2015-07-27 00:35:07 +00:00
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//
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// This file is part of Dire Wolf, an amateur radio packet TNC.
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//
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2015-07-27 01:17:23 +00:00
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// Copyright (C) 2011, 2012, 2013, 2014, 2015 John Langner, WB2OSZ
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2015-07-27 00:35:07 +00:00
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//
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// This program is free software: you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation, either version 2 of the License, or
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// (at your option) any later version.
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//
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with this program. If not, see <http://www.gnu.org/licenses/>.
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//
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// #define DEBUG1 1 /* display debugging info */
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// #define DEBUG3 1 /* print carrier detect changes. */
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// #define DEBUG4 1 /* capture AFSK demodulator output to log files */
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// #define DEBUG5 1 /* capture 9600 output to log files */
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/*------------------------------------------------------------------
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*
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* Module: demod.c
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*
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* Purpose: Common entry point for multiple types of demodulators.
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*
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* Input: Audio samples from either a file or the "sound card."
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*
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* Outputs: Calls hdlc_rec_bit() for each bit demodulated.
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*
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*---------------------------------------------------------------*/
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#include <stdlib.h>
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#include <stdio.h>
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#include <math.h>
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#include <unistd.h>
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#include <sys/stat.h>
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#include <string.h>
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#include <assert.h>
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#include <ctype.h>
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#include "direwolf.h"
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#include "audio.h"
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#include "demod.h"
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#include "tune.h"
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#include "fsk_demod_state.h"
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#include "fsk_gen_filter.h"
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#include "fsk_fast_filter.h"
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#include "hdlc_rec.h"
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#include "textcolor.h"
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#include "demod_9600.h"
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#include "demod_afsk.h"
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// Properties of the radio channels.
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2015-07-27 01:17:23 +00:00
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static struct audio_s *save_audio_config_p;
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2015-07-27 00:35:07 +00:00
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// Current state of all the decoders.
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static struct demodulator_state_s demodulator_state[MAX_CHANS][MAX_SUBCHANS];
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#define UPSAMPLE 2
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static int sample_sum[MAX_CHANS][MAX_SUBCHANS];
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static int sample_count[MAX_CHANS][MAX_SUBCHANS];
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/*------------------------------------------------------------------
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*
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* Name: demod_init
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*
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* Purpose: Initialize the demodulator(s) used for reception.
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*
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2015-07-27 01:17:23 +00:00
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* Inputs: pa - Pointer to audio_s structure with
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2015-07-27 00:35:07 +00:00
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* various parameters for the modem(s).
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*
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* Returns: 0 for success, -1 for failure.
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*
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*
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* Bugs: This doesn't do much error checking so don't give it
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* anything crazy.
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*
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*----------------------------------------------------------------*/
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int demod_init (struct audio_s *pa)
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{
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int j;
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int chan; /* Loop index over number of radio channels. */
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char profile;
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2015-07-27 01:17:23 +00:00
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2015-07-27 00:35:07 +00:00
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2015-07-27 01:17:23 +00:00
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/*
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* Save audio configuration for later use.
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*/
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save_audio_config_p = pa;
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for (chan = 0; chan < MAX_CHANS; chan++) {
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if (save_audio_config_p->achan[chan].valid) {
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char *p;
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char just_letters[16];
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int num_letters;
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int have_plus;
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switch (save_audio_config_p->achan[chan].modem_type) {
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case MODEM_OFF:
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break;
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case MODEM_AFSK:
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2015-07-27 00:35:07 +00:00
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/*
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2015-07-27 01:17:23 +00:00
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* Tear apart the profile and put it back together in a normalized form:
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* - At least one letter, supply suitable default if necessary.
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* - Upper case only.
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* - Any plus will be at the end.
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2015-07-27 00:35:07 +00:00
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*/
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2015-07-27 01:17:23 +00:00
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num_letters = 0;
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just_letters[num_letters] = '\0';
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have_plus = 0;
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for (p = save_audio_config_p->achan[chan].profiles; *p != '\0'; p++) {
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if (islower(*p)) {
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just_letters[num_letters] = toupper(*p);
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num_letters++;
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just_letters[num_letters] = '\0';
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}
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else if (isupper(*p)) {
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just_letters[num_letters] = *p;
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num_letters++;
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just_letters[num_letters] = '\0';
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}
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2015-07-27 00:35:07 +00:00
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2015-07-27 01:17:23 +00:00
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else if (*p == '+') {
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have_plus = 1;
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if (p[1] != '\0') {
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text_color_set(DW_COLOR_ERROR);
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dw_printf ("Channel %d: + option must appear at end of demodulator types \"%s\" \n",
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chan, save_audio_config_p->achan[chan].profiles);
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}
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}
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2015-07-27 00:35:07 +00:00
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2015-07-27 01:17:23 +00:00
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else if (*p == '-') {
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have_plus = -1;
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if (p[1] != '\0') {
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text_color_set(DW_COLOR_ERROR);
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dw_printf ("Channel %d: - option must appear at end of demodulator types \"%s\" \n",
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chan, save_audio_config_p->achan[chan].profiles);
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}
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} else {
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text_color_set(DW_COLOR_ERROR);
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dw_printf ("Channel %d: Demodulator types \"%s\" can contain only letters and + - characters.\n",
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chan, save_audio_config_p->achan[chan].profiles);
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}
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}
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2015-07-27 00:35:07 +00:00
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2015-07-27 01:17:23 +00:00
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assert (num_letters == strlen(just_letters));
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2015-07-27 00:35:07 +00:00
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/*
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* Pick a good default demodulator if none specified.
