Get FREEDV_MODE_FSK_LDPC working with freedv data API and small fix to README_data.md

CMakeLists.txt

@@ -472,7 +472,7 @@ endif()
 
     add_test(NAME test_OFDM_modem_octave_qam16_uncoded
              COMMAND sh -c "cd ${CMAKE_CURRENT_SOURCE_DIR}/octave;
-                            echo \"ofdm_tx('test_qam16.raw','qam16c1',3,12,'awgn','bursts',3); ofdm_rx('test_qam16.raw','qam16c1', 'passber', 0.05, 'packetsperburst', 1); quit\" |
+                            echo \"ofdm_tx('test_qam16.raw','qam16c2',1,12,'awgn','bursts',3); ofdm_rx('test_qam16.raw','qam16c2', 'passber', 0.05, 'packetsperburst', 1); quit\" |
                             DISPLAY=\"\" octave-cli")
              set_tests_properties(test_OFDM_modem_octave_qam16_uncoded PROPERTIES PASS_REGULAR_EXPRESSION "Pass")
 
@@ -669,6 +669,13 @@ endif()
                             cd ${CMAKE_CURRENT_BINARY_DIR}/src;
                             cat test.raw | ./ofdm_demod --mode datac14 --out /dev/null --testframes --ldpc --verbose 2 --packetsperburst 1")
 
+    # QAM16C2 Octave Tx, C Rx, burst mode
+    add_test(NAME test_OFDM_modem_qam16c2_octave
+             COMMAND sh -c "cd ${CMAKE_CURRENT_SOURCE_DIR}/octave;
+                            DISPLAY=\"\" octave-cli -qf --eval 'ofdm_ldpc_tx(\"${CMAKE_CURRENT_BINARY_DIR}/src/test.raw\",\"qam16c2\",1,10,\"awgn\",\"bursts\",2)';
+                            cd ${CMAKE_CURRENT_BINARY_DIR}/src;
+                            cat test.raw | ./ofdm_demod --mode qam16c2 --out /dev/null --testframes --ldpc --verbose 2 --packetsperburst 1")
+
     # DATAC4 C Tx, C Rx, burst mode
     add_test(NAME test_OFDM_modem_datac4_ldpc_burst
              COMMAND sh -c "cd ${CMAKE_CURRENT_BINARY_DIR}/src;
@@ -690,6 +697,13 @@ endif()
                             ./ch - - --No -17 |
                             ./ofdm_demod --mode datac14 --out /dev/null --testframes --ldpc --verbose 2 --packetsperburst 1")
 
+    # QAM16C2 C Tx, C Rx, burst mode
+    add_test(NAME test_OFDM_modem_qam16c2_ldpc_burst
+             COMMAND sh -c "cd ${CMAKE_CURRENT_BINARY_DIR}/src;
+                            ./ofdm_mod --mode qam16c2 --in /dev/zero --testframes 1 --verbose 1 --ldpc --bursts 10 |
+                            ./ch - - --No -30 |
+                            ./ofdm_demod --mode qam16c2 --out /dev/null --testframes --ldpc --verbose 2 --packetsperburst 1")
+
     # -------------------------------------------------------------------------
     #                                LDPC
     # -------------------------------------------------------------------------
@@ -1340,6 +1354,13 @@ endif(NOT APPLE)
                             ./freedv_data_raw_rx DATAC14 - binaryOut.bin -v;
                             diff binaryIn.bin binaryOut.bin")
 
+     add_test(NAME test_freedv_data_raw_ofdm_qam16c2_burst_file
+             COMMAND sh -c "cd ${CMAKE_CURRENT_BINARY_DIR}/src;
+                            head -c $((1213*10)) </dev/urandom > binaryIn.bin;
+                            ./freedv_data_raw_tx qam16c2 binaryIn.bin - --bursts 10 |
+                            ./freedv_data_raw_rx qam16c2 - binaryOut.bin -v;
+                            diff binaryIn.bin binaryOut.bin")
+
      # FSK LDPC default 100 bit/s 2FSK, enough noise for several % raw BER to give
      # FEC/acquisition a work out, bursts of 1 frame as that stresses acquisition
      add_test(NAME test_freedv_data_raw_fsk_ldpc_100
@@ -1426,6 +1447,7 @@ endif(NOT APPLE)
         test_OFDM_modem_datac4_octave
         test_OFDM_modem_datac13_octave
         test_OFDM_modem_datac14_octave
+        test_OFDM_modem_qam16c2_octave
         test_fsk_lib_4fsk_ldpc
         test_OFDM_modem_datac0_compression
         PROPERTIES

