#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 bool do_crop = false;
+static float crop_start = 0.0f, crop_end = HUGE_VAL;
+static float filter_coeff[NUM_FILTER_COEFF] = { 1.0f }; // The rest is filled with 0.
+static bool output_filtered = false;
+static bool quiet = false;
// between [x,x+1]
double find_zerocrossing(const std::vector<float> &pcm, int x)
sync_pulse_end = try_end;
sync_pulse_stddev = stddev;
}
- fprintf(stderr, "Sync pulse length standard deviation: %.2f cycles\n",
- sync_pulse_stddev);
+ if (!quiet) {
+ fprintf(stderr, "Sync pulse length standard deviation: %.2f cycles\n",
+ sync_pulse_stddev);
+ }
double sum = 0.0;
for (int i = SYNC_PULSE_START; i < sync_pulse_end; ++i) {
}
double mean_length = C64_FREQUENCY * sum / (sync_pulse_end - SYNC_PULSE_START);
double calibration_factor = SYNC_PULSE_LENGTH / mean_length;
- fprintf(stderr, "Calibrated sync pulse length: %.2f -> %.2f (change %+.2f%%)\n",
- mean_length, SYNC_PULSE_LENGTH, 100.0 * (calibration_factor - 1.0));
+ if (!quiet) {
+ fprintf(stderr, "Calibrated sync pulse length: %.2f -> %.2f (change %+.2f%%)\n",
+ mean_length, SYNC_PULSE_LENGTH, 100.0 * (calibration_factor - 1.0));
+ }
// Check for pulses outside +/- 10% (sign of misdetection).
for (int i = SYNC_PULSE_START; i < sync_pulse_end; ++i) {
{"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' },
+ {"crop", required_argument, 0, 'c' },
+ {"quiet", 0, 0, 'q' },
{"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, " -c, --crop START[:END] use only the given part of the file\n");
+ fprintf(stderr, " -q, --quiet suppress some informational messages\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:Fc:qh", long_options, &option_index);
if (c == -1)
break;
case 'p':
output_cycles_plot = true;
break;
+
case 'l':
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 'c': {
+ const char *cropstr = strtok(optarg, ":");
+ crop_start = atof(cropstr);
+ cropstr = strtok(NULL, ":");
+ if (cropstr == NULL) {
+ crop_end = HUGE_VAL;
+ } else {
+ crop_end = atof(cropstr);
+ }
+ do_crop = true;
+ break;
+ }
+
+ case 'q':
+ quiet = true;
+ break;
+
case 'h':
default:
help();
}
}
-int main(int argc, char **argv)
+std::vector<float> crop(const std::vector<float>& pcm, float crop_start, float crop_end, int sample_rate)
{
- parse_options(argc, argv);
-
- make_lanczos_weight_table();
- std::vector<float> pcm;
- int sample_rate;
- if (!read_audio_file(argv[optind], &pcm, &sample_rate)) {
- exit(1);
+ size_t start_sample, end_sample;
+ if (crop_start >= 0.0f) {
+ start_sample = std::min<size_t>(lrintf(crop_start * sample_rate), pcm.size());
+ }
+ if (crop_end >= 0.0f) {
+ end_sample = std::min<size_t>(lrintf(crop_end * sample_rate), pcm.size());
}
+ return std::vector<float>(pcm.begin() + start_sample, pcm.begin() + end_sample);
+}
-#if 0
- for (int i = 0; i < LEN; ++i) {
- in[i] += rand() % 10000;
+// 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);
}
-#endif
-#if 0
- for (int i = 0; i < LEN; ++i) {
- printf("%d\n", in[i]);
+ if (output_filtered) {
+ FILE *fp = fopen("filtered.raw", "wb");
+ fwrite(filtered_pcm.data(), filtered_pcm.size() * sizeof(filtered_pcm[0]), 1, fp);
+ fclose(fp);
}
-#endif
- std::vector<pulse> pulses; // in seconds
+ return filtered_pcm;
+}
+
+std::vector<pulse> detect_pulses(const std::vector<float> &pcm, int sample_rate)
+{
+ std::vector<pulse> pulses;
// Find the flanks.
int last_bit = -1;
}
// down-flank!
- double t = find_zerocrossing(pcm, i - 1) * (1.0 / sample_rate);
+ double t = find_zerocrossing(pcm, i - 1) * (1.0 / sample_rate) + crop_start;
if (last_downflank > 0) {
pulse p;
p.time = t;
}
last_bit = bit;
}
+ return pulses;
+}
+
+int main(int argc, char **argv)
+{
+ parse_options(argc, argv);
+
+ make_lanczos_weight_table();
+ std::vector<float> pcm;
+ int sample_rate;
+ if (!read_audio_file(argv[optind], &pcm, &sample_rate)) {
+ exit(1);
+ }
+
+ if (do_crop) {
+ pcm = crop(pcm, crop_start, crop_end, sample_rate);
+ }
+
+ if (use_filter) {
+ pcm = do_filter(pcm, filter_coeff);
+ }
+
+#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 = detect_pulses(pcm, sample_rate);
double calibration_factor = 1.0;
if (do_calibrate) {