changed function name and description

more self explaining name for function: freedv_set_tuning_range

Author: DJ2LS

src/freedv_api.c

@@ -1378,13 +1378,18 @@ void freedv_get_fsk_S_and_N               (struct freedv *f, float *S, float *N)
   FUNCTIONS...: freedv_set_fmin_fmax
   AUTHOR......: Simon Lang - DJ2LS
   DATE CREATED: 18 feb 2022
-
-  Set fmin / fmax for ofdm modem
-
+  DEFAULT.....: fmin: -50.0Hz fmax: 50.0Hz
+  DESCRIPTION.:
+  
+  |<---fmin - | rx centre frequency | + fmax--->|
+  
+  Useful for handling frequency offsets, 
+  e.g. caused by an imprecise VFO, the trade off is more CPU power is required.  
+  
 \*---------------------------------------------------------------------------*/
-int freedv_set_fmin_fmax(struct freedv *freedv, float val_fmin, float val_fmax) {
+int freedv_set_tuning_range(struct freedv *freedv, float val_fmin, float val_fmax) {
 
-    if (is_ofdm_data_mode(freedv)) {
+    if (is_ofdm_mode(freedv)) {
         freedv->ofdm->fmin = val_fmin;
         freedv->ofdm->fmax = val_fmax;
         return 1;

src/freedv_api.h

@@ -240,7 +240,7 @@ void freedv_set_phase_est_bandwidth_mode(struct freedv *f, int val);
 void freedv_set_eq                      (struct freedv *f, int val);
 void freedv_set_frames_per_burst        (struct freedv *f, int framesperburst);
 void freedv_passthrough_gain            (struct freedv *f, float g);
-int freedv_set_fmin_fmax                (struct freedv *freedv, float val_fmin, float val_fmax);
+int freedv_set_tuning_range             (struct freedv *freedv, float val_fmin, float val_fmax);
 
 // Get parameters -------------------------------------------------------------------------
 

src/ofdm.c

@@ -219,8 +219,8 @@ struct OFDM *ofdm_create(const struct OFDM_CONFIG *config) {
         ofdm->clip_en = false;
         ofdm->foff_limiter = false;
         ofdm->data_mode = "";
-        ofdm->fmin = -50.0;
-        ofdm->fmax = 50.0;
+        ofdm->fmin = -50.0;                       /* frequency minimum for ofdm acquisition range */
+        ofdm->fmax = 50.0;                        /* frequency maximum for ofdm acquisition range */
         memset(ofdm->tx_uw, 0, ofdm->nuwbits);
     } else {
         /* Use the users values */
@@ -254,8 +254,8 @@ struct OFDM *ofdm_create(const struct OFDM_CONFIG *config) {
         ofdm->clip_en = config->clip_en;
         memcpy(ofdm->tx_uw, config->tx_uw, ofdm->nuwbits);
         ofdm->data_mode = config->data_mode;
-        ofdm->fmin = config->fmin;
-        ofdm->fmax = config->fmax;
+        ofdm->fmin = config->fmin;              /* frequency minimum for ofdm acquisition range */
+        ofdm->fmax = config->fmax;              /* frequency maximum for ofdm acquisition range */
 
     }