Control channels decoding with libosmocore
diff --git a/lib/decoding/control_channels_decoder_impl.cc b/lib/decoding/control_channels_decoder_impl.cc
index ddea256..71695e2 100644
--- a/lib/decoding/control_channels_decoder_impl.cc
+++ b/lib/decoding/control_channels_decoder_impl.cc
@@ -82,42 +82,42 @@
{
ubit_t bursts_u[116 * 4];
sbit_t bursts_s[116 * 4];
- uint8_t result[23];
- int n_errors, n_bits_total;
-
+ uint8_t result[23];
+ int n_errors, n_bits_total;
+ int8_t header_plus_data[sizeof(gsmtap_hdr)+DATA_BYTES];
+
d_bursts[d_collected_bursts_num] = msg;
d_collected_bursts_num++;
+
//get convecutive bursts
-
if(d_collected_bursts_num==4)
{
d_collected_bursts_num=0;
- //reorganize data
+ //reorganize data from input bursts
for(int ii = 0; ii < 4; ii++)
{
pmt::pmt_t header_plus_burst = pmt::cdr(d_bursts[ii]);
int8_t * burst_bits = (int8_t *)(pmt::blob_data(header_plus_burst))+sizeof(gsmtap_hdr);
-
+
memcpy(&bursts_u[ii*116], &burst_bits[3],58);
- memcpy(&bursts_u[ii*116+58], &burst_bits[3+57+1+26],58);
+ memcpy(&bursts_u[ii*116+58], &burst_bits[3+57+1+26],58);
}
//convert to soft bits
ubits2sbits(bursts_u, bursts_s, 116 * 4);
//decode
gsm0503_xcch_decode(result, bursts_s, &n_errors, &n_bits_total);
- //send to the output
+ //extract header of the first burst of the four bursts
pmt::pmt_t first_header_plus_burst = pmt::cdr(d_bursts[0]);
gsmtap_hdr * header = (gsmtap_hdr *)pmt::blob_data(first_header_plus_burst);
- int8_t header_plus_data[sizeof(gsmtap_hdr)+DATA_BYTES];
+ //copy header and data
memcpy(header_plus_data, header, sizeof(gsmtap_hdr));
-
memcpy(header_plus_data+sizeof(gsmtap_hdr), result, DATA_BYTES);
+ //set data type in the header
((gsmtap_hdr*)header_plus_data)->type = GSMTAP_TYPE_UM;
-
- pmt::pmt_t msg_binary_blob = pmt::make_blob(header_plus_data,DATA_BYTES+sizeof(gsmtap_hdr));
- pmt::pmt_t msg_out = pmt::cons(pmt::PMT_NIL, msg_binary_blob);
-
+ //prepare message
+ pmt::pmt_t msg_out = pmt::cons(pmt::PMT_NIL, pmt::make_blob(header_plus_data,DATA_BYTES+sizeof(gsmtap_hdr)));
+ //send message to the output
message_port_pub(pmt::mp("msgs"), msg_out);
}
return;