+
+int main(int argc, char **argv)
+{
+ make_lanczos_weight_table();
+ std::vector<float> pcm;
+ int sample_rate;
+ if (!read_audio_file(argv[1], &pcm, &sample_rate)) {
+ exit(1);
+ }
+
+#if 0
+ for (int i = 0; i < LEN; ++i) {
+ in[i] += rand() % 10000;
+ }
+#endif
+
+#if 0
+ for (int i = 0; i < LEN; ++i) {
+ printf("%d\n", in[i]);
+ }
+#endif
+
+ std::vector<pulse> pulses; // in seconds
+
+ // Find the flanks.
+ int last_bit = -1;
+ double last_downflank = -1;
+ for (unsigned i = 0; i < pcm.size(); ++i) {
+ int bit = (pcm[i] > 0) ? 1 : 0;
+ if (bit == 0 && last_bit == 1) {
+ // Check if we ever go up above HYSTERESIS_LIMIT before we dip down again.
+ bool true_pulse = false;
+ unsigned j;
+ int min_level_after = 32767;
+ for (j = i; j < pcm.size(); ++j) {
+ min_level_after = std::min<int>(min_level_after, pcm[j]);
+ if (pcm[j] > 0) break;
+ if (pcm[j] < -HYSTERESIS_LIMIT) {
+ true_pulse = true;
+ break;
+ }
+ }
+
+ if (!true_pulse) {
+#if 0
+ fprintf(stderr, "Ignored down-flank at %.6f seconds due to hysteresis (%d < %d).\n",
+ double(i) / sample_rate, -min_level_after, HYSTERESIS_LIMIT);
+#endif
+ i = j;
+ continue;
+ }
+
+ // down-flank!
+ double t = find_zerocrossing(pcm, i - 1) * (1.0 / sample_rate);
+ if (last_downflank > 0) {
+ pulse p;
+ p.time = t;
+ p.len = t - last_downflank;
+ pulses.push_back(p);
+ }
+ last_downflank = t;
+ }
+ last_bit = bit;
+ }
+
+ double calibration_factor = calibrate(pulses);
+
+ FILE *fp = fopen("cycles.plot", "w");
+ std::vector<char> tap_data;
+ for (unsigned i = 0; i < pulses.size(); ++i) {
+ double cycles = pulses[i].len * calibration_factor * C64_FREQUENCY;
+ fprintf(fp, "%f %f\n", pulses[i].time, cycles);
+ }
+ fclose(fp);
+
+ output_tap(pulses, calibration_factor);
+}