diff --git a/src/BlockFile.cpp b/src/BlockFile.cpp
index aaa2a5c24..12c051163 100644
--- a/src/BlockFile.cpp
+++ b/src/BlockFile.cpp
@@ -213,6 +213,16 @@ void *BlockFile::CalcSummary(samplePtr buffer, sampleCount len,
    CopySamples(buffer, format,
                (samplePtr)fbuffer, floatSample, len);
 
+   CalcSummaryFromBuffer(fbuffer, len, summary256, summary64K);
+
+   delete[] fbuffer;
+
+   return fullSummary.get();
+}
+
+void BlockFile::CalcSummaryFromBuffer(const float *fbuffer, sampleCount len,
+                                      float *summary256, float *summary64K)
+{
    sampleCount sumLen;
    sampleCount i, j, jcount;
 
@@ -306,10 +316,6 @@ void *BlockFile::CalcSummary(samplePtr buffer, sampleCount len,
 
    mMin = min;
    mMax = max;
-
-   delete[] fbuffer;
-
-   return fullSummary.get();
 }
 
 static void ComputeMinMax256(float *summary256,
diff --git a/src/BlockFile.h b/src/BlockFile.h
index 3fbaf53c2..a9f17dca1 100644
--- a/src/BlockFile.h
+++ b/src/BlockFile.h
@@ -167,10 +167,15 @@ class PROFILE_DLL_API BlockFile /* not final, abstract */ {
 
  protected:
    /// Calculate summary data for the given sample data
+   /// Overrides have differing details of memory management
    virtual void *CalcSummary(samplePtr buffer, sampleCount len,
                              sampleFormat format,
                              // This gets filled, if the caller needs to deallocate.  Else it is null.
                              ArrayOf<char> &cleanup);
+   // Common, nonvirtual calculation routine for the use of the above
+   void CalcSummaryFromBuffer(const float *fbuffer, sampleCount len,
+                              float *summary256, float *summary64K);
+
    /// Read the summary section of the file.  Derived classes implement.
    virtual bool ReadSummary(void *data) = 0;
 
diff --git a/src/blockfile/ODDecodeBlockFile.cpp b/src/blockfile/ODDecodeBlockFile.cpp
index 4626118ab..d25066cda 100644
--- a/src/blockfile/ODDecodeBlockFile.cpp
+++ b/src/blockfile/ODDecodeBlockFile.cpp
@@ -415,95 +415,8 @@ void *ODDecodeBlockFile::CalcSummary(samplePtr buffer, sampleCount len,
       CopySamples(buffer, format,
                (samplePtr)fbuffer, floatSample, len);
    }
-   sampleCount sumLen;
-   sampleCount i, j, jcount;
-
-   float min, max;
-   float sumsq;
-
-   // Recalc 256 summaries
-   sumLen = (len + 255) / 256;
-
-
-   for (i = 0; i < sumLen; i++) {
-      min = fbuffer[i * 256];
-      max = fbuffer[i * 256];
-      sumsq = ((float)min) * ((float)min);
-      jcount = 256;
-      if (i * 256 + jcount > len)
-         jcount = len - i * 256;
-      for (j = 1; j < jcount; j++) {
-         float f1 = fbuffer[i * 256 + j];
-         sumsq += ((float)f1) * ((float)f1);
-         if (f1 < min)
-            min = f1;
-         else if (f1 > max)
-            max = f1;
-      }
-
-      float rms = (float)sqrt(sumsq / jcount);
-
-      summary256[i * 3] = min;
-      summary256[i * 3 + 1] = max;
-      summary256[i * 3 + 2] = rms;
-   }
-
-   for (i = sumLen; i < mSummaryInfo.frames256; i++) {
-      // filling in the remaining bits with non-harming/contributing values
-      summary256[i * 3] = FLT_MAX;  // min
-      summary256[i * 3 + 1] = -FLT_MAX;   // max
-      summary256[i * 3 + 2] = 0.0f; // rms
-   }
-
-   // Recalc 64K summaries
-   sumLen = (len + 65535) / 65536;
-
-   for (i = 0; i < sumLen; i++) {
-      min = summary256[3 * i * 256];
-      max = summary256[3 * i * 256 + 1];
-      sumsq = (float)summary256[3 * i * 256 + 2];
-      sumsq *= sumsq;
-
-      for (j = 1; j < 256; j++) {
-         if (summary256[3 * (i * 256 + j)] < min)
-            min = summary256[3 * (i * 256 + j)];
-         if (summary256[3 * (i * 256 + j) + 1] > max)
-            max = summary256[3 * (i * 256 + j) + 1];
-         float r1 = summary256[3 * (i * 256 + j) + 2];
-         sumsq += r1*r1;
-      }
-
-      float rms = (float)sqrt(sumsq / 256);
-
-      summary64K[i * 3] = min;
-      summary64K[i * 3 + 1] = max;
-      summary64K[i * 3 + 2] = rms;
-   }
-   for (i = sumLen; i < mSummaryInfo.frames64K; i++) {
-      summary64K[i * 3] = 0.0f;
-      summary64K[i * 3 + 1] = 0.0f;
-      summary64K[i * 3 + 2] = 0.0f;
-   }
-
-   // Recalc block-level summary
-   min = summary64K[0];
-   max = summary64K[1];
-   sumsq = (float)summary64K[2];
-   sumsq *= sumsq;
-
-   for (i = 1; i < sumLen; i++) {
-      if (summary64K[3*i] < min)
-         min = summary64K[3*i];
-      else if (summary64K[3*i+1] > max)
-         max = summary64K[3*i+1];
-      float r1 = (float)summary64K[3*i+2];
-      sumsq += (r1*r1);
-   }
-
-   mMin = min;
-   mMax = max;
-   mRMS = sqrt(sumsq / sumLen);
 
