2 files changed, 16 insertions, 34 deletions
diff --git a/gr-vocoder/lib/freedv_tx_ss_impl.cc b/gr-vocoder/lib/freedv_tx_ss_impl.cc
index 310a2137e6..1f3dadeb52 100644
--- a/gr-vocoder/lib/freedv_tx_ss_impl.cc
+++ b/gr-vocoder/lib/freedv_tx_ss_impl.cc
@@ -19,24 +19,6 @@
 #include <iostream>
 #include <stdexcept>
 
-extern "C" {
-char get_next_tx_char(void* callback_state)
-{
-    char c;
-    struct freedv_tx_callback_state* pstate;
-
-    pstate = (struct freedv_tx_callback_state*)callback_state;
-    c = *pstate->ptx_str++;
-
-    if (*pstate->ptx_str == 0) {
-        pstate->ptx_str = pstate->tx_str;
-        c = 0x0d; // FreeDV uses Carriage Return termination
-    }
-
-    return c;
-}
-}
-
 namespace gr {
 namespace vocoder {
 
@@ -69,9 +51,8 @@ freedv_tx_ss_impl::freedv_tx_ss_impl(int mode,
     if ((d_freedv = freedv_open(mode)) == NULL)
         throw std::runtime_error("freedv_tx_ss_impl: freedv_open failed");
 #endif
-    snprintf(d_cb_state.tx_str, 79, "%s", d_msg_text.c_str());
-    d_cb_state.ptx_str = d_cb_state.tx_str;
-    freedv_set_callback_txt(d_freedv, NULL, get_next_tx_char, (void*)&d_cb_state);
+    d_tx_str = msg_txt + "\r"; // FreeDV uses Carriage Return termination
+    freedv_set_callback_txt(d_freedv, NULL, get_next_tx_char, this);
     d_nom_modem_samples = freedv_get_n_nom_modem_samples(d_freedv);
     set_output_multiple(d_nom_modem_samples);
 }
@@ -124,5 +105,16 @@ int freedv_tx_ss_impl::work(int noutput_items,
     return noutput_items;
 }
 
+char freedv_tx_ss_impl::get_next_tx_char(void* callback_state)
+{
+    freedv_tx_ss_impl* instance = static_cast<freedv_tx_ss_impl*>(callback_state);
+    char c = instance->d_tx_str[instance->d_tx_str_offset++];
+
+    if (instance->d_tx_str_offset == instance->d_tx_str.length())
+        instance->d_tx_str_offset = 0;
+
+    return c;
+}
+
 } /* namespace vocoder */
 } /* namespace gr */
diff --git a/gr-vocoder/lib/freedv_tx_ss_impl.h b/gr-vocoder/lib/freedv_tx_ss_impl.h
index 31ed023eb7..f4f341b97e 100644
--- a/gr-vocoder/lib/freedv_tx_ss_impl.h
+++ b/gr-vocoder/lib/freedv_tx_ss_impl.h
@@ -13,18 +13,6 @@
 
 #include <gnuradio/vocoder/freedv_tx_ss.h>
 
-extern "C" {
-struct freedv_tx_callback_state {
-    char tx_str[80];
-    char* ptx_str;
-    int calls;
-};
-char get_next_tx_char(void* callback_state);
-void get_next_proto(void* callback_state, char* proto_bits);
-void datarx(void* callback_state, unsigned char* packet, size_t size);
-void datatx(void* callback_state, unsigned char* packet, size_t* size);
-}
-
 namespace gr {
 namespace vocoder {
 
@@ -33,7 +21,9 @@ class freedv_tx_ss_impl : public freedv_tx_ss
 private:
     short* d_speech_in;
     short* d_mod_out;
-    struct freedv_tx_callback_state d_cb_state;
+    std::string d_tx_str;
+    std::string::size_type d_tx_str_offset = 0;
+    static char get_next_tx_char(void* callback_state);
     struct freedv* d_freedv;
     int d_mode;
     std::string d_msg_text;