[PATCH] Add ubit <-> sbit convertors

[msuraev]

From: Max <msur...@sysmocom.de>

Move functions for conversion between soft and unpacked bits to main
library as they are generally useful.
---
 include/osmocom/core/bits.h |  3 +++
 src/bits.c                  | 24 ++++++++++++++++++++++++
 tests/conv/conv_test.c      | 23 ++---------------------
 3 files changed, 29 insertions(+), 21 deletions(-)

diff --git a/include/osmocom/core/bits.h b/include/osmocom/core/bits.h
index 46f0c8b..e082313 100644
--- a/include/osmocom/core/bits.h
+++ b/include/osmocom/core/bits.h
@@ -42,6 +42,9 @@ int osmo_ubit2pbit(pbit_t *out, const ubit_t *in, unsigned 
int num_bits);

 int osmo_pbit2ubit(ubit_t *out, const pbit_t *in, unsigned int num_bits);

+void osmo_ubit2sbit(sbit_t *out, const ubit_t *in, unsigned int num_bits);
+void osmo_sbit2ubit(ubit_t *out, const sbit_t *in, unsigned int num_bits);
+
 int osmo_ubit2pbit_ext(pbit_t *out, unsigned int out_ofs,
                        const ubit_t *in, unsigned int in_ofs,
                        unsigned int num_bits, int lsb_mode);
diff --git a/src/bits.c b/src/bits.c
index a0a9d9e..48314af 100644
--- a/src/bits.c
+++ b/src/bits.c
@@ -61,6 +61,30 @@ int osmo_ubit2pbit(pbit_t *out, const ubit_t *in, unsigned 
int num_bits)
        return outptr - out;
 }

+/*! \brief convert unpacked bits to soft bits
+ *  \param[out] out output buffer of soft bits
+ *  \param[in] in input buffer of unpacked bits
+ *  \param[in] num_bits number of bits
+ */
+void osmo_ubit2sbit(sbit_t *out, const ubit_t *in, unsigned int num_bits)
+{
+       unsigned int i;
+       for (i = 0; i < num_bits; i++)
+               out[i] = in[i] ? -127 : 127;
+}
+
+/*! \brief convert soft bits to unpacked bits
+ *  \param[out] out output buffer of unpacked bits
+ *  \param[in] in input buffer of soft bits
+ *  \param[in] num_bits number of bits
+ */
+void osmo_sbit2ubit(ubit_t *out, const sbit_t *in, unsigned int num_bits)
+{
+       unsigned int i;
+       for (i = 0; i < num_bits; i++)
+               out[i] = in[i] < 0;
+}
+
 /*! \brief convert packed bits to unpacked bits, return length in bytes
  *  \param[out] out output buffer of unpacked bits
  *  \param[in] in input buffer of packed bits
diff --git a/tests/conv/conv_test.c b/tests/conv/conv_test.c
index 182ae20..baebdbe 100644
--- a/tests/conv/conv_test.c
+++ b/tests/conv/conv_test.c
@@ -314,25 +314,6 @@ fill_random(ubit_t *b, int n)
                b[i] = random() & 1;
 }

-static void
-ubit_to_sbit(sbit_t *dst, ubit_t *src, int n)
-{
-       int i;
-       for (i=0; i<n; i++)
-               dst[i] = src[i] ? -127 : 127;
-}
-
-static void sbit_to_ubit(ubit_t *dst, sbit_t *src, int n) 
__attribute__((unused));
-
-static void
-sbit_to_ubit(ubit_t *dst, sbit_t *src, int n)
-{
-       int i;
-       for (i=0; i<n; i++)
-               dst[i] = src[i] < 0;
-}
-
-
 int main(int argc, char *argv[])
 {
        const struct conv_test_vector *tst;
@@ -399,7 +380,7 @@ int main(int argc, char *argv[])

                        printf("[..] Decoding: ");

-                       ubit_to_sbit(bs, bu0, l);
+                       osmo_ubit2sbit(bs, bu0, l);

                        l = osmo_conv_decode(tst->code, bs, bu1);
                        if (l != 0) {
@@ -434,7 +415,7 @@ int main(int argc, char *argv[])
                                return -1;
                        }

-                       ubit_to_sbit(bs, bu1, l);
+                       osmo_ubit2sbit(bs, bu1, l);

                        l = osmo_conv_decode(tst->code, bs, bu1);
                        if (l != 0) {
-- 
2.8.1