Re-organized even more the repo, separated broadcast and arq

Makefile

@@ -1,12 +1,16 @@
-.PHONY: all modem/freedv datalink audioio common clean
+.PHONY: all modem datalink_arq datalink_broadcast audioio common clean
 
-all: modem/freedv datalink audioio common
+all: datalink_arq
 
-modem/freedv:
-	$(MAKE) -C modem/freedv
+modem:
+	$(MAKE) -C modem
 
-datalink: modem/freedv common audioio
-	$(MAKE) -C datalink
+# main is temporarily here, will be moved to a separate directory later
+datalink_arq: modem common audioio datalink_broadcast
+	$(MAKE) -C datalink_arq
+
+datalink_broadcast: modem common audioio
+	$(MAKE) -C datalink_broadcast
 
 audioio: 
 	$(MAKE) -C audioio
@@ -15,7 +19,8 @@ common:
 	$(MAKE) -C common
 
 clean:
-	$(MAKE) -C modem/freedv clean
-	$(MAKE) -C datalink clean
+	$(MAKE) -C modem clean
+	$(MAKE) -C datalink_arq clean
+	$(MAKE) -C datalink_broadcast clean
 	$(MAKE) -C audioio clean
 	$(MAKE) -C common clean

audioio/audioio.c

@@ -19,7 +19,7 @@
 
 #include "ring_buffer_posix.h"
 #include "shm_posix.h"
-#include "../datalink/defines.h"
+#include "../common/defines_modem.h"
 #include "os_interop.h"
 
 #include "audioio.h"

common/defines_modem.h

@@ -1,6 +1,6 @@
 
-#ifndef HAVE_DEFINES_H
-#define HAVE_DEFINES_H
+#ifndef HAVE_DEFINES_MODEM_H
+#define HAVE_DEFINES_MODEM_H
 
 #define MAX_PATH 255
 
@@ -26,4 +26,4 @@
 #endif
 
 
-#endif // HAVE_DEFINES_H
+#endif // HAVE_DEFINES_MODEM_H

datalink_arq/Makefile

@@ -40,16 +40,16 @@ endif
 
 
 CC = gcc
-CFLAGS = -Wall -O2 -std=gnu11 -pthread -D_GNU_SOURCE -I../modem/freedv -I.. -I../audioio/ffaudio -I../common
+CFLAGS = -Wall -O2 -std=gnu11 -pthread -D_GNU_SOURCE -I../modem/freedv -I../modem -I../datalink_broadcast -I.. -I../audioio/ffaudio -I../common
 
 LDFLAGS=$(FFAUDIO_LINKFLAGS) -lm
 
 all: ../mercury
 
-../mercury: main.o arq.o net.o fsm.o arith.o crc6.o modem.o broadcast.o ../modem/freedv/libfreedvdata.a ../audioio/audioio.a \
+../mercury: main.o arq.o net.o fsm.o arith.o crc6.o ../datalink_broadcast/broadcast.o ../modem/modem.o ../modem/freedv/libfreedvdata.a ../audioio/audioio.a \
 		../common/os_interop.o ../common/ring_buffer_posix.o ../common/shm_posix.o
 	$(CC) -o ../mercury  \
-		main.o arq.o net.o fsm.o arith.o crc6.o modem.o broadcast.o ../modem/freedv/libfreedvdata.a ../audioio/audioio.a \
+		main.o arq.o net.o fsm.o arith.o crc6.o ../datalink_broadcast/broadcast.o ../modem/modem.o ../modem/freedv/libfreedvdata.a ../audioio/audioio.a \
 		../common/os_interop.o ../common/ring_buffer_posix.o ../common/shm_posix.o $(LDFLAGS)
 
 main.o: main.c
@@ -70,11 +70,5 @@ arith.o: arith.c
 crc6.o: crc6.c
 	$(CC) $(CFLAGS) -c crc6.c
 
