misc_utils/resampler: Add offsets of tags at the input

This change is done to make keeping track of sample counter
at the input of the resampler easier from blocks connected
to its output. Each tag leaving the resampler has accompanying
"original_offset" tag with its offset before sample rate change.

Change-Id: Iea8ca4a092029f774406dced8a97a17810f21f62

1 files changed, 5 insertions, 2 deletions

diff --git a/lib/misc_utils/controlled_fractional_resampler_cc_impl.cc b/lib/misc_utils/controlled_fractional_resampler_cc_impl.cc
index 82c5a04..cd1d777 100644
--- a/lib/misc_utils/controlled_fractional_resampler_cc_impl.cc
+++ b/lib/misc_utils/controlled_fractional_resampler_cc_impl.cc
@@ -110,13 +110,16 @@ namespace gr {
           {
             break;
           } else {
-              add_item_tag(0, produced_out_sum + nitems_written(0), i_tag->key, i_tag->value);                       
-              set_resamp_ratio(pmt::to_double(i_tag->value));
+            set_resamp_ratio(pmt::to_double(i_tag->value));
+            tag_t original_offset_tag;
+            add_item_tag(0, produced_out_sum + nitems_written(0), pmt::mp("original_offset"), pmt::from_uint64(i_tag->offset));
+            add_item_tag(0, produced_out_sum + nitems_written(0), i_tag->key, i_tag->value);
           }
         } else {
           uint64_t out_samples_to_tag = round(static_cast<double>(tag_offset_rel-processed_in_sum)/d_mu_inc);
           if( (out_samples_to_tag + produced_out_sum) < noutput_items)
           {
+            add_item_tag(0, produced_out_sum + out_samples_to_tag + nitems_written(0), pmt::mp("original_offset"), pmt::from_uint64(i_tag->offset));
             add_item_tag(0, produced_out_sum + out_samples_to_tag + nitems_written(0), i_tag->key, i_tag->value);
           }
         }