CHG: minor LF adjustments.

[proxmark3-svn] / common / lfdemod.c

diff --git a/common/lfdemod.c b/common/lfdemod.c
index 439699c6266643bca9053527d0cd00f500d9abf3..7f8333ac1185420dc039ebfb334e6b404ac5e36d 100644 (file)
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -243,6 +243,7 @@ int Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *h
 
 //by marshmellow
 //demodulates strong heavily clipped samples
+//RETURN: num of errors.  if 0, is ok.
 int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low)
 {
        size_t bitCnt=0, smplCnt=0, errCnt=0;
@@ -386,25 +387,30 @@ int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr
 //by marshmellow
 //take 10 and 01 and manchester decode
 //run through 2 times and take least errCnt
-int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert){
+int manrawdecode(uint8_t *BitStream, size_t *size, uint8_t invert){
+
+       // sanity check
+       if (*size < 16) return -1;
+       
        int errCnt = 0, bestErr = 1000;
        uint16_t bitnum = 0, MaxBits = 512, bestRun = 0;
        size_t i, k;
-       if (*size < 16) return -1;
+
        //find correct start position [alignment]
-       for (k=0; k < 2; ++k){
-               for (i=k; i<*size-3; i += 2)
+       for (k = 0; k < 2; ++k){
+               for (i = k; i < *size-3; i += 2) {
                        if (BitStream[i] == BitStream[i+1])
                                errCnt++;
-
+               }
                if (bestErr > errCnt){
                        bestErr = errCnt;
                        bestRun = k;
                }
-               errCnt=0;
+               errCnt = 0;
        }
+       
        //decode
-       for (i=bestRun; i < *size-3; i += 2){
+       for (i = bestRun; i < *size-3; i += 2){
                if (BitStream[i] == 1 && (BitStream[i+1] == 0)){
                        BitStream[bitnum++] = invert;
                } else if ((BitStream[i] == 0) && BitStream[i+1] == 1){
@@ -412,9 +418,9 @@ int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert){
                } else {
                        BitStream[bitnum++] = 7;
                }
-               if (bitnum>MaxBits) break;
+               if (bitnum > MaxBits) break;
        }
-       *size=bitnum;
+       *size = bitnum;
        return bestErr;
 }