| /* |
| * (C) 2013 by Andreas Eversberg <jolly@eversberg.eu> |
| * (C) 2015 by Alexander Chemeris <Alexander.Chemeris@fairwaves.co> |
| * (C) 2016 by Tom Tsou <tom.tsou@ettus.com> |
| * (C) 2017 by Harald Welte <laforge@gnumonks.org> |
| * |
| * All Rights Reserved |
| * |
| * SPDX-License-Identifier: GPL-2.0+ |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License along |
| * with this program; if not, write to the Free Software Foundation, Inc., |
| * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| */ |
| |
| #include <stdio.h> |
| #include <stdint.h> |
| #include <string.h> |
| #include <stdlib.h> |
| #include <errno.h> |
| |
| #include <osmocom/core/bits.h> |
| #include <osmocom/core/conv.h> |
| #include <osmocom/core/utils.h> |
| #include <osmocom/core/crcgen.h> |
| #include <osmocom/core/endian.h> |
| |
| #include <osmocom/gprs/protocol/gsm_04_60.h> |
| #include <osmocom/gprs/gprs_rlc.h> |
| |
| #include <osmocom/gsm/protocol/gsm_04_08.h> |
| #include <osmocom/gsm/gsm0503.h> |
| #include <osmocom/codec/codec.h> |
| |
| #include <osmocom/coding/gsm0503_interleaving.h> |
| #include <osmocom/coding/gsm0503_mapping.h> |
| #include <osmocom/coding/gsm0503_tables.h> |
| #include <osmocom/coding/gsm0503_coding.h> |
| #include <osmocom/coding/gsm0503_parity.h> |
| |
| /*! \mainpage libosmocoding Documentation |
| * |
| * \section sec_intro Introduction |
| * This library is a collection of definitions, tables and functions |
| * implementing the GSM/GPRS/EGPRS channel coding (and decoding) as |
| * specified in 3GPP TS 05.03 / 45.003. |
| * |
| * libosmocoding is developed as part of the Osmocom (Open Source Mobile |
| * Communications) project, a community-based, collaborative development |
| * project to create Free and Open Source implementations of mobile |
| * communications systems. For more information about Osmocom, please |
| * see https://osmocom.org/ |
| * |
| * \section sec_copyright Copyright and License |
| * Copyright © 2013 by Andreas Eversberg\n |
| * Copyright © 2015 by Alexander Chemeris\n |
| * Copyright © 2016 by Tom Tsou\n |
| * Documentation Copyright © 2017 by Harald Welte\n |
| * All rights reserved. \n\n |
| * The source code of libosmocoding is licensed under the terms of the GNU |
| * General Public License as published by the Free Software Foundation; |
| * either version 2 of the License, or (at your option) any later |
| * version.\n |
| * See <http://www.gnu.org/licenses/> or COPYING included in the source |
| * code package istelf.\n |
| * The information detailed here is provided AS IS with NO WARRANTY OF |
| * ANY KIND, INCLUDING THE WARRANTY OF DESIGN, MERCHANTABILITY AND |
| * FITNESS FOR A PARTICULAR PURPOSE. |
| * \n\n |
| * |
| * \section sec_tracker Homepage + Issue Tracker |
| * libosmocoding is distributed as part of libosmocore and shares its |
| * project page at http://osmocom.org/projects/libosmocore |
| * |
| * An Issue Tracker can be found at |
| * https://osmocom.org/projects/libosmocore/issues |
| * |
| * \section sec_contact Contact and Support |
| * Community-based support is available at the OpenBSC mailing list |
| * <http://lists.osmocom.org/mailman/listinfo/openbsc>\n |
| * Commercial support options available upon request from |
| * <http://sysmocom.de/> |
| */ |
| |
| |
| /*! \addtogroup coding |
| * @{ |
| * |
| * GSM TS 05.03 coding |
| * |
| * This module is the "master module" of libosmocoding. It uses the |
| * various other modules (mapping, parity, interleaving) in order to |
| * implement the complete channel coding (and decoding) chain for the |
| * various channel types as defined in TS 05.03 / 45.003. |
| * |
| * \file gsm0503_coding.c */ |
| |
| /* |
| * EGPRS coding limits |
| */ |
| |
| /* Max header size with parity bits */ |
| #define EGPRS_HDR_UPP_MAX 54 |
| |
| /* Max encoded header size */ |
| #define EGPRS_HDR_C_MAX 162 |
| |
| /* Max punctured header size */ |
| #define EGPRS_HDR_HC_MAX 160 |
| |
| /* Max data block size with parity bits */ |
| #define EGPRS_DATA_U_MAX 612 |
| |
| /* Max encoded data block size */ |
| #define EGPRS_DATA_C_MAX 1836 |
| |
| /* Max single block punctured data size */ |
| #define EGPRS_DATA_DC_MAX 1248 |
| |
| /* Dual block punctured data size */ |
| #define EGPRS_DATA_C1 612 |
