Reclaim more than 19K of ARM flash memory.

[proxmark3-svn] / common / lfdemod.c

diff --git a/common/lfdemod.c b/common/lfdemod.c
index fae612060b462392bd4e1e99457b4d40577a2b01..e6552e129fafb8c775da743f9482b7f609c22a96 100644 (file)
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -36,8 +36,8 @@ int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi
                if (BitStream[i] < *low) *low = BitStream[i];
        }
        if (*high < 123) return -1; // just noise
-       *high = (int)(((*high-128)*(((float)fuzzHi)/100))+128);
-       *low = (int)(((*low-128)*(((float)fuzzLo)/100))+128);
+       *high = ((*high-128)*fuzzHi + 12800)/100;
+       *low =  ((*low-128)*fuzzLo + 12800)/100;
        return 1;
 }
 
@@ -639,12 +639,6 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow
        return numBits; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0
 }
 
-uint32_t myround2(float f)
-{
-       if (f >= 2000) return 2000;//something bad happened
-       return (uint32_t) (f + (float)0.5);
-}
-
 //translate 11111100000 to 10
 size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t maxConsequtiveBits,
                uint8_t invert, uint8_t fchigh, uint8_t fclow)
@@ -653,8 +647,6 @@ size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t maxCons
        uint32_t idx=0;
        size_t numBits=0;
        uint32_t n=1;
-       float lowWaves = (((float)(rfLen))/((float)fclow));
-       float highWaves = (((float)(rfLen))/((float)fchigh));
        for( idx=1; idx < size; idx++) {
 
                if (dest[idx]==lastval) {
@@ -664,20 +656,20 @@ size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t maxCons
                n++;
                //if lastval was 1, we have a 1->0 crossing
                if (dest[idx-1]==1) {
-                       if (!numBits && n < (uint8_t)lowWaves) {
+                       if (!numBits && n < rfLen/fclow) {
                                n=0;
                                lastval = dest[idx];
                                continue;
                        }
-                       n=myround2(((float)n)/lowWaves);
+                       n = (n * fclow + rfLen/2) / rfLen;
                } else {// 0->1 crossing 
                        //test first bitsample too small
-                       if (!numBits && n < (uint8_t)highWaves) {
+                       if (!numBits && n < rfLen/fchigh) {
                                n=0;
                                lastval = dest[idx];
                                continue;
                        }
-                       n = myround2(((float)n)/highWaves);  //-1 for fudge factor
+                       n = (n * fchigh + rfLen/2) / rfLen;  //-1 for fudge factor
                }
                if (n == 0) n = 1;
 
@@ -695,11 +687,11 @@ size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t maxCons
        }//end for
 
        // if valid extra bits at the end were all the same frequency - add them in
-       if (n > lowWaves && n > highWaves) {
+       if (n > rfLen/fclow && n > rfLen/fchigh) {
                if (dest[idx-2]==1) {
-                       n=myround2((float)(n+1)/((float)(rfLen)/(float)fclow));
-               } else {
-                       n=myround2((float)(n+1)/((float)(rfLen-1)/(float)fchigh));  //-1 for fudge factor                       
+                       n = ((n+1) * fclow + rfLen/2) / rfLen;
+               } else {// 0->1 crossing
+                       n = ((n+1) * fchigh + (rfLen-1)/2) / (rfLen-1);  //-1 for fudge factor
                }
                memset(dest, dest[idx-1]^invert , n);
                numBits += n;