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

5 files changed, 210 insertions, 0 deletions

diff --git a/include/osmocom/coding/gsm0503_coding.h b/include/osmocom/coding/gsm0503_coding.h
new file mode 100644
index 00000000..b8eb2052
--- /dev/null
+++ b/include/osmocom/coding/gsm0503_coding.h
@@ -0,0 +1,63 @@
+#pragma once
+
+#include <stdint.h>
+#include <osmocom/core/bits.h>
+
+#define GSM0503_GPRS_BURSTS_NBITS	(116 * 4)
+#define GSM0503_EGPRS_BURSTS_NBITS	(348 * 4)
+#define NUM_BYTES(N) ((N + 8 - 1) / 8)
+
+enum gsm0503_egprs_mcs {
+	EGPRS_MCS0,
+	EGPRS_MCS1,
+	EGPRS_MCS2,
+	EGPRS_MCS3,
+	EGPRS_MCS4,
+	EGPRS_MCS5,
+	EGPRS_MCS6,
+	EGPRS_MCS7,
+	EGPRS_MCS8,
+	EGPRS_MCS9,
+	EGPRS_NUM_MCS,
+};
+
+int gsm0503_xcch_encode(ubit_t *bursts, uint8_t *l2_data);
+int gsm0503_xcch_decode(uint8_t *l2_data, sbit_t *bursts,
+	int *n_errors, int *n_bits_total);
+
+int gsm0503_pdtch_encode(ubit_t *bursts, uint8_t *l2_data, uint8_t l2_len);
+int gsm0503_pdtch_decode(uint8_t *l2_data, sbit_t *bursts, uint8_t *usf_p,
+	int *n_errors, int *n_bits_total);
+
+int gsm0503_pdtch_egprs_encode(ubit_t *bursts, uint8_t *l2_data,
+	uint8_t l2_len);
+int gsm0503_pdtch_egprs_decode(uint8_t *l2_data, sbit_t *bursts,
+	uint16_t nbits, uint8_t *usf_p, int *n_errors, int *n_bits_total);
+
+int gsm0503_tch_fr_encode(ubit_t *bursts, uint8_t *tch_data, int len,
+	int net_order);
+int gsm0503_tch_fr_decode(uint8_t *tch_data, sbit_t *bursts, int net_order,
+	int efr, int *n_errors, int *n_bits_total);
+
+int gsm0503_tch_hr_encode(ubit_t *bursts, uint8_t *tch_data, int len);
+int gsm0503_tch_hr_decode(uint8_t *tch_data, sbit_t *bursts, int odd,
+	int *n_errors, int *n_bits_total);
+
+int gsm0503_tch_afs_encode(ubit_t *bursts, uint8_t *tch_data, int len,
+	int codec_mode_req, uint8_t *codec, int codecs, uint8_t ft,
+	uint8_t cmr);
+int gsm0503_tch_afs_decode(uint8_t *tch_data, sbit_t *bursts,
+	int codec_mode_req, uint8_t *codec, int codecs, uint8_t *ft,
+	uint8_t *cmr, int *n_errors, int *n_bits_total);
+
+int gsm0503_tch_ahs_encode(ubit_t *bursts, uint8_t *tch_data, int len,
+	int codec_mode_req, uint8_t *codec, int codecs, uint8_t ft, uint8_t cmr);
+int gsm0503_tch_ahs_decode(uint8_t *tch_data, sbit_t *bursts, int odd,
+	int codec_mode_req, uint8_t *codec, int codecs, uint8_t *ft,
+	uint8_t *cmr, int *n_errors, int *n_bits_total);
+
+int gsm0503_rach_encode(ubit_t *burst, uint8_t *ra, uint8_t bsic);
+int gsm0503_rach_decode(uint8_t *ra, sbit_t *burst, uint8_t bsic);
+
+int gsm0503_sch_encode(ubit_t *burst, uint8_t *sb_info);
+int gsm0503_sch_decode(uint8_t *sb_info, sbit_t *burst);
diff --git a/include/osmocom/coding/gsm0503_interleaving.h b/include/osmocom/coding/gsm0503_interleaving.h
new file mode 100644
index 00000000..f97dff4f
--- /dev/null
+++ b/include/osmocom/coding/gsm0503_interleaving.h
