From 29ea5bbf5b9c3b3679aa40e4ee7029284cb424c6 Mon Sep 17 00:00:00 2001 From: henryk Date: Sat, 24 Nov 2007 07:59:42 +0000 Subject: Add load modulation and encoding/decoding code from harald git-svn-id: https://svn.openpcd.org:2342/trunk@351 6dc7ffe9-61d6-0310-9af1-9938baff3ed1 --- openpicc/application/decoder.c | 81 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 81 insertions(+) create mode 100644 openpicc/application/decoder.c (limited to 'openpicc/application/decoder.c') diff --git a/openpicc/application/decoder.c b/openpicc/application/decoder.c new file mode 100644 index 0000000..a4287fd --- /dev/null +++ b/openpicc/application/decoder.c @@ -0,0 +1,81 @@ +/* Decoder Core for OpenPICC + * (C) 2006 by Harald Welte + * + * 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 +#include + +#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); +} -- cgit v1.2.3