X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/146c201cbe67cf3967cb497b3d67fb579c3ccb0e..0d704c7f5e1ddcf2a4e18f9f5759e6779a30119a:/client/data_operations.c

diff --git a/client/data_operations.c b/client/data_operations.c
new file mode 100644
index 00000000..f694600c
--- /dev/null
+++ b/client/data_operations.c
@@ -0,0 +1,58 @@
+#include <data_operations.h>
+
+extern void PrintAndLog(char *fmt, ...);
+
+int autoCorr(const int* in, int *out, size_t len, int window)
+{
+	static int CorrelBuffer[MAX_GRAPH_TRACE_LEN];
+
+	if (window == 0) {
+		PrintAndLog("needs a window");
+		return 0;
+	}
+	if (window >= len) {
+		PrintAndLog("window must be smaller than trace (%d samples)",
+		len);
+		return 0;
+	}
+
+	PrintAndLog("performing %d correlations", len - window);
+
+	for (int i = 0; i < len - window; ++i) {
+		int sum = 0;
+		for (int j = 0; j < window; ++j) {
+			sum += (in[j]*in[i + j]) / 256;
+		}
+		CorrelBuffer[i] = sum;
+	}
+	//GraphTraceLen = GraphTraceLen - window;
+	memcpy(out, CorrelBuffer, len * sizeof (int));
+	return 0;
+}
+int directionalThreshold(const int* in, int *out, size_t len, int8_t up, int8_t down)
+{
+	int lastValue = in[0];
+	out[0] = 0; // Will be changed at the end, but init 0 as we adjust to last samples value if no threshold kicks in.
+
+	for (int i = 1; i < len; ++i) {
+		// Apply first threshold to samples heading up
+		if (in[i] >= up && in[i] > lastValue)
+		{
+			lastValue = out[i]; // Buffer last value as we overwrite it.
+			out[i] = 1;
+		}
+		// Apply second threshold to samples heading down
+		else if (in[i] <= down && in[i] < lastValue)
+		{
+			lastValue = out[i]; // Buffer last value as we overwrite it.
+			out[i] = -1;
+		}
+		else
+		{
+			lastValue = out[i]; // Buffer last value as we overwrite it.
+			out[i] = out[i-1];
+		}
+	}
+	out[0] = out[1]; // Align with first edited sample.
+	return 0;
+}