WIP freedv API support for custom raw data modes

src/freedv_700.c

@@ -189,7 +189,7 @@ void freedv_ofdm_voice_open(struct freedv *f, char *mode) {
 
 // open function for OFDM data modes, TODO consider moving to a new
 // (freedv_ofdm_data.c) file
-void freedv_ofdm_data_open(struct freedv *f) {
+void freedv_ofdm_data_open(struct freedv *f, struct freedv_advanced *adv) {
   struct OFDM_CONFIG ofdm_config;
   char mode[32];
   if (f->mode == FREEDV_MODE_DATAC0) strcpy(mode, "datac0");
@@ -198,8 +198,14 @@ void freedv_ofdm_data_open(struct freedv *f) {
   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");
-
-  ofdm_init_mode(mode, &ofdm_config);
+  if (f->mode == FREEDV_MODE_DATA_CUSTOM) {
+    assert(adv != NULL);
+    assert(adv->config != NULL);
+    memcpy(&ofdm_config, (struct OFDM_CONFIG *)adv->config,
+           sizeof(struct OFDM_CONFIG));
+  } else {
+    ofdm_init_mode(mode, &ofdm_config);
+  }
   f->ofdm = ofdm_create(&ofdm_config);
   assert(f->ofdm != NULL);
 
@@ -219,8 +225,8 @@ void freedv_ofdm_data_open(struct freedv *f) {
   f->ofdm_ntxtbits = ofdm_config.txtbits;
 
   /* payload bits per FreeDV API "frame".  In OFDM modem nomenclature this is
-     the number of payload data bits per packet, or the number of data bits in a
-     LDPC codeword */
+     the number of payload data bits per packet, or the number of data bits in
+     a LDPC codeword */
   f->bits_per_modem_frame = f->ldpc->data_bits_per_frame;
 
   // buffers for received symbols for one packet/LDPC codeword - may span many
@@ -299,8 +305,8 @@ int freedv_comprx_700c(struct freedv *f, COMP demod_in_8kHz[]) {
 
   int rx_status = 0;
 
-  // quisk_cfInterpDecim() modifies input data so lets make a copy just in case
-  // there is no sync and we need to echo input to output
+  // quisk_cfInterpDecim() modifies input data so lets make a copy just in
+  // case there is no sync and we need to echo input to output
 
   // freedv_nin(f): input samples at Fs=8000 Hz
   // f->nin: input samples at Fs=7500 Hz
@@ -332,7 +338,8 @@ int freedv_comprx_700c(struct freedv *f, COMP demod_in_8kHz[]) {
       rx_status |= FREEDV_RX_BITS;
     } else {
       if (f->test_frames_diversity) {
-        /* normal operation - error pattern on frame after diveristy combination
+        /* normal operation - error pattern on frame after diveristy
+         * combination
          */
         short error_pattern[COHPSK_BITS_PER_FRAME];
         int bit_errors;
@@ -471,8 +478,8 @@ int freedv_comp_short_rx_ofdm(struct freedv *f, void *demod_in_8kHz,
     memcpy(&rx_amps[Nsymsperpacket - Nsymsperframe], ofdm->rx_amp,
            sizeof(float) * Nsymsperframe);
 
-    /* look for UW as frames enter packet buffer, note UW may span several modem
-     * frames */
+    /* look for UW as frames enter packet buffer, note UW may span several
+     * modem frames */
     int st_uw = Nsymsperpacket - ofdm->nuwframes * Nsymsperframe;
     ofdm_extract_uw(ofdm, &rx_syms[st_uw], &rx_amps[st_uw], rx_uw);
 
@@ -510,8 +517,8 @@ int freedv_comp_short_rx_ofdm(struct freedv *f, void *demod_in_8kHz,
         else
           rx_status |= FREEDV_RX_BIT_ERRORS;
       } else {
-        // voice modes aren't as strict - pass everything through to the speech
-        // decoder, but flag frame with possible errors
+        // voice modes aren't as strict - pass everything through to the
+        // speech decoder, but flag frame with possible errors
         rx_status |= FREEDV_RX_BITS;
         if (parityCheckCount != ldpc->NumberParityBits)
           rx_status |= FREEDV_RX_BIT_ERRORS;

src/freedv_api.c

@@ -60,7 +60,7 @@
 /* The API version number.  The first version is 10.  Increment if the API
    changes in a way that would require changes by the API user. */
 
-#define VERSION 15
+#define VERSION 16
 
 /*
   Version 10   Initial version August 2, 2015.
@@ -79,6 +79,9 @@
 
   Version 15   December 2022 Removing rarely used DPSK support which is not
                needed given fast fading modes
+
+  Version 16   April 2024, added field to struct freedv_advanced to support
+               FREEDV_MODE_DATA_CUSTOM
  */
 
 char *ofdm_statemode[] = {"search", "trial", "synced"};
@@ -101,7 +104,8 @@ char *rx_sync_flags_to_text[] = {"----", "---T", "--S-", "--ST", "-B--", "-B-T",
 
 struct freedv *freedv_open(int mode) {
   // defaults for those modes that support the use of adv
-  struct freedv_advanced adv = {0, 2, 100, 8000, 1000, 200, "H_256_512_4"};
+  struct freedv_advanced adv = {0,    2,   100,           8000,
+                                1000, 200, "H_256_512_4", NULL};
   return freedv_open_advanced(mode, &adv);
 }
 
