include/common/fftlib.h

   1 long FFTInit(long *fftMptr, long fftN, float *Utbl);
   2 /* Compute cosine table and check size for complex ffts */
   3 /* INPUTS */
   4 /* fftN = size of fft   */
   5 /* OUTPUTS */
   6 /* *fftMptr = log2 of fft size  */
   7 /* *Utbl = cosine table with fftN/4 + 1 entries (angles = 0 to pi/2 inclusive)  */
   8 /* RETURNS */
   9 /* 1 if fftN is invalid, 0 otherwise    */
  10
  11 long rFFTInit(long *fftMptr, long fftN, float *Utbl);
  12 /* Compute cosine table and check size for a real input fft     */
  13 /* INPUTS */
  14 /* fftN = size of fft   */
  15 /* OUTPUTS */
  16 /* *fftMptr = log2 of fft size  */
  17 /* *Utbl = cosine table with fftN/4 + 1 entries (angles = 0 to pi/2 inclusive)  */
  18 /* RETURNS */
  19 /* 1 if fftN is invalid, 0 otherwise    */
  20
  21 void ffts(float *ioptr, long M, long Rows, float *Utbl);
  22 /* Compute in-place complex fft on the rows of the input array  */
  23 /* INPUTS */
  24 /* M = log2 of fft size */
  25 /* *ioptr = input data array    */
  26 /* *Utbl = cosine table */
  27 /* Rows = number of rows in ioptr array (use Rows of 1 if ioptr is a 1 dimensional array)       */
  28 /* OUTPUTS */
  29 /* *ioptr = output data array   */
  30
  31 void iffts(float *ioptr, long M, long Rows, float *Utbl);
  32 /* Compute in-place inverse complex fft on the rows of the input array  */
  33 /* INPUTS */
  34 /* M = log2 of fft size */
  35 /* *ioptr = input data array    */
  36 /* *Utbl = cosine table */
  37 /* Rows = number of rows in ioptr array (use Rows of 1 if ioptr is a 1 dimensional array)       */
  38 /* OUTPUTS */
  39 /* *ioptr = output data array   */
  40
  41 void rffts(float *ioptr, long M, long Rows, float *Utbl);
  42 /* Compute in-place real fft on the rows of the input array     */
  43 /* INPUTS */
  44 /* M = log2 of fft size */
  45 /* *ioptr = real input data array       */
  46 /* *Utbl = cosine table */
  47 /* Rows = number of rows in ioptr array (use Rows of 1 if ioptr is a 1 dimensional array)       */
  48 /* OUTPUTS */
  49 /* *ioptr = output data array   in the following order */
  50 /* Re(x[0]), Re(x[N/2]), Re(x[1]), Im(x[1]), Re(x[2]), Im(x[2]), ... Re(x[N/2-1]), Im(x[N/2-1]). */
  51
  52
  53 void riffts(float *ioptr, long M, long Rows, float *Utbl);
  54 /* Compute in-place real ifft on the rows of the input array    */
  55 /* INPUTS */
  56 /* M = log2 of fft size */
  57 /* *ioptr = input data array in the following order     */
  58 /* Re(x[0]), Re(x[N/2]), Re(x[1]), Im(x[1]), Re(x[2]), Im(x[2]), ... Re(x[N/2-1]), Im(x[N/2-1]). */
  59 /* *Utbl = cosine table */
  60 /* Rows = number of rows in ioptr array (use Rows of 1 if ioptr is a 1 dimensional array)       */
  61 /* OUTPUTS */
  62 /* *ioptr = real output data array      */