conv.h

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/*
 * Copyright (C) 2011  Sylvain Munaut <tnt@246tNt.com>
 *
 * All Rights Reserved
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */
 
#pragma once
 
#include <stdint.h>
 
#include <osmocom/core/bits.h>
 
enum osmo_conv_term {
        CONV_TERM_FLUSH = 0,    
        CONV_TERM_TRUNCATION,   
        CONV_TERM_TAIL_BITING,  
};
 
struct osmo_conv_code {
        int N;                          
        int K;                          
        int len;                        
        enum osmo_conv_term term;       
        const uint8_t (*next_output)[2];
        const uint8_t (*next_state)[2]; 
        const uint8_t *next_term_output;
        const uint8_t *next_term_state; 
        const int *puncture;            
};
 
 
/* Common */
 
int osmo_conv_get_input_length(const struct osmo_conv_code *code, int len);
int osmo_conv_get_output_length(const struct osmo_conv_code *code, int len);
 
 
/* Encoding */
 
        /* Low level API */
 
struct osmo_conv_encoder {
        const struct osmo_conv_code *code; 
        int i_idx;      
        int p_idx;      
        uint8_t state;  
};
 
void osmo_conv_encode_init(struct osmo_conv_encoder *encoder,
                           const struct osmo_conv_code *code);
void osmo_conv_encode_load_state(struct osmo_conv_encoder *encoder,
                                 const ubit_t *input);
int  osmo_conv_encode_raw(struct osmo_conv_encoder *encoder,
                          const ubit_t *input, ubit_t *output, int n);
int  osmo_conv_encode_flush(struct osmo_conv_encoder *encoder, ubit_t *output);
 
        /* All-in-one */
int  osmo_conv_encode(const struct osmo_conv_code *code,
                      const ubit_t *input, ubit_t *output);
 
 
/* Decoding */
 
        /* Low level API */
 
struct osmo_conv_decoder {
        const struct osmo_conv_code *code; 
        int n_states;           
        int len;                
        int o_idx;              
        int p_idx;              
        unsigned int *ae;       
        unsigned int *ae_next;  
        uint8_t *state_history; 
};
 
void osmo_conv_decode_init(struct osmo_conv_decoder *decoder,
                           const struct osmo_conv_code *code,
                           int len, int start_state);
void osmo_conv_decode_reset(struct osmo_conv_decoder *decoder, int start_state);
void osmo_conv_decode_rewind(struct osmo_conv_decoder *decoder);
void osmo_conv_decode_deinit(struct osmo_conv_decoder *decoder);
 
int osmo_conv_decode_scan(struct osmo_conv_decoder *decoder,
                          const sbit_t *input, int n);
int osmo_conv_decode_flush(struct osmo_conv_decoder *decoder,
                           const sbit_t *input);
int osmo_conv_decode_get_best_end_state(struct osmo_conv_decoder *decoder);
int osmo_conv_decode_get_output(struct osmo_conv_decoder *decoder,
                                ubit_t *output, int has_flush, int end_state);
 
        /* All-in-one */
int osmo_conv_decode(const struct osmo_conv_code *code,
                     const sbit_t *input, ubit_t *output);