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authorhenryk <henryk@6dc7ffe9-61d6-0310-9af1-9938baff3ed1>2007-11-24 07:59:42 +0000
committerhenryk <henryk@6dc7ffe9-61d6-0310-9af1-9938baff3ed1>2007-11-24 07:59:42 +0000
commit29ea5bbf5b9c3b3679aa40e4ee7029284cb424c6 (patch)
tree0e20e9c665d05c228684e815ca142c0814057a80 /openpicc/application/decoder.c
parent341b884abc8c29790dfffab1921a1f4fa127d62d (diff)
Add load modulation and encoding/decoding code from harald
git-svn-id: https://svn.openpcd.org:2342/trunk@351 6dc7ffe9-61d6-0310-9af1-9938baff3ed1
Diffstat (limited to 'openpicc/application/decoder.c')
-rw-r--r--openpicc/application/decoder.c81
1 files changed, 81 insertions, 0 deletions
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 <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);
+}
personal git repositories of Harald Welte. Your mileage may vary