boo/soxr/src/poly-fir0.h

33 lines
1.1 KiB
C

/* SoX Resampler Library Copyright (c) 2007-13 robs@users.sourceforge.net
* Licence for this file: LGPL v2.1 See LICENCE for details. */
/* Resample using a non-interpolated poly-phase FIR with length LEN.*/
/* Input must be followed by LEN-1 samples. */
#define _ sum += (coef(p->shared->poly_fir_coefs, 0, FIR_LENGTH, rem, 0, j)) *at[j], ++j;
static void FUNCTION(stage_t * p, fifo_t * output_fifo)
{
sample_t const * input = stage_read_p(p);
int i, num_in = stage_occupancy(p), max_num_out = 1 + (int)(num_in*p->out_in_ratio);
sample_t * output = fifo_reserve(output_fifo, max_num_out);
for (i = 0; p->at.integer < num_in * p->L; ++i, p->at.integer += p->step.integer) {
int div = p->at.integer / p->L, rem = p->at.integer % p->L;
sample_t const * at = input + div;
sample_t sum = 0;
int j = 0;
CONVOLVE
output[i] = sum;
}
assert(max_num_out - i >= 0);
fifo_trim_by(output_fifo, max_num_out - i);
fifo_read(&p->fifo, p->at.integer / p->L, NULL);
p->at.integer = p->at.integer % p->L;
}
#undef _
#undef CONVOLVE
#undef FIR_LENGTH
#undef FUNCTION