft_size / 2));
 }
 
 void BarsVisualizationWidget::context_menu_event(GUI::ContextMenuEvent& event)
diff --git a/Userland/Applications/SoundPlayer/BarsVisualizationWidget.h b/Userland/Applications/SoundPlayer/BarsVisualizationWidget.h
index ae44cc3253..d2bd539422 100644
--- a/Userland/Applications/SoundPlayer/BarsVisualizationWidget.h
+++ b/Userland/Applications/SoundPlayer/BarsVisualizationWidget.h
@@ -26,12 +26,13 @@ private:
     void render(GUI::PaintEvent&, FixedArray<double> const&) override;
     void context_menu_event(GUI::ContextMenuEvent& event) override;
 
-    static constexpr size_t fft_size = 256;
+    static constexpr size_t fft_size = 512;
     static constexpr size_t bar_count = 64;
     static constexpr size_t values_per_bar = (fft_size / 2) / bar_count;
 
     Array<Complex<double>, fft_size> m_fft_samples {};
     Array<double, fft_size> m_fft_window {};
+    Array<double, fft_size / 2> m_previous_samples {};
     Array<int, bar_count> m_gfx_falling_bars {};
     bool m_is_using_last;
     bool m_adjust_frequencies;