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*/
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2015-07-27 01:17:23 +00:00
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if (num_letters == 0) {
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2015-07-27 00:35:07 +00:00
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2015-07-27 01:17:23 +00:00
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if (save_audio_config_p->achan[chan].baud < 600) {
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2015-07-27 00:35:07 +00:00
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/* This has been optimized for 300 baud. */
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2015-07-27 01:17:23 +00:00
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strcpy (just_letters, "D");
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2015-07-27 00:35:07 +00:00
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}
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else {
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#if __arm__
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/* We probably don't have a lot of CPU power available. */
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2015-07-27 01:17:23 +00:00
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/* Previously we would use F if possible otherwise fall back to A. */
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#if 0
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if (save_audio_config_p->achan[chan].baud == FFF_BAUD &&
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save_audio_config_p->achan[chan].mark_freq == FFF_MARK_FREQ &&
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save_audio_config_p->achan[chan].space_freq == FFF_SPACE_FREQ &&
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save_audio_config_p->adev[ACHAN2ADEV(chan)].samples_per_sec == FFF_SAMPLES_PER_SEC) {
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2015-07-27 00:35:07 +00:00
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2015-07-27 01:17:23 +00:00
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just_letters[0] = FFF_PROFILE;
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just_letters[1] = '\0';
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2015-07-27 00:35:07 +00:00
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}
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else {
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2015-07-27 01:17:23 +00:00
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strcpy (just_letters, "A");
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}
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#else
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/* In version 1.2, new default is E+ /3. */
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strcpy (just_letters, "E"); // version 1.2 now E.
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if (have_plus != -1) have_plus = 1; // Add as default for version 1.2
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// If not explicitly turned off.
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if (save_audio_config_p->achan[chan].decimate == 0) {
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save_audio_config_p->achan[chan].decimate = 3;
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2015-07-27 00:35:07 +00:00
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}
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2015-07-27 01:17:23 +00:00
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#endif
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2015-07-27 00:35:07 +00:00
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#else
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2015-07-27 01:17:23 +00:00
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strcpy (just_letters, "E"); // version 1.2 changed C to E.
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if (have_plus != -1) have_plus = 1; // Add as default for version 1.2
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// If not explicitly turned off.
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2015-07-27 00:35:07 +00:00
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#endif
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}
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2015-07-27 01:17:23 +00:00
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num_letters = 1;
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}
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assert (num_letters == strlen(just_letters));
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/*
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* Put it back together again.
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*/
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/* At this point, have_plus can have 3 values: */
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/* 1 = turned on, either explicitly or by applied default */
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/* -1 = explicitly turned off. change to 0 here so it is false. */
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/* 0 = off by default. */
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if (have_plus == -1) have_plus = 0;
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strcpy (save_audio_config_p->achan[chan].profiles, just_letters);
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assert (strlen(save_audio_config_p->achan[chan].profiles) >= 1);
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if (have_plus) {
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strcat (save_audio_config_p->achan[chan].profiles, "+");
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}
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/* These can be increased later for the multi-frequency case. */
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save_audio_config_p->achan[chan].num_subchan = num_letters;
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save_audio_config_p->achan[chan].num_demod = num_letters;
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/*
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* Some error checking - Can use only one of these:
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*
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* - Multiple letters.
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* - New + multi-slicer.
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* - Multiple frequencies.
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*/
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if (have_plus && num_letters > 1) {
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text_color_set(DW_COLOR_ERROR);
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dw_printf ("Channel %d: Demodulator + option can't be combined with multiple letters.\n", chan);
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strcpy (save_audio_config_p->achan[chan].profiles, "C+"); // Reduce to one letter.
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num_letters = 1;
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save_audio_config_p->achan[chan].num_demod = 1;
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save_audio_config_p->achan[chan].num_subchan = 1; // Will be set higher later.
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save_audio_config_p->achan[chan].num_freq = 1;
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}
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if (have_plus && save_audio_config_p->achan[chan].num_freq > 1) {
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text_color_set(DW_COLOR_ERROR);
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dw_printf ("Channel %d: Demodulator + option can't be combined with multiple frequencies.\n", chan);
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save_audio_config_p->achan[chan].num_demod = 1;
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save_audio_config_p->achan[chan].num_subchan = 1; // Will be set higher later.
