-int CmdVchDemod(const char *Cmd)
-{
- // Is this the entire sync pattern, or does this also include some
- // data bits that happen to be the same everywhere? That would be
- // lovely to know.
- static const int SyncPattern[] = {
- 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
- 1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
- 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
- 1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
- 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
- 1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
- 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
- 1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
- 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
- 1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
- };
-
- // So first, we correlate for the sync pattern, and mark that.
- int bestCorrel = 0, bestPos = 0;
- int i;
- // It does us no good to find the sync pattern, with fewer than
- // 2048 samples after it...
- for (i = 0; i < (GraphTraceLen-2048); i++) {
- int sum = 0;
- int j;
- for (j = 0; j < arraylen(SyncPattern); j++) {
- sum += GraphBuffer[i+j]*SyncPattern[j];
- }
- if (sum > bestCorrel) {
- bestCorrel = sum;
- bestPos = i;
- }
- }
- PrintAndLog("best sync at %d [metric %d]", bestPos, bestCorrel);
-
- char bits[257];
- bits[256] = '\0';
-
- int worst = INT_MAX;
- int worstPos = 0;
-
- for (i = 0; i < 2048; i += 8) {
- int sum = 0;
- int j;
- for (j = 0; j < 8; j++) {
- sum += GraphBuffer[bestPos+i+j];
- }
- if (sum < 0) {
- bits[i/8] = '.';
- } else {
- bits[i/8] = '1';
- }
- if(abs(sum) < worst) {
- worst = abs(sum);
- worstPos = i;
- }
- }
- PrintAndLog("bits:");
- PrintAndLog("%s", bits);
- PrintAndLog("worst metric: %d at pos %d", worst, worstPos);
-
- if (strcmp(Cmd, "clone")==0) {
- GraphTraceLen = 0;
- char *s;
- for(s = bits; *s; s++) {
- int j;
- for(j = 0; j < 16; j++) {
- GraphBuffer[GraphTraceLen++] = (*s == '1') ? 1 : 0;
- }
- }
- RepaintGraphWindow();
- }
- return 0;