Question

I opened wav file with libsndfile library and want to read through this file and get N number of points in FFT and get time-domain samples and calculate FFT.

any ideas how I could replace fscanf with function from libsndfile library?
here is line of code:

for(i=0; i < N; i++) fscanf(fs, "%lg%lg", &x[i][0], &x[i][1]);

So, problem is I don’t know how to work with wav. without libsndfile and how to implement some things using libsndfile.

thanks,
a.

Answer 1

You say you want to read N samples and then you do:

for(i=0; i < N; i++) fscanf(fs, "%lg%lg", &x[i][0], &x[i][1]);

so you’re reading 2 * N samples and I’m not sure why.

If you grab the libsndfile source code tarball, there are example programs in the examples/ directory. Basically you do:

SNDFILE * sf ;
SF_INFO info ;
double  array [N] ;

memset (&info, 0, sizeof (info));
if ((sf = sf_open (filename, SFM_READ, &info)) == NULL)
   handle_error () ;

sf_read_double (sf, array, N) ;
sf_close (sf) ;

This code assumes you file is mono (only one channel).