| #define EGPRS_DATA_C2 EGPRS_DATA_C1 |
| |
| /*! union across the three different EGPRS Uplink header types */ |
| union gprs_rlc_ul_hdr_egprs { |
| struct gprs_rlc_ul_header_egprs_1 type1; |
| struct gprs_rlc_ul_header_egprs_2 type2; |
| struct gprs_rlc_ul_header_egprs_3 type3; |
| }; |
| |
| /*! union across the three different EGPRS Downlink header types */ |
| union gprs_rlc_dl_hdr_egprs { |
| struct gprs_rlc_dl_header_egprs_1 type1; |
| struct gprs_rlc_dl_header_egprs_2 type2; |
| struct gprs_rlc_dl_header_egprs_3 type3; |
| }; |
| |
| /*! Structure describing a Modulation and Coding Scheme */ |
| struct gsm0503_mcs_code { |
| /*! Modulation and Coding Scheme (MSC) number */ |
| uint8_t mcs; |
| /*! Length of Uplink Stealing Flag (USF) in bits */ |
| uint8_t usf_len; |
| |
| /* Header coding */ |
| /*! Length of header (bits) */ |
| uint8_t hdr_len; |
| /*! Length of header convolutional code */ |
| uint8_t hdr_code_len; |
| /*! Length of header code puncturing sequence */ |
| uint8_t hdr_punc_len; |
| /*! header convolutional code */ |
| const struct osmo_conv_code *hdr_conv; |
| /*! header puncturing sequence */ |
| const uint8_t *hdr_punc; |
| |
| /* Data coding */ |
| /*! length of data (bits) */ |
| uint16_t data_len; |
| /*! length of data convolutional code */ |
| uint16_t data_code_len; |
| /*! length of data code puncturing sequence */ |
| uint16_t data_punc_len; |
| /*! data convolutional code */ |
| const struct osmo_conv_code *data_conv; |
| /*! data puncturing sequences */ |
| const uint8_t *data_punc[3]; |
| }; |
| |
| /* |
| * EGPRS UL coding parameters |
| */ |
| const struct gsm0503_mcs_code gsm0503_mcs_ul_codes[EGPRS_NUM_MCS] = { |
| { |
| .mcs = EGPRS_MCS0, |
| }, |
| { |
| .mcs = EGPRS_MCS1, |
| .hdr_len = 31, |
| .hdr_code_len = 117, |
| .hdr_punc_len = 80, |
| .hdr_conv = &gsm0503_mcs1_ul_hdr, |
| .hdr_punc = gsm0503_puncture_mcs1_ul_hdr, |
| |
| .data_len = 178, |
| .data_code_len = 588, |
| .data_punc_len = 372, |
| .data_conv = &gsm0503_mcs1, |
| .data_punc = { |
| gsm0503_puncture_mcs1_p1, |
| gsm0503_puncture_mcs1_p2, |
| NULL, |
| }, |
| }, |
| { |
| .mcs = EGPRS_MCS2, |
| .hdr_len = 31, |
| .hdr_code_len = 117, |
| .hdr_punc_len = 80, |
| .hdr_conv = &gsm0503_mcs1_ul_hdr, |
| .hdr_punc = gsm0503_puncture_mcs1_ul_hdr, |
| |
| .data_len = 226, |
| .data_code_len = 732, |
| .data_punc_len = 372, |
| .data_conv = &gsm0503_mcs2, |
| .data_punc = { |
| gsm0503_puncture_mcs2_p1, |
| gsm0503_puncture_mcs2_p2, |
| NULL, |
| }, |
| }, |
| { |
| .mcs = EGPRS_MCS3, |
| .hdr_len = 31, |
| .hdr_code_len = 117, |
| .hdr_punc_len = 80, |
| .hdr_conv = &gsm0503_mcs1_ul_hdr, |
| .hdr_punc = gsm0503_puncture_mcs1_ul_hdr, |
| |
| .data_len = 298, |
| .data_code_len = 948, |
| .data_punc_len = 372, |
| .data_conv = &gsm0503_mcs3, |
| .data_punc = { |
| gsm0503_puncture_mcs3_p1, |
| gsm0503_puncture_mcs3_p2, |
| gsm0503_puncture_mcs3_p3, |
| }, |
| }, |
| { |
| .mcs = EGPRS_MCS4, |
| .hdr_len = 31, |
| .hdr_code_len = 117, |
| .hdr_punc_len = 80, |
| .hdr_conv = &gsm0503_mcs1_ul_hdr, |
| .hdr_punc = gsm0503_puncture_mcs1_ul_hdr, |
| |
| .data_len = 354, |
| .data_code_len = 1116, |
| .data_punc_len = 372, |
| .data_conv = &gsm0503_mcs4, |
| .data_punc = { |
| gsm0503_puncture_mcs4_p1, |
| gsm0503_puncture_mcs4_p2, |
| gsm0503_puncture_mcs4_p3, |
| }, |
| }, |
| { |
| .mcs = EGPRS_MCS5, |
| .hdr_len = 37, |
| .hdr_code_len = 135, |
| .hdr_punc_len = 136, |
| .hdr_conv = &gsm0503_mcs5_ul_hdr, |
| .hdr_punc = NULL, |
| |
| .data_len = 450, |
| .data_code_len = 1404, |
| .data_punc_len = 1248, |
| .data_conv = &gsm0503_mcs5, |
| .data_punc = { |
| gsm0503_puncture_mcs5_p1, |
| gsm0503_puncture_mcs5_p2, |
| NULL, |
| }, |
| }, |
| { |
| .mcs = EGPRS_MCS6, |
| .hdr_len = 37, |
| .hdr_code_len = 135, |
| .hdr_punc_len = 136, |
| .hdr_conv = &gsm0503_mcs5_ul_hdr, |
| .hdr_punc = NULL, |
| |
| .data_len = 594, |
| .data_code_len = 1836, |
| .data_punc_len = 1248, |
| .data_conv = &gsm0503_mcs6, |
| .data_punc = { |
| gsm0503_puncture_mcs6_p1, |
| gsm0503_puncture_mcs6_p2, |
| NULL, |
| }, |
| }, |
| { |
| .mcs = EGPRS_MCS7, |
| .hdr_len = 46, |
| .hdr_code_len = 162, |
| .hdr_punc_len = 160, |
| .hdr_conv = &gsm0503_mcs7_ul_hdr, |
| .hdr_punc = gsm0503_puncture_mcs7_ul_hdr, |
| |
| .data_len = 900, |