-modem.o: modem.c
-	$(CC) $(CFLAGS) -c modem.c
-
-broadcast.o: broadcast.c
-	$(CC) $(CFLAGS) -c broadcast.c
-
 clean:
 	rm -f *.o

datalink_arq/arq.c

@@ -25,7 +25,7 @@
 #include "fsm.h"
 #include "../audioio/audioio.h"
 #include "net.h"
-#include "defines.h"
+#include "defines_modem.h"
 
 extern cbuf_handle_t capture_buffer;
 extern cbuf_handle_t playback_buffer;

datalink_arq/main.c

@@ -36,7 +36,7 @@
 #include "arq.h"
 #include "modem.h"
 #include "broadcast.h"
-#include "defines.h"
+#include "defines_modem.h"
 #include "audioio/audioio.h"
 
 extern cbuf_handle_t capture_buffer;
@@ -318,14 +318,13 @@ int main(int argc, char *argv[])
         return EXIT_SUCCESS;
     }    
 
-    struct freedv *freedv = NULL;
-    pthread_t radio_capture;
-    pthread_t radio_playback;
+    generic_modem_t g_modem;
+    pthread_t radio_capture, radio_playback;
     
     if (audio_system == AUDIO_SUBSYSTEM_SHM)
     {
         printf("Initializing I/O from Shared Memory (SHM)\n");
-        init_modem(&freedv, mod_config, 1, &radio_capture, &radio_playback); // frames per burst is 1 for now
+        init_modem(&g_modem, mod_config, 1); // frames per burst is 1 for now
     }
     else
     {
@@ -337,11 +336,11 @@ int main(int argc, char *argv[])
     // arq_init(base_tcp_port, mod_config);
 
     // we block here
-    broadcast_run(freedv, broadcast_port);
+    broadcast_run(&g_modem, broadcast_port);
 
     if (audio_system == AUDIO_SUBSYSTEM_SHM)
     {
-        shutdown_modem(freedv, &radio_capture, &radio_playback);
+        shutdown_modem(&g_modem);
     }
     else
     {

datalink_broadcast/Makefile

@@ -0,0 +1,13 @@
+CC=gcc
+CFLAGS=-Wall -O2 -std=gnu11 -pthread -D_GNU_SOURCE=1 -I../modem -I../modem/freedv -I../common -I../datalink_arq
+all: broadcast.o kiss.o
+
+kiss.o: kiss.c
+	$(CC) $(CFLAGS) -c kiss.c
+
+broadcast.o: broadcast.c
+	$(CC) $(CFLAGS) -c broadcast.c
+
+
+clean:
+	rm *.o

datalink_broadcast/broadcast.c

@@ -28,9 +28,10 @@
 #include <arpa/inet.h>
 
 #include "modem.h"
-#include "defines.h"
-#include "ring_buffer_posix.h"
 #include "arq.h"
+#include "defines_modem.h"
+#include "ring_buffer_posix.h"
+
 
 extern cbuf_handle_t data_tx_buffer;
 extern cbuf_handle_t data_rx_buffer;
@@ -39,9 +40,9 @@ extern bool shutdown_; // global shutdown flag
 extern arq_info arq_conn; // ARQ connection info
 
 // Function to handle TX logic
-void *broadcast_tx_thread(void *freedv_ptr)
+void *broadcast_tx_thread(void *g_modem)
 {
-    struct freedv *freedv = (struct freedv *)freedv_ptr;
+    struct freedv *freedv = ((generic_modem_t *)g_modem)->freedv;
     size_t bytes_per_modem_frame = freedv_get_bits_per_modem_frame(freedv) / 8;
     uint8_t *data = (uint8_t *)malloc(bytes_per_modem_frame);
 
@@ -65,7 +66,7 @@ void *broadcast_tx_thread(void *freedv_ptr)
             read_buffer(data_tx_buffer, data, bytes_per_modem_frame);
 
             // Transmit the data
-            send_modulated_data(freedv, data, 1);
+            send_modulated_data(g_modem, data, 1);
             usleep(5000000); // 5s for now - TODO !!! some delay for transmission
         }
     }
@@ -75,9 +76,9 @@ void *broadcast_tx_thread(void *freedv_ptr)
 }
 
