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/* Decoder Core for OpenPICC
* (C) 2006 by Harald Welte <hwelte@hmw-consulting.de>
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <errno.h>
#include <sys/types.h>
#include "openpicc.h"
#include "dbgu.h"
#include "decoder.h"
static struct decoder_algo *decoder_algo[DECODER_NUM_ALGOS];
static int get_next_data(struct decoder_state *st, u_int8_t *data)
{
u_int8_t parity_sample;
u_int32_t bytesample;
bytesample = st->algo->get_next_bytesample(st, &parity_sample);
return st->algo->decode_sample(bytesample, data);
}
/* iterate over sample buffer (size N bytes) and decode data */
int decoder_decode(u_int8_t algo, const char *sample_buf,
int sample_buf_size, unsigned char *data_buf)
{
int i, ret;
struct decoder_state st;
if (algo >= DECODER_NUM_ALGOS)
return -EINVAL;
st.buf = sample_buf;
st.buf32 = (u_int32_t *) st.buf;
st.bit_ofs = 0;
st.algo = decoder_algo[algo];
for (i = 0; i < (sample_buf_size*8)/st.algo->bits_per_sampled_char;
i++) {
ret = get_next_data(&st, &data_buf[i]);
if (ret < 0) {
DEBUGPCR("decoder error %d at data byte %u",
ret, i);
return ret;
}
}
return i+1;
}
int decoder_register(int algnum, struct decoder_algo *algo)
{
if (algnum >= DECODER_NUM_ALGOS)
return -EINVAL;
decoder_algo[algnum] = algo;
return 0;
}
void decoder_init(void)
{
decoder_register(DECODER_MILLER, &miller_decoder);
decoder_register(DECODER_NRZL, &nrzl_decoder);
}
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