feat(burst_downmix): Make multiple frames per burst optional

apps/iridium-extractor

@@ -102,7 +102,8 @@ if __name__ == "__main__":
                                                             'burstsize=',
                                                             'uplink',
                                                             'downlink',
-                                                            'decimation'
+                                                            'decimation',
+                                                            'multi-frame'
                                                             ])
 
     center = None
@@ -118,6 +119,7 @@ if __name__ == "__main__":
     burst_size = 20
     direction = None
     decimation = 1
+    handle_multiple_frames_per_burst = False
 
     if len(remainder) == 0 or remainder[0] == '-':
         filename = "/dev/stdin"
@@ -168,6 +170,8 @@ if __name__ == "__main__":
         #    direction = iridium.DOWNLINK
         elif opt in ('-D', '--decimation'):
             decimation = int(arg)
+        elif opt == '--multi-frame':
+            handle_multiple_frames_per_burst = True
 
     if sample_rate == None:
         print >> sys.stderr, "Sample rate missing!"
@@ -190,6 +194,7 @@ if __name__ == "__main__":
             filename=filename, sample_format=fmt,
             threshold=threshold, signal_width=search_window,
             offline=offline, max_queue_len = max_queue_len,
+            handle_multiple_frames_per_burst=handle_multiple_frames_per_burst,
             verbose=verbose)
 
     statistics_thread = threading.Thread(target=print_stats, args=(tb,))

grc/iridium_burst_downmix.xml

@@ -4,7 +4,7 @@
   <key>iridium_burst_downmix</key>
   <category>iridium</category>
   <import>import iridium</import>
-  <make>iridium.burst_downmix($sample_rate, $search_depth, $hard_max_queue_len, $input_taps, $start_finder_taps)</make>
+  <make>iridium.burst_downmix($sample_rate, $search_depth, $hard_max_queue_len, $input_taps, $start_finder_taps, $handle_multiple_frames_per_burst)</make>
 
   <param>
     <name>Sample Rate</name>
@@ -36,6 +36,12 @@
     <type>real_vector</type>
   </param>
 
+  <param>
+    <name>Handle Multiple Frames Per Burst</name>
+    <key>handle_multiple_frames_per_burst</key>
+    <type>bool</type>
+  </param>
+
 
   <sink>
     <name>cpdus</name>

include/iridium/burst_downmix.h

@@ -47,7 +47,8 @@ namespace gr {
        * creating new instances.
        */
       static sptr make(int sample_rate, int search_depth, size_t hard_max_queue_len,
-            const std::vector<float> &input_taps, const std::vector<float> &start_finder_taps);
+            const std::vector<float> &input_taps, const std::vector<float> &start_finder_taps,
+            bool handle_multiple_frames_per_burst);
 
       virtual uint64_t get_n_dropped_bursts() = 0;
       virtual size_t get_input_queue_size() = 0;

lib/burst_downmix_impl.cc

@@ -58,17 +58,20 @@ namespace gr {
 
     burst_downmix::sptr
     burst_downmix::make(int sample_rate, int search_depth, size_t hard_max_queue_len,
-            const std::vector<float> &input_taps,  const std::vector<float> &start_finder_taps)
+            const std::vector<float> &input_taps, const std::vector<float> &start_finder_taps,
+            bool handle_multiple_frames_per_burst)
     {
       return gnuradio::get_initial_sptr
-        (new burst_downmix_impl(sample_rate, search_depth, hard_max_queue_len, input_taps, start_finder_taps));
+        (new burst_downmix_impl(sample_rate, search_depth, hard_max_queue_len, input_taps, start_finder_taps,
+            handle_multiple_frames_per_burst));
     }
 
     /*
      * The private constructor
      */
     burst_downmix_impl::burst_downmix_impl(int sample_rate, int search_depth, size_t hard_max_queue_len,
-            const std::vector<float> &input_taps, const std::vector<float> &start_finder_taps)
+            const std::vector<float> &input_taps, const std::vector<float> &start_finder_taps,
+            bool handle_multiple_frames_per_burst)
       : gr::sync_block("burst_downmix",
               gr::io_signature::make(0, 0, 0),
               gr::io_signature::make(0, 0, 0)),
@@ -86,6 +89,7 @@ namespace gr {
               d_fft_over_size_facor(16),
               d_sync_search_len((::iridium::PREAMBLE_LENGTH_LONG + ::iridium::UW_LENGTH + 2) * d_output_samples_per_symbol),
               d_hard_max_queue_len(hard_max_queue_len),
+              d_handle_multiple_frames_per_burst(handle_multiple_frames_per_burst),
               d_debug(false),
 
               d_frame(NULL),
@@ -551,7 +555,7 @@ namespace gr {
     }
 
     void burst_downmix_impl::handler(pmt::pmt_t msg)
-	{
+    {
       /*
        * Extract the burst and meta data from the cpdu
        */
@@ -691,11 +695,17 @@ namespace gr {
         write_data_c(d_frame + start, burst_size - start, (char *)"signal-filtered-deci-cut-start", id);
       }
 
