// $Id: wavlength.cc 750 2006-08-26 18:41:32Z flaterco $
// Determine length in minutes:seconds of a collecton of 44.1 kHz wav files.
//
// Usage:  wavlength file [file...]
//
// g++ -O2 -Wall -Wextra -pedantic -s -o wavlength wavlength.cc

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <math.h>

// Return length in seconds.
double lengthofwav (char *fname) {
  struct stat s;
  if (stat (fname, &s) != 0) {
    perror (fname);
    exit (-1);
  }
  if (s.st_size < 44) {
    fprintf (stderr, "%s: too short to be a wav file\n", fname);
    exit (-1);
  }
  // wav files from sox and normalize have 44 bytes of header.
  // 1 second = 44100 samples * 2 channels * 16 bits = 176400 bytes.
  return (double)(s.st_size - 44) / 176400.0;
}

int main (int argc, char **argv) {
  if (argc < 2) {
    fprintf (stderr, "wavlength file [file...]\n");
    exit (-1);
  }
  double len = 0.0;
  for (int i=1; i<argc; ++i)
    len += lengthofwav (argv[i]);
  printf ("%02lu:%05.2f\n", (unsigned long)(len/60), fmod(len,60.0));
  return 0;
}