Mercurial > hg > audiostuff
view spandsp-0.0.3/spandsp-0.0.3/src/silence_gen.c @ 5:f762bf195c4b
import spandsp-0.0.3
author | Peter Meerwald <pmeerw@cosy.sbg.ac.at> |
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date | Fri, 25 Jun 2010 16:00:21 +0200 |
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/* * SpanDSP - a series of DSP components for telephony * * silence_gen.c - A silence generator, for inserting timed silences. * * Written by Steve Underwood <steveu@coppice.org> * * Copyright (C) 2006 Steve Underwood * * All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2, as * published by the Free Software Foundation. * * This program 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * * $Id: silence_gen.c,v 1.6 2006/11/19 14:07:25 steveu Exp $ */ /*! \file */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include <inttypes.h> #include <stdlib.h> #include <stdio.h> #include <fcntl.h> #include <string.h> #if defined(HAVE_TGMATH_H) #include <tgmath.h> #endif #if defined(HAVE_MATH_H) #include <math.h> #endif #include <assert.h> #include <limits.h> #include "spandsp/telephony.h" #include "spandsp/logging.h" #include "spandsp/silence_gen.h" int silence_gen(silence_gen_state_t *s, int16_t *amp, int max_len) { if (s->remaining_samples != INT_MAX) { if (max_len > s->remaining_samples) max_len = s->remaining_samples; s->remaining_samples -= max_len; } if (INT_MAX - s->total_samples >= max_len) s->total_samples += max_len; memset(amp, 0, max_len*sizeof(int16_t)); return max_len; } /*- End of function --------------------------------------------------------*/ void silence_gen_always(silence_gen_state_t *s) { s->remaining_samples = INT_MAX; } /*- End of function --------------------------------------------------------*/ void silence_gen_set(silence_gen_state_t *s, int silent_samples) { s->remaining_samples = silent_samples; s->total_samples = 0; } /*- End of function --------------------------------------------------------*/ void silence_gen_alter(silence_gen_state_t *s, int silent_samples) { /* Block negative silences */ if (silent_samples < 0) { if (-silent_samples > s->remaining_samples) silent_samples = -s->remaining_samples; } s->remaining_samples += silent_samples; s->total_samples += silent_samples; } /*- End of function --------------------------------------------------------*/ int silence_gen_remainder(silence_gen_state_t *s) { return s->remaining_samples; } /*- End of function --------------------------------------------------------*/ int silence_gen_generated(silence_gen_state_t *s) { return s->total_samples; } /*- End of function --------------------------------------------------------*/ silence_gen_state_t *silence_gen_init(silence_gen_state_t *s, int silent_samples) { memset(s, 0, sizeof(*s)); s->remaining_samples = silent_samples; return s; } /*- End of function --------------------------------------------------------*/ /*- End of file ------------------------------------------------------------*/