diff options
Diffstat (limited to 'src/FIRFilter.cpp')
| -rw-r--r-- | src/FIRFilter.cpp | 87 |
1 files changed, 60 insertions, 27 deletions
diff --git a/src/FIRFilter.cpp b/src/FIRFilter.cpp index 86f558b..7e6014c 100644 --- a/src/FIRFilter.cpp +++ b/src/FIRFilter.cpp @@ -2,8 +2,10 @@ Copyright (C) 2007, 2008, 2009, 2010, 2011 Her Majesty the Queen in Right of Canada (Communications Research Center Canada) - Written by - 2012, Matthias P. Braendli, matthias.braendli@mpb.li + Copyright (C) 2016 + Matthias P. Braendli, matthias.braendli@mpb.li + + http://opendigitalradio.org This block implements a FIR filter. The real filter taps are given as floats, and the block can take advantage of SSE. @@ -34,6 +36,7 @@ #include <stdio.h> #include <stdexcept> +#include <array> #include <iostream> #include <fstream> #include <memory> @@ -46,6 +49,29 @@ using namespace std; #include <sys/time.h> +/* This is the FIR Filter calculated with the doc/fir-filter/generate-filter.py script + * with settings + * gain = 1 + * sampling_freq = 2.048e6 + * cutoff = 810e3 + * transition_width = 250e3 + * + * It is a good default filter for the common scenarios. + */ +static const std::array<float, 45> default_filter_taps({ + -0.00110450468492, 0.00120703084394, -0.000840645749122, -0.000187368263141, + 0.00184351124335, -0.00355578539893, 0.00419321097434, -0.00254214904271, + -0.00183473504148, 0.00781436730176, -0.0125957569107, 0.0126200336963, + -0.00537294941023, -0.00866683479398, 0.0249746385962, -0.0356550291181, + 0.0319730602205, -0.00795613788068, -0.0363943465054, 0.0938014090061, + -0.151176810265, 0.193567320704, 0.791776955128, 0.193567320704, + -0.151176810265, 0.0938014090061, -0.0363943465054, -0.00795613788068, + 0.0319730602205, -0.0356550291181, 0.0249746385962, -0.00866683479398, + -0.00537294941023, 0.0126200336963, -0.0125957569107, 0.00781436730176, + -0.00183473504148, -0.00254214904271, 0.00419321097434, -0.00355578539893, + 0.00184351124335, -0.000187368263141, -0.000840645749122, 0.00120703084394, + -0.00110450468492}); + void FIRFilterWorker::process(struct FIRFilterWorkerData *fwd) { size_t i; @@ -238,7 +264,7 @@ void FIRFilterWorker::process(struct FIRFilterWorkerData *fwd) } -FIRFilter::FIRFilter(std::string& taps_file) : +FIRFilter::FIRFilter(const std::string& taps_file) : ModCodec(ModFormat(sizeof(complexf)), ModFormat(sizeof(complexf))), RemoteControllable("firfilter"), myTapsFile(taps_file) @@ -257,37 +283,44 @@ FIRFilter::FIRFilter(std::string& taps_file) : worker.start(&firwd); } -void FIRFilter::load_filter_taps(std::string tapsFile) +void FIRFilter::load_filter_taps(const std::string &tapsFile) { - std::ifstream taps_fstream(tapsFile.c_str()); - if(!taps_fstream) { - fprintf(stderr, "FIRFilter: file %s could not be opened !\n", tapsFile.c_str()); - throw std::runtime_error("FIRFilter: Could not open file with taps! "); + std::vector<float> filter_taps; + if (tapsFile == "default") { + std::copy(default_filter_taps.begin(), default_filter_taps.end(), + std::back_inserter(filter_taps)); } - int n_taps; - taps_fstream >> n_taps; + else { + std::ifstream taps_fstream(tapsFile.c_str()); + if(!taps_fstream) { + fprintf(stderr, "FIRFilter: file %s could not be opened !\n", tapsFile.c_str()); + throw std::runtime_error("FIRFilter: Could not open file with taps! "); + } + int n_taps; + taps_fstream >> n_taps; - if (n_taps <= 0) { - fprintf(stderr, "FIRFilter: warning: taps file has invalid format\n"); - throw std::runtime_error("FIRFilter: taps file has invalid format."); - } + if (n_taps <= 0) { + fprintf(stderr, "FIRFilter: warning: taps file has invalid format\n"); + throw std::runtime_error("FIRFilter: taps file has invalid format."); + } - if (n_taps > 100) { - fprintf(stderr, "FIRFilter: warning: taps file has more than 100 taps\n"); - } + if (n_taps > 100) { + fprintf(stderr, "FIRFilter: warning: taps file has more than 100 taps\n"); + } - fprintf(stderr, "FIRFilter: Reading %d taps...\n", n_taps); + fprintf(stderr, "FIRFilter: Reading %d taps...\n", n_taps); - std::vector<float> filter_taps(n_taps); + filter_taps.resize(n_taps); - int n; - for (n = 0; n < n_taps; n++) { - taps_fstream >> filter_taps[n]; - PDEBUG("FIRFilter: tap: %f\n", filter_taps[n] ); - if (taps_fstream.eof()) { - fprintf(stderr, "FIRFilter: file %s should contains %d taps, but EOF reached "\ - "after %d taps !\n", tapsFile.c_str(), n_taps, n); - throw std::runtime_error("FIRFilter: filtertaps file invalid ! "); + int n; + for (n = 0; n < n_taps; n++) { + taps_fstream >> filter_taps[n]; + PDEBUG("FIRFilter: tap: %f\n", filter_taps[n] ); + if (taps_fstream.eof()) { + fprintf(stderr, "FIRFilter: file %s should contains %d taps, but EOF reached "\ + "after %d taps !\n", tapsFile.c_str(), n_taps, n); + throw std::runtime_error("FIRFilter: filtertaps file invalid ! "); + } } } |