| .data_code_len = 1404, |
| .data_punc_len = 612, |
| .data_conv = &gsm0503_mcs7, |
| .data_punc = { |
| gsm0503_puncture_mcs7_p1, |
| gsm0503_puncture_mcs7_p2, |
| gsm0503_puncture_mcs7_p3, |
| } |
| }, |
| { |
| .mcs = EGPRS_MCS8, |
| .hdr_len = 46, |
| .hdr_code_len = 162, |
| .hdr_punc_len = 160, |
| .hdr_conv = &gsm0503_mcs7_ul_hdr, |
| .hdr_punc = gsm0503_puncture_mcs7_ul_hdr, |
| |
| .data_len = 1092, |
| .data_code_len = 1692, |
| .data_punc_len = 612, |
| .data_conv = &gsm0503_mcs8, |
| .data_punc = { |
| gsm0503_puncture_mcs8_p1, |
| gsm0503_puncture_mcs8_p2, |
| gsm0503_puncture_mcs8_p3, |
| } |
| }, |
| { |
| .mcs = EGPRS_MCS9, |
| .hdr_len = 46, |
| .hdr_code_len = 162, |
| .hdr_punc_len = 160, |
| .hdr_conv = &gsm0503_mcs7_ul_hdr, |
| .hdr_punc = gsm0503_puncture_mcs7_ul_hdr, |
| |
| .data_len = 1188, |
| .data_code_len = 1836, |
| .data_punc_len = 612, |
| .data_conv = &gsm0503_mcs9, |
| .data_punc = { |
| gsm0503_puncture_mcs9_p1, |
| gsm0503_puncture_mcs9_p2, |
| gsm0503_puncture_mcs9_p3, |
| } |
| }, |
| }; |
| |
| /* |
| * EGPRS DL coding parameters |
| */ |
| const struct gsm0503_mcs_code gsm0503_mcs_dl_codes[EGPRS_NUM_MCS] = { |
| { |
| .mcs = EGPRS_MCS0, |
| }, |
| { |
| .mcs = EGPRS_MCS1, |
| .usf_len = 3, |
| .hdr_len = 28, |
| .hdr_code_len = 108, |
| .hdr_punc_len = 68, |
| .hdr_conv = &gsm0503_mcs1_dl_hdr, |
| .hdr_punc = gsm0503_puncture_mcs1_dl_hdr, |
| |
| .data_len = 178, |
| .data_code_len = 588, |
| .data_punc_len = 372, |
| .data_conv = &gsm0503_mcs1, |
| .data_punc = { |
| gsm0503_puncture_mcs1_p1, |
| gsm0503_puncture_mcs1_p2, |
| NULL, |
| }, |
| }, |
| { |
| .mcs = EGPRS_MCS2, |
| .usf_len = 3, |
| .hdr_len = 28, |
| .hdr_code_len = 108, |
| .hdr_punc_len = 68, |
| .hdr_conv = &gsm0503_mcs1_dl_hdr, |
| .hdr_punc = gsm0503_puncture_mcs1_dl_hdr, |
| |
| .data_len = 226, |
| .data_code_len = 732, |
| .data_punc_len = 372, |
| .data_conv = &gsm0503_mcs2, |
| .data_punc = { |
| gsm0503_puncture_mcs2_p1, |
| gsm0503_puncture_mcs2_p2, |
| NULL, |
| }, |
| }, |
| { |
| .mcs = EGPRS_MCS3, |
| .usf_len = 3, |
| .hdr_len = 28, |
| .hdr_code_len = 108, |
| .hdr_punc_len = 68, |
| .hdr_conv = &gsm0503_mcs1_dl_hdr, |
| .hdr_punc = gsm0503_puncture_mcs1_dl_hdr, |
| |
| .data_len = 298, |
| .data_code_len = 948, |
| .data_punc_len = 372, |
| .data_conv = &gsm0503_mcs3, |
| .data_punc = { |
| gsm0503_puncture_mcs3_p1, |
| gsm0503_puncture_mcs3_p2, |
| gsm0503_puncture_mcs3_p3, |
| }, |
| }, |
| { |
| .mcs = EGPRS_MCS4, |
| .usf_len = 3, |
| .hdr_len = 28, |
| .hdr_code_len = 108, |
| .hdr_punc_len = 68, |
| .hdr_conv = &gsm0503_mcs1_dl_hdr, |
| .hdr_punc = gsm0503_puncture_mcs1_dl_hdr, |
| |
| .data_len = 354, |
| .data_code_len = 1116, |
| .data_punc_len = 372, |
| .data_conv = &gsm0503_mcs4, |
| .data_punc = { |
| gsm0503_puncture_mcs4_p1, |
| gsm0503_puncture_mcs4_p2, |
| gsm0503_puncture_mcs4_p3, |
| }, |
| }, |
| { |
| .mcs = EGPRS_MCS5, |
| .usf_len = 3, |
| .hdr_len = 25, |
| .hdr_code_len = 99, |
| .hdr_punc_len = 100, |
| .hdr_conv = &gsm0503_mcs5_dl_hdr, |
| .hdr_punc = NULL, |
| |
| .data_len = 450, |
| .data_code_len = 1404, |
| .data_punc_len = 1248, |
| .data_conv = &gsm0503_mcs5, |
| .data_punc = { |
| gsm0503_puncture_mcs5_p1, |
| gsm0503_puncture_mcs5_p2, |
| NULL, |
| }, |
| }, |
| { |
| .mcs = EGPRS_MCS6, |
| .usf_len = 3, |
| .hdr_len = 25, |
| .hdr_code_len = 99, |
| .hdr_punc_len = 100, |
| .hdr_conv = &gsm0503_mcs5_dl_hdr, |
| .hdr_punc = NULL, |
| |
| .data_len = 594, |
| .data_code_len = 1836, |
| .data_punc_len = 1248, |
| .data_conv = &gsm0503_mcs6, |
| .data_punc = { |
| gsm0503_puncture_mcs6_p1, |
| gsm0503_puncture_mcs6_p2, |
| NULL, |
| }, |
| }, |
| { |
| .mcs = EGPRS_MCS7, |
| .usf_len = 3, |
| .hdr_len = 37, |
| .hdr_code_len = 135, |
| .hdr_punc_len = 124, |
| .hdr_conv = &gsm0503_mcs7_dl_hdr, |
| .hdr_punc = gsm0503_puncture_mcs7_dl_hdr, |
| |
| .data_len = 900, |
| .data_code_len = 1404, |
| .data_punc_len = 612, |
| .data_conv = &gsm0503_mcs7, |
| .data_punc = { |
| gsm0503_puncture_mcs7_p1, |
| gsm0503_puncture_mcs7_p2, |
| gsm0503_puncture_mcs7_p3, |
| } |
| }, |
| { |
| .mcs = EGPRS_MCS8, |
| .usf_len = 3, |
| .hdr_len = 37, |
| .hdr_code_len = 135, |
| .hdr_punc_len = 124, |
| .hdr_conv = &gsm0503_mcs7_dl_hdr, |
| .hdr_punc = gsm0503_puncture_mcs7_dl_hdr, |
