[BITS] introduce new packed/unpacked bit conversion routines
diff --git a/include/osmocore/bits.h b/include/osmocore/bits.h
new file mode 100644
index 0000000..662c4a9
--- /dev/null
+++ b/include/osmocore/bits.h
@@ -0,0 +1,27 @@
+#ifndef _OSMO_BITS_H
+#define _OSMO_BITS_H
+
+#include <stdint.h>
+
+typedef uint8_t sbit_t;		/* soft bit (-127...127) */
+typedef uint8_t ubit_t;		/* unpacked bit (0 or 1) */
+typedef uint8_t pbit_t;		/* packed bis (8 bits in a byte) */
+
+/* determine how many bytes we would need for 'num_bits' packed bits */
+static inline unsigned int osmo_pbit_bytesize(unsigned int num_bits)
+{
+	unsigned int pbit_bytesize = num_bits / 8;
+
+	if (num_bits % 8)
+		pbit_bytesize++;
+
+	return pbit_bytesize;
+}
+
+/* convert unpacked bits to packed bits, return length in bytes */
+int osmo_ubit2pbit(pbit_t *out, const ubit_t *in, unsigned int num_bits);
+
+/* convert packed bits to unpacked bits, return length in bytes */
+int osmo_pbit2ubit(ubit_t *out, const pbit_t *in, unsigned int num_bits);
+
+#endif