/* 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); }