uhd: added multi-finite-aquisition

1 files changed, 33 insertions, 5 deletions

diff --git a/gr-uhd/lib/gr_uhd_usrp_source.cc b/gr-uhd/lib/gr_uhd_usrp_source.cc
index 2244238bd..33596e37b 100644
--- a/gr-uhd/lib/gr_uhd_usrp_source.cc
+++ b/gr-uhd/lib/gr_uhd_usrp_source.cc
@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2011 Free Software Foundation, Inc.
+ * Copyright 2010-2012 Free Software Foundation, Inc.
  * 
  * This file is part of GNU Radio
  * 
@@ -410,17 +410,45 @@ public:
     }
 
     std::vector<std::complex<float> > finite_acquisition(const size_t nsamps){
+        if (_nchan != 1) throw std::runtime_error("finite_acquisition: usrp source has multiple channels, call finite_acquisition_v");
+        return finite_acquisition_v(nsamps).front();
+    }
+
+    std::vector<std::vector<std::complex<float> > > finite_acquisition_v(const size_t nsamps){
         #ifdef GR_UHD_USE_STREAM_API
+
+        //kludgy way to ensure rx streamer exsists
+        if (!_rx_stream){
+            this->start();
+            this->stop();
+        }
+
+        //create a multi-dimensional container to hold an array of sample buffers
+        std::vector<std::vector<std::complex<float> > > samps(_nchan, std::vector<std::complex<float> >(nsamps));
+
+        //load the void* vector of buffer pointers
+        std::vector<void *> buffs(_nchan);
+        for (size_t i = 0; i < _nchan; i++){
+            buffs[i] = &samps[i].front();
+        }
+
+        //tell the device to stream a finite amount
         uhd::stream_cmd_t cmd(uhd::stream_cmd_t::STREAM_MODE_NUM_SAMPS_AND_DONE);
         cmd.num_samps = nsamps;
-        cmd.stream_now = true;
+        cmd.stream_now = _stream_now;
+        static const double reasonable_delay = 0.1; //order of magnitude over RTT
+        cmd.time_spec = get_time_now() + uhd::time_spec_t(reasonable_delay);
         _dev->issue_stream_cmd(cmd);
 
-        std::vector<std::complex<float> > samps(nsamps);
+        //receive samples until timeout
         const size_t actual_num_samps = _rx_stream->recv(
-            &samps.front(), nsamps, _metadata, 0.1
+            buffs, nsamps, _metadata, 0.1
         );
-        samps.resize(actual_num_samps);
+
+        //resize the resulting sample buffers
+        for (size_t i = 0; i < _nchan; i++){
+            samps[i].resize(actual_num_samps);
+        }
 
         return samps;
         #else