README_data.md

@@ -144,9 +144,10 @@ These modes use an OFDM modem with powerful LDPC codes and are designed for send
 | DATAC0 | 500 | 291 | 14 | (256,128) | 0.44 | 70/100 at 0dB | Reverse link ACK packets |
 | DATAC1 | 1700 | 980 | 510 | (8192,4096) | 4.18 | 92/100 at 5dB | Forward link data (medium SNR) |
 | DATAC3 | 500 | 321 | 126 | (2048,1024) | 3.19 | 74/100 at 0dB | Forward link data (low SNR) |
-| DATAC4 | 250 | 87 | 56 | (1472,448) | 5.17 | 90/100 at -4dB | Forward link data (low SNR) |
+| DATAC4 | 250 | 87 | 54 | (1472,448) | 5.17 | 90/100 at -4dB | Forward link data (low SNR) |
 | DATAC13 | 200 | 64 | 14 | (384,128) | 2.0 | 90/100 at -4dB | Reverse link ACK packets (low SNR) |
 | DATAC14 | 250 | 58 | 3 | (112,56) | 0.69 | 90/100 at -2dB | Reverse link ACK packets (low SNR) |
+| QAM16C2 | 2100 | 3100 | 1213 | (16200,9720) | 3.2 | 90/100 at 15dB | Forward link data (high SNR) |
 
 Notes:
 1. 16 bits (2 bytes) per frame are reserved for a 16 bit CRC, e.g. for `datac3` we have 128 byte frames, and 128-2=126 bytes/frame of payload data.

octave/ofdm_lib.m

@@ -52,7 +52,6 @@
   bad_uw_errors = config.bad_uw_errors;
   amp_scale = config.amp_scale;
   amp_est_mode = config.amp_est_mode;
-  EsNo_est_all_symbols = config.EsNo_est_all_symbols;
   EsNodB = config.EsNodB; 
   state_machine = config.state_machine; 
   edge_pilots = config.edge_pilots;
@@ -74,10 +73,10 @@
   states.Nsampersymbol = states.M+states.Ncp;     % number of samples in a single symbol
   states.Nsamperframe  = Ns*states.Nsampersymbol; % number of samples in a modem frame
   states.qam16 = [
-    1 + j,  1 + j*3,  3 + j,  3 + j*3;
-    1 - j,  1 - j*3,  3 - j,  3 - j*3;
-   -1 + j, -1 + j*3, -3 + j, -3 + j*3;
-   -1 - j, -1 - j*3, -3 - j, -3 - j*3]/3;
+    1 + j,  1 + j*3,  3 + j,  3 + j*3, ...
+    1 - j,  1 - j*3,  3 - j,  3 - j*3, ...
+   -1 + j, -1 + j*3, -3 + j, -3 + j*3, ...
+   -1 - j, -1 - j*3, -3 - j, -3 - j*3];
   rms = sqrt(states.qam16(:)'*states.qam16(:)/16);% set average Es to 1
   states.qam16 /= rms;
   states.qam16 *= exp(-j*pi/4);                   % same rotation as QPSK constellation
@@ -128,7 +127,7 @@
       states.uw_ind = [states.uw_ind bps*ind_sym-b];   % bit index
     end
   end
-
+  
   % how many of the first few frames have UW symbols in them
   Nsymsperframe = states.Nbitsperframe/states.bps;
   states.Nuwframes = ceil(states.uw_ind_sym(end)/Nsymsperframe);
@@ -275,7 +274,6 @@
 
   % Es/No (SNR) est states
 
-  states.EsNo_est_all_symbols = EsNo_est_all_symbols;
   states.clock_offset_est = 0;
 