@@ -0,0 +1,51 @@
+#pragma once
+
+#include <osmocom/core/bits.h>
+
+void gsm0503_xcch_deinterleave(sbit_t *cB, const sbit_t *iB);
+void gsm0503_xcch_interleave(ubit_t *cB, ubit_t *iB);
+
+void gsm0503_tch_fr_deinterleave(sbit_t *cB, sbit_t *iB);
+void gsm0503_tch_fr_interleave(ubit_t *cB, ubit_t *iB);
+
+void gsm0503_tch_hr_deinterleave(sbit_t *cB, sbit_t *iB);
+void gsm0503_tch_hr_interleave(ubit_t *cB, ubit_t *iB);
+
+void gsm0503_mcs1_ul_deinterleave(sbit_t *hc, sbit_t *dc, const sbit_t *iB);
+void gsm0503_mcs1_ul_interleave(const ubit_t *hc,
+	const ubit_t *dc, ubit_t *iB);
+
+void gsm0503_mcs1_dl_deinterleave(sbit_t *u, sbit_t *hc,
+	sbit_t *dc, const sbit_t *iB);
+void gsm0503_mcs1_dl_interleave(const ubit_t *up, const ubit_t *hc,
+	const ubit_t *dc, ubit_t *iB);
+
+void gsm0503_mcs5_ul_deinterleave(sbit_t *hc, sbit_t *dc,
+	const sbit_t *hi, const sbit_t *di);
+void gsm0503_mcs5_ul_interleave(const ubit_t *hc, const ubit_t *dc,
+	ubit_t *hi, ubit_t *di);
+
+void gsm0503_mcs5_dl_deinterleave(sbit_t *hc, sbit_t *dc,
+	const sbit_t *hi, const sbit_t *di);
+void gsm0503_mcs5_dl_interleave(const ubit_t *hc, const ubit_t *dc,
+	ubit_t *hi, ubit_t *di);
+
+void gsm0503_mcs7_ul_deinterleave(sbit_t *hc, sbit_t *c1, sbit_t *c2,
+	const sbit_t *hi, const sbit_t *di);
+void gsm0503_mcs7_ul_interleave(const ubit_t *hc, const ubit_t *c1,
+	const ubit_t *c2, ubit_t *hi, ubit_t *di);
+
+void gsm0503_mcs7_dl_deinterleave(sbit_t *hc, sbit_t *c1, sbit_t *c2,
+	const sbit_t *hi, const sbit_t *di);
+void gsm0503_mcs7_dl_interleave(const ubit_t *hc, const ubit_t *c1,
+	const ubit_t *c2, ubit_t *hi, ubit_t *di);
+
+void gsm0503_mcs8_ul_deinterleave(sbit_t *hc, sbit_t *c1, sbit_t *c2,
+	const sbit_t *hi, const sbit_t *di);
+void gsm0503_mcs8_ul_interleave(const ubit_t *hc, const ubit_t *c1,
+	const ubit_t *c2, ubit_t *hi, ubit_t *di);
+
+void gsm0503_mcs8_dl_deinterleave(sbit_t *hc, sbit_t *c1, sbit_t *c2,
+	const sbit_t *hi, const sbit_t *di);
+void gsm0503_mcs8_dl_interleave(const ubit_t *hc, const ubit_t *c1,
+	const ubit_t *c2, ubit_t *hi, ubit_t *di);
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);
diff --git a/include/osmocom/coding/gsm0503_parity.h b/include/osmocom/coding/gsm0503_parity.h
new file mode 100644
index 00000000..540124a7
--- /dev/null
+++ b/include/osmocom/coding/gsm0503_parity.h
@@ -0,0 +1,13 @@
+#pragma once
+
+#include <osmocom/core/crcgen.h>
+
+const struct osmo_crc64gen_code gsm0503_fire_crc40;
+const struct osmo_crc16gen_code gsm0503_cs234_crc16;
+const struct osmo_crc8gen_code gsm0503_mcs_crc8_hdr;
+const struct osmo_crc16gen_code gsm0503_mcs_crc12;
+const struct osmo_crc8gen_code gsm0503_rach_crc6;
+const struct osmo_crc16gen_code gsm0503_sch_crc10;
+const struct osmo_crc8gen_code gsm0503_tch_fr_crc3;