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save_audio_config_p->achan[chan].num_freq = 1;
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}
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if (num_letters > 1 && save_audio_config_p->achan[chan].num_freq > 1) {
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text_color_set(DW_COLOR_ERROR);
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dw_printf ("Channel %d: Multiple demodulator types can't be combined with multiple frequencies.\n", chan);
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save_audio_config_p->achan[chan].profiles[1] = '\0';
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num_letters = 1;
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2015-07-27 00:35:07 +00:00
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}
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2015-07-27 01:17:23 +00:00
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if (save_audio_config_p->achan[chan].decimate == 0) {
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save_audio_config_p->achan[chan].decimate = 1;
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if (strchr (just_letters, 'D') != NULL && save_audio_config_p->adev[ACHAN2ADEV(chan)].samples_per_sec > 40000) {
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save_audio_config_p->achan[chan].decimate = 3;
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}
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}
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2015-07-27 00:35:07 +00:00
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text_color_set(DW_COLOR_DEBUG);
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dw_printf ("Channel %d: %d baud, AFSK %d & %d Hz, %s, %d sample rate",
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2015-07-27 01:17:23 +00:00
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chan, save_audio_config_p->achan[chan].baud,
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save_audio_config_p->achan[chan].mark_freq, save_audio_config_p->achan[chan].space_freq,
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save_audio_config_p->achan[chan].profiles,
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save_audio_config_p->adev[ACHAN2ADEV(chan)].samples_per_sec);
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if (save_audio_config_p->achan[chan].decimate != 1)
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dw_printf (" / %d", save_audio_config_p->achan[chan].decimate);
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if (save_audio_config_p->achan[chan].dtmf_decode != DTMF_DECODE_OFF)
|
|
|
|
|
dw_printf (", DTMF decoder enabled");
|
2015-07-27 00:35:07 +00:00
|
|
|
dw_printf (".\n");
|
|
|
|
|
|
|
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
/*
|
|
|
|
|
* Initialize the demodulator(s).
|
|
|
|
|
*
|
|
|
|
|
* We have 3 cases to consider.
|
2015-07-27 00:35:07 +00:00
|
|
|
*/
|
2015-07-27 01:17:23 +00:00
|
|
|
|
|
|
|
|
|
|
|
|
|
if (num_letters > 1) {
|
|
|
|
|
int d;
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Multiple letters, usually for 1200 baud.
|
|
|
|
|
* Each one corresponds to a demodulator and subchannel.
|
|
|
|
|
*
|
|
|
|
|
* An interesting experiment but probably not too useful.
|
|
|
|
|
* Can't have multiple frequency pairs or the + option.
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
save_audio_config_p->achan[chan].num_subchan = num_letters;
|
|
|
|
|
save_audio_config_p->achan[chan].num_demod = num_letters;
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
if (save_audio_config_p->achan[chan].num_demod != num_letters) {
|
|
|
|
|
text_color_set(DW_COLOR_ERROR);
|
|
|
|
|
dw_printf ("INTERNAL ERROR, %s:%d, chan=%d, num_demod(%d) != strlen(\"%s\")\n",
|
|
|
|
|
__FILE__, __LINE__, chan, save_audio_config_p->achan[chan].num_demod, save_audio_config_p->achan[chan].profiles);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (save_audio_config_p->achan[chan].num_freq != 1) {
|
|
|
|
|
text_color_set(DW_COLOR_ERROR);
|
|
|
|
|
dw_printf ("INTERNAL ERROR, %s:%d, chan=%d, num_freq(%d) != 1\n",
|
|
|
|
|
__FILE__, __LINE__, chan, save_audio_config_p->achan[chan].num_freq);
|
|
|
|
|
}
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
for (d = 0; d < save_audio_config_p->achan[chan].num_demod; d++) {
|
2015-07-27 00:35:07 +00:00
|
|
|
|
|
|
|
|
int mark, space;
|
2015-07-27 01:17:23 +00:00
|
|
|
assert (d >= 0 && d < MAX_SUBCHANS);
|
|
|
|
|
|
|
|
|
|
struct demodulator_state_s *D;
|
|
|
|
|
D = &demodulator_state[chan][d];
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
profile = save_audio_config_p->achan[chan].profiles[d];
|
|
|
|
|
mark = save_audio_config_p->achan[chan].mark_freq;
|
|
|
|
|
space = save_audio_config_p->achan[chan].space_freq;
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
if (save_audio_config_p->achan[chan].num_demod != 1) {
|
2015-07-27 00:35:07 +00:00
|
|
|
text_color_set(DW_COLOR_DEBUG);
|
2015-07-27 01:17:23 +00:00
|
|
|
dw_printf (" %d.%d: %c %d & %d\n", chan, d, profile, mark, space);
|
2015-07-27 00:35:07 +00:00
|
|
|
}
|
|
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
demod_afsk_init (save_audio_config_p->adev[ACHAN2ADEV(chan)].samples_per_sec / save_audio_config_p->achan[chan].decimate,
|
|
|
|
|
save_audio_config_p->achan[chan].baud,
|
|
|
|
|
mark,
|
|
|
|
|
space,
|
2015-07-27 00:35:07 +00:00
|
|
|
profile,
|
|
|
|
|
D);
|
2015-07-27 01:17:23 +00:00
|
|
|
|
|
|
|
|
/* For siginal level reporting, we want a longer term view. */
|
|
|
|
|
// TODO: Should probably move this into the init functions.