| |
| .data_len = 1092, |
| .data_code_len = 1692, |
| .data_punc_len = 612, |
| .data_conv = &gsm0503_mcs8, |
| .data_punc = { |
| gsm0503_puncture_mcs8_p1, |
| gsm0503_puncture_mcs8_p2, |
| gsm0503_puncture_mcs8_p3, |
| } |
| }, |
| { |
| .mcs = EGPRS_MCS9, |
| .usf_len = 3, |
| .hdr_len = 37, |
| .hdr_code_len = 135, |
| .hdr_punc_len = 124, |
| .hdr_conv = &gsm0503_mcs7_dl_hdr, |
| .hdr_punc = gsm0503_puncture_mcs7_dl_hdr, |
| |
| .data_len = 1188, |
| .data_code_len = 1836, |
| .data_punc_len = 612, |
| .data_conv = &gsm0503_mcs9, |
| .data_punc = { |
| gsm0503_puncture_mcs9_p1, |
| gsm0503_puncture_mcs9_p2, |
| gsm0503_puncture_mcs9_p3, |
| } |
| }, |
| }; |
| |
| /*! Convolutional Decode + compute BER for punctured codes |
| * \param[in] code Description of Convolutional Code |
| * \param[in] input Input soft-bits (-127...127) |
| * \param[out] output bits |
| * \param[out] n_errors Number of bit-errors |
| * \param[out] n_bits_total Number of bits |
| * \param[in] data_punc Puncturing mask array. Can be NULL. |
| */ |
| static int osmo_conv_decode_ber_punctured(const struct osmo_conv_code *code, |
| const sbit_t *input, ubit_t *output, |
| int *n_errors, int *n_bits_total, |
| const uint8_t *data_punc) |
| { |
| int res, i, coded_len; |
| ubit_t recoded[EGPRS_DATA_C_MAX]; |
| |
| res = osmo_conv_decode(code, input, output); |
| |
| if (n_bits_total || n_errors) { |
| coded_len = osmo_conv_encode(code, output, recoded); |
| OSMO_ASSERT(sizeof(recoded) / sizeof(recoded[0]) >= coded_len); |
| } |
| |
| /* Count bit errors */ |
| if (n_errors) { |
| *n_errors = 0; |
| for (i = 0; i < coded_len; i++) { |
| if (((!data_punc) || (data_punc && !data_punc[i])) && |
| !((recoded[i] && input[i] < 0) || |
| (!recoded[i] && input[i] > 0)) ) |
| *n_errors += 1; |
| } |
| } |
| |
| if (n_bits_total) |
| *n_bits_total = coded_len; |
| |
| return res; |
| } |
| |
| /*! Convolutional Decode + compute BER for non-punctured codes |
| * \param[in] code Description of Convolutional Code |
| * \param[in] input Input soft-bits (-127...127) |
| * \param[out] output bits |
| * \param[out] n_errors Number of bit-errors |
| * \param[out] n_bits_total Number of bits |
| */ |
| static int osmo_conv_decode_ber(const struct osmo_conv_code *code, |
| const sbit_t *input, ubit_t *output, |
| int *n_errors, int *n_bits_total) |
| { |
| return osmo_conv_decode_ber_punctured(code, input, output, |
| n_errors, n_bits_total, NULL); |
| } |
| |
| /*! convenience wrapper for decoding coded bits |
| * \param[out] l2_data caller-allocated buffer for L2 Frame |
| * \param[in] cB 456 coded (soft) bits as per TS 05.03 4.1.3 |
| * \param[out] n_errors Number of detected errors |
| * \param[out] n_bits_total Number of total coded bits |
| * \returns 0 on success; -1 on CRC error */ |
| static int _xcch_decode_cB(uint8_t *l2_data, const sbit_t *cB, |
| int *n_errors, int *n_bits_total) |
| { |
| ubit_t conv[224]; |
| int rv; |
| |
| osmo_conv_decode_ber(&gsm0503_xcch, cB, |
| conv, n_errors, n_bits_total); |
| |
| rv = osmo_crc64gen_check_bits(&gsm0503_fire_crc40, |
| conv, 184, conv + 184); |
| if (rv) |
| return -1; |
| |
| osmo_ubit2pbit_ext(l2_data, 0, conv, 0, 184, 1); |
| |
| return 0; |
| } |
| |
| /*! convenience wrapper for encoding to coded bits |
| * \param[out] cB caller-allocated buffer for 456 coded bits as per TS 05.03 4.1.3 |
| * \param[out] l2_data to-be-encoded L2 Frame |
| * \returns 0 */ |
| static int _xcch_encode_cB(ubit_t *cB, const uint8_t *l2_data) |
| { |
| ubit_t conv[224]; |
| |
| osmo_pbit2ubit_ext(conv, 0, l2_data, 0, 184, 1); |
| |
| osmo_crc64gen_set_bits(&gsm0503_fire_crc40, conv, 184, conv + 184); |
| |
| osmo_conv_encode(&gsm0503_xcch, conv, cB); |
| |
| return 0; |
| } |
| |
| /* |
| * GSM xCCH block transcoding |
| */ |
| |
| /*! Decoding of xCCH data from bursts to L2 frame |
| * \param[out] l2_data caller-allocated output data buffer |
| * \param[in] bursts four GSM bursts in soft-bits |
| * \param[out] n_errors Number of detected errors |
| * \param[out] n_bits_total Number of total coded bits |
| */ |
| int gsm0503_xcch_decode(uint8_t *l2_data, const sbit_t *bursts, |
| int *n_errors, int *n_bits_total) |
| { |
| sbit_t iB[456], cB[456]; |
| int i; |
| |
| for (i = 0; i < 4; i++) |