   % pre-amble for data modes

octave/ofdm_mode.m

@@ -25,7 +25,6 @@
   config.bad_uw_errors = 3;
   config.amp_scale = 245E3;
   config.amp_est_mode = 0;
-  config.EsNo_est_all_symbols = 1;
   config.EsNodB = 3;
   config.state_machine = "voice1";
   config.edge_pilots = 1;
@@ -59,12 +58,12 @@
     config.bps=4; config.Ntxtbits = 0; config.Nuwbits = 15*4; config.bad_uw_errors = 5;
     config.state_machine = "data";
     config.ftwindow_width = 32; config.amp_scale = 132E3;
-    config.EsNo_est_all_symbols = 0; config.amp_est_mode = 1; config.EsNodB = 10;
+    config.amp_est_mode = 1; config.EsNodB = 10;
   elseif strcmp(mode,"qam16c2")
     Ns=5; config.Np=31; Tcp = 0.004; Ts = 0.016; Nc = 33; config.data_mode = "streaming";
-    config.bps=4; config.Ntxtbits = 0; config.Nuwbits = 42*4; config.bad_uw_errors = 15;
+    config.bps=4; config.Ntxtbits = 0; config.Nuwbits = 42*4; config.bad_uw_errors = 50;
     config.ftwindow_width = 80; config.amp_scale = 135E3; config.state_machine = "data";
-    config.EsNo_est_all_symbols = 0; config.amp_est_mode = 1; config.EsNodB = 10;
+    config.amp_est_mode = 1; config.EsNodB = 10;
     config.tx_uw = zeros(1,config.Nuwbits = 42*4);
     config.tx_uw(1:24) = [1 1 0 0  1 0 1 0  1 1 1 1  0 0 0 0  1 1 1 1  0 0 0 0];
     config.tx_uw(end-24+1:end) = [1 1 0 0  1 0 1 0  1 1 1 1  0 0 0 0  1 1 1 1  0 0 0 0];

octave/qam16.m

@@ -25,7 +25,7 @@ function test_qam16_mod_demod(constellation)
     for decimal=0:15
       tx_bits = zeros(1,4);
       for i=1:4
-        tx_bits(1,5-i) = bitand(bitshift(decimal-1,1-i),1);
+        tx_bits(1,5-i) = bitand(bitshift(decimal,1-i),1);
       end
       symbol = qam16_mod(constellation, tx_bits);
       rx_bits = qam16_demod(constellation,symbol);

src/freedv_2020.c

@@ -229,8 +229,7 @@ int freedv_comprx_2020(struct freedv *f, COMP demod_in[]) {
 
   f->sync = 0;
 
-  // TODO: should be higher for 2020?
-  float EsNo = 3.0;
+  float EsNo = pow(10.0, ofdm->EsNodB / 10);
 
   /* looking for modem sync */
 
@@ -249,7 +248,7 @@ int freedv_comprx_2020(struct freedv *f, COMP demod_in[]) {
 
     ofdm_demod(ofdm, rx_bits, demod_in);
     ofdm_extract_uw(ofdm, ofdm->rx_np, ofdm->rx_amp, rx_uw);
-    ofdm_disassemble_qpsk_modem_packet_with_text_amps(
+    ofdm_disassemble_psk_modem_packet_with_text_amps(
         ofdm, ofdm->rx_np, ofdm->rx_amp, payload_syms, payload_amps, txt_bits,
         &txt_sym_index);
 
@@ -280,14 +279,14 @@ int freedv_comprx_2020(struct freedv *f, COMP demod_in[]) {
     uint8_t out_char[coded_bits_per_frame];
 
     if (f->test_frames) {
-      Nerrs_raw =
-          count_uncoded_errors(ldpc, &f->ofdm->config, codeword_symbols_de, 0);
+      Nerrs_raw = count_uncoded_errors(
+          ldpc, &f->ofdm->config, codeword_symbols_de, codeword_amps_de, 0);
       f->total_bit_errors += Nerrs_raw;
       f->total_bits += f->ofdm_bitsperframe;
     }
 
     symbols_to_llrs(llr, codeword_symbols_de, codeword_amps_de, EsNo,
-                    ofdm->mean_amp, coded_syms_per_frame);
+                    ofdm->mean_amp, ofdm->bps, coded_syms_per_frame);
     ldpc_decode_frame(ldpc, &parityCheckCount, &iter, out_char, llr);
     if (parityCheckCount != ldpc->NumberParityBits)
       rx_status |= FREEDV_RX_BIT_ERRORS;

src/freedv_700.c

@@ -198,6 +198,7 @@ void freedv_ofdm_data_open(struct freedv *f, struct freedv_advanced *adv) {
   if (f->mode == FREEDV_MODE_DATAC4) strcpy(mode, "datac4");
   if (f->mode == FREEDV_MODE_DATAC13) strcpy(mode, "datac13");
   if (f->mode == FREEDV_MODE_DATAC14) strcpy(mode, "datac14");
+  if (f->mode == FREEDV_MODE_QAM16C2) strcpy(mode, "qam16c2");
   if (f->mode == FREEDV_MODE_DATA_CUSTOM) {
     assert(adv != NULL);
     assert(adv->config != NULL);
@@ -447,7 +448,7 @@ int freedv_comp_short_rx_ofdm(struct freedv *f, void *demod_in_8kHz,
   assert((demod_in_is_short == 0) || (demod_in_is_short == 1));
 
   int rx_status = 0;
-  float EsNo = 3.0; /* further work: estimate this properly from signal */
+  float EsNo = pow(10.0, ofdm->EsNodB / 10);
   f->sync = 0;
 