|
|
|
|
|
|
|
|
|
|
D->quick_attack = D->agc_fast_attack * 0.2;
|
|
|
|
|
D->sluggish_decay = D->agc_slow_decay * 0.2;
|
2015-07-27 00:35:07 +00:00
|
|
|
}
|
|
|
|
|
}
|
2015-07-27 01:17:23 +00:00
|
|
|
else if (have_plus) {
|
|
|
|
|
|
2015-07-27 00:35:07 +00:00
|
|
|
/*
|
2015-07-27 01:17:23 +00:00
|
|
|
* PLUS - which implies we have only one letter and one frequency pair.
|
|
|
|
|
*
|
|
|
|
|
* One demodulator feeds multiple slicers, each a subchannel.
|
2015-07-27 00:35:07 +00:00
|
|
|
*/
|
2015-07-27 01:17:23 +00:00
|
|
|
|
|
|
|
|
if (num_letters != 1) {
|
|
|
|
|
text_color_set(DW_COLOR_ERROR);
|
|
|
|
|
dw_printf ("INTERNAL ERROR, %s:%d, chan=%d, strlen(\"%s\") != 1\n",
|
|
|
|
|
__FILE__, __LINE__, chan, just_letters);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (save_audio_config_p->achan[chan].num_freq != 1) {
|
|
|
|
|
text_color_set(DW_COLOR_ERROR);
|
|
|
|
|
dw_printf ("INTERNAL ERROR, %s:%d, chan=%d, num_freq(%d) != 1\n",
|
|
|
|
|
__FILE__, __LINE__, chan, save_audio_config_p->achan[chan].num_freq);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (save_audio_config_p->achan[chan].num_demod != save_audio_config_p->achan[chan].num_demod) {
|
|
|
|
|
text_color_set(DW_COLOR_ERROR);
|
|
|
|
|
dw_printf ("INTERNAL ERROR, %s:%d, chan=%d, num_freq(%d) != num_demod(%d)\n",
|
|
|
|
|
__FILE__, __LINE__, chan, save_audio_config_p->achan[chan].num_freq, save_audio_config_p->achan[chan].num_demod);
|
|
|
|
|
}
|
2015-07-27 00:35:07 +00:00
|
|
|
|
|
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
struct demodulator_state_s *D;
|
|
|
|
|
D = &demodulator_state[chan][0];
|
|
|
|
|
|
|
|
|
|
/* I'm not happy about putting this hack here. */
|
|
|
|
|
/* This belongs in demod_afsk_init but it doesn't have access to the audio config. */
|
|
|
|
|
|
|
|
|
|
save_audio_config_p->achan[chan].num_demod = 1;
|
|
|
|
|
save_audio_config_p->achan[chan].num_subchan = MAX_SUBCHANS;
|
|
|
|
|
|
|
|
|
|
demod_afsk_init (save_audio_config_p->adev[ACHAN2ADEV(chan)].samples_per_sec / save_audio_config_p->achan[chan].decimate,
|
|
|
|
|
save_audio_config_p->achan[chan].baud,
|
|
|
|
|
save_audio_config_p->achan[chan].mark_freq,
|
|
|
|
|
save_audio_config_p->achan[chan].space_freq,
|
|
|
|
|
save_audio_config_p->achan[chan].profiles[0],
|
|
|
|
|
D);
|
|
|
|
|
|
|
|
|
|
/* I'm not happy about putting this hack here. */
|
|
|
|
|
/* should pass in as a parameter rather than adding on later. */
|
|
|
|
|
|
|
|
|
|
D->num_slicers = MAX_SUBCHANS;
|
|
|
|
|
|
|
|
|
|
/* For siginal level reporting, we want a longer term view. */
|
|
|
|
|
|
|
|
|
|
D->quick_attack = D->agc_fast_attack * 0.2;
|
|
|
|
|
D->sluggish_decay = D->agc_slow_decay * 0.2;
|
|
|
|
|
}
|
|
|
|
|
else {
|
|
|
|
|
int d;
|
|
|
|
|
/*
|
|
|
|
|
* One letter.
|
|
|
|
|
* Can be combined with multiple frequencies.
