#define SYNC_PULSE_LENGTH 378.0
#define SYNC_TEST_TOLERANCE 1.10
+#define NUM_FILTER_COEFF 32
+
static float hysteresis_limit = 3000.0 / 32768.0;
static bool do_calibrate = true;
static bool output_cycles_plot = false;
+static bool use_filter = false;
+static float filter_coeff[NUM_FILTER_COEFF] = { 1.0f }; // The rest is filled with 0.
+static bool output_filtered = false;
// between [x,x+1]
double find_zerocrossing(const std::vector<float> &pcm, int x)
{"no-calibrate", 0, 0, 's' },
{"plot-cycles", 0, 0, 'p' },
{"hysteresis-limit", required_argument, 0, 'l' },
+ {"filter", required_argument, 0, 'f' },
+ {"output-filtered", 0, 0, 'F' },
{"help", 0, 0, 'h' },
{0, 0, 0, 0 }
};
fprintf(stderr, " -s, --no-calibrate do not try to calibrate on sync pulse length\n");
fprintf(stderr, " -p, --plot-cycles output debugging info to cycles.plot\n");
fprintf(stderr, " -l, --hysteresis-limit VAL change amplitude threshold for ignoring pulses (0..32768)\n");
+ fprintf(stderr, " -f, --filter C1:C2:C3:... specify FIR filter (up to %d coefficients)\n", NUM_FILTER_COEFF);
+ fprintf(stderr, " -F, --output-filtered output filtered waveform to filtered.raw\n");
fprintf(stderr, " -h, --help display this help, then exit\n");
exit(1);
}
{
for ( ;; ) {
int option_index = 0;
- int c = getopt_long(argc, argv, "spl:h", long_options, &option_index);
+ int c = getopt_long(argc, argv, "spl:f:Fh", long_options, &option_index);
if (c == -1)
break;
hysteresis_limit = atof(optarg) / 32768.0;
break;
+ case 'f': {
+ const char *coeffstr = strtok(optarg, ":");
+ int coeff_index = 0;
+ while (coeff_index < NUM_FILTER_COEFF && coeffstr != NULL) {
+ filter_coeff[coeff_index++] = atof(coeffstr);
+ coeffstr = strtok(NULL, ":");
+ }
+ use_filter = true;
+ break;
+ }
+
+ case 'F':
+ output_filtered = true;
+ break;
+
case 'h':
default:
help();
}
}
+// TODO: Support AVX here.
+std::vector<float> do_filter(const std::vector<float>& pcm, const float* filter)
+{
+ std::vector<float> filtered_pcm;
+ filtered_pcm.reserve(pcm.size());
+ for (unsigned i = NUM_FILTER_COEFF; i < pcm.size(); ++i) {
+ float s = 0.0f;
+ for (int j = 0; j < NUM_FILTER_COEFF; ++j) {
+ s += filter[j] * pcm[i - j];
+ }
+ filtered_pcm.push_back(s);
+ }
+
+ if (output_filtered) {
+ FILE *fp = fopen("filtered.raw", "wb");
+ fwrite(filtered_pcm.data(), filtered_pcm.size() * sizeof(filtered_pcm[0]), 1, fp);
+ fclose(fp);
+ }
+
+ return filtered_pcm;
+}
+
int main(int argc, char **argv)
{
parse_options(argc, argv);
exit(1);
}
+ if (use_filter) {
+ pcm = do_filter(pcm, filter_coeff);
+ }
+
#if 0
for (int i = 0; i < LEN; ++i) {
in[i] += rand() % 10000;