   /* looking for OFDM modem sync */
@@ -490,7 +491,7 @@ int freedv_comp_short_rx_ofdm(struct freedv *f, void *demod_in_8kHz,
       /* we have received enough modem frames to complete packet and run LDPC
        * decoder */
       int txt_sym_index = 0;
-      ofdm_disassemble_qpsk_modem_packet_with_text_amps(
+      ofdm_disassemble_psk_modem_packet_with_text_amps(
           ofdm, rx_syms, rx_amps, payload_syms, payload_amps, txt_bits,
           &txt_sym_index);
 
@@ -504,15 +505,48 @@ int freedv_comp_short_rx_ofdm(struct freedv *f, void *demod_in_8kHz,
       float llr[Npayloadbitsperpacket];
       uint8_t decoded_codeword[Npayloadbitsperpacket];
       symbols_to_llrs(llr, payload_syms_de, payload_amps_de, EsNo,
-                      ofdm->mean_amp, Npayloadsymsperpacket);
+                      ofdm->mean_amp, ofdm->bps, Npayloadsymsperpacket);
       ldpc_decode_frame(ldpc, &parityCheckCount, &iter, decoded_codeword, llr);
-      // iter = run_ldpc_decoder(ldpc, decoded_codeword, llr,
-      // &parityCheckCount);
       memcpy(f->rx_payload_bits, decoded_codeword, Ndatabitsperpacket);
 
       if (strlen(ofdm->data_mode)) {
+        int crc_ok =
+            freedv_check_crc16_unpacked(f->rx_payload_bits, Ndatabitsperpacket);
+        if (!crc_ok && f->verbose) {
+          int bytes_per_frame = (Ndatabitsperpacket + 7) / 8;
+          uint8_t rx_bytes[bytes_per_frame];
+          freedv_pack(rx_bytes, f->rx_payload_bits, Ndatabitsperpacket);
+          uint16_t rx_crc16 =
+              ((uint16_t)rx_bytes[bytes_per_frame - 2] << 8) |
+              rx_bytes[bytes_per_frame - 1];
+          uint16_t calc_crc16 =
+              freedv_gen_crc16(rx_bytes, bytes_per_frame - 2);
+          fprintf(stderr,
+                  "OFDM data CRC fail: mode=%s bytes=%d rx_crc=%04x calc_crc=%04x "
+                  "pcc=%d/%d iter=%d euw=%d foff=%4.1f\n",
+                  ofdm->mode, bytes_per_frame, rx_crc16, calc_crc16,
+                  parityCheckCount, ldpc->NumberParityBits, iter, ofdm->uw_errors,
+                  (double)ofdm->foff_est_hz);
+          if (f->verbose >= 2) {
+            int n = bytes_per_frame < 16 ? bytes_per_frame : 16;
+            fprintf(stderr, "  payload[0:%d] =", n);
+            for (int bi = 0; bi < n; bi++) fprintf(stderr, " %02x", rx_bytes[bi]);
+            fprintf(stderr, "\n");
+          }
+        } else if (crc_ok && f->verbose >= 2) {
+          int bytes_per_frame = (Ndatabitsperpacket + 7) / 8;
+          uint8_t rx_bytes[bytes_per_frame];
+          freedv_pack(rx_bytes, f->rx_payload_bits, Ndatabitsperpacket);
+          fprintf(stderr, "OFDM data OK: mode=%s bytes=%d pcc=%d/%d iter=%d\n",
+                  ofdm->mode, bytes_per_frame, parityCheckCount,
+                  ldpc->NumberParityBits, iter);
+          int n = bytes_per_frame < 16 ? bytes_per_frame : 16;
+          fprintf(stderr, "  payload[0:%d] =", n);
+          for (int bi = 0; bi < n; bi++) fprintf(stderr, " %02x", rx_bytes[bi]);
+          fprintf(stderr, "\n");
+        }
         // we need a valid CRC to declare a data packet valid
-        if (freedv_check_crc16_unpacked(f->rx_payload_bits, Ndatabitsperpacket))
+        if (crc_ok)
           rx_status |= FREEDV_RX_BITS;
         else
           rx_status |= FREEDV_RX_BIT_ERRORS;
@@ -526,8 +560,9 @@ int freedv_comp_short_rx_ofdm(struct freedv *f, void *demod_in_8kHz,
 
