From fce59d949c0a4767009a9db94f0af0903ff31be1 Mon Sep 17 00:00:00 2001 From: Dimitri Sokolyuk Date: Sat, 12 Mar 2011 01:53:00 +0000 Subject: sio spectrogram --- fifo.c | 101 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 101 insertions(+) create mode 100644 fifo.c (limited to 'fifo.c') diff --git a/fifo.c b/fifo.c new file mode 100644 index 0000000..5b80ec8 --- /dev/null +++ b/fifo.c @@ -0,0 +1,101 @@ +/* $Id$ */ +/* + * Copyright (c) 2010 Dimitri Sokolyuk + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include +#include +#include +#include + +struct buf { + double *buf; + double *end; + double *wr; + double *rd; +}; + +struct fifo { + struct buf l; + struct buf r; + size_t sz; +}; + +struct fifo * +init_fifo(int n) +{ + struct fifo *ff; + + ff = malloc(sizeof(struct fifo)); + + ff->l.buf = malloc(n * sizeof(double)); + ff->l.end = ff->l.buf + n; + ff->l.wr = ff->l.buf; + ff->l.rd = ff->l.buf; + + ff->r.buf = malloc(n * sizeof(double)); + ff->r.end = ff->r.buf + n; + ff->r.wr = ff->r.buf; + ff->r.rd = ff->r.buf; + + ff->sz = 0; + + return ff; +} + +int +wr_fifo(struct fifo *ff, double *l, double *r, int n) +{ + int i; + + for (i = 0; i < n; i++) { + *ff->l.wr++ = *l++; + *ff->r.wr++ = *r++; + if (ff->l.wr >= ff->l.end) { + ff->l.wr = ff->l.buf; + ff->r.wr = ff->r.buf; + } + } + ff->sz += n; + + return ff->sz; +} + +int +rd_fifo(struct fifo *ff, double *l, double *r, int n, double *w) +{ + int i; + double *lnext = ff->l.rd; + double *rnext = ff->r.rd; + + for (i = 0; i < n; i++) { + if (i == n / 4) { + lnext = ff->l.rd; + rnext = ff->r.rd; + } + *l++ = *ff->l.rd++ * w[i]; + *r++ = *ff->r.rd++ * w[i]; + if (ff->l.rd >= ff->l.end) { + ff->l.rd = ff->l.buf; + ff->r.rd = ff->r.buf; + } + } + ff->l.rd = lnext; + ff->r.rd = rnext; + + ff->sz -= n / 4; + + return ff->sz; +} -- cgit v1.2.3