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
if (num_letters != 1) {
|
|
|
|
|
text_color_set(DW_COLOR_ERROR);
|
|
|
|
|
dw_printf ("INTERNAL ERROR, %s:%d, chan=%d, strlen(\"%s\") != 1\n",
|
|
|
|
|
__FILE__, __LINE__, chan, save_audio_config_p->achan[chan].profiles);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
save_audio_config_p->achan[chan].num_demod = save_audio_config_p->achan[chan].num_freq;
|
|
|
|
|
save_audio_config_p->achan[chan].num_subchan = save_audio_config_p->achan[chan].num_freq;
|
|
|
|
|
|
|
|
|
|
for (d = 0; d < save_audio_config_p->achan[chan].num_freq; d++) {
|
2015-07-27 00:35:07 +00:00
|
|
|
|
|
|
|
|
int mark, space, k;
|
2015-07-27 01:17:23 +00:00
|
|
|
assert (d >= 0 && d < MAX_SUBCHANS);
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
struct demodulator_state_s *D;
|
|
|
|
|
D = &demodulator_state[chan][d];
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
profile = save_audio_config_p->achan[chan].profiles[0];
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
k = d * save_audio_config_p->achan[chan].offset - ((save_audio_config_p->achan[chan].num_freq - 1) * save_audio_config_p->achan[chan].offset) / 2;
|
|
|
|
|
mark = save_audio_config_p->achan[chan].mark_freq + k;
|
|
|
|
|
space = save_audio_config_p->achan[chan].space_freq + k;
|
|
|
|
|
|
|
|
|
|
if (save_audio_config_p->achan[chan].num_freq != 1) {
|
2015-07-27 00:35:07 +00:00
|
|
|
text_color_set(DW_COLOR_DEBUG);
|
2015-07-27 01:17:23 +00:00
|
|
|
dw_printf (" %d.%d: %c %d & %d\n", chan, d, profile, mark, space);
|
2015-07-27 00:35:07 +00:00
|
|
|
}
|
|
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
demod_afsk_init (save_audio_config_p->adev[ACHAN2ADEV(chan)].samples_per_sec / save_audio_config_p->achan[chan].decimate,
|
|
|
|
|
save_audio_config_p->achan[chan].baud,
|
2015-07-27 00:35:07 +00:00
|
|
|
mark, space,
|
|
|
|
|
profile,
|
|
|
|
|
D);
|
|
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
/* For siginal level reporting, we want a longer term view. */
|
|
|
|
|
|
|
|
|
|
D->quick_attack = D->agc_fast_attack * 0.2;
|
|
|
|
|
D->sluggish_decay = D->agc_slow_decay * 0.2;
|
|
|
|
|
|
|
|
|
|
} /* for each freq pair */
|
2015-07-27 00:35:07 +00:00
|
|
|
}
|
|
|
|
|
break;
|
|
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
//TODO: how about MODEM_OFF case?
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
case MODEM_BASEBAND:
|
|
|
|
|
case MODEM_SCRAMBLE:
|
|
|
|
|
default: /* Not AFSK */
|
|
|
|
|
{
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
if (strcmp(save_audio_config_p->achan[chan].profiles, "") == 0) {
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
/* Apply default if not set earlier. */
|
|
|
|
|
/* Not sure if it should be on for ARM too. */
|
|
|
|
|
/* Need to take a look at CPU usage and performance difference. */
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
#ifndef __arm__
|
|
|
|
|
strcpy (save_audio_config_p->achan[chan].profiles, "+");
|
|
|
|
|
#endif
|
|
|
|
|
}
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
text_color_set(DW_COLOR_DEBUG);
|
|
|
|
|
dw_printf ("Channel %d: %d baud, K9NG/G3RUH, %s, %d sample rate x %d",
|
|
|
|
|
chan, save_audio_config_p->achan[chan].baud,
|
|
|
|
|
save_audio_config_p->achan[chan].profiles,
|
|
|
|
|
save_audio_config_p->adev[ACHAN2ADEV(chan)].samples_per_sec, UPSAMPLE);
|
|
|
|
|
if (save_audio_config_p->achan[chan].dtmf_decode != DTMF_DECODE_OFF)
|
|
|
|
|
dw_printf (", DTMF decoder enabled");
|
|
|
|
|
dw_printf (".\n");
|
|
|
|
|
|
|
|
|
|
struct demodulator_state_s *D;
|
|
|
|
|
D = &demodulator_state[chan][0]; // first subchannel
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
save_audio_config_p->achan[chan].num_subchan = 1;
|
|
|
|
|
save_audio_config_p->achan[chan].num_demod = 1;
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
if (strchr(save_audio_config_p->achan[chan].profiles, '+') != NULL) {
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
/* I'm not happy about putting this hack here. */
|
|
|
|
|
/* This belongs in demod_9600_init but it doesn't have access to the audio config. */
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
save_audio_config_p->achan[chan].num_demod = 1;
|
|
|
|
|
save_audio_config_p->achan[chan].num_subchan = MAX_SUBCHANS;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
demod_9600_init (UPSAMPLE * save_audio_config_p->adev[ACHAN2ADEV(chan)].samples_per_sec, save_audio_config_p->achan[chan].baud, D);
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
if (strchr(save_audio_config_p->achan[chan].profiles, '+') != NULL) {
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
/* I'm not happy about putting this hack here. */
|
|
|
|
|
/* should pass in as a parameter rather than adding on later. */
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
D->num_slicers = MAX_SUBCHANS;
|
|
|
|
|
}
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
/* For siginal level reporting, we want a longer term view. */
|
|
|
|
|
|
|
|
|
|
D->quick_attack = D->agc_fast_attack * 0.2;
|
|
|
|
|
D->sluggish_decay = D->agc_slow_decay * 0.2;
|
|
|
|
|
}
|
|
|
|
|
break;
|
|
|
|
|
|
|
|
|
|
} /* switch on modulation type. */
|
|
|
|
|
|
|
|
|
|
} /* if channel number is valid */
|
|
|
|
|
|
|
|
|
|
} /* for chan ... */
|
2015-07-27 00:35:07 +00:00
|
|
|
|
|
|
|
|
|
|
|
|
|
return (0);
|
|
|
|
|
|
|
|
|
|
} /* end demod_init */
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
/*------------------------------------------------------------------
|
|
|
|
|
*
|
|
|
|
|
* Name: demod_get_sample
|
|
|
|
|
*
|
2015-07-27 01:17:23 +00:00
|
|
|
* Purpose: Get one audio sample fromt the specified sound input source.
