Fix memory corruption: wrong size of HPFBuffer.

2 files changed, 8 insertions, 9 deletions

diff --git a/src/transient_detector.cpp b/src/transient_detector.cpp
index fb46aad..43897d6 100644
--- a/src/transient_detector.cpp
+++ b/src/transient_detector.cpp
@@ -13,25 +13,23 @@ static double calculateRMS(const double* in, uint32_t n) {
 }
 
 void TTransientDetector::HPFilter(const double* in, double* out) {
-    const uint32_t firLen = 21;
     static const double fircoef[] = {
         -8.65163e-18 * 2.0, -0.00851586 * 2.0, -6.74764e-18 * 2.0, 0.0209036 * 2.0,
         -3.36639e-17 * 2.0, -0.0438162 * 2.0, -1.54175e-17 * 2.0, 0.0931738 * 2.0,
         -5.52212e-17 * 2.0, -0.313819 * 2.0
     };
-    const uint32_t x = prevBufSz;
-    memcpy(HPFBuffer.data() + x, in, BlockSz * sizeof(double));
+    memcpy(HPFBuffer.data() + PrevBufSz, in, BlockSz * sizeof(double));
     const double* inBuf = HPFBuffer.data();
     for (int i = 0; i < BlockSz; ++i) {
         double s = inBuf[i + 10];
         double s2 = 0;
-        for (int j = 0; j < ((firLen - 1) / 2) - 1 ; j += 2) {
-            s += fircoef[j] * (inBuf[i + j] + inBuf[i + firLen - j]);
-            s2 += fircoef[j + 1] * (inBuf[i + j + 1] + inBuf[i + firLen - j - 1]);
+        for (int j = 0; j < ((FIRLen - 1) / 2) - 1 ; j += 2) {
+            s += fircoef[j] * (inBuf[i + j] + inBuf[i + FIRLen - j]);
+            s2 += fircoef[j + 1] * (inBuf[i + j + 1] + inBuf[i + FIRLen - j - 1]);
         }
         out[i] = (s + s2)/2;
     }
-    memcpy(HPFBuffer.data(), in + (BlockSz - x),  x * sizeof(double));
+    memcpy(HPFBuffer.data(), in + (BlockSz - PrevBufSz),  PrevBufSz * sizeof(double));
 }
 
 
diff --git a/src/transient_detector.h b/src/transient_detector.h
index 9e066d4..b3db6ba 100644
--- a/src/transient_detector.h
+++ b/src/transient_detector.h
@@ -8,7 +8,8 @@ class TTransientDetector {
     const uint32_t ShortSz;
     const uint32_t BlockSz;
     const uint32_t NShortBlocks;
-    static const uint32_t prevBufSz = 20;
+    static const uint32_t PrevBufSz = 20;
+    static const uint32_t FIRLen = 21;
     void HPFilter(const double* in, double* out);
     std::vector<double> HPFBuffer;
     double LastEnergy = 0.0;
@@ -18,7 +19,7 @@ public:
         , BlockSz(blockSz)
         , NShortBlocks(blockSz/shortSz)
     {
-        HPFBuffer.resize(BlockSz + prevBufSz); 
+        HPFBuffer.resize(BlockSz + FIRLen); 
     }
     bool Detect(const double* buf);
 };