From bc5214b3e1b3afcc7c9430a75625ad9a41a8ea38 Mon Sep 17 00:00:00 2001
From: Daniel Hams <daniel.hams@gmail.com>
Date: Sun, 24 Apr 2011 19:54:25 +0800
Subject: [PATCH] Use Hann window function instead of Hamming (issue 48)

This helps to clear up spectral bleeding.

Signed-off-by: Alexander Kojevnikov <alexander@kojevnikov.com>
---
 src/spek-pipeline.vala | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/spek-pipeline.vala b/src/spek-pipeline.vala
index c6d66bb..d10f2b7 100644
--- a/src/spek-pipeline.vala
+++ b/src/spek-pipeline.vala
@@ -243,8 +243,11 @@ namespace Spek {
 						prev_head = head;
 						for (int i = 0; i < nfft; i++) {
 							float val = input[(input_size + head - nfft + i) % input_size];
+							// TODO: allow the user to chose the window function
 							// Hamming window.
-							val *= 0.53836f - 0.46164f * coss[i];
+//							val *= 0.53836f - 0.46164f * coss[i];
+							// Hann window.
+							val *= 0.5f * (1f - coss[i]);
 							fft.input[i] = val;
 						}
 						fft.execute ();