       if (f->test_frames) {
         /* est uncoded BER from payload bits */
-        Nerrs_raw = count_uncoded_errors(
-            ldpc, &f->ofdm->config, payload_syms_de, strlen(ofdm->data_mode));
+        Nerrs_raw =
+            count_uncoded_errors(ldpc, &f->ofdm->config, payload_syms_de,
+                                 payload_amps_de, strlen(ofdm->data_mode));
         f->total_bit_errors += Nerrs_raw;
         f->total_bits += Npayloadbitsperpacket;
 

src/freedv_api.c

@@ -131,7 +131,8 @@ struct freedv *freedv_open_advanced(int mode, struct freedv_advanced *adv) {
        FDV_MODE_ACTIVE(FREEDV_MODE_DATAC4, mode) ||
        FDV_MODE_ACTIVE(FREEDV_MODE_DATAC13, mode) ||
        FDV_MODE_ACTIVE(FREEDV_MODE_DATAC14, mode) ||
-       FDV_MODE_ACTIVE(FREEDV_MODE_DATA_CUSTOM, mode)) == false)
+       FDV_MODE_ACTIVE(FREEDV_MODE_DATA_CUSTOM, mode) ||
+       FDV_MODE_ACTIVE(FREEDV_MODE_QAM16C2, mode)) == false)
     return NULL;
 
   /* set everything to zero just in case */
@@ -165,6 +166,8 @@ struct freedv *freedv_open_advanced(int mode, struct freedv_advanced *adv) {
     freedv_ofdm_data_open(f, NULL);
   if (FDV_MODE_ACTIVE(FREEDV_MODE_DATA_CUSTOM, mode))
     freedv_ofdm_data_open(f, adv);
+  if (FDV_MODE_ACTIVE(FREEDV_MODE_QAM16C2, mode))
+    freedv_ofdm_data_open(f, NULL);
 
   varicode_decode_init(&f->varicode_dec_states, 1);
 
@@ -248,6 +251,7 @@ void freedv_close(struct freedv *freedv) {
       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC4, freedv->mode) ||
       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC13, freedv->mode) ||
       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC14, freedv->mode) ||
+      FDV_MODE_ACTIVE(FREEDV_MODE_QAM16C2, freedv->mode) ||
       FDV_MODE_ACTIVE(FREEDV_MODE_DATA_CUSTOM, freedv->mode)) {
     FREE(freedv->rx_syms);
     FREE(freedv->rx_amps);
@@ -281,6 +285,7 @@ static int is_ofdm_mode(struct freedv *f) {
          FDV_MODE_ACTIVE(FREEDV_MODE_DATAC4, f->mode) ||
          FDV_MODE_ACTIVE(FREEDV_MODE_DATAC13, f->mode) ||
          FDV_MODE_ACTIVE(FREEDV_MODE_DATAC14, f->mode) ||
+         FDV_MODE_ACTIVE(FREEDV_MODE_QAM16C2, f->mode) ||
          FDV_MODE_ACTIVE(FREEDV_MODE_DATA_CUSTOM, f->mode);
 }
 
@@ -291,6 +296,7 @@ static int is_ofdm_data_mode(struct freedv *f) {
          FDV_MODE_ACTIVE(FREEDV_MODE_DATAC4, f->mode) ||
          FDV_MODE_ACTIVE(FREEDV_MODE_DATAC13, f->mode) ||
          FDV_MODE_ACTIVE(FREEDV_MODE_DATAC14, f->mode) ||
+         FDV_MODE_ACTIVE(FREEDV_MODE_QAM16C2, f->mode) ||
          FDV_MODE_ACTIVE(FREEDV_MODE_DATA_CUSTOM, f->mode);
 }
 
@@ -483,6 +489,7 @@ void freedv_rawdatacomptx(struct freedv *f, COMP mod_out[],
       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC4, f->mode) ||
       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC13, f->mode) ||
       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC14, f->mode) ||
+      FDV_MODE_ACTIVE(FREEDV_MODE_QAM16C2, f->mode) ||
       FDV_MODE_ACTIVE(FREEDV_MODE_DATA_CUSTOM, f->mode))
     freedv_comptx_ofdm(f, mod_out);
 
