M17_Implementations/SP5WWP/m17-coder/m17-coder-sym.c

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>

//libm17
#include <m17.h>

//#define FN60_DEBUG

struct LSF lsf, next_lsf;

uint8_t lich[6];                    //48 bits packed raw, unencoded LICH
uint8_t lich_encoded[12];           //96 bits packed, encoded LICH
uint8_t enc_bits[SYM_PER_PLD*2];    //type-2 bits, unpacked
uint8_t rf_bits[SYM_PER_PLD*2];     //type-4 bits, unpacked

float frame_buff[192];
uint32_t frame_buff_cnt;

uint8_t data[16], next_data[16];    //raw payload, packed bits
uint16_t fn=0;                      //16-bit Frame Number (for the stream mode)
uint8_t lich_cnt=0;                 //0..5 LICH counter
uint8_t got_lsf=0;                  //have we filled the LSF struct yet?
uint8_t finished=0;

//main routine
int main(void)
{
    //debug
    //printf("%06X\n", golay24_encode(1)); //golay encoder codeword test
    //printf("%d -> %d -> %d\n", 1, intrl_seq[1], intrl_seq[intrl_seq[1]]); //interleaver bijective reciprocality test, f(f(x))=x
    //return 0;

    if(fread(&(next_lsf.dst), 6, 1, stdin)<1) finished=1;
    if(fread(&(next_lsf.src), 6, 1, stdin)<1) finished=1;
    if(fread(&(next_lsf.type), 2, 1, stdin)<1) finished=1;
    if(fread(&(next_lsf.meta), 14, 1, stdin)<1) finished=1;
    if(fread(next_data, 16, 1, stdin)<1) finished=1;

    while(!finished)
    {
        if(lich_cnt == 0)
        {
            lsf = next_lsf;

            //calculate LSF CRC
            uint16_t ccrc=LSF_CRC(&lsf);
            lsf.crc[0]=ccrc>>8;
            lsf.crc[1]=ccrc&0xFF;
        }

        memcpy(data, next_data, sizeof(data));

        //we could discard the data we already have
        if(fread(&(next_lsf.dst), 6, 1, stdin)<1) finished=1;
        if(fread(&(next_lsf.src), 6, 1, stdin)<1) finished=1;
        if(fread(&(next_lsf.type), 2, 1, stdin)<1) finished=1;
        if(fread(&(next_lsf.meta), 14, 1, stdin)<1) finished=1;
        if(fread(next_data, 16, 1, stdin)<1) finished=1;

        if(got_lsf) //stream frames
        {
            //send stream frame syncword
            frame_buff_cnt=0;
            send_syncword(frame_buff, &frame_buff_cnt, SYNC_STR);

            //extract LICH from the whole LSF
            extract_LICH(lich, lich_cnt, &lsf);

            //encode the LICH
            encode_LICH(lich_encoded, lich);

            //unpack LICH (12 bytes)
            unpack_LICH(enc_bits, lich_encoded);

            //encode the rest of the frame (starting at bit 96 - 0..95 are filled with LICH)
            conv_encode_stream_frame(&enc_bits[96], data, finished ? (fn | 0x8000) : fn);

            //reorder bits
            reorder_bits(rf_bits, enc_bits);

            //randomize
            randomize_bits(rf_bits);

            //send dummy symbols (debug)
            /*float s=0.0;
            for(uint8_t i=0; i<SYM_PER_PLD; i++) //40ms * 4800 - 8 (syncword)
                fwrite((uint8_t*)&s, sizeof(float), 1, stdout);*/

			//send frame data
            frame_buff_cnt=0;
			send_data(frame_buff, &frame_buff_cnt, rf_bits);
            fwrite((uint8_t*)frame_buff, SYM_PER_FRA*sizeof(float), 1, stdout);

            /*printf("\tDATA: ");
            for(uint8_t i=0; i<16; i++)
                printf("%02X", data[i]);
            printf("\n");*/

            //increment the Frame Number
            fn = (fn + 1) % 0x8000;

            //increment the LICH counter
            lich_cnt = (lich_cnt + 1) % 6;

            //debug-only
			#ifdef FN60_DEBUG
            if(fn==6*10)
                return 0;
			#endif
        }
        else //LSF
        {
            got_lsf=1;

            //send out the preamble
            frame_buff_cnt=0;
			send_preamble(frame_buff, &frame_buff_cnt, 0); //0 - LSF preamble, as opposed to 1 - BERT preamble
            fwrite((uint8_t*)frame_buff, SYM_PER_FRA*sizeof(float), 1, stdout);

            //send LSF syncword
            frame_buff_cnt=0;
			send_syncword(frame_buff, &frame_buff_cnt, SYNC_LSF);
            fwrite((uint8_t*)frame_buff, SYM_PER_SWD*sizeof(float), 1, stdout);

            //encode LSF data
            conv_encode_LSF(enc_bits, &lsf);

            //reorder bits
            reorder_bits(rf_bits, enc_bits);

            //randomize
            randomize_bits(rf_bits);

			//send LSF data
            frame_buff_cnt=0;
			send_data(frame_buff, &frame_buff_cnt, rf_bits);
            fwrite((uint8_t*)frame_buff, SYM_PER_PLD*sizeof(float), 1, stdout);

            //send dummy symbols (debug)
            /*float s=0.0;
            for(uint8_t i=0; i<184; i++) //40ms * 4800 - 8 (syncword)
                write((uint8_t*)&s, sizeof(float), 1, stdout);*/

            /*printf("DST: ");
            for(uint8_t i=0; i<6; i++)
                printf("%02X", lsf.dst[i]);
            printf(" SRC: ");
            for(uint8_t i=0; i<6; i++)
                printf("%02X", lsf.src[i]);
            printf(" TYPE: ");
            for(uint8_t i=0; i<2; i++)
                printf("%02X", lsf.type[i]);
            printf(" META: ");
            for(uint8_t i=0; i<14; i++)
                printf("%02X", lsf.meta[i]);
            printf(" CRC: ");
            for(uint8_t i=0; i<2; i++)
                printf("%02X", lsf.crc[i]);
			printf("\n");*/
		}

        if(finished)
        {
            frame_buff_cnt=0;
            send_eot(frame_buff, &frame_buff_cnt);
            fwrite((uint8_t*)frame_buff, SYM_PER_PLD*sizeof(float), 1, stdout);
        }
	}

	return 0;
}