diff options
Diffstat (limited to 'gr-blocks/lib/keep_m_in_n_impl.cc')
| -rw-r--r-- | gr-blocks/lib/keep_m_in_n_impl.cc | 21 |
1 files changed, 16 insertions, 5 deletions
diff --git a/gr-blocks/lib/keep_m_in_n_impl.cc b/gr-blocks/lib/keep_m_in_n_impl.cc index 4784d3c1a2..2c67af9c34 100644 --- a/gr-blocks/lib/keep_m_in_n_impl.cc +++ b/gr-blocks/lib/keep_m_in_n_impl.cc @@ -1,6 +1,6 @@ /* -*- c++ -*- */ /* - * Copyright 2012 Free Software Foundation, Inc. + * Copyright 2012,2018 Free Software Foundation, Inc. * * This file is part of GNU Radio * @@ -59,9 +59,14 @@ namespace gr { std::string s = boost::str(boost::format("keep_m_in_n: m (%1%) <= n %2%") % d_m % d_n); throw std::runtime_error(s); } - if(d_offset > (d_n - d_m)) { - std::string s = boost::str(boost::format("keep_m_in_n: offset (%1%) <= n (%2%) - m (%3%)") \ - % d_offset % d_n % d_m); + if(d_offset < 0) { + std::string s = boost::str(boost::format("keep_m_in_n: offset (%1%) must be >= 0") \ + % d_offset); + throw std::runtime_error(s); + } + if(d_offset >= d_n) { + std::string s = boost::str(boost::format("keep_m_in_n: offset (%1%) < n (%2%)") \ + % d_offset % d_n); throw std::runtime_error(s); } @@ -107,13 +112,19 @@ namespace gr { // iterate over data blocks of size {n, input : m, output} int blks = std::min(noutput_items/d_m, ninput_items[0]/d_n); + int excess = (d_offset + d_m - d_n) * d_itemsize; for(int i=0; i<blks; i++) { // set up copy pointers const uint8_t* iptr = &in[(i*d_n + d_offset)*d_itemsize]; uint8_t* optr = &out[i*d_m*d_itemsize]; // perform copy - memcpy( optr, iptr, d_m*d_itemsize ); + if(excess <= 0) { + memcpy( optr, iptr, d_m*d_itemsize ); + } else { + memcpy( optr, &in[i*d_n*d_itemsize], excess); + memcpy( optr + excess, iptr, d_m*d_itemsize - excess); + } } consume_each(blks*d_n); |