 // Function to handle RX logic
-void *broadcast_rx_thread(void *freedv_ptr)
+void *broadcast_rx_thread(void *g_modem)
 {
-    struct freedv *freedv = (struct freedv *)freedv_ptr;
+    struct freedv *freedv = ((generic_modem_t *)g_modem)->freedv;
     size_t bytes_per_modem_frame = freedv_get_bits_per_modem_frame(freedv) / 8;
     uint8_t *data = (uint8_t *)malloc(bytes_per_modem_frame);
     size_t nbytes_out = 0;
@@ -93,7 +94,7 @@ void *broadcast_rx_thread(void *freedv_ptr)
         if (arq_conn.TRX == RX)
         {
             // Receive data
-            receive_modulated_data(freedv, data, &nbytes_out);
+            receive_modulated_data(g_modem, data, &nbytes_out);
             if (nbytes_out > 0)
             {
                 write_buffer(data_rx_buffer, data, nbytes_out);
@@ -156,7 +157,7 @@ void *tcp_server_thread(void *port_ptr)
 
         printf("Client connected.\n");
 
-        uint8_t *buffer = (uint8_t *)malloc(DATA_TX_BUFFER_SIZE);
+        uint8_t *buffer = (uint8_t *)malloc(DATA_TX_BUFFER_SIZE);;
         if (!buffer)
         {
             fprintf(stderr, "Failed to allocate memory for TCP buffer.\n");
@@ -211,15 +212,15 @@ void *tcp_server_thread(void *port_ptr)
 }
 
 // Main function to handle broadcast operations
-void broadcast_run(struct freedv *freedv, int tcp_port)
+void broadcast_run(generic_modem_t *g_modem, int tcp_port)
 {
     printf("Starting broadcast system...\n");
 
     pthread_t tx_thread, rx_thread, server_thread;
 
     // Create TX and RX threads
-    pthread_create(&tx_thread, NULL, broadcast_tx_thread, (void *)freedv);
-    pthread_create(&rx_thread, NULL, broadcast_rx_thread, (void *)freedv);
+    pthread_create(&tx_thread, NULL, broadcast_tx_thread, (void *)g_modem);
+    pthread_create(&rx_thread, NULL, broadcast_rx_thread, (void *)g_modem);
 
     // Create TCP server thread
     pthread_create(&server_thread, NULL, tcp_server_thread, (void *)&tcp_port);

datalink_broadcast/broadcast.h

@@ -23,7 +23,7 @@
 
 #include <stdint.h>
 #include <stdbool.h>
-#include "freedv_api.h"
+#include "modem.h"
 
 /* Function declarations */
 
@@ -33,7 +33,7 @@
  * @param freedv Pointer to the FreeDV structure.
  * @param tcp_port The TCP port to use for the server.
  */
-void broadcast_run(struct freedv *freedv, int tcp_port);
+void broadcast_run(generic_modem_t *g_modem, int tcp_port);
 
