shallow zip-file copy from codec2 e9d726bf20

1 files changed, 128 insertions, 0 deletions

diff --git a/demo/freedv_datac0c1_rx.c b/demo/freedv_datac0c1_rx.c
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+++ b/demo/freedv_datac0c1_rx.c
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+/*---------------------------------------------------------------------------*\
+
+  FILE........: freedv_datac0c1_rx.c
+  AUTHOR......: David Rowe
+  DATE CREATED: Dec 2021
+
+  Demonstrates receiving frames of raw data bytes using the FreeDV
+  API.  Two parallel receivers are running, so we can receive either
+  DATAC0 or DATAC1 frames.  Demonstrates a common use case for HF data
+  - the ability to receive signalling as well as payload data frames.
+
+  usage: 
+
+  cd codec2/build_linux
+  ./demo/freedv_datacc01_tx | ./demo/freedv_datac0c1_rx
+
+  Give it a hard time with some channel noise, frequency offset, and sample 
+  clock offsets:
+
+  ./demo/freedv_datac0c1_tx | ./src/cohpsk_ch - - -24 -f 20 --Fs 8000 | 
+  sox -t .s16 -c 1 -r 8000 - -t .s16 -c 1 -r 8008 - | 
+  ./demo/freedv_datac0c1_rx
+
+  Replace the final line with "aplay -f S16" to listen to the
+  simulated Rx signal.
+
+\*---------------------------------------------------------------------------*/
+
+/*
+  Copyright (C) 2021 David Rowe
+
+  All rights reserved.
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU Lesser General Public License version 2.1, 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 Lesser General Public License
+  along with this program; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <assert.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+
+#include "freedv_api.h"
+
+#define NBUF 160
+
+int run_receiver(struct freedv *freedv, short buf[], short demod_in[], int *pn, uint8_t bytes_out[]);
+
+int main(int argc, char *argv[]) {
+
+    // set up DATAC0 Rx
+    struct freedv *freedv_c0 = freedv_open(FREEDV_MODE_DATAC0);
+    assert(freedv_c0 != NULL);
+    freedv_set_frames_per_burst(freedv_c0, 1);
+    freedv_set_verbose(freedv_c0, 0);
+    int bytes_per_modem_frame_c0 = freedv_get_bits_per_modem_frame(freedv_c0)/8;
+    uint8_t bytes_out_c0[bytes_per_modem_frame_c0];
+    short  demod_in_c0[freedv_get_n_max_modem_samples(freedv_c0)];
+    
+    // set up DATAC1 Rx
+    struct freedv *freedv_c1 = freedv_open(FREEDV_MODE_DATAC1);
+    assert(freedv_c1 != NULL);
+    freedv_set_frames_per_burst(freedv_c1, 1);
+    freedv_set_verbose(freedv_c1, 0);
+    int bytes_per_modem_frame_c1 = freedv_get_bits_per_modem_frame(freedv_c1)/8;
+    uint8_t bytes_out_c1[bytes_per_modem_frame_c1];
+    short  demod_in_c1[freedv_get_n_max_modem_samples(freedv_c1)];
+
+    // number of samples in demod_in buffer for each Rx
+    int n_c0 = 0;
+    int n_c1 = 0;
+    // number of frames received in each mode
+    int c0_frames = 0;
+    int c1_frames = 0;
+
+    short buf[NBUF];
+
+    // read a fixed buffer from stdin, use that to fill c0 and c1 demod_in buffers
+    while(fread(buf, sizeof(short), NBUF, stdin) == NBUF) {
+        
+        if (run_receiver(freedv_c0, buf, demod_in_c0, &n_c0, bytes_out_c0)) {
+            fprintf(stderr, "DATAC0 frame received!\n");
+            c0_frames++;
+        }
+        if (run_receiver(freedv_c1, buf, demod_in_c1, &n_c1, bytes_out_c1)) {
+            fprintf(stderr, "DATAC1 frame received!\n");
+            c1_frames++;
+        }
+        
+    }
+
+    fprintf(stderr, "DATAC0 Frames: %d DATAC1 Frames: %d\n", c0_frames, c1_frames);
+
+    freedv_close(freedv_c0);
+    freedv_close(freedv_c1);
+
+    return 0;
+}
+
+int run_receiver(struct freedv *freedv, short buf[], short demod_in[], int *pn, uint8_t bytes_out[]) {
+    int n = *pn;
+    int nbytes_out = 0;
+    int nin;
+    
+    // NBUF new samples into DATAC1 Rx
+    memcpy(&demod_in[n], buf, sizeof(short)*NBUF);
+    n += NBUF; assert(n <= freedv_get_n_max_modem_samples(freedv));
+    nin = freedv_nin(freedv);
+    while (n > nin) {
+        nbytes_out = freedv_rawdatarx(freedv, bytes_out, demod_in);
+        // nin samples were read
+        n -= nin; assert(n >= 0);
+        memmove(demod_in, &demod_in[nin], sizeof(short)*n);
+        nin = freedv_nin(freedv);
+    }
+
+    *pn = n;
+    return nbytes_out;
+}