| gsm0503_xcch_burst_unmap(&iB[i * 114], &bursts[i * 116], NULL, NULL); |
| |
| gsm0503_xcch_deinterleave(cB, iB); |
| |
| return _xcch_decode_cB(l2_data, cB, n_errors, n_bits_total); |
| } |
| |
| /*! Encoding of xCCH data from L2 frame to bursts |
| * \param[out] bursts caller-allocated burst data (unpacked bits) |
| * \param[in] l2_data L2 input data (MAC block) |
| * \returns 0 |
| */ |
| int gsm0503_xcch_encode(ubit_t *bursts, const uint8_t *l2_data) |
| { |
| ubit_t iB[456], cB[456], hl = 1, hn = 1; |
| int i; |
| |
| _xcch_encode_cB(cB, l2_data); |
| |
| gsm0503_xcch_interleave(cB, iB); |
| |
| for (i = 0; i < 4; i++) |
| gsm0503_xcch_burst_map(&iB[i * 114], &bursts[i * 116], &hl, &hn); |
| |
| return 0; |
| } |
| |
| /* |
| * EGPRS PDTCH UL block decoding |
| */ |
| |
| /* |
| * Type 3 - MCS-1,2,3,4 |
| * Unmapping and deinterleaving |
| */ |
| static int egprs_type3_unmap(const sbit_t *bursts, sbit_t *hc, sbit_t *dc) |
| { |
| int i; |
| sbit_t iB[456], q[8]; |
| |
| for (i = 0; i < 4; i++) { |
| gsm0503_xcch_burst_unmap(&iB[i * 114], &bursts[i * 116], |
| q + i * 2, q + i * 2 + 1); |
| } |
| |
| gsm0503_mcs1_ul_deinterleave(hc, dc, iB); |
| |
| return 0; |
| } |
| |
| /* |
| * Type 2 - MCS-5,6 |
| * Unmapping and deinterleaving |
| */ |
| static int egprs_type2_unmap(const sbit_t *bursts, sbit_t *hc, sbit_t *dc) |
| { |
| int i; |
| sbit_t burst[348]; |
| sbit_t hi[EGPRS_HDR_HC_MAX]; |
| sbit_t di[EGPRS_DATA_DC_MAX]; |
| |
| for (i = 0; i < 4; i++) { |
| memcpy(burst, &bursts[i * 348], 348); |
| |
| gsm0503_mcs5_burst_swap(burst); |
| gsm0503_mcs5_ul_burst_unmap(di, burst, hi, i); |
| } |
| |
| gsm0503_mcs5_ul_deinterleave(hc, dc, hi, di); |
| |
| return 0; |
| } |
| |
| /* |
| * Type 1 - MCS-7,8,9 |
| * Unmapping and deinterleaving - Note that MCS-7 interleaver is unique |
| */ |
| static int egprs_type1_unmap(const sbit_t *bursts, sbit_t *hc, |
| sbit_t *c1, sbit_t *c2, int msc) |
| { |
| int i; |
| sbit_t burst[348]; |
| sbit_t hi[EGPRS_HDR_HC_MAX]; |
| sbit_t di[EGPRS_DATA_C1 * 2]; |
| |
| for (i = 0; i < 4; i++) { |
| memcpy(burst, &bursts[i * 348], 348); |
| |
| gsm0503_mcs5_burst_swap(burst); |
| gsm0503_mcs7_ul_burst_unmap(di, burst, hi, i); |
| } |
| |
| if (msc == EGPRS_MCS7) |
| gsm0503_mcs7_ul_deinterleave(hc, c1, c2, hi, di); |
| else |
| gsm0503_mcs8_ul_deinterleave(hc, c1, c2, hi, di); |
| |
| return 0; |
| } |
| |
| /* |
| * Decode EGPRS UL header section |
| * |
| * 1. Depuncture |
| * 2. Convolutional decoding |
| * 3. CRC check |
| */ |
| static int _egprs_decode_hdr(const sbit_t *hc, int mcs, |
| union gprs_rlc_ul_hdr_egprs *hdr) |
| { |
| sbit_t C[EGPRS_HDR_C_MAX]; |
| ubit_t upp[EGPRS_HDR_UPP_MAX]; |
| int i, j, rc; |
| const struct gsm0503_mcs_code *code; |
| |
| code = &gsm0503_mcs_ul_codes[mcs]; |
| |
| /* Skip depuncturing on MCS-5,6 header */ |
| if ((mcs == EGPRS_MCS5) || (mcs == EGPRS_MCS6)) { |
| memcpy(C, hc, code->hdr_code_len); |
| goto hdr_conv_decode; |
| } |
| |
| if (!code->hdr_punc) { |
| /* Invalid MCS-X header puncture matrix */ |
| return -1; |
| } |
| |
| i = code->hdr_code_len - 1; |
| j = code->hdr_punc_len - 1; |
| |
| for (; i >= 0; i--) { |
| if (!code->hdr_punc[i]) |
| C[i] = hc[j--]; |
| else |
| C[i] = 0; |
| } |
| |
| hdr_conv_decode: |
| osmo_conv_decode_ber(code->hdr_conv, C, upp, NULL, NULL); |
| rc = osmo_crc8gen_check_bits(&gsm0503_mcs_crc8_hdr, upp, |
| code->hdr_len, upp + code->hdr_len); |
| if (rc) |
| return -1; |
| |
| osmo_ubit2pbit_ext((pbit_t *) hdr, 0, upp, 0, code->hdr_len, 1); |
| |
| return 0; |
| } |
| |
| /* |
| * Blind MCS header decoding based on burst length and CRC validation. |
| * Ignore 'q' value coding identification. This approach provides |
| * the strongest chance of header recovery. |
| */ |
| static int egprs_decode_hdr(union gprs_rlc_ul_hdr_egprs *hdr, |
| const sbit_t *bursts, uint16_t nbits) |
| { |
| int rc; |
| sbit_t hc[EGPRS_HDR_HC_MAX]; |
| |
| if (nbits == GSM0503_GPRS_BURSTS_NBITS) { |
| /* MCS-1,2,3,4 */ |
| egprs_type3_unmap(bursts, hc, NULL); |
| rc = _egprs_decode_hdr(hc, EGPRS_MCS1, hdr); |
| if (!rc) |
| return EGPRS_HDR_TYPE3; |
| } else if (nbits == GSM0503_EGPRS_BURSTS_NBITS) { |
| /* MCS-5,6 */ |
| egprs_type2_unmap(bursts, hc, NULL); |
| rc = _egprs_decode_hdr(hc, EGPRS_MCS5, hdr); |
| if (!rc) |
