added new function

- unpack_LICH()

SP5WWP/include/m17/m17.h

@@ -69,6 +69,7 @@ uint16_t LSF_CRC(const struct LSF *in);
 
 // M17 C library - lib/payload/lich.c
 void extract_LICH(uint8_t outp[6], const uint8_t cnt, const struct LSF *inp);
+void unpack_LICH(uint8_t *out, const uint8_t in[12]);
 
 // M17 C library - lib/math/golay.c
 extern const uint16_t encode_matrix[12];

SP5WWP/lib/payload/lich.c

@@ -76,3 +76,18 @@ void extract_LICH(uint8_t outp[6], const uint8_t cnt, const struct LSF *inp)
 
     outp[5]=cnt<<5;
 }
+
+/**
+ * @brief Unpack LICH bytes.
+ * 
+ * @param out Unpacked, encoded LICH bits (array of at least 96 bytes).
+ * @param in 12-byte (96 bits) encoded LICH, packed.
+ */
+void unpack_LICH(uint8_t *out, const uint8_t in[12])
+{
+    for(uint8_t i=0; i<12; i++)
+    {
+        for(uint8_t j=0; j<8; j++)
+            out[i*8+j]=(in[i]>>(7-j))&1;
+    }
+}

SP5WWP/m17-coder/m17-coder-sym.c

@@ -72,14 +72,9 @@ int main(void)
             encode_LICH(lich_encoded, lich);
 
             //unpack LICH (12 bytes)
-            memset(enc_bits, 0, SYM_PER_PLD*2);
-            for(uint8_t i=0; i<12; i++)
-            {
-                for(uint8_t j=0; j<8; j++)
-                    enc_bits[i*8+j]=(lich_encoded[i]>>(7-j))&1;
-            }
+            unpack_LICH(enc_bits, lich_encoded);
 
-            //encode the rest of the frame
+            //encode the rest of the frame (starting at bit 96 - 0..95 are filled with LICH)
             conv_encode_stream_frame(&enc_bits[96], data, finished ? (fn | 0x8000) : fn);
 
             //reorder bits
@@ -119,9 +114,6 @@ int main(void)
         {
             got_lsf=1;
 
-            //encode LSF data
-            conv_encode_LSF(enc_bits, &lsf);
-
             //send out the preamble
             frame_buff_cnt=0;
 			send_preamble(frame_buff, &frame_buff_cnt, 0); //0 - LSF preamble, as opposed to 1 - BERT preamble
@@ -132,21 +124,14 @@ int main(void)
 			send_syncword(frame_buff, &frame_buff_cnt, SYNC_LSF);
             fwrite((uint8_t*)frame_buff, SYM_PER_SWD*sizeof(float), 1, stdout);
 
+            //encode LSF data
+            conv_encode_LSF(enc_bits, &lsf);
+
             //reorder bits
-            for(uint16_t i=0; i<SYM_PER_PLD*2; i++)
-                rf_bits[i]=enc_bits[intrl_seq[i]];
+            reorder_bits(rf_bits, enc_bits);
 
             //randomize
-            for(uint16_t i=0; i<SYM_PER_PLD*2; i++)
-            {
-                if((rand_seq[i/8]>>(7-(i%8)))&1) //flip bit if '1'
-                {
-                    if(rf_bits[i])
-                        rf_bits[i]=0;
-                    else
-                        rf_bits[i]=1;
-                }
-            }
+            randomize_bits(rf_bits);
 
 			//send LSF data
             frame_buff_cnt=0;