Added ZMQ option to delay/advance Rx samples

lib/src/phy/rf/rf_helper.h

@@ -118,4 +118,17 @@ static inline int parse_uint32(char* args, const char* config_arg_base, int chan
   return ret;
 }
 
+static inline int parse_int32(char* args, const char* config_arg_base, int channel_index, int32_t* value)
+{
+  char tmp_value[RF_PARAM_LEN] = {0};
+  int  ret                     = parse_string(args, config_arg_base, channel_index, tmp_value);
+
+  // Copy parsed value only if was found, otherwise it keeps the default
+  if (ret == SRSLTE_SUCCESS) {
+    *value = (int32_t)strtof(tmp_value, NULL);
+  }
+
+  return ret;
+}
+
 #endif /* SRSLTE_RF_HELPER_H_ */

lib/src/phy/rf/rf_zmq_imp.c

@@ -286,10 +286,8 @@ int rf_zmq_open_multi(char* args, void** h, uint32_t nof_channels)
     }
 
     for (int i = 0; i < handler->nof_channels; i++) {
-      char rx_port[RF_PARAM_LEN] = {};
-      char tx_port[RF_PARAM_LEN] = {};
-
       // rx_port
+      char rx_port[RF_PARAM_LEN] = {};
       parse_string(args, "rx_port", i, rx_port);
 
       // rx_freq
@@ -297,7 +295,11 @@ int rf_zmq_open_multi(char* args, void** h, uint32_t nof_channels)
       parse_double(args, "rx_freq", i, &rx_freq);
       rx_opts.frequency_mhz = (uint32_t)(rx_freq / 1e6);
 
+      // rx_offset
+      parse_int32(args, "rx_offset", i, &rx_opts.sample_offset);
+
       // tx_port
+      char tx_port[RF_PARAM_LEN] = {};
       parse_string(args, "tx_port", i, tx_port);
 
       // tx_freq

lib/src/phy/rf/rf_zmq_imp_rx.c

@@ -108,6 +108,7 @@ int rf_zmq_rx_open(rf_zmq_rx_t* q, rf_zmq_opts_t opts, void* zmq_ctx, char* sock
     q->sample_format      = opts.sample_format;
     q->frequency_mhz      = opts.frequency_mhz;
     q->fail_on_disconnect = opts.fail_on_disconnect;
+    q->sample_offset      = opts.sample_offset;
 
     if (opts.socket_type == ZMQ_SUB) {
       zmq_setsockopt(q->sock, ZMQ_SUBSCRIBE, "", 0);
@@ -201,6 +202,27 @@ int rf_zmq_rx_baseband(rf_zmq_rx_t* q, cf_t* buffer, uint32_t nsamples)
     sample_sz  = 2 * sizeof(short);
   }
 
+  // If the read needs to be delayed
+  while (q->sample_offset > 0) {
+    uint32_t n_offset = SRSLTE_MIN(q->sample_offset, NBYTES2NSAMPLES(ZMQ_MAX_BUFFER_SIZE));
+    srslte_vec_zero(q->temp_buffer, n_offset);
+    int n = srslte_ringbuffer_write(&q->ringbuffer, q->temp_buffer, (int)(n_offset * sample_sz));
+    if (n < SRSLTE_SUCCESS) {
+      return n;
+    }
+    q->sample_offset -= n_offset;
+  }
+
+  // If the read needs to be advanced
+  while (q->sample_offset < 0) {
+    uint32_t n_offset = SRSLTE_MIN(-q->sample_offset, NBYTES2NSAMPLES(ZMQ_MAX_BUFFER_SIZE));
+    int n = srslte_ringbuffer_read_timed(&q->ringbuffer, q->temp_buffer, (int)(n_offset * sample_sz), ZMQ_TIMEOUT_MS);
+    if (n < SRSLTE_SUCCESS) {
+      return n;
+    }
+    q->sample_offset += n_offset;
+  }
+
   int n = srslte_ringbuffer_read_timed(&q->ringbuffer, dst_buffer, sample_sz * nsamples, ZMQ_TIMEOUT_MS);
   if (n < 0) {
     return n;

lib/src/phy/rf/rf_zmq_imp_trx.h

@@ -62,6 +62,7 @@ typedef struct {
   void*               temp_buffer_convert;
   uint32_t            frequency_mhz;
   bool                fail_on_disconnect;
+  int32_t             sample_offset;
 } rf_zmq_rx_t;
 
 typedef struct {
@@ -70,6 +71,7 @@ typedef struct {
   rf_zmq_format_t sample_format;
   uint32_t        frequency_mhz;
   bool            fail_on_disconnect;
+  int32_t         sample_offset; ///< offset in samples
 } rf_zmq_opts_t;
 
 /*