| return EGPRS_HDR_TYPE2; |
| |
| /* MCS-7,8,9 */ |
| egprs_type1_unmap(bursts, hc, NULL, NULL, EGPRS_MCS7); |
| rc = _egprs_decode_hdr(hc, EGPRS_MCS7, hdr); |
| if (!rc) |
| return EGPRS_HDR_TYPE1; |
| } |
| |
| return -1; |
| } |
| |
| /* |
| * Parse EGPRS UL header for coding and puncturing scheme (CPS) |
| * |
| * Type 1 - MCS-7,8,9 |
| * Type 2 - MCS-5,6 |
| * Type 3 - MCS-1,2,3,4 |
| */ |
| static int egprs_parse_ul_cps(struct egprs_cps *cps, |
| union gprs_rlc_ul_hdr_egprs *hdr, int type) |
| { |
| uint8_t bits; |
| |
| switch (type) { |
| case EGPRS_HDR_TYPE1: |
| bits = hdr->type1.cps; |
| break; |
| case EGPRS_HDR_TYPE2: |
| bits = (hdr->type2.cps_lo << 2) | hdr->type2.cps_hi; |
| break; |
| case EGPRS_HDR_TYPE3: |
| bits = (hdr->type3.cps_lo << 2) | hdr->type3.cps_hi; |
| break; |
| default: |
| return -1; |
| } |
| |
| return egprs_get_cps(cps, type, bits); |
| } |
| |
| /* |
| * Decode EGPRS UL data section |
| * |
| * 1. Depuncture |
| * 2. Convolutional decoding |
| * 3. CRC check |
| * 4. Block combining (MCS-7,8,9 only) |
| */ |
| static int egprs_decode_data(uint8_t *l2_data, const sbit_t *c, |
| int mcs, int p, int blk, int *n_errors, int *n_bits_total) |
| { |
| ubit_t u[EGPRS_DATA_U_MAX]; |
| sbit_t C[EGPRS_DATA_C_MAX]; |
| |
| int i, j, rc, data_len; |
| const struct gsm0503_mcs_code *code; |
| |
| if (blk && mcs < EGPRS_MCS7) { |
| /* Invalid MCS-X block state */ |
| return -1; |
| } |
| |
| code = &gsm0503_mcs_ul_codes[mcs]; |
| if (!code->data_punc[p]) { |
| /* Invalid MCS-X data puncture matrix */ |
| return -1; |
| } |
| |
| /* |
| * MCS-1,6 - single block processing |
| * MCS-7,9 - dual block processing |
| */ |
| if (mcs >= EGPRS_MCS7) |
| data_len = code->data_len / 2; |
| else |
| data_len = code->data_len; |
| |
| i = code->data_code_len - 1; |
| j = code->data_punc_len - 1; |
| |
| for (; i >= 0; i--) { |
| if (!code->data_punc[p][i]) |
| C[i] = c[j--]; |
| else |
| C[i] = 0; |
| } |
| |
| osmo_conv_decode_ber_punctured(code->data_conv, C, u, |
| n_errors, n_bits_total, code->data_punc[p]); |
| rc = osmo_crc16gen_check_bits(&gsm0503_mcs_crc12, u, |
| data_len, u + data_len); |
| if (rc) |
| return -1; |
| |
| /* Offsets output pointer on the second block of Type 1 MCS */ |
| osmo_ubit2pbit_ext(l2_data, code->hdr_len + blk * data_len, |
| u, 0, data_len, 1); |
| |
| /* Return the number of bytes required for the bit message */ |
| return OSMO_BYTES_FOR_BITS(code->hdr_len + code->data_len); |
| } |
| |
| /*! Decode EGPRS UL message |
| * 1. Header section decoding |
| * 2. Extract CPS settings |
| * 3. Burst unmapping and deinterleaving |
| * 4. Data section decoding |
| * \param[out] l2_data caller-allocated buffer for L2 Frame |
| * \param[in] bursts burst input data as soft unpacked bits |
| * \param[in] nbits number of bits in \a bursts |
| * \param usf_p unused argument ?!? |
| * \param[out] n_errors number of detected bit-errors |
| * \param[out] n_bits_total total number of decoded bits |
| * \returns 0 on success; negative on error */ |
| int gsm0503_pdtch_egprs_decode(uint8_t *l2_data, const sbit_t *bursts, uint16_t nbits, |
| uint8_t *usf_p, int *n_errors, int *n_bits_total) |
| { |
| sbit_t dc[EGPRS_DATA_DC_MAX]; |
| sbit_t c1[EGPRS_DATA_C1], c2[EGPRS_DATA_C2]; |
| int type, rc; |
| struct egprs_cps cps; |
| union gprs_rlc_ul_hdr_egprs *hdr; |
| |
| if (n_errors) |
| *n_errors = 0; |
| if (n_bits_total) |
| *n_bits_total = 0; |
| |
| if ((nbits != GSM0503_GPRS_BURSTS_NBITS) && |
| (nbits != GSM0503_EGPRS_BURSTS_NBITS)) { |
| /* Invalid EGPRS bit length */ |
| return -EOVERFLOW; |
| } |
| |
| hdr = (union gprs_rlc_ul_hdr_egprs *) l2_data; |
| type = egprs_decode_hdr(hdr, bursts, nbits); |
| if (egprs_parse_ul_cps(&cps, hdr, type) < 0) |
| return -EIO; |
| |
| switch (cps.mcs) { |
| case EGPRS_MCS0: |
| return -ENOTSUP; |
| case EGPRS_MCS1: |
| case EGPRS_MCS2: |
| case EGPRS_MCS3: |
| case EGPRS_MCS4: |
| egprs_type3_unmap(bursts, NULL, dc); |
| break; |
| case EGPRS_MCS5: |
| case EGPRS_MCS6: |
| egprs_type2_unmap(bursts, NULL, dc); |
| break; |
| case EGPRS_MCS7: |
| case EGPRS_MCS8: |
| case EGPRS_MCS9: |
| egprs_type1_unmap(bursts, NULL, c1, c2, cps.mcs); |
| break; |
| default: |
| /* Invalid MCS-X */ |
| return -EINVAL; |
| } |
| |
| /* Decode MCS-X block, where X = cps.mcs */ |