@@ -126,7 +130,8 @@ struct freedv *freedv_open_advanced(int mode, struct freedv_advanced *adv) {
        FDV_MODE_ACTIVE(FREEDV_MODE_DATAC3, mode) ||
        FDV_MODE_ACTIVE(FREEDV_MODE_DATAC4, mode) ||
        FDV_MODE_ACTIVE(FREEDV_MODE_DATAC13, mode) ||
-       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC14, mode)) == false)
+       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC14, mode) ||
+       FDV_MODE_ACTIVE(FREEDV_MODE_DATA_CUSTOM, mode)) == false)
     return NULL;
 
   /* set everything to zero just in case */
@@ -150,12 +155,16 @@ struct freedv *freedv_open_advanced(int mode, struct freedv_advanced *adv) {
   if (FDV_MODE_ACTIVE(FREEDV_MODE_2400B, mode)) freedv_2400b_open(f);
   if (FDV_MODE_ACTIVE(FREEDV_MODE_800XA, mode)) freedv_800xa_open(f);
   if (FDV_MODE_ACTIVE(FREEDV_MODE_FSK_LDPC, mode)) freedv_fsk_ldpc_open(f, adv);
-  if (FDV_MODE_ACTIVE(FREEDV_MODE_DATAC0, mode)) freedv_ofdm_data_open(f);
-  if (FDV_MODE_ACTIVE(FREEDV_MODE_DATAC1, mode)) freedv_ofdm_data_open(f);
-  if (FDV_MODE_ACTIVE(FREEDV_MODE_DATAC3, mode)) freedv_ofdm_data_open(f);
-  if (FDV_MODE_ACTIVE(FREEDV_MODE_DATAC4, mode)) freedv_ofdm_data_open(f);
-  if (FDV_MODE_ACTIVE(FREEDV_MODE_DATAC13, mode)) freedv_ofdm_data_open(f);
-  if (FDV_MODE_ACTIVE(FREEDV_MODE_DATAC14, mode)) freedv_ofdm_data_open(f);
+  if (FDV_MODE_ACTIVE(FREEDV_MODE_DATAC0, mode)) freedv_ofdm_data_open(f, NULL);
+  if (FDV_MODE_ACTIVE(FREEDV_MODE_DATAC1, mode)) freedv_ofdm_data_open(f, NULL);
+  if (FDV_MODE_ACTIVE(FREEDV_MODE_DATAC3, mode)) freedv_ofdm_data_open(f, NULL);
+  if (FDV_MODE_ACTIVE(FREEDV_MODE_DATAC4, mode)) freedv_ofdm_data_open(f, NULL);
+  if (FDV_MODE_ACTIVE(FREEDV_MODE_DATAC13, mode))
+    freedv_ofdm_data_open(f, NULL);
+  if (FDV_MODE_ACTIVE(FREEDV_MODE_DATAC14, mode))
+    freedv_ofdm_data_open(f, NULL);
+  if (FDV_MODE_ACTIVE(FREEDV_MODE_DATA_CUSTOM, mode))
+    freedv_ofdm_data_open(f, adv);
 
   varicode_decode_init(&f->varicode_dec_states, 1);
 

src/freedv_api.h

@@ -62,6 +62,7 @@ extern "C" {
 #define FREEDV_MODE_DATAC4 18
 #define FREEDV_MODE_DATAC13 19
 #define FREEDV_MODE_DATAC14 20
+#define FREEDV_MODE_DATA_CUSTOM 21
 
 // Sample rates used
 #define FREEDV_FS_8000 8000
@@ -144,6 +145,9 @@ extern "C" {
 #if !defined(FREEDV_MODE_DATAC14_EN)
 #define FREEDV_MODE_DATAC14_EN FREEDV_MODE_EN_DEFAULT
 #endif
+#if !defined(FREEDV_MODE_DATA_CUSTOM_EN)
+#define FREEDV_MODE_DATA_CUSTOM_EN FREEDV_MODE_EN_DEFAULT
+#endif
 
 #define FDV_MODE_ACTIVE(mode_name, var) \
   ((mode_name##_EN) == 0 ? 0 : (var) == mode_name)
@@ -163,6 +167,9 @@ struct freedv_advanced {
   int first_tone;    // Freq of first tone Hz
   int tone_spacing;  // Spacing between tones Hz
   char *codename;    // LDPC codename, from codes listed in ldpc_codes.c
+
+  // parameters for FREEDV_MODE_DATA_CUSTOM
+  void *config;  // ptr to struct OFDM_CONFIG
 };
 
 // Called when text message char is decoded

src/freedv_api_internal.h

@@ -221,7 +221,7 @@ void freedv_2400a_open(struct freedv *f);
 void freedv_2400b_open(struct freedv *f);
 void freedv_800xa_open(struct freedv *f);
 void freedv_fsk_ldpc_open(struct freedv *f, struct freedv_advanced *adv);
-void freedv_ofdm_data_open(struct freedv *f);
+void freedv_ofdm_data_open(struct freedv *f, struct freedv_advanced *adv);
 
 // each mode has tx and rx functions in various flavours for real and complex
 // valued samples