 
 #endif // BROADCAST_H_

datalink_broadcast/kiss.c

@@ -0,0 +1,101 @@
+/* KISS framer
+ *
+ * Copyright (C) 2020-2024 Rhizomatica
+ * Author: Rafael Diniz <rafael@rhizomatica.org>
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ */
+
+#include <unistd.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include "kiss.h"
+
+int frame_len;
+bool IN_FRAME;
+bool ESCAPE;
+
+uint8_t kiss_command = CMD_UNKNOWN;
+uint8_t frame_buffer[MAX_PAYLOAD];
+uint8_t write_buffer[MAX_PAYLOAD*2+3];
+
+void kiss_frame_received(int frame_len)
+{
+    // do something here...
+    int written = write(1, frame_buffer, frame_len);
+}
+
+void kiss_read(uint8_t sbyte)
+{
+    if (IN_FRAME && sbyte == FEND && kiss_command == CMD_DATA)
+    {
+        IN_FRAME = false;
+        kiss_frame_received(frame_len);
+        return;
+    }
+    if (sbyte == FEND)
+    {
+        IN_FRAME = true;
+        kiss_command = CMD_UNKNOWN;
+        frame_len = 0;
+        return;
+    }
+    if (IN_FRAME && frame_len < MAX_PAYLOAD)
+    {
+        // Have a look at the command byte first
+        if (frame_len == 0 && kiss_command == CMD_UNKNOWN)
+        {
+            // Strip of port nibble
+            kiss_command = sbyte & 0x0F;
+            return;
+        }
+        if (kiss_command == CMD_DATA)
+        {
+            if (sbyte == FESC)
+            {
+                ESCAPE = true;
+                return;
+            }
+            if (ESCAPE)
+            {
+                if (sbyte == TFEND) sbyte = FEND;
+                if (sbyte == TFESC) sbyte = FESC;
+                ESCAPE = false;
+            }
+            if (frame_len < MAX_PAYLOAD)
+            {
+                frame_buffer[frame_len++] = sbyte;
+            }
+        }
+    }
+}
+
+int kiss_write_frame(uint8_t* buffer, int frame_len)
+{
+    int write_len = 0;
+    write_buffer[write_len++] = FEND;
+    write_buffer[write_len++] = CMD_DATA;
+    for (int i = 0; i < frame_len; i++)
+    {
+        uint8_t byte = buffer[i];
+        switch(byte)
+        {
+        case FEND:
+            write_buffer[write_len++] = FESC;
+            write_buffer[write_len++] = TFEND;
+            break;
+        case FESC:
+            write_buffer[write_len++] = FESC;
+            write_buffer[write_len++] = TFESC;
+            break;
+        default:
+            write_buffer[write_len++] = byte;
+        }
+    }
+    write_buffer[write_len++] = FEND;
+
+    // TODO: write the buffer somewhere...
+    return write(1, write_buffer, write_len);
+}

datalink_broadcast/kiss.h

@@ -0,0 +1,38 @@
+/* KISS framer
+ *
+ * Copyright (C) 2020-2024 Rhizomatica
+ * Author: Rafael Diniz <rafael@rhizomatica.org>
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ */
+
+#pragma once
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define FEND 0xC0
+#define FESC 0xDB
+#define TFEND 0xDC
+#define TFESC 0xDD
+
+#define CMD_UNKNOWN 0xFE
+#define CMD_AX25 0x00 //  AX25 Frame (standard) in VARA
+#define CMD_AX25CALLSIGN 0x01 // AX25 Frame (7 chrs Call Signs) in VARA
+#define CMD_DATA 0x02 // VARA / Mercury unformatted frame
+#define CMD_RQ_CONFIG 0x03 // Mercury special fountain code configuration frame
+#define CMD_RQ_PAYLOAD 0x04 // Fountain code payload
+
+#define MAX_PAYLOAD 756 // ~ 18 frames at VARA Level 4
+
+void kiss_read(uint8_t sbyte);
+int kiss_write_frame(uint8_t* buffer, int frame_len);
+
+
+#ifdef __cplusplus
+};
+#endif

modem/Makefile

@@ -0,0 +1,16 @@
+CFLAGS=-D_GNU_SOURCE=1 -I. -I../common -I../modem -I../modem/freedv -I../datalink_arq -Wall -Wno-strict-overflow -std=gnu11 -fPIC -O2
+CC=gcc
+
+.PHONY: all freedv 
+
+all: freedv modem.o
+
+freedv:
+	$(MAKE) -C freedv
+
+modem.o: modem.c modem.h
+	$(CC) $(CFLAGS) -c modem.c
+
+clean:
+	$(MAKE) -C freedv clean
+	rm -f *.o

modem/modem.c

@@ -34,7 +34,7 @@
 #include "ldpc_codes.h"
 #include "ofdm_internal.h"
 
-#include "defines.h"
+#include "defines_modem.h"
 
 extern bool shutdown_; // global shutdown flag
 
@@ -45,7 +45,7 @@ cbuf_handle_t data_tx_buffer;
 cbuf_handle_t data_rx_buffer;
 
