libosmocoding: migrate transcoding routines from OsmoBTS

There are some projects, such as GR-GSM and OsmocomBB, which would
benefit from using one shared implementation of GSM 05.03 code. So,
this commit introduces a new sub-library called libosmocoding, which
(for now) provides GSM, GPRS and EDGE transcoding routines, migrated
from OsmoBTS.

The original GSM 05.03 code from OsmoBTS was relicensed under
GPLv2-or-later with permission of copyright holders (Andreas Eversberg,
Alexander Chemeris and Tom Tsou).

The following data types are currently supported:

 - xCCH
 - PDTCH (CS 1-4 and MCS 1-9)
 - TCH/FR
 - TCH/HR
 - TCH/AFS
 - RCH/AHS
 - RACH
 - SCH

Change-Id: I0c3256b87686d878e4e716d12393cad5924fdfa1

1 files changed, 33 insertions, 0 deletions

diff --git a/include/osmocom/coding/gsm0503_mapping.h b/include/osmocom/coding/gsm0503_mapping.h
new file mode 100644
index 00000000..4c6550a4
--- /dev/null
+++ b/include/osmocom/coding/gsm0503_mapping.h
@@ -0,0 +1,33 @@
+#pragma once
+
+#include <osmocom/core/bits.h>
+
+void gsm0503_xcch_burst_unmap(sbit_t *iB, const sbit_t *eB,
+	sbit_t *hl, sbit_t *hn);
+void gsm0503_xcch_burst_map(ubit_t *iB, ubit_t *eB, const ubit_t *hl,
+	const ubit_t *hn);
+
+void gsm0503_tch_burst_unmap(sbit_t *iB, sbit_t *eB, sbit_t *h, int odd);
+void gsm0503_tch_burst_map(ubit_t *iB, ubit_t *eB, const ubit_t *h, int odd);
+
+void gsm0503_mcs5_ul_burst_map(const ubit_t *di, ubit_t *eB,
+	const ubit_t *hi, int B);
+void gsm0503_mcs5_ul_burst_unmap(sbit_t *di, const sbit_t *eB,
+	sbit_t *hi, int B);
+
+void gsm0503_mcs7_ul_burst_map(const ubit_t *di, ubit_t *eB,
+	const ubit_t *hi, int B);
+void gsm0503_mcs7_ul_burst_unmap(sbit_t *di, const sbit_t *eB,
+	sbit_t *hi, int B);
+
+void gsm0503_mcs5_dl_burst_map(const ubit_t *di, ubit_t *eB,
+	const ubit_t *hi, const ubit_t *up, int B);
+void gsm0503_mcs5_dl_burst_unmap(sbit_t *di, const sbit_t *eB,
+	sbit_t *hi, sbit_t *up, int B);
+
+void gsm0503_mcs7_dl_burst_map(const ubit_t *di, ubit_t *eB,
+	const ubit_t *hi, const ubit_t *up, int B);
+void gsm0503_mcs7_dl_burst_unmap(sbit_t *di, const sbit_t *eB,
+	sbit_t *hi, sbit_t *up, int B);
+
+void gsm0503_mcs5_burst_swap(sbit_t *eB);