ref: 41783531471a5c9378ac992b907fbb28fb46a24e
dir: /src/rate_poly_fir0.h/
/* Effect: change sample rate Copyright (c) 2008 robs@users.sourceforge.net * * This library is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation; either version 2.1 of the License, or (at * your option) any later version. * * This library is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser * General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this library; if not, write to the Free Software Foundation, * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /* Up-sample by rational step in (0,1) using a poly-phase FIR, length LEN.*/ /* Input must be preceded by LEN >> 1 samples. */ /* Input must be followed by (LEN-1) >> 1 samples. */ #define _ sum += (coef(p->shared->poly_fir_coefs, 0, FIR_LENGTH, divided.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 + num_in*p->out_in_ratio; sample_t * output = fifo_reserve(output_fifo, max_num_out); div_t divided; for (i = 0; p->at.parts.integer < num_in * p->divisor; ++i, p->at.parts.integer += p->step.parts.integer) { div_t divided = div(p->at.parts.integer, p->divisor); sample_t const * at = input + divided.quot; sample_t sum = 0; int j = 0; CONVOLVE assert(j == FIR_LENGTH); output[i] = sum; } assert(max_num_out - i >= 0); fifo_trim_by(output_fifo, max_num_out - i); divided = div(p->at.parts.integer, p->divisor); fifo_read(&p->fifo, divided.quot, NULL); p->at.parts.integer -= divided.quot * p->divisor; } #undef _ #undef CONVOLVE #undef FIR_LENGTH #undef FUNCTION