|
|
|
|
|
*
|
|
|
|
|
* Inputs: a - Index for audio device. 0 = first.
|
2015-07-27 00:35:07 +00:00
|
|
|
*
|
|
|
|
|
* Returns: -32768 .. 32767 for a valid audio sample.
|
|
|
|
|
* 256*256 for end of file or other error.
|
|
|
|
|
*
|
2015-07-27 01:17:23 +00:00
|
|
|
* Global In: save_audio_config_p->adev[ACHAN2ADEV(chan)].bits_per_sample - So we know whether to
|
2015-07-27 00:35:07 +00:00
|
|
|
* read 1 or 2 bytes from audio stream.
|
|
|
|
|
*
|
|
|
|
|
* Description: Grab 1 or two btyes depending on data source.
|
|
|
|
|
*
|
|
|
|
|
* When processing stereo, the caller will call this
|
|
|
|
|
* at twice the normal rate to obtain alternating left
|
|
|
|
|
* and right samples.
|
|
|
|
|
*
|
|
|
|
|
*----------------------------------------------------------------*/
|
|
|
|
|
|
|
|
|
|
#define FSK_READ_ERR (256*256)
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
__attribute__((hot))
|
2015-07-27 01:17:23 +00:00
|
|
|
int demod_get_sample (int a)
|
2015-07-27 00:35:07 +00:00
|
|
|
{
|
|
|
|
|
int x1, x2;
|
|
|
|
|
signed short sam; /* short to force sign extention. */
|
|
|
|
|
|
|
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
assert (save_audio_config_p->adev[a].bits_per_sample == 8 || save_audio_config_p->adev[a].bits_per_sample == 16);
|
2015-07-27 00:35:07 +00:00
|
|
|
|
|
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
if (save_audio_config_p->adev[a].bits_per_sample == 8) {
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
x1 = audio_get(a);
|
2015-07-27 00:35:07 +00:00
|
|
|
if (x1 < 0) return(FSK_READ_ERR);
|
|
|
|
|
|
|
|
|
|
assert (x1 >= 0 && x1 <= 255);
|
|
|
|
|
|
|
|
|
|
/* Scale 0..255 into -32k..+32k */
|
|
|
|
|
|
|
|
|
|
sam = (x1 - 128) * 256;
|
|
|
|
|
|
|
|
|
|
}
|
|
|
|
|
else {
|
2015-07-27 01:17:23 +00:00
|
|
|
x1 = audio_get(a); /* lower byte first */
|
2015-07-27 00:35:07 +00:00
|
|
|
if (x1 < 0) return(FSK_READ_ERR);
|
|
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
x2 = audio_get(a);
|
2015-07-27 00:35:07 +00:00
|
|
|
if (x2 < 0) return(FSK_READ_ERR);
|
|
|
|
|
|
|
|
|
|
assert (x1 >= 0 && x1 <= 255);
|
|
|
|
|
assert (x2 >= 0 && x2 <= 255);
|
|
|
|
|
|
|
|
|
|
sam = ( x2 << 8 ) | x1;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return (sam);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
/*-------------------------------------------------------------------
|
|
|
|
|
*
|
|
|
|
|
* Name: demod_process_sample
|
|
|
|
|
*
|
|
|
|
|
* Purpose: (1) Demodulate the AFSK signal.
|
|
|
|
|
* (2) Recover clock and data.
|
|
|
|
|
*
|
|
|
|
|
* Inputs: chan - Audio channel. 0 for left, 1 for right.
|
|
|
|
|
* subchan - modem of the channel.
|
|
|
|
|
* sam - One sample of audio.
|
|
|
|
|
* Should be in range of -32768 .. 32767.
|
|
|
|
|
*
|
|
|
|
|
* Returns: None
|
|
|
|
|
*
|
|
|
|
|
* Descripion: We start off with two bandpass filters tuned to
|
|
|
|
|
* the given frequencies. In the case of VHF packet
|
|
|
|
|
* radio, this would be 1200 and 2200 Hz.
|
|
|
|
|
*
|
|
|
|
|
* The bandpass filter amplitudes are compared to
|
|
|
|
|
* obtain the demodulated signal.
|
|
|
|
|
*
|
|
|
|
|
* We also have a digital phase locked loop (PLL)
|
|
|
|
|
* to recover the clock and pick out data bits at
|
|
|
|
|
* the proper rate.
