# HG changeset patch
# User Chris Cannam
# Date 1400167332 -3600
# Node ID d72c054fc8bf3a4cf30d54cd7791772cd4c5130c
# Parent  b218e23622462d706200ab2ae34fcd618f1878cd
Limit white noise to +/-0.5

diff -r b218e2362246 -r d72c054fc8bf src/may/stream/syntheticstream.yeti
--- a/src/may/stream/syntheticstream.yeti	Tue May 13 16:42:07 2014 +0100
+++ b/src/may/stream/syntheticstream.yeti	Thu May 15 16:22:12 2014 +0100
@@ -43,8 +43,20 @@
         result);
     generated sampleRate generator);
 
+/**
+ * Generate a white noise stream with a maximum amplitude of 0.5.
+ * 
+ * This is limited to 0.5 rather than 1.0 to help avoid
+ * situations in which subsequent processing causes hard-to-spot
+ * clipping. For example, filtering noise to limit its bandwidth
+ * may increase the levels of some samples: if you do this naively
+ * and then export the result to an audio file, it will clip and
+ * the resulting noise will be neither correctly distributed nor
+ * band-limited. But because individual samples are random, it's
+ * very easy to miss what is happening.
+ */
 whiteNoise sampleRate =
-    generated sampleRate \((Math#random() * 2.0) - 1.0);
+    generated sampleRate \((Math#random() * 1.0) - 0.5);
 
 silent sampleRate =
     generated sampleRate \0;