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/* -*- c++ -*- */
/*
* Copyright 2015 Free Software Foundation, Inc.
*
* SPDX-License-Identifier: GPL-3.0-or-later
*
*/
#ifndef INCLUDED_DTV_DVBT_VITERBI_DECODER_IMPL_H
#define INCLUDED_DTV_DVBT_VITERBI_DECODER_IMPL_H
#include "dvbt_configure.h"
#include <gnuradio/dtv/dvbt_viterbi_decoder.h>
#ifdef DTV_SSE2
#include <xmmintrin.h>
#endif
/* The two generator polynomials for the NASA Standard K=7 code.
* Since these polynomials are known to be optimal for this constraint
* length there is not much point in changing them.
*/
#define POLYA 0x4f
#define POLYB 0x6d
// Maximum number of traceback bytes
#define TRACEBACK_MAX 24
#ifdef DTV_SSE2
union branchtab27 {
unsigned char c[32];
__m128i v[2];
};
#else
struct branchtab27 {
unsigned char c[32];
};
#endif
namespace gr {
namespace dtv {
class dvbt_viterbi_decoder_impl : public dvbt_viterbi_decoder
{
private:
dvbt_configure config;
// Puncturing vectors
static const unsigned char d_puncture_1_2[];
static const unsigned char d_puncture_2_3[];
static const unsigned char d_puncture_3_4[];
static const unsigned char d_puncture_5_6[];
static const unsigned char d_puncture_7_8[];
static const unsigned char d_Partab[];
#ifdef DTV_SSE2
static __m128i d_metric0[4];
static __m128i d_metric1[4];
static __m128i d_path0[4];
static __m128i d_path1[4];
#else
static unsigned char d_metric0_generic[64];
static unsigned char d_metric1_generic[64];
static unsigned char d_path0_generic[64];
static unsigned char d_path1_generic[64];
#endif
#ifdef DTV_SSE2
static branchtab27 Branchtab27_sse2[2];
#else
static branchtab27 Branchtab27_generic[2];
#endif
// Metrics for each state
static unsigned char mmresult[64];
// Paths for each state
static unsigned char ppresult[TRACEBACK_MAX][64];
// Current puncturing vector
const unsigned char* d_puncture;
// Code rate k/n
const int d_k;
const int d_n;
// Constellation with m
const int d_m;
// Block size
const int d_bsize;
// Symbols to consume on decoding from one block.
// It is also the number of input bytes since
// one byte always contains just one symbol.
const int d_nsymbols;
// Number of bits after depuncturing a block (before decoding)
const int d_nbits;
// Number of full packed out bytes
const int d_nout;
// Traceback (in bytes)
int d_ntraceback;
// Viterbi tables
int mettab[2][256];
// Buffer to keep the input bits
std::vector<unsigned char> d_inbits;
// This is used to get rid of traceback on the first frame
int d_init = 0;
// Position in circular buffer where the current decoded byte is stored
int store_pos = 0;
#ifdef DTV_SSE2
void dvbt_viterbi_chunks_init_sse2(__m128i* mm0, __m128i* pp0);
void dvbt_viterbi_butterfly2_sse2(
unsigned char* symbols, __m128i m0[], __m128i m1[], __m128i p0[], __m128i p1[]);
unsigned char dvbt_viterbi_get_output_sse2(__m128i* mm0,
__m128i* pp0,
int ntraceback,
unsigned char* outbuf);
#else
void dvbt_viterbi_chunks_init_generic(unsigned char* mm0, unsigned char* pp0);
void dvbt_viterbi_butterfly2_generic(unsigned char* symbols,
unsigned char m0[],
unsigned char m1[],
unsigned char p0[],
unsigned char p1[]);
unsigned char dvbt_viterbi_get_output_generic(unsigned char* mm0,
unsigned char* pp0,
int ntraceback,
unsigned char* outbuf);
#endif
public:
dvbt_viterbi_decoder_impl(dvb_constellation_t constellation,
dvbt_hierarchy_t hierarchy,
dvb_code_rate_t coderate,
int bsize);
~dvbt_viterbi_decoder_impl() override;
void forecast(int noutput_items, gr_vector_int& ninput_items_required) override;
int general_work(int noutput_items,
gr_vector_int& ninput_items,
gr_vector_const_void_star& input_items,
gr_vector_void_star& output_items) override;
};
} // namespace dtv
} // namespace gr
#endif /* INCLUDED_DTV_DVBT_VITERBI_DECODER_IMPL_H */
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