+   BlockFile::CalcSummaryFromBuffer(fbuffer, len, summary256, summary64K);
 
    //if we've used the float sample..
    if(format!=floatSample)
diff --git a/src/blockfile/ODPCMAliasBlockFile.cpp b/src/blockfile/ODPCMAliasBlockFile.cpp
index b548da2e1..f88ba4ea4 100644
--- a/src/blockfile/ODPCMAliasBlockFile.cpp
+++ b/src/blockfile/ODPCMAliasBlockFile.cpp
@@ -482,95 +482,8 @@ void *ODPCMAliasBlockFile::CalcSummary(samplePtr buffer, sampleCount len,
       CopySamples(buffer, format,
                (samplePtr)fbuffer, floatSample, len);
    }
-   sampleCount sumLen;
-   sampleCount i, j, jcount;
-
-   float min, max;
-   float sumsq;
-
-   // Recalc 256 summaries
-   sumLen = (len + 255) / 256;
-
-
-   for (i = 0; i < sumLen; i++) {
-      min = fbuffer[i * 256];
-      max = fbuffer[i * 256];
-      sumsq = ((float)min) * ((float)min);
-      jcount = 256;
-      if (i * 256 + jcount > len)
-         jcount = len - i * 256;
-      for (j = 1; j < jcount; j++) {
-         float f1 = fbuffer[i * 256 + j];
-         sumsq += ((float)f1) * ((float)f1);
-         if (f1 < min)
-            min = f1;
-         else if (f1 > max)
-            max = f1;
-      }
-
-      float rms = (float)sqrt(sumsq / jcount);
-
-      summary256[i * 3] = min;
-      summary256[i * 3 + 1] = max;
-      summary256[i * 3 + 2] = rms;
-   }
-
-   for (i = sumLen; i < mSummaryInfo.frames256; i++) {
-      // filling in the remaining bits with non-harming/contributing values
-      summary256[i * 3] = FLT_MAX;  // min
-      summary256[i * 3 + 1] = -FLT_MAX;   // max
-      summary256[i * 3 + 2] = 0.0f; // rms
-   }
-
-   // Recalc 64K summaries
-   sumLen = (len + 65535) / 65536;
-
-   for (i = 0; i < sumLen; i++) {
-      min = summary256[3 * i * 256];
-      max = summary256[3 * i * 256 + 1];
-      sumsq = (float)summary256[3 * i * 256 + 2];
-      sumsq *= sumsq;
-
-      for (j = 1; j < 256; j++) {
-         if (summary256[3 * (i * 256 + j)] < min)
-            min = summary256[3 * (i * 256 + j)];
-         if (summary256[3 * (i * 256 + j) + 1] > max)
-            max = summary256[3 * (i * 256 + j) + 1];
-         float r1 = summary256[3 * (i * 256 + j) + 2];
-         sumsq += r1*r1;
-      }
-
-      float rms = (float)sqrt(sumsq / 256);
-
-      summary64K[i * 3] = min;
-      summary64K[i * 3 + 1] = max;
-      summary64K[i * 3 + 2] = rms;
-   }
-   for (i = sumLen; i < mSummaryInfo.frames64K; i++) {
-      summary64K[i * 3] = 0.0f;
-      summary64K[i * 3 + 1] = 0.0f;
-      summary64K[i * 3 + 2] = 0.0f;
-   }
-
-   // Recalc block-level summary
-   min = summary64K[0];
-   max = summary64K[1];
-   sumsq = (float)summary64K[2];
-   sumsq *= sumsq;
-
-   for (i = 1; i < sumLen; i++) {
-      if (summary64K[3*i] < min)
-         min = summary64K[3*i];
-      if (summary64K[3*i+1] > max)
-         max = summary64K[3*i+1];
-      float r1 = (float)summary64K[3*i+2];
-      sumsq += (r1*r1);
-   }
-
-   mMin = min;
-   mMax = max;
-   mRMS = sqrt(sumsq / sumLen);
 
+   BlockFile::CalcSummaryFromBuffer(fbuffer, len, summary256, summary64K);
 
    //if we've used the float sample..
    if(format!=floatSample)