cvs.zerfleddert.de Git - proxmark3-svn/blob - client/data_operations.c

   1 #include <data_operations.h>
   2
   3 extern void PrintAndLog(char *fmt, ...);
   4
   5 int autoCorr(const int* in, int *out, size_t len, int window)
   6 {
   7         static int CorrelBuffer[MAX_GRAPH_TRACE_LEN];
   8
   9         if (window == 0) {
  10                 PrintAndLog("needs a window");
  11                 return 0;
  12         }
  13         if (window >= len) {
  14                 PrintAndLog("window must be smaller than trace (%d samples)",
  15                 len);
  16                 return 0;
  17         }
  18
  19         PrintAndLog("performing %d correlations", len - window);
  20
  21         for (int i = 0; i < len - window; ++i) {
  22                 int sum = 0;
  23                 for (int j = 0; j < window; ++j) {
  24                         sum += (in[j]*in[i + j]) / 256;
  25                 }
  26                 CorrelBuffer[i] = sum;
  27         }
  28         //GraphTraceLen = GraphTraceLen - window;
  29         memcpy(out, CorrelBuffer, len * sizeof (int));
  30         return 0;
  31 }
  32 int directionalThreshold(const int* in, int *out, size_t len, int8_t up, int8_t down)
  33 {
  34         int lastValue = in[0];
  35         out[0] = 0; // Will be changed at the end, but init 0 as we adjust to last samples value if no threshold kicks in.
  36
  37         for (int i = 1; i < len; ++i) {
  38                 // Apply first threshold to samples heading up
  39                 if (in[i] >= up && in[i] > lastValue)
  40                 {
  41                         lastValue = out[i]; // Buffer last value as we overwrite it.
  42                         out[i] = 1;
  43                 }
  44                 // Apply second threshold to samples heading down
  45                 else if (in[i] <= down && in[i] < lastValue)
  46                 {
  47                         lastValue = out[i]; // Buffer last value as we overwrite it.
  48                         out[i] = -1;
  49                 }
  50                 else
  51                 {
  52                         lastValue = out[i]; // Buffer last value as we overwrite it.
  53                         out[i] = out[i-1];
  54                 }
  55         }
  56         out[0] = out[1]; // Align with first edited sample.
  57         return 0;
  58 }