Fixes for bugs 2534 and 1215

src/effects/ChangePitch.cpp

@@ -247,7 +247,7 @@ bool EffectChangePitch::Process()
       // eliminate the next line:
       mSemitones = m_dSemitonesChange;
 #endif
-      return EffectSoundTouch::ProcessWithTimeWarper(initer, warper);
+      return EffectSoundTouch::ProcessWithTimeWarper(initer, warper, true);
    }
 }
 

src/effects/ChangeTempo.cpp

@@ -217,7 +217,7 @@ bool EffectChangeTempo::Process()
       double mT1Dashed = mT0 + (mT1 - mT0)/(m_PercentChange/100.0 + 1.0);
       RegionTimeWarper warper{ mT0, mT1,
          std::make_unique<LinearTimeWarper>(mT0, mT0, mT1, mT1Dashed )  };
-      success = EffectSoundTouch::ProcessWithTimeWarper(initer, warper);
+      success = EffectSoundTouch::ProcessWithTimeWarper(initer, warper, false);
    }
 
    if(success)

src/effects/SoundTouchEffect.cpp

@@ -20,6 +20,7 @@ effect that uses SoundTouch to do its processing (ChangeTempo
 #include <math.h>
 
 #include "../LabelTrack.h"
+#include "../WaveClip.h"
 #include "../WaveTrack.h"
 #include "../NoteTrack.h"
 #include "TimeWarper.h"
@@ -67,7 +68,9 @@ bool EffectSoundTouch::ProcessNoteTrack(NoteTrack *nt, const TimeWarper &warper)
 }
 #endif
 
-bool EffectSoundTouch::ProcessWithTimeWarper(InitFunction initer, const TimeWarper &warper)
+bool EffectSoundTouch::ProcessWithTimeWarper(InitFunction initer,
+                                             const TimeWarper &warper,
+                                             bool preserveLength)
 {
    // Assumes that mSoundTouch has already been initialized
    // by the subclass for subclass-specific parameters. The
@@ -85,6 +88,7 @@ bool EffectSoundTouch::ProcessWithTimeWarper(InitFunction initer, const TimeWarp
    this->CopyInputTracks(true);
    bool bGoodResult = true;
 
+   mPreserveLength = preserveLength;
    mCurTrackNum = 0;
    m_maxNewLength = 0.0;
 
@@ -107,14 +111,9 @@ bool EffectSoundTouch::ProcessWithTimeWarper(InitFunction initer, const TimeWarp
          if (!leftTrack->GetSelected())
             return fallthrough();
 
-         //Get start and end times from track
-         mCurT0 = leftTrack->GetStartTime();
-         mCurT1 = leftTrack->GetEndTime();
-
-         //Set the current bounds to whichever left marker is
-         //greater and whichever right marker is less
-         mCurT0 = wxMax(mT0, mCurT0);
-         mCurT1 = wxMin(mT1, mCurT1);
+         //Get start and end times from selection
+         mCurT0 = mT0;
+         mCurT1 = mT1;
 
          // Process only if the right marker is to the right of the left marker
          if (mCurT1 > mCurT0) {
@@ -250,9 +249,8 @@ bool EffectSoundTouch::ProcessOne(WaveTrack *track,
       outputTrack->Flush();
    }
 
-   // Take the output track and insert it in place of the original
-   // sample data
-   track->ClearAndPaste(mCurT0, mCurT1, outputTrack.get(), false, true, &warper);
+   // Transfer output samples to the original
+   Finalize(track, outputTrack.get(), warper);
 
    double newLength = outputTrack->GetEndTime();
    m_maxNewLength = wxMax(m_maxNewLength, newLength);
@@ -345,12 +343,10 @@ bool EffectSoundTouch::ProcessStereo(
       outputRightTrack->Flush();
    }
 
-   // Take the output tracks and insert in place of the original
-   // sample data.
-   leftTrack->ClearAndPaste(
-      mCurT0, mCurT1, outputLeftTrack.get(), false, true, &warper);
-   rightTrack->ClearAndPaste(
-      mCurT0, mCurT1, outputRightTrack.get(), false, true, &warper);
+   // Transfer output samples to the original
+   Finalize(leftTrack, outputLeftTrack.get(), warper);
+   Finalize(rightTrack, outputRightTrack.get(), warper);
+
 
    // Track the longest result length
    double newLength = outputLeftTrack->GetEndTime();
@@ -384,4 +380,57 @@ bool EffectSoundTouch::ProcessStereoResults(const size_t outputCount,
    return true;
 }
 
+void EffectSoundTouch::Finalize(WaveTrack* orig, WaveTrack* out, const TimeWarper &warper)
+{
+   if (mPreserveLength) {
+      auto newLen = out->GetNumSamples();
+      auto oldLen = out->TimeToLongSamples(mCurT1) - out->TimeToLongSamples(mCurT0);
+
+      // Pad output track to original length since SoundTouch may remove samples
+      if (newLen < oldLen) {
+         out->InsertSilence(out->LongSamplesToTime(newLen - 1),
+                                 out->LongSamplesToTime(oldLen - newLen));
+      }
+      // Trim output track to original length since SoundTouch may add extra samples
+      else if (newLen > oldLen) {
+         out->Trim(0, out->LongSamplesToTime(oldLen));
+      }
+   }
+
+   // Silenced samples will be inserted in gaps between clips, so capture where these
+   // gaps are for later deletion
+   std::vector<std::pair<double, double>> gaps;
+   double last = 0.0;
+   auto clips = orig->SortedClipArray();
+   auto front = clips.front();
+   auto back = clips.back();
+   for (auto &clip : clips) {
+      auto st = clip->GetStartTime();
+      auto et = clip->GetEndTime();
+
+      if (st >= mCurT0 || et < mCurT1) {
+         if (mCurT0 < st && clip == front) {
+            gaps.push_back(std::make_pair(mCurT0, st));
+         }
+         if (mCurT1 > et && clip == back) {
+            gaps.push_back(std::make_pair(et, mCurT1));
+         }
+         if (last >= mCurT0) {
+            gaps.push_back(std::make_pair(last, st));
+         }
+      }
+      last = et;
+   }
+
+   // Take the output track and insert it in place of the original sample data
+   orig->ClearAndPaste(mCurT0, mCurT1, out, true, true, &warper);
+
+   // Finally, recreate the gaps
+   for (auto gap : gaps) {
+      auto st = orig->LongSamplesToTime(orig->TimeToLongSamples(gap.first));
+      auto et = orig->LongSamplesToTime(orig->TimeToLongSamples(gap.second));
+      orig->SplitDelete(warper.Warp(st), warper.Warp(et));
+   }
+}
+
 #endif // USE_SOUNDTOUCH

src/effects/SoundTouchEffect.h

@@ -49,7 +49,9 @@ protected:
    // Effect implementation
 
    using InitFunction = std::function< void(soundtouch::SoundTouch *soundtouch) >;
-   bool ProcessWithTimeWarper(InitFunction initer, const TimeWarper &warper);
+   bool ProcessWithTimeWarper(InitFunction initer,
+                              const TimeWarper &warper,
+                              bool preserveLength);
 
    std::unique_ptr<soundtouch::SoundTouch> mSoundTouch;
    double mCurT0;
@@ -69,6 +71,9 @@ private:
    bool ProcessStereoResults(const size_t outputCount,
                               WaveTrack* outputLeftTrack,
                               WaveTrack* outputRightTrack);
+   void Finalize(WaveTrack* orig, WaveTrack* out, const TimeWarper &warper);
+
+   bool   mPreserveLength;
 
    int    mCurTrackNum;