|
|
|
|
|
*
|
|
|
|
|
* For each recovered data bit, we call:
|
|
|
|
|
*
|
|
|
|
|
* hdlc_rec (channel, demodulated_bit);
|
|
|
|
|
*
|
|
|
|
|
* to decode HDLC frames from the stream of bits.
|
|
|
|
|
*
|
|
|
|
|
* Future: This could be generalized by passing in the name
|
|
|
|
|
* of the function to be called for each bit recovered
|
|
|
|
|
* from the demodulator. For now, it's simply hard-coded.
|
|
|
|
|
*
|
|
|
|
|
*--------------------------------------------------------------------*/
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
__attribute__((hot))
|
|
|
|
|
void demod_process_sample (int chan, int subchan, int sam)
|
|
|
|
|
{
|
|
|
|
|
float fsam, abs_fsam;
|
|
|
|
|
int k;
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
#if DEBUG4
|
|
|
|
|
static FILE *demod_log_fp = NULL;
|
|
|
|
|
static int seq = 0; /* for log file name */
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
int j;
|
|
|
|
|
int demod_data;
|
|
|
|
|
struct demodulator_state_s *D;
|
|
|
|
|
|
|
|
|
|
assert (chan >= 0 && chan < MAX_CHANS);
|
|
|
|
|
assert (subchan >= 0 && subchan < MAX_SUBCHANS);
|
|
|
|
|
|
|
|
|
|
D = &demodulator_state[chan][subchan];
|
|
|
|
|
|
|
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
/* Scale to nice number, actually -2.0 to +2.0 for extra headroom */
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
fsam = sam / 16384.0f;
|
2015-07-27 00:35:07 +00:00
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Accumulate measure of the input signal level.
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
/*
|
|
|
|
|
* Version 1.2: Try new approach to capturing the amplitude.
|
|
|
|
|
* This is same as the later AGC without the normalization step.
|
|
|
|
|
* We want decay to be substantially slower to get a longer
|
|
|
|
|
* range idea of the received audio.
|
|
|
|
|
*/
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
if (fsam >= D->alevel_rec_peak) {
|
|
|
|
|
D->alevel_rec_peak = fsam * D->quick_attack + D->alevel_rec_peak * (1.0f - D->quick_attack);
|
|
|
|
|
}
|
|
|
|
|
else {
|
|
|
|
|
D->alevel_rec_peak = fsam * D->sluggish_decay + D->alevel_rec_peak * (1.0f - D->sluggish_decay);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (fsam <= D->alevel_rec_valley) {
|
|
|
|
|
D->alevel_rec_valley = fsam * D->quick_attack + D->alevel_rec_valley * (1.0f - D->quick_attack);
|
|
|
|
|
}
|
|
|
|
|
else {
|
|
|
|
|
D->alevel_rec_valley = fsam * D->sluggish_decay + D->alevel_rec_valley * (1.0f - D->sluggish_decay);
|
2015-07-27 00:35:07 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Select decoder based on modulation type.
|
|
|
|
|
*/
|
|
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
switch (save_audio_config_p->achan[chan].modem_type) {
|
|
|
|
|
|
|
|
|
|
case MODEM_OFF:
|
|
|
|
|
|
|
|
|
|
// Might have channel only listening to DTMF for APRStt gateway.
|
|
|
|
|
// Don't waste CPU time running a demodulator here.
|
|
|
|
|
break;
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
case MODEM_AFSK:
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
if (save_audio_config_p->achan[chan].decimate > 1) {
|
2015-07-27 00:35:07 +00:00
|
|
|
|
|
|
|
|
sample_sum[chan][subchan] += sam;
|
|
|
|
|
sample_count[chan][subchan]++;
|
2015-07-27 01:17:23 +00:00
|
|
|
if (sample_count[chan][subchan] >= save_audio_config_p->achan[chan].decimate) {
|
|
|
|
|
demod_afsk_process_sample (chan, subchan, sample_sum[chan][subchan] / save_audio_config_p->achan[chan].decimate, D);
|
2015-07-27 00:35:07 +00:00
|
|
|
sample_sum[chan][subchan] = 0;
|
|
|
|
|
sample_count[chan][subchan] = 0;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
else {
|
|
|
|
|
demod_afsk_process_sample (chan, subchan, sam, D);
|
|
|
|
|
}
|
|
|
|
|
break;
|
|
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
case MODEM_BASEBAND:
|
|
|
|
|
case MODEM_SCRAMBLE:
|
2015-07-27 00:35:07 +00:00
|
|
|
default:
|
|
|
|
|
|
|
|
|
|
#define ZEROSTUFF 1
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
#if ZEROSTUFF
|
|
|
|
|
/* Literature says this is better if followed */
|
|
|
|
|
/* by appropriate low pass filter. */
|
|
|
|
|
/* So far, both are same in tests with different */
|
|
|
|
|
/* optimal low pass filter parameters. */
|
|
|
|
|
|
|
|
|
|
for (k=1; k<UPSAMPLE; k++) {
|
|
|
|
|
demod_9600_process_sample (chan, 0, D);
