diff options
Diffstat (limited to 'gr-uhd/lib/uhd_multi_usrp_sink.cc')
| -rw-r--r-- | gr-uhd/lib/uhd_multi_usrp_sink.cc | 39 |
1 files changed, 23 insertions, 16 deletions
diff --git a/gr-uhd/lib/uhd_multi_usrp_sink.cc b/gr-uhd/lib/uhd_multi_usrp_sink.cc index ee16e2928..a1d0a2584 100644 --- a/gr-uhd/lib/uhd_multi_usrp_sink.cc +++ b/gr-uhd/lib/uhd_multi_usrp_sink.cc @@ -56,6 +56,7 @@ public: void set_samp_rate(double rate){ _dev->set_tx_rate(rate); + _sample_rate = this->get_samp_rate(); } double get_samp_rate(void){ @@ -128,28 +129,31 @@ public: gr_vector_const_void_star &input_items, gr_vector_void_star &output_items ){ - uhd::tx_metadata_t metadata; - metadata.start_of_burst = true; + //send a mid-burst packet with time spec + _metadata.start_of_burst = false; + _metadata.end_of_burst = false; + _metadata.has_time_spec = true; - return _dev->get_device()->send( - input_items, noutput_items, metadata, + size_t num_sent = _dev->get_device()->send( + input_items, noutput_items, _metadata, _type, uhd::device::SEND_MODE_FULL_BUFF, 1.0 ); + + //increment the timespec by the number of samples sent + _metadata.time_spec += uhd::time_spec_t(0, num_sent, _sample_rate); + return num_sent; } //Send an empty start-of-burst packet to begin streaming. - //Set at a time in the near future so data will be sync'd. + //Set at a time in the near future to avoid late packets. bool start(void){ - uhd::tx_metadata_t metadata; - metadata.start_of_burst = true; - metadata.has_time_spec = true; - //TODO: Time in the near future, must be less than source time in future - //because ethernet pause frames with throttle stream commands. - //It will be fixed with the invention of host-based flow control. - metadata.time_spec = get_time_now() + uhd::time_spec_t(0.05); + _metadata.start_of_burst = true; + _metadata.end_of_burst = false; + _metadata.has_time_spec = true; + _metadata.time_spec = get_time_now() + uhd::time_spec_t(0.01); _dev->get_device()->send( - gr_vector_const_void_star(_nchan), 0, metadata, + gr_vector_const_void_star(_nchan), 0, _metadata, _type, uhd::device::SEND_MODE_ONE_PACKET, 1.0 ); return true; @@ -158,11 +162,12 @@ public: //Send an empty end-of-burst packet to end streaming. //Ending the burst avoids an underflow error on stop. bool stop(void){ - uhd::tx_metadata_t metadata; - metadata.end_of_burst = true; + _metadata.start_of_burst = false; + _metadata.end_of_burst = true; + _metadata.has_time_spec = false; _dev->get_device()->send( - gr_vector_const_void_star(_nchan), 0, metadata, + gr_vector_const_void_star(_nchan), 0, _metadata, _type, uhd::device::SEND_MODE_ONE_PACKET, 1.0 ); return true; @@ -172,6 +177,8 @@ protected: uhd::usrp::multi_usrp::sptr _dev; const uhd::io_type_t _type; size_t _nchan; + uhd::tx_metadata_t _metadata; + double _sample_rate; }; /*********************************************************************** |