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authorHarald Welte <laforge@gnumonks.org>2011-01-19 10:10:16 +0100
committerHarald Welte <laforge@gnumonks.org>2011-01-19 10:10:16 +0100
commit2230c133a69e8f9660051aff61626996deba4ed8 (patch)
tree9475e8a923355e5741ecebf5c8180005ca8b0d63 /src
parentc035ec63f509573408069340b4d40a906a40b8f7 (diff)
[BITS] introduce new packed/unpacked bit conversion routines
Diffstat (limited to 'src')
-rw-r--r--src/Makefile.am2
-rw-r--r--src/bits.c65
2 files changed, 66 insertions, 1 deletions
diff --git a/src/Makefile.am b/src/Makefile.am
index 64310e0f..d4c6e127 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -9,7 +9,7 @@ AM_CFLAGS = -fPIC -Wall
lib_LTLIBRARIES = libosmocore.la
-libosmocore_la_SOURCES = timer.c select.c signal.c msgb.c rxlev_stat.c \
+libosmocore_la_SOURCES = timer.c select.c signal.c msgb.c rxlev_stat.c bits.c \
tlv_parser.c bitvec.c comp128.c gsm_utils.c statistics.c \
write_queue.c utils.c rsl.c gsm48.c gsm48_ie.c \
logging.c gsm0808.c rate_ctr.c gsmtap_util.c \
diff --git a/src/bits.c b/src/bits.c
new file mode 100644
index 00000000..fb3c7224
--- /dev/null
+++ b/src/bits.c
@@ -0,0 +1,65 @@
+
+#include <stdint.h>
+
+#include <osmocore/bits.h>
+
+/* convert unpacked bits to packed bits, return length in bytes */
+int osmo_ubit2pbit(pbit_t *out, const ubit_t *in, unsigned int num_bits)
+{
+ unsigned int i;
+ uint8_t curbyte = 0;
+ pbit_t *outptr = out;
+
+ for (i = 0; i < num_bits; i++) {
+ uint8_t bitnum = 7 - (i % 8);
+
+ curbyte |= (in[i] << bitnum);
+
+ if (i > 0 && i % 8 == 0) {
+ *outptr++ = curbyte;
+ curbyte = 0;
+ }
+ }
+ /* we have a non-modulo-8 bitcount */
+ if (i % 8)
+ *outptr++ = curbyte;
+
+ return outptr - out;
+}
+
+/* convert packed bits to unpacked bits, return length in bytes */
+int osmo_pbit2ubit(ubit_t *out, const pbit_t *in, unsigned int num_bits)
+{
+ unsigned int i;
+ ubit_t *cur = out;
+ ubit_t *limit = out + num_bits;
+
+ for (i = 0; i < (num_bits/8)+1; i++) {
+ pbit_t byte = in[i];
+ *cur++ = (byte >> 7) & 1;
+ if (cur >= limit)
+ break;
+ *cur++ = (byte >> 6) & 1;
+ if (cur >= limit)
+ break;
+ *cur++ = (byte >> 5) & 1;
+ if (cur >= limit)
+ break;
+ *cur++ = (byte >> 4) & 1;
+ if (cur >= limit)
+ break;
+ *cur++ = (byte >> 3) & 1;
+ if (cur >= limit)
+ break;
+ *cur++ = (byte >> 2) & 1;
+ if (cur >= limit)
+ break;
+ *cur++ = (byte >> 1) & 1;
+ if (cur >= limit)
+ break;
+ *cur++ = (byte >> 0) & 1;
+ if (cur >= limit)
+ break;
+ }
+ return cur - out;
+}