xdf_define_arrays - Specify the number of input/output arrays
int xdf_define_arrays(struct xdf* xdf,
unsigned int narrays, const size_t *strides);
xdf_define_arrays() specifies the number of arrays and its strides for
upcoming calls to xdf_write(3) and xdf_read(3) using xdf. This
function is used to configure the upcoming transfer. As such, it must
be called before xdf_prepare_transfer(3) (calling it after will produce
an error). However the function may be called several times but only
the last call is meaningful for the transfer.
narrays specifies the number of arrays that will be provided in the
argument list of xdf_write(3) or xdf_read(3).
strides argument should point to an array of narrays unsigned int
corresponding respectively to the stride of each arrays that will be
supplied to the upcoming call to xdf_write(3) or xdf_read(3). The
stride corresponds to the length in byte between two consecutive
samples of the same channel in the array.
xdf_define_arrays() returns 0 in case of success, otherwise -1 and
errno is set appropriately.
ENOMEM The system is unable to allocate resources.
xdf_prepare_transfer(3), xdf_read(3), xdf_write(3)