+const struct osmo_crc8gen_code gsm0503_tch_efr_crc8;
+const struct osmo_crc8gen_code gsm0503_amr_crc6;
diff --git a/include/osmocom/coding/gsm0503_tables.h b/include/osmocom/coding/gsm0503_tables.h
new file mode 100644
index 00000000..e6761ca4
--- /dev/null
+++ b/include/osmocom/coding/gsm0503_tables.h
@@ -0,0 +1,50 @@
+#pragma once
+
+#include <stdint.h>
+#include <osmocom/core/bits.h>
+
+extern const ubit_t gsm0503_pdtch_hl_hn_ubit[4][8];
+extern const ubit_t gsm0503_pdtch_edge_hl_hn_ubit[3][8];
+extern const sbit_t gsm0503_pdtch_hl_hn_sbit[4][8];
+extern const sbit_t gsm0503_pdtch_edge_hl_hn_sbit[3][8];
+extern const ubit_t gsm0503_usf2six[8][6];
+extern const ubit_t gsm0503_usf2twelve_ubit[8][12];
+extern const sbit_t gsm0503_usf2twelve_sbit[8][12];
+extern const uint8_t gsm0503_puncture_cs2[588];
+extern const uint8_t gsm0503_puncture_cs3[676];
+extern const uint8_t gsm0503_puncture_mcs1_dl_hdr[108];
+extern const uint8_t gsm0503_puncture_mcs1_ul_hdr[117];
+extern const uint8_t gsm0503_puncture_mcs1_p1[588];
+extern const uint8_t gsm0503_puncture_mcs1_p2[588];
+extern const uint8_t gsm0503_puncture_mcs2_p1[732];
+extern const uint8_t gsm0503_puncture_mcs2_p2[732];
+extern const uint8_t gsm0503_puncture_mcs3_p1[948];
+extern const uint8_t gsm0503_puncture_mcs3_p2[948];
+extern const uint8_t gsm0503_puncture_mcs3_p3[948];
+extern const uint8_t gsm0503_puncture_mcs4_p1[1116];
+extern const uint8_t gsm0503_puncture_mcs4_p2[1116];
+extern const uint8_t gsm0503_puncture_mcs4_p3[1116];
+extern const uint8_t gsm0503_puncture_mcs5_p1[1404];
+extern const uint8_t gsm0503_puncture_mcs5_p2[1404];
+extern const uint8_t gsm0503_puncture_mcs6_p1[1836];
+extern const uint8_t gsm0503_puncture_mcs6_p2[1836];
+extern const uint8_t gsm0503_puncture_mcs7_dl_hdr[135];
+extern const uint8_t gsm0503_puncture_mcs7_ul_hdr[162];
+extern const uint8_t gsm0503_puncture_mcs7_p1[1404];
+extern const uint8_t gsm0503_puncture_mcs7_p2[1404];
+extern const uint8_t gsm0503_puncture_mcs7_p3[1404];
+extern const uint8_t gsm0503_puncture_mcs8_p1[1692];
+extern const uint8_t gsm0503_puncture_mcs8_p2[1692];
+extern const uint8_t gsm0503_puncture_mcs8_p3[1692];
+extern const uint8_t gsm0503_puncture_mcs9_p1[1836];
+extern const uint8_t gsm0503_puncture_mcs9_p2[1836];
+extern const uint8_t gsm0503_puncture_mcs9_p3[1836];
+extern const uint16_t gsm0503_interleave_mcs5[1248];
+extern const uint8_t gsm0503_gsm_fr_map[76];
+extern const uint8_t gsm0503_gsm_efr_protected_bits[65];
+extern const ubit_t gsm0503_afs_ic_ubit[4][8];
+extern const sbit_t gsm0503_afs_ic_sbit[4][8];
+extern const ubit_t gsm0503_ahs_ic_ubit[4][4];
+extern const sbit_t gsm0503_ahs_ic_sbit[4][4];
+extern const uint8_t gsm0503_tch_hr_interleaving[228][2];
+extern const ubit_t gsm0503_mcs5_usf_precode_table[8][36];