/* libSoX DVMS format module (implementation in cvsd.c) * * Copyright (C) 1996-2007 Thomas Sailer and SoX Contributors * Thomas Sailer (sailer@ife.ee.ethz.ch) (HB9JNX/AE4WA) * Swiss Federal Institute of Technology, Electronics Lab * * 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 * */ #include "sox_i.h" #define CVSD_ENC_FILTERLEN 16 /* PCM sampling rate */ #define CVSD_DEC_FILTERLEN 48 /* CVSD sampling rate */ typedef struct { struct { unsigned overload; float mla_int; float mla_tc0; float mla_tc1; unsigned phase; unsigned phase_inc; float v_min, v_max; } com; union { struct { /* mirror circular buffer */ float output_filter[CVSD_DEC_FILTERLEN*2]; unsigned offset; /* into output_filter; always in first half */ } dec; struct { float recon_int; /* mirror circular buffer */ float input_filter[CVSD_ENC_FILTERLEN*2]; unsigned offset; /* into input_filter; always in first half */ } enc; } c; struct { unsigned char shreg; unsigned mask; unsigned cnt; } bit; unsigned bytes_written; unsigned cvsd_rate; } cvsd_priv_t; int lsx_cvsdstartread(sox_format_t * ft); int lsx_cvsdstartwrite(sox_format_t * ft); size_t lsx_cvsdread(sox_format_t * ft, sox_sample_t *buf, size_t nsamp); size_t lsx_cvsdwrite(sox_format_t * ft, const sox_sample_t *buf, size_t nsamp); int lsx_cvsdstopread(sox_format_t * ft); int lsx_cvsdstopwrite(sox_format_t * ft); int lsx_dvmsstartread(sox_format_t * ft); int lsx_dvmsstartwrite(sox_format_t * ft); int lsx_dvmsstopwrite(sox_format_t * ft);