@@ -1084,6 +1091,7 @@ int freedv_rawdatacomprx(struct freedv *f, unsigned char *packed_payload_bits,
       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC4, f->mode) ||
       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC13, f->mode) ||
       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC14, f->mode) ||
+      FDV_MODE_ACTIVE(FREEDV_MODE_QAM16C2, f->mode) ||
       FDV_MODE_ACTIVE(FREEDV_MODE_DATA_CUSTOM, f->mode))
     rx_status = freedv_comp_short_rx_ofdm(f, (void *)demod_in, 0, 1.0f);
   if (FDV_MODE_ACTIVE(FREEDV_MODE_FSK_LDPC, f->mode)) {

src/freedv_api.h

@@ -63,6 +63,7 @@ extern "C" {
 #define FREEDV_MODE_DATAC13 19
 #define FREEDV_MODE_DATAC14 20
 #define FREEDV_MODE_DATA_CUSTOM 21
+#define FREEDV_MODE_QAM16C2 22
 
 // Sample rates used
 #define FREEDV_FS_8000 8000
@@ -148,6 +149,9 @@ extern "C" {
 #if !defined(FREEDV_MODE_DATA_CUSTOM_EN)
 #define FREEDV_MODE_DATA_CUSTOM_EN FREEDV_MODE_EN_DEFAULT
 #endif
+#if !defined(FREEDV_MODE_QAM16C2_EN)
+#define FREEDV_MODE_QAM16C2_EN FREEDV_MODE_EN_DEFAULT
+#endif
 
 #define FDV_MODE_ACTIVE(mode_name, var) \
   ((mode_name##_EN) == 0 ? 0 : (var) == mode_name)

src/freedv_data_raw_rx.c

@@ -217,6 +217,8 @@ int main(int argc, char *argv[]) {
     mode = FREEDV_MODE_DATAC13;
   if (!strcmp(argv[dx], "DATAC14") || !strcmp(argv[dx], "datac14"))
     mode = FREEDV_MODE_DATAC14;
+  if (!strcmp(argv[dx], "QAM16C2") || !strcmp(argv[dx], "qam16c2"))
+    mode = FREEDV_MODE_QAM16C2;
   if (!strcmp(argv[dx], "CUSTOM") || !strcmp(argv[dx], "custom"))
     mode = FREEDV_MODE_DATA_CUSTOM;
   if (mode == -1) {

src/freedv_data_raw_tx.c

@@ -238,6 +238,8 @@ int main(int argc, char *argv[]) {
     mode = FREEDV_MODE_DATAC13;
   if (!strcmp(argv[dx], "DATAC14") || !strcmp(argv[dx], "datac14"))
     mode = FREEDV_MODE_DATAC14;
+  if (!strcmp(argv[dx], "QAM16C2") || !strcmp(argv[dx], "qam16c2"))
+    mode = FREEDV_MODE_QAM16C2;
   if (!strcmp(argv[dx], "CUSTOM") || !strcmp(argv[dx], "custom"))
     mode = FREEDV_MODE_DATA_CUSTOM;
   if (mode == -1) {

src/freedv_fsk.c

@@ -612,9 +612,13 @@ int freedv_rx_fsk_ldpc_data(struct freedv *f, COMP demod_in[]) {
       for (int i = 0; i < 8; i++) seq |= f->rx_payload_bits[8 + i] << (7 - i);
     }
 
-    if (f->fsk_ldpc_state == 1)
+    if (f->fsk_ldpc_state == 1) {
       rx_status |=
           FREEDV_RX_SYNC; /* need this set before verbose logging fprintf() */
+      f->sync = 1;
+    } else {
+      f->sync = 0;
+    }
     if (((f->verbose == 1) && (rx_status & FREEDV_RX_BITS)) ||
         (f->verbose == 2)) {
       fprintf(stderr,
@@ -628,7 +632,12 @@ int freedv_rx_fsk_ldpc_data(struct freedv *f, COMP demod_in[]) {
     }
   } else {
     /* set RX_SYNC flag even if we don't perform frame processing */
-    if (f->fsk_ldpc_state == 1) rx_status |= FREEDV_RX_SYNC;
+    if (f->fsk_ldpc_state == 1) {
+      rx_status |= FREEDV_RX_SYNC;
+      f->sync = 1;
+    } else {
+      f->sync = 0;
+    }
   }
 
   return rx_status;