 
-int init_modem(struct freedv **freedv, int mode, int frames_per_burst, pthread_t *radio_capture, pthread_t *radio_playback)
+int init_modem(generic_modem_t *g_modem, int mode, int frames_per_burst)
 {
 // connect to shared memory buffers
 try_shm_connect1:
@@ -72,21 +72,21 @@ try_shm_connect2:
     data_tx_buffer = circular_buf_init(buffer_tx, DATA_TX_BUFFER_SIZE);
     data_rx_buffer = circular_buf_init(buffer_rx, DATA_RX_BUFFER_SIZE);
     printf("Created data buffers for TX and RX.\n");
-    
+
     char codename[80] = "H_256_512_4";
     struct freedv_advanced adv = {0, 2, 100, 8000, 1000, 200, codename};
 
     if (mode == FREEDV_MODE_FSK_LDPC)
-        *freedv = freedv_open_advanced(mode, &adv);
+        g_modem->freedv = freedv_open_advanced(mode, &adv);
     else 
-        *freedv = freedv_open(mode);
+        g_modem->freedv = freedv_open(mode);
     
-    freedv_set_frames_per_burst(*freedv, frames_per_burst);
+    freedv_set_frames_per_burst(g_modem->freedv, frames_per_burst);
 
     return 0;
 }
 
-int shutdown_modem(struct freedv *freedv, pthread_t *radio_capture, pthread_t *radio_playback)
+int shutdown_modem(generic_modem_t *g_modem)
 {
     circular_buf_destroy_shm(capture_buffer, SIGNAL_BUFFER_SIZE, SIGNAL_INPUT);
     circular_buf_destroy_shm(playback_buffer, SIGNAL_BUFFER_SIZE, SIGNAL_OUTPUT);
@@ -98,13 +98,14 @@ int shutdown_modem(struct freedv *freedv, pthread_t *radio_capture, pthread_t *r
     circular_buf_free(data_tx_buffer);
     circular_buf_free(data_rx_buffer);
     
-    freedv_close(freedv);   
+    freedv_close(g_modem->freedv);   
 
     return 0;
 }
 
-int send_modulated_data(struct freedv *freedv, uint8_t *bytes_in, int frames_per_burst)
+int send_modulated_data(generic_modem_t *g_modem, uint8_t *bytes_in, int frames_per_burst)
 {
+    struct freedv *freedv = g_modem->freedv;
     size_t bytes_per_modem_frame = freedv_get_bits_per_modem_frame(freedv) / 8;
     size_t payload_bytes_per_modem_frame = bytes_per_modem_frame - 2; /* 16 bits used for the CRC */
     size_t n_mod_out = freedv_get_n_tx_modem_samples(freedv);
@@ -155,8 +156,9 @@ int send_modulated_data(struct freedv *freedv, uint8_t *bytes_in, int frames_per
     return 0;
 }
 
-int receive_modulated_data(struct freedv *freedv, uint8_t *bytes_out, size_t *nbytes_out)
+int receive_modulated_data(generic_modem_t *g_modem, uint8_t *bytes_out, size_t *nbytes_out)
 {
+    struct freedv *freedv = g_modem->freedv;
     size_t bytes_per_modem_frame = freedv_get_bits_per_modem_frame(freedv) / 8;
     size_t payload_bytes_per_modem_frame = bytes_per_modem_frame - 2; /* 16 bits used for the CRC */
 

modem/modem.h

@@ -27,14 +27,19 @@
 
 #include "freedv_api.h"
 
-int init_modem(struct freedv **freedv, int mode, int frames_per_burst, pthread_t *radio_capture, pthread_t *radio_playback);
+typedef struct generic_modem {
+    struct freedv *freedv;
+    void *future_extension; // Placeholder for future extensions
+} generic_modem_t;
 
-int shutdown_modem(struct freedv *freedv, pthread_t *radio_capture, pthread_t *radio_playback);
+int init_modem(generic_modem_t *g_modem, int mode, int frames_per_burst);
+
+int shutdown_modem(generic_modem_t *g_modem);
 
 // always send the frame size in bytes_in
-int send_modulated_data(struct freedv *freedv, uint8_t *bytes_in, int frames_per_burst);
+int send_modulated_data(generic_modem_t *g_modem, uint8_t *bytes_in, int frames_per_burst);
 
-int receive_modulated_data(struct freedv *freedv, uint8_t *bytes_out, size_t *nbytes_out);
+int receive_modulated_data(generic_modem_t *g_modem, uint8_t *bytes_out, size_t *nbytes_out);
 
 
 #endif // MODEM_H