|
|
|
|
|
}
|
|
|
|
|
demod_9600_process_sample (chan, sam*UPSAMPLE, D);
|
|
|
|
|
#else
|
|
|
|
|
/* Linear interpolation. */
|
|
|
|
|
static int prev_sam;
|
|
|
|
|
switch (UPSAMPLE) {
|
|
|
|
|
case 1:
|
|
|
|
|
demod_9600_process_sample (chan, sam);
|
|
|
|
|
|
|
|
|
|
break;
|
|
|
|
|
case 2:
|
|
|
|
|
demod_9600_process_sample (chan, (prev_sam + sam) / 2, D);
|
|
|
|
|
demod_9600_process_sample (chan, sam, D);
|
|
|
|
|
break;
|
|
|
|
|
case 3:
|
|
|
|
|
demod_9600_process_sample (chan, (2 * prev_sam + sam) / 3, D);
|
|
|
|
|
demod_9600_process_sample (chan, (prev_sam + 2 * sam) / 3, D);
|
|
|
|
|
demod_9600_process_sample (chan, sam, D);
|
|
|
|
|
break;
|
|
|
|
|
case 4:
|
|
|
|
|
demod_9600_process_sample (chan, (3 * prev_sam + sam) / 4, D);
|
|
|
|
|
demod_9600_process_sample (chan, (prev_sam + sam) / 2, D);
|
|
|
|
|
demod_9600_process_sample (chan, (prev_sam + 3 * sam) / 4, D);
|
|
|
|
|
demod_9600_process_sample (chan, sam, D);
|
|
|
|
|
break;
|
|
|
|
|
default:
|
|
|
|
|
assert (0);
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
prev_sam = sam;
|
|
|
|
|
#endif
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
} /* end demod_process_sample */
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
/* Doesn't seem right. Need to revisit this. */
|
|
|
|
|
/* Resulting scale is 0 to almost 100. */
|
|
|
|
|
/* Cranking up the input level produces no more than 97 or 98. */
|
|
|
|
|
/* We currently produce a message when this goes over 90. */
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
alevel_t demod_get_audio_level (int chan, int subchan)
|
|
|
|
|
{
|
|
|
|
|
struct demodulator_state_s *D;
|
|
|
|
|
alevel_t alevel;
|
|
|
|
|
int pk;
|
2015-07-27 00:35:07 +00:00
|
|
|
|
|
|
|
|
assert (chan >= 0 && chan < MAX_CHANS);
|
|
|
|
|
assert (subchan >= 0 && subchan < MAX_SUBCHANS);
|
|
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
/* We have to consider two different cases here. */
|
|
|
|
|
/* N demodulators, each with own slicer and HDLC decoder. */
|
|
|
|
|
/* Single demodulator, multiple slicers each with own HDLC decoder. */
|
|
|
|
|
|
|
|
|
|
if (demodulator_state[chan][0].num_slicers > 1) {
|
|
|
|
|
subchan = 0;
|
|
|
|
|
}
|
|
|
|
|
|
2015-07-27 00:35:07 +00:00
|
|
|
D = &demodulator_state[chan][subchan];
|
|
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
// Take half of peak-to-peak for received audio level.
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
alevel.rec = (int) (( D->alevel_rec_peak - D->alevel_rec_valley ) * 50.0f + 0.5f);
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
if (save_audio_config_p->achan[chan].modem_type == MODEM_AFSK) {
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
/* For AFSK, we have mark and space amplitudes. */
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
alevel.mark = (int) ((D->alevel_mark_peak ) * 100.0f + 0.5f);
|
|
|
|
|
alevel.space = (int) ((D->alevel_space_peak ) * 100.0f + 0.5f);
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
//alevel.ms_ratio = D->alevel_mark_peak / D->alevel_space_peak; // TODO: remove after temp test
|
|
|
|
|
}
|
|
|
|
|
else {
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
#if 1
|
|
|
|
|
/* Display the + and - peaks. */
|
|
|
|
|
/* Normally we'd expect them to be about the same. */
|
|
|
|
|
/* However, with SDR, or other DC coupling, we could have an offset. */
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
alevel.mark = (int) ((D->alevel_mark_peak) * 200.0f + 0.5f);
|
|
|
|
|
alevel.space = (int) ((D->alevel_space_peak) * 200.0f - 0.5f);
|
2015-07-27 00:35:07 +00:00
|
|
|
|
|
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
#else
|
|
|
|
|
/* Here we have + and - peaks after filtering. */
|
|
|
|
|
/* Take half of the peak to peak. */
|
|
|
|
|
/* The "5/6" factor worked out right for the current low pass filter. */
|
|
|
|
|
/* Will it need to be different if the filter is tweaked? */
|
2015-07-27 00:35:07 +00:00
|
|
|
|
2015-07-27 01:17:23 +00:00
|
|
|
alevel.mark = (int) ((D->alevel_mark_peak - D->alevel_space_peak) * 100.0f * 5.0f/6.0f + 0.5f);
|
|
|
|
|
alevel.space = -1; /* to print one number inside of ( ) */
|
|
|
|
|
#endif
|
|
|
|
|
}
|
|
|
|
|
return (alevel);
|
2015-07-27 00:35:07 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
/* end demod.c */
|