-      int handled_samples;
-      do {
-        handled_samples = process_next_frame(sample_rate, center_frequency, offset, id, burst_size, start);
-        start += handled_samples;
-      } while(handled_samples > 0);
+      if(d_handle_multiple_frames_per_burst) {
+        // Make some room in the id space
+        uint64_t new_id = id * 10;
+        int handled_samples;
+        do {
+            handled_samples = process_next_frame(sample_rate, center_frequency, offset, new_id++, burst_size, start);
+            start += handled_samples;
+        } while(d_handle_multiple_frames_per_burst && handled_samples > 0);
+      } else {
+        process_next_frame(sample_rate, center_frequency, offset, id, burst_size, start);
+      }
 
       message_port_pub(pmt::mp("burst_handled"), pmt::mp(id));
     }

lib/burst_downmix_impl.h

@@ -43,6 +43,7 @@ namespace gr {
       int d_sync_search_len;
       int d_hard_max_queue_len;
       uint64_t d_n_dropped_bursts;
+      bool d_handle_multiple_frames_per_burst;
       bool d_debug;
 
       gr_complex * d_frame;
@@ -80,7 +81,8 @@ namespace gr {
 
      public:
       burst_downmix_impl(int sample_rate, int search_depth, size_t hard_max_queue_len,
-            const std::vector<float> &input_taps, const std::vector<float> &start_finder_taps);
+            const std::vector<float> &input_taps, const std::vector<float> &start_finder_taps,
+            bool handle_multiple_frames_per_burst);
       ~burst_downmix_impl();
 
       size_t get_input_queue_size();

python/iridium_extractor_flowgraph.py

@@ -16,7 +16,7 @@
 
 
 class FlowGraph(gr.top_block):
-    def __init__(self, center_frequency, sample_rate, decimation, filename, sample_format=None, threshold=7.0, signal_width=40e3, offline=False, max_queue_len=500, verbose=False):
+    def __init__(self, center_frequency, sample_rate, decimation, filename, sample_format=None, threshold=7.0, signal_width=40e3, offline=False, max_queue_len=500, handle_multiple_frames_per_burst=False, verbose=False):
         gr.top_block.__init__(self, "Top Block")
         self._center_frequency = center_frequency
         self._signal_width = 40e3
@@ -26,6 +26,7 @@ def __init__(self, center_frequency, sample_rate, decimation, filename, sample_f
         self._filename = filename
         self._offline = offline
         self._max_queue_len = max_queue_len
+        self._handle_multiple_frames_per_burst = handle_multiple_frames_per_burst
 
         self._fft_size = int(math.pow(2, 1 + int(math.log(self._input_sample_rate / 1000, 2)))) # fft is approx 1ms long
         self._burst_pre_len = 2 * self._fft_size
@@ -211,7 +212,7 @@ def __init__(self, center_frequency, sample_rate, decimation, filename, sample_f
                 burst_to_pdu_converter = iridium.tagged_burst_to_pdu(self._max_burst_len, relative_center,
                                             relative_span, relative_sample_rate, self._max_queue_len, not self._offline)
                 burst_downmixer = iridium.burst_downmix(self._burst_sample_rate,
-                                    int(0.007 * 250000), 0, (input_filter), (start_finder_filter))
+                                    int(0.007 * 250000), 0, (input_filter), (start_finder_filter), self._handle_multiple_frames_per_burst)
 
                 self._burst_downmixers.append(burst_downmixer)
                 self._burst_to_pdu_converters.append(burst_to_pdu_converter)
@@ -236,7 +237,7 @@ def __init__(self, center_frequency, sample_rate, decimation, filename, sample_f
 
                 tb.msg_connect((self._burst_downmixers[i], 'cpdus'), (self._iridium_qpsk_demod, 'cpdus'))
         else:
-            burst_downmix = iridium.burst_downmix(self._burst_sample_rate, int(0.007 * 250000), 0, (input_filter), (start_finder_filter))
+            burst_downmix = iridium.burst_downmix(self._burst_sample_rate, int(0.007 * 250000), 0, (input_filter), (start_finder_filter), self._handle_multiple_frames_per_burst)
             burst_to_pdu = iridium.tagged_burst_to_pdu(self._max_burst_len, 0.0, 1.0, 1.0, self._max_queue_len, not self._offline)
 
             if converter: