//
// This file is part of Dire Wolf, an amateur radio packet TNC.
//
// Copyright (C) 2014, 2015, 2016 John Langner, WB2OSZ
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 2 of the License, or
// (at your option) any later version.
//
// 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, see <http://www.gnu.org/licenses/>.
//
/*------------------------------------------------------------------
*
* Module: recv.c
*
* Purpose: Process audio input for receiving.
*
* This is for all platforms.
*
*
* Description: In earlier versions, we supported a single audio device
* and the main program looped around processing the
* audio samples. The structure looked like this:
*
* main in direwolf.c:
*
* audio_init()
* various other *_init()
*
* loop forever:
* s = demod_get_sample.
* multi_modem_process_sample(s)
*
*
* When a packet is succesfully decoded, somebody calls
* app_process_rec_frame, also in direwolf.c
*
*
* Starting in version 1.2, we support multiple audio
* devices at the same time. We now have a separate
* thread for each audio device. Decoded frames are
* sent to a single queue for serial processing.
*
* The new flow looks like this:
*
* main in direwolf.c:
*
* audio_init()
* various other *_init()
* recv_init()
* recv_process() -- does not return
*
*
* recv_init() This starts up a separate thread
* for each audio device.
* Each thread reads audio samples and
* passes them to multi_modem_process_sample.
*
* The difference is that app_process_rec_frame
* is no longer called directly. Instead
* the frame is appended to a queue with dlq_rec_frame.
*
* Received frames can now be processed one at
* a time and we don't need to worry about later
* processing being reentrant.
*
* recv_process() This simply waits for something to show up
* in the dlq queue and calls app_process_rec_frame
* for each.
*
*---------------------------------------------------------------*/
//#define DEBUG 1
#include "direwolf.h"
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
//#include <sys/stat.h>
//#include <sys/ioctl.h>
//#include <fcntl.h>
#include <assert.h>
#ifdef __FreeBSD__
#include <errno.h>
#endif
#include "audio.h"
#include "demod.h"
#include "multi_modem.h"
#include "textcolor.h"
#include "dlq.h"
#include "recv.h"
#include "dtmf.h"
#include "aprs_tt.h"
#include "dtime_now.h"
#include "ax25_link.h"
#if __WIN32__
static unsigned __stdcall recv_adev_thread (void *arg);
#else
static void * recv_adev_thread (void *arg);
#endif
static struct audio_s *save_pa; /* Keep pointer to audio configuration */
/* for later use. */
/*------------------------------------------------------------------
*
* Name: recv_init
*
* Purpose: Start up a thread for each audio device.
*
*
* Inputs: pa - Address of structure of type audio_s.
*
*
* Returns: None.
*
* Errors: Exit if error.
* No point in going on if we can't get audio.
*
*----------------------------------------------------------------*/
void recv_init (struct audio_s *pa)
{
#if __WIN32__
HANDLE xmit_th[MAX_ADEVS];
#else
pthread_t xmit_tid[MAX_ADEVS];
#endif
int a;
save_pa = pa;
for (a=0; a<MAX_ADEVS; a++) {
if (pa->adev[a].defined) {
#if DEBUG
text_color_set(DW_COLOR_DEBUG);
dw_printf ("recv_init: start up thread, a=%d\n", a);
#endif
#if __WIN32__
xmit_th[a] = (HANDLE)_beginthreadex (NULL, 0, recv_adev_thread, (void*)(long)a, 0, NULL);
if (xmit_th[a] == NULL) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("FATAL: Could not create audio receive thread for device %d.\n", a);
exit(1);
}
#else
int e;
e = pthread_create (&xmit_tid[a], NULL, recv_adev_thread, (void *)(long)a);
if (e != 0) {
text_color_set(DW_COLOR_ERROR);
dw_printf ("FATAL: Could not create audio receive thread for device %d.\n", a);
exit(1);
}
#endif
}
#if DEBUG
text_color_set(DW_COLOR_DEBUG);
dw_printf ("recv_init: all done\n");
#endif
}
} /* end recv_init */
/* Try using "hot" attribute for all functions */
/* which are used for each audio sample. */
/* Compiler & linker might gather */
/* them together to improve memory cache performance. */
/* Or maybe it won't make any difference. */
__attribute__((hot))
#if __WIN32__
static unsigned __stdcall recv_adev_thread (void *arg)
#else
static void * recv_adev_thread (void *arg)
#endif
{
int a = (int)(long)arg; // audio device number.
int eof;
/* This audio device can have one (mono) or two (stereo) channels. */
/* Find number of the first channel. */
int first_chan = ADEVFIRSTCHAN(a);
int num_chan = save_pa->adev[a].num_channels;
#if DEBUG
text_color_set(DW_COLOR_DEBUG);
dw_printf ("recv_adev_thread is now running for a=%d\n", a);
#endif
/*
* Get sound samples and decode them.