| if (cps.mcs < EGPRS_MCS7) { |
| rc = egprs_decode_data(l2_data, dc, cps.mcs, cps.p[0], |
| 0, n_errors, n_bits_total); |
| if (rc < 0) |
| return -EFAULT; |
| } else { |
| /* Bit counters for the second block */ |
| int n_errors2, n_bits_total2; |
| |
| /* MCS-7,8,9 block 1 */ |
| rc = egprs_decode_data(l2_data, c1, cps.mcs, cps.p[0], |
| 0, n_errors, n_bits_total); |
| if (rc < 0) |
| return -EFAULT; |
| |
| /* MCS-7,8,9 block 2 */ |
| rc = egprs_decode_data(l2_data, c2, cps.mcs, cps.p[1], |
| 1, &n_errors2, &n_bits_total2); |
| if (n_errors) |
| *n_errors += n_errors2; |
| if (n_bits_total) |
| *n_bits_total += n_bits_total2; |
| if (rc < 0) |
| return -EFAULT; |
| } |
| |
| return rc; |
| } |
| |
| /* |
| * GSM PDTCH block transcoding |
| */ |
| |
| /*! Decode GPRS PDTCH |
| * \param[out] l2_data caller-allocated buffer for L2 Frame |
| * \param[in] bursts burst input data as soft unpacked bits |
| * \param[out] usf_p uplink stealing flag |
| * \param[out] n_errors number of detected bit-errors |
| * \param[out] n_bits_total total number of dcoded bits |
| * \returns 0 on success; negative on error */ |
| int gsm0503_pdtch_decode(uint8_t *l2_data, const sbit_t *bursts, uint8_t *usf_p, |
| int *n_errors, int *n_bits_total) |
| { |
| sbit_t iB[456], cB[676], hl_hn[8]; |
| ubit_t conv[456]; |
| int i, j, k, rv, best = 0, cs = 0, usf = 0; /* make GCC happy */ |
| |
| for (i = 0; i < 4; i++) |
| gsm0503_xcch_burst_unmap(&iB[i * 114], &bursts[i * 116], |
| hl_hn + i * 2, hl_hn + i * 2 + 1); |
| |
| for (i = 0; i < 4; i++) { |
| for (j = 0, k = 0; j < 8; j++) |
| k += abs(((int)gsm0503_pdtch_hl_hn_sbit[i][j]) - ((int)hl_hn[j])); |
| |
| if (i == 0 || k < best) { |
| best = k; |
| cs = i + 1; |
| } |
| } |
| |
| gsm0503_xcch_deinterleave(cB, iB); |
| |
| switch (cs) { |
| case 1: |
| osmo_conv_decode_ber(&gsm0503_xcch, cB, |
| conv, n_errors, n_bits_total); |
| |
| rv = osmo_crc64gen_check_bits(&gsm0503_fire_crc40, |
| conv, 184, conv + 184); |
| if (rv) |
| return -1; |
| |
| osmo_ubit2pbit_ext(l2_data, 0, conv, 0, 184, 1); |
| |
| return 23; |
| case 2: |
| for (i = 587, j = 455; i >= 0; i--) { |
| if (!gsm0503_puncture_cs2[i]) |
| cB[i] = cB[j--]; |
| else |
| cB[i] = 0; |
| } |
| |
| osmo_conv_decode_ber(&gsm0503_cs2_np, cB, |
| conv, n_errors, n_bits_total); |
| |
| for (i = 0; i < 8; i++) { |
| for (j = 0, k = 0; j < 6; j++) |
| k += abs(((int)gsm0503_usf2six[i][j]) - ((int)conv[j])); |
| |
| if (i == 0 || k < best) { |
| best = k; |
| usf = i; |
| } |
| } |
| |
| conv[3] = usf & 1; |
| conv[4] = (usf >> 1) & 1; |
| conv[5] = (usf >> 2) & 1; |
| if (usf_p) |
| *usf_p = usf; |
| |
| rv = osmo_crc16gen_check_bits(&gsm0503_cs234_crc16, |
| conv + 3, 271, conv + 3 + 271); |
| if (rv) |
| return -1; |
| |
| osmo_ubit2pbit_ext(l2_data, 0, conv, 3, 271, 1); |
| |
| return 34; |
| case 3: |
| for (i = 675, j = 455; i >= 0; i--) { |
| if (!gsm0503_puncture_cs3[i]) |
| cB[i] = cB[j--]; |
| else |
| cB[i] = 0; |
| } |
| |
| osmo_conv_decode_ber(&gsm0503_cs3_np, cB, |
| conv, n_errors, n_bits_total); |
| |
| for (i = 0; i < 8; i++) { |
| for (j = 0, k = 0; j < 6; j++) |
| k += abs(((int)gsm0503_usf2six[i][j]) - ((int)conv[j])); |
| |
| if (i == 0 || k < best) { |
| best = k; |
| usf = i; |
| } |
| } |
| |
| conv[3] = usf & 1; |
| conv[4] = (usf >> 1) & 1; |
| conv[5] = (usf >> 2) & 1; |
| if (usf_p) |
| *usf_p = usf; |
| |
| rv = osmo_crc16gen_check_bits(&gsm0503_cs234_crc16, |
| conv + 3, 315, conv + 3 + 315); |
| if (rv) |
| return -1; |
| |
| osmo_ubit2pbit_ext(l2_data, 0, conv, 3, 315, 1); |
| |
| return 40; |
| case 4: |
| for (i = 12; i < 456; i++) |
| conv[i] = (cB[i] < 0) ? 1 : 0; |
| |
| for (i = 0; i < 8; i++) { |
| for (j = 0, k = 0; j < 12; j++) |
| k += abs(((int)gsm0503_usf2twelve_sbit[i][j]) - ((int)cB[j])); |
| |
| if (i == 0 || k < best) { |
| best = k; |
| usf = i; |
| } |
| } |
| |
| conv[9] = usf & 1; |
| conv[10] = (usf >> 1) & 1; |
| conv[11] = (usf >> 2) & 1; |
| if (usf_p) |
| *usf_p = usf; |
| |
| rv = osmo_crc16gen_check_bits(&gsm0503_cs234_crc16, |
| conv + 9, 431, conv + 9 + 431); |
| if (rv) { |
| *n_bits_total = 456 - 12; |
| *n_errors = *n_bits_total; |
| return -1; |
| } |
| |
| *n_bits_total = 456 - 12; |
| *n_errors = 0; |
| |
| osmo_ubit2pbit_ext(l2_data, 0, conv, 9, 431, 1); |
