From 0c9111608de81c5bcd54e51ab91dd73496fc1795 Mon Sep 17 00:00:00 2001
From: Leland Lucius <github@homerow.net>
Date: Mon, 11 May 2015 10:51:53 -0500
Subject: [PATCH] Fix for bug #927

At least I'm pretty sure this addresses all of the example Peter
mentions.
---
 src/effects/Amplify.cpp | 26 ++++++++++++++++----------
 src/effects/Amplify.h   |  1 +
 2 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/src/effects/Amplify.cpp b/src/effects/Amplify.cpp
index 7a9377a7f..ae0ed6669 100644
--- a/src/effects/Amplify.cpp
+++ b/src/effects/Amplify.cpp
@@ -66,6 +66,7 @@ EffectAmplify::EffectAmplify()
    mRatio = powf(10.0f, mAmp / 20.0f);
    mCanClip = false;
    mPeak = 0.0f;
+   mTracksAnalyzed = false;
 }
 
 EffectAmplify::~EffectAmplify()
@@ -134,20 +135,25 @@ bool EffectAmplify::SetAutomationParameters(EffectAutomationParameters & parms)
 
 bool EffectAmplify::Init()
 {
-   mPeak = 0.0f;
-
-   SelectedTrackListOfKindIterator iter(Track::Wave, mTracks);
-
-   for (Track *t = iter.First(); t; t = iter.Next())
+   if (!mTracksAnalyzed)
    {
-      float min, max;
-      ((WaveTrack *)t)->GetMinMax(&min, &max, mT0, mT1);
-      float newpeak = (fabs(min) > fabs(max) ? fabs(min) : fabs(max));
+      mPeak = 0.0f;
 
-      if (newpeak > mPeak)
+      SelectedTrackListOfKindIterator iter(Track::Wave, mTracks);
+
+      for (Track *t = iter.First(); t; t = iter.Next())
       {
-         mPeak = newpeak;
+         float min, max;
+         ((WaveTrack *)t)->GetMinMax(&min, &max, mT0, mT1);
+         float newpeak = (fabs(min) > fabs(max) ? fabs(min) : fabs(max));
+
+         if (newpeak > mPeak)
+         {
+            mPeak = newpeak;
+         }
       }
+
+      mTracksAnalyzed = true;
    }
 
    return true;
diff --git a/src/effects/Amplify.h b/src/effects/Amplify.h
index e15dfbcba..9e8505530 100644
--- a/src/effects/Amplify.h
+++ b/src/effects/Amplify.h
@@ -68,6 +68,7 @@ private:
 
 private:
    float mPeak;
+   bool mTracksAnalyzed;
 
    float mRatio;
    float mAmp;