*/
eof = 0;
while ( ! eof)
{
int audio_sample;
int c;
char tt;
for (c=0; c<num_chan; c++)
{
audio_sample = demod_get_sample (a);
if (audio_sample >= 256 * 256)
eof = 1;
multi_modem_process_sample(first_chan + c, audio_sample);
/* Originally, the DTMF decoder was always active. */
/* It took very little CPU time and the thinking was that an */
/* attached application might be interested in this even when */
/* the APRStt gateway was not being used. */
/* Unfortunately it resulted in too many false detections of */
/* touch tones when hearing other types of digital communications */
/* on HF. Starting in version 1.0, the DTMF decoder is active */
/* only when the APRStt gateway is configured. */
/* The test below allows us to listen to only a single channel for */
/* for touch tone sequences. The DTMF decoder and the accumulation */
/* of digits into a sequence maintain separate data for each channel. */
/* We should be able to accept touch tone sequences concurrently on */
/* all channels. The only issue is when a complete sequence is */
/* sent to aprs_tt_sequence which doesn't have separate data for each */
/* channel. This shouldn't be a problem unless we have multiple */
/* sequences arriving at the same instant. */
if (save_pa->achan[first_chan + c].dtmf_decode != DTMF_DECODE_OFF) {
tt = dtmf_sample (first_chan + c, audio_sample/16384.);
if (tt != ' ') {
aprs_tt_button (first_chan + c, tt);
}
}
}
/* When a complete frame is accumulated, */
/* dlq_rec_frame, is called. */
/* recv_process, below, drains the queue. */
}
// What should we do now?
// Seimply terminate the application?
// Try to re-init the audio device a couple times before giving up?
text_color_set(DW_COLOR_ERROR);
dw_printf ("Terminating after audio input failure.\n");
exit (1);
}
void recv_process (void)
{
struct dlq_item_s *pitem;
while (1) {
int timed_out;
double timeout_value = ax25_link_get_next_timer_expiry();
timed_out = dlq_wait_while_empty (timeout_value);
#if DEBUG
text_color_set(DW_COLOR_DEBUG);
dw_printf ("recv_process: woke up, timed_out=%d\n", timed_out);
#endif
if (timed_out) {
#if DEBUG
text_color_set(DW_COLOR_ERROR);
dw_printf ("recv_process: time waiting on dlq. call dl_timer_expiry.\n");
#endif
dl_timer_expiry ();
}
else {
pitem = dlq_remove ();
#if DEBUG
text_color_set(DW_COLOR_DEBUG);
dw_printf ("recv_process: dlq_remove() returned pitem=%p\n", pitem);
#endif
if (pitem != NULL) {
switch (pitem->type) {
case DLQ_REC_FRAME:
/*
* This is the traditional processing.
* For all frames:
* - Print in standard monitoring format.
* - Send to KISS client applications.
* - Send to AGw client applications in raw mode.
* For APRS frames:
* - Explain what it means.
* - Send to Igate.
* - Digipeater.
*/
app_process_rec_packet (pitem->chan, pitem->subchan, pitem->slice, pitem->pp, pitem->alevel, pitem->retries, pitem->spectrum);
/*
* Link processing.
*/
lm_data_indication(pitem);
break;
case DLQ_CONNECT_REQUEST:
dl_connect_request (pitem);
break;
case DLQ_DISCONNECT_REQUEST:
dl_disconnect_request (pitem);
break;
case DLQ_XMIT_DATA_REQUEST:
dl_data_request (pitem);
break;
case DLQ_REGISTER_CALLSIGN:
dl_register_callsign (pitem);
break;
case DLQ_UNREGISTER_CALLSIGN:
dl_unregister_callsign (pitem);
break;
case DLQ_CHANNEL_BUSY:
lm_channel_busy (pitem);
break;
case DLQ_CLIENT_CLEANUP:
dl_client_cleanup (pitem);
break;
}
dlq_delete (pitem);
}
#if DEBUG
else {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("recv_process: spurious wakeup. (Temp debugging message - not a problem if only occasional.)\n");
}
#endif
}
}
} /* end recv_process */
/* end recv.c */