| |
| return 54; |
| default: |
| *n_bits_total = 0; |
| *n_errors = 0; |
| break; |
| } |
| |
| return -1; |
| } |
| |
| /* |
| * EGPRS PDTCH UL block encoding |
| */ |
| static int egprs_type3_map(ubit_t *bursts, const ubit_t *hc, const ubit_t *dc, int usf) |
| { |
| int i; |
| ubit_t iB[456]; |
| const ubit_t *hl_hn = gsm0503_pdtch_hl_hn_ubit[3]; |
| |
| gsm0503_mcs1_dl_interleave(gsm0503_usf2six[usf], hc, dc, iB); |
| |
| for (i = 0; i < 4; i++) { |
| gsm0503_xcch_burst_map(&iB[i * 114], &bursts[i * 116], |
| hl_hn + i * 2, hl_hn + i * 2 + 1); |
| } |
| |
| return 0; |
| } |
| |
| static int egprs_type2_map(ubit_t *bursts, const ubit_t *hc, const ubit_t *dc, int usf) |
| { |
| int i; |
| const ubit_t *up; |
| ubit_t hi[EGPRS_HDR_HC_MAX]; |
| ubit_t di[EGPRS_DATA_DC_MAX]; |
| |
| gsm0503_mcs5_dl_interleave(hc, dc, hi, di); |
| up = gsm0503_mcs5_usf_precode_table[usf]; |
| |
| for (i = 0; i < 4; i++) { |
| gsm0503_mcs5_dl_burst_map(di, &bursts[i * 348], hi, up, i); |
| gsm0503_mcs5_burst_swap((sbit_t *) &bursts[i * 348]); |
| } |
| |
| return 0; |
| } |
| |
| static int egprs_type1_map(ubit_t *bursts, const ubit_t *hc, |
| const ubit_t *c1, const ubit_t *c2, int usf, int mcs) |
| { |
| int i; |
| const ubit_t *up; |
| ubit_t hi[EGPRS_HDR_HC_MAX]; |
| ubit_t di[EGPRS_DATA_C1 * 2]; |
| |
| if (mcs == EGPRS_MCS7) |
| gsm0503_mcs7_dl_interleave(hc, c1, c2, hi, di); |
| else |
| gsm0503_mcs8_dl_interleave(hc, c1, c2, hi, di); |
| |
| up = gsm0503_mcs5_usf_precode_table[usf]; |
| |
| for (i = 0; i < 4; i++) { |
| gsm0503_mcs7_dl_burst_map(di, &bursts[i * 348], hi, up, i); |
| gsm0503_mcs5_burst_swap((sbit_t *) &bursts[i * 348]); |
| } |
| |
| return 0; |
| } |
| |
| static int egprs_encode_hdr(ubit_t *hc, const uint8_t *l2_data, int mcs) |
| { |
| int i, j; |
| ubit_t upp[EGPRS_HDR_UPP_MAX], C[EGPRS_HDR_C_MAX]; |
| const struct gsm0503_mcs_code *code; |
| |
| code = &gsm0503_mcs_dl_codes[mcs]; |
| |
| osmo_pbit2ubit_ext(upp, 0, l2_data, code->usf_len, code->hdr_len, 1); |
| osmo_crc8gen_set_bits(&gsm0503_mcs_crc8_hdr, upp, |
| code->hdr_len, upp + code->hdr_len); |
| |
| osmo_conv_encode(code->hdr_conv, upp, C); |
| |
| /* MCS-5,6 header direct puncture instead of table */ |
| if ((mcs == EGPRS_MCS5) || (mcs == EGPRS_MCS6)) { |
| memcpy(hc, C, code->hdr_code_len); |
| hc[99] = hc[98]; |
| return 0; |
| } |
| |
| if (!code->hdr_punc) { |
| /* Invalid MCS-X header puncture matrix */ |
| return -1; |
| } |
| |
| for (i = 0, j = 0; i < code->hdr_code_len; i++) { |
| if (!code->hdr_punc[i]) |
| hc[j++] = C[i]; |
| } |
| |
| return 0; |
| } |
| |
| static int egprs_encode_data(ubit_t *c, const uint8_t *l2_data, |
| int mcs, int p, int blk) |
| { |
| int i, j, data_len; |
| ubit_t u[EGPRS_DATA_U_MAX], C[EGPRS_DATA_C_MAX]; |
| const struct gsm0503_mcs_code *code; |
| |
| code = &gsm0503_mcs_dl_codes[mcs]; |
| |
| /* |
| * Dual block - MCS-7,8,9 |
| * Single block - MCS-1,2,3,4,5,6 |
| */ |
| if (mcs >= EGPRS_MCS7) |
| data_len = code->data_len / 2; |
| else |
| data_len = code->data_len; |
| |
| osmo_pbit2ubit_ext(u, 0, l2_data, |
| code->usf_len + code->hdr_len + blk * data_len, data_len, 1); |
| |
| osmo_crc16gen_set_bits(&gsm0503_mcs_crc12, u, data_len, u + data_len); |
| |
| osmo_conv_encode(code->data_conv, u, C); |
| |
| if (!code->data_punc[p]) { |
| /* Invalid MCS-X data puncture matrix */ |
| return -1; |
| } |
| |
| for (i = 0, j = 0; i < code->data_code_len; i++) { |
| if (!code->data_punc[p][i]) |
| c[j++] = C[i]; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * Parse EGPRS DL header for coding and puncturing scheme (CPS) |
| * |
| * Type 1 - MCS-7,8,9 |
| * Type 2 - MCS-5,6 |
| * Type 3 - MCS-1,2,3,4 |
| */ |
| static int egprs_parse_dl_cps(struct egprs_cps *cps, |
| const union gprs_rlc_dl_hdr_egprs *hdr, int type) |
| { |
| uint8_t bits; |
| |
| switch (type) { |
| case EGPRS_HDR_TYPE1: |
| bits = hdr->type1.cps; |
| break; |
| case EGPRS_HDR_TYPE2: |
| bits = hdr->type2.cps; |
| break; |
| case EGPRS_HDR_TYPE3: |
| bits = hdr->type3.cps; |
| break; |
| default: |
| return -1; |
| } |
| |
| return egprs_get_cps(cps, type, bits); |
| } |
| |
| /*! EGPRS DL message encoding |
| * \param[out] bursts caller-allocated buffer for unpacked burst bits |
| * \param[in] l2_data L2 (MAC) block to