diff options
Diffstat (limited to 'gr-dtv/lib/dvbt/dvbt_reed_solomon_dec_impl.cc')
| -rw-r--r-- | gr-dtv/lib/dvbt/dvbt_reed_solomon_dec_impl.cc | 72 |
1 files changed, 49 insertions, 23 deletions
diff --git a/gr-dtv/lib/dvbt/dvbt_reed_solomon_dec_impl.cc b/gr-dtv/lib/dvbt/dvbt_reed_solomon_dec_impl.cc index 4a5530cfbe..fd6fedcf8d 100644 --- a/gr-dtv/lib/dvbt/dvbt_reed_solomon_dec_impl.cc +++ b/gr-dtv/lib/dvbt/dvbt_reed_solomon_dec_impl.cc @@ -1,6 +1,6 @@ /* -*- c++ -*- */ /* - * Copyright 2015 Free Software Foundation, Inc. + * Copyright 2015,2016 Free Software Foundation, Inc. * * This is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by @@ -24,11 +24,15 @@ #include <gnuradio/io_signature.h> #include "dvbt_reed_solomon_dec_impl.h" -#include <stdio.h> namespace gr { namespace dtv { + static const int rs_init_symsize = 8; + static const int rs_init_fcr = 0; // first consecutive root + static const int rs_init_prim = 1; // primitive is 1 (alpha) + static const int N = (1 << rs_init_symsize) - 1; // 255 + dvbt_reed_solomon_dec::sptr dvbt_reed_solomon_dec::make(int p, int m, int gfpoly, int n, int k, int t, int s, int blocks) { @@ -43,15 +47,16 @@ namespace gr { : block("dvbt_reed_solomon_dec", io_signature::make(1, 1, sizeof(unsigned char) * blocks * (n - s)), io_signature::make(1, 1, sizeof(unsigned char) * blocks * (k - s))), - d_p(p), d_m(m), d_gfpoly(gfpoly), d_n(n), d_k(k), d_t(t), d_s(s), d_blocks(blocks), - d_rs(p, m, gfpoly, n, k, t, s, blocks) + d_n(n), d_k(k), d_s(s), d_blocks(blocks) { - d_in = new unsigned char[d_n]; - if (d_in == NULL) { - std::cout << "Cannot allocate memory for d_in" << std::endl; - exit(1); + d_rs = init_rs_char(rs_init_symsize, gfpoly, rs_init_fcr, rs_init_prim, (n - k)); + if (d_rs == NULL) { + GR_LOG_FATAL(d_logger, "Reed-Solomon Decoder, cannot allocate memory for d_rs."); + throw std::bad_alloc(); } - memset(&d_in[0], 0, d_n); + d_nerrors_corrected_count = 0; + d_bad_packet_count = 0; + d_total_packets = 0; } /* @@ -59,7 +64,7 @@ namespace gr { */ dvbt_reed_solomon_dec_impl::~dvbt_reed_solomon_dec_impl() { - delete [] d_in; + free_rs_char(d_rs); } void @@ -69,6 +74,25 @@ namespace gr { } int + dvbt_reed_solomon_dec_impl::decode (unsigned char &out, const unsigned char &in) + { + unsigned char tmp[N]; + int ncorrections; + + // add missing prefix zero padding to message + memset(tmp, 0, d_s); + memcpy(&tmp[d_s], &in, (d_n - d_s)); + + // correct message... + ncorrections = decode_rs_char(d_rs, tmp, 0, 0); + + // copy corrected message to output, skipping prefix zero padding + memcpy (&out, &tmp[d_s], (d_k - d_s)); + + return ncorrections; + } + + int dvbt_reed_solomon_dec_impl::general_work (int noutput_items, gr_vector_int &ninput_items, gr_vector_const_void_star &input_items, @@ -76,21 +100,23 @@ namespace gr { { const unsigned char *in = (const unsigned char *) input_items[0]; unsigned char *out = (unsigned char *) output_items[0]; - - // We receive only nonzero data - int in_bsize = d_n - d_s; - int out_bsize = d_k - d_s; + int j = 0; + int k = 0; for (int i = 0; i < (d_blocks * noutput_items); i++) { - //TODO - zero copy? - // Set first d_s symbols to zero - memset(&d_in[0], 0, d_s); - // Then copy actual data - memcpy(&d_in[d_s], &in[i * in_bsize], in_bsize); - - d_rs.rs_decode(d_in, NULL, 0); - - memcpy(&out[i * out_bsize], &d_in[d_s], out_bsize); + int nerrors_corrected = decode(out[k], in[j]); + + if (nerrors_corrected == -1) { + d_bad_packet_count++; + d_nerrors_corrected_count += ((d_n - d_s) - (d_k - d_s)) / 2; // lower bound estimate; most this RS can fix + } + else { + d_nerrors_corrected_count += nerrors_corrected; + } + + d_total_packets++; + j += (d_n - d_s); + k += (d_k - d_s); } // Tell runtime system how many input items we consumed on |