From de53f6475726807c2fd6cb8da7ef7feaf9a822a7 Mon Sep 17 00:00:00 2001
From: James Crook <james.k.crook@gmail.com>
Date: Sun, 25 Mar 2018 15:42:14 +0100
Subject: [PATCH] Bug 499 - Normalize includes white space in offset
 calculation

---
 src/WaveTrack.cpp         |  8 ++++++--
 src/WaveTrack.h           |  2 +-
 src/effects/Normalize.cpp | 12 +++++++++---
 3 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/src/WaveTrack.cpp b/src/WaveTrack.cpp
index 4f1aa8873..8fe26772f 100644
--- a/src/WaveTrack.cpp
+++ b/src/WaveTrack.cpp
@@ -1993,13 +1993,14 @@ float WaveTrack::GetRMS(double t0, double t1, bool mayThrow) const
 
 bool WaveTrack::Get(samplePtr buffer, sampleFormat format,
                     sampleCount start, size_t len, fillFormat fill,
-                    bool mayThrow) const
+                    bool mayThrow, sampleCount * pNumCopied) const
 {
    // Simple optimization: When this buffer is completely contained within one clip,
    // don't clear anything (because we won't have to). Otherwise, just clear
    // everything to be on the safe side.
    bool doClear = true;
    bool result = true;
+   sampleCount samplesCopied = 0;
    for (const auto &clip: mClips)
    {
       if (start >= clip->GetStartSample() && start+len <= clip->GetEndSample())
@@ -2062,9 +2063,12 @@ bool WaveTrack::Get(samplePtr buffer, sampleFormat format,
                            SAMPLE_SIZE(format)),
                format, inclipDelta, samplesToCopy.as_size_t(), mayThrow ))
             result = false;
+         else
+            samplesCopied += samplesToCopy;
       }
    }
-
+   if( pNumCopied )
+      *pNumCopied = samplesCopied;
    return result;
 }
 
diff --git a/src/WaveTrack.h b/src/WaveTrack.h
index 07afb95de..a2c93c2d4 100644
--- a/src/WaveTrack.h
+++ b/src/WaveTrack.h
@@ -253,7 +253,7 @@ private:
    ///
    bool Get(samplePtr buffer, sampleFormat format,
                    sampleCount start, size_t len,
-                   fillFormat fill = fillZero, bool mayThrow = true) const;
+                   fillFormat fill = fillZero, bool mayThrow = true, sampleCount * pNumCopied = nullptr) const;
    void Set(samplePtr buffer, sampleFormat format,
                    sampleCount start, size_t len);
 
diff --git a/src/effects/Normalize.cpp b/src/effects/Normalize.cpp
index 0c7ef6550..109bb1213 100644
--- a/src/effects/Normalize.cpp
+++ b/src/effects/Normalize.cpp
@@ -412,6 +412,9 @@ bool EffectNormalize::AnalyseDC(const WaveTrack * track, const wxString &msg,
    mSum = 0.0; // dc offset inits
    mCount = 0;
 
+   sampleCount blockSamples;
+   sampleCount totalSamples = 0;
+
    //Go through the track one buffer at a time. s counts which
    //sample the current buffer starts at.
    auto s = start;
@@ -424,7 +427,8 @@ bool EffectNormalize::AnalyseDC(const WaveTrack * track, const wxString &msg,
       );
 
       //Get the samples from the track and put them in the buffer
-      track->Get((samplePtr) buffer.get(), floatSample, s, block);
+      track->Get((samplePtr) buffer.get(), floatSample, s, block, fillZero, true, &blockSamples);
+      totalSamples += blockSamples;
 
       //Process the buffer.
       AnalyzeData(buffer.get(), block);
@@ -439,8 +443,10 @@ bool EffectNormalize::AnalyseDC(const WaveTrack * track, const wxString &msg,
          break;
       }
    }
-
-   offset = -mSum / mCount.as_double();  // calculate actual offset (amount that needs to be added on)
+   if( totalSamples > 0 )
+      offset = -mSum / totalSamples.as_double();  // calculate actual offset (amount that needs to be added on)
+   else
+      offset = 0.0;
 
    //Return true because the effect processing succeeded ... unless cancelled
    return rc;