+#include <stdio.h>
+#include <string.h>
+#include <math.h>
+#include <stdlib.h>
+
+double frac(double x)
+{
+ return x - (int)x;
+}
+
+int main(int argc, char **argv)
+{
+ FILE *in, *skew, *out;
+
+ // open input
+ if (strcmp(argv[1], "-") == 0) {
+ in = stdin;
+ } else {
+ in = fopen(argv[1], "rb");
+ if (in == NULL) {
+ perror(argv[1]);
+ exit(1);
+ }
+ }
+
+ // open skew
+ if (strcmp(argv[2], "-") == 0) {
+ skew = stdin;
+ } else {
+ skew = fopen(argv[2], "rb");
+ if (skew == NULL) {
+ perror(argv[2]);
+ exit(1);
+ }
+ }
+
+ // open output
+ if (strcmp(argv[3], "-") == 0) {
+ out = stderr;
+ } else {
+ out = fopen(argv[3], "wb");
+ if (in == NULL) {
+ perror(argv[3]);
+ exit(1);
+ }
+ }
+
+ short prev_sample, sample = 0;
+ unsigned in_pos = -1;
+ double p = -1.0;
+
+ while (!feof(in) && !feof(skew)) {
+ double delta_p;
+ if (fread(&delta_p, sizeof(double), 1, skew) != 1) {
+ exit(0);
+ }
+
+ p += delta_p;
+
+ // read samples until we're at the right position
+ while ((unsigned)(ceil(p)) > in_pos) {
+ prev_sample = sample;
+ if (fread(&sample, sizeof(short), 1, in) != 1) {
+ exit(0);
+ }
+ }
+
+ // linear interpolation (works well since delta_p varies so slowly)
+ double t = frac(p);
+ short intp_sample = prev_sample * (1.0 - t) + sample * t;
+
+ fwrite(&intp_sample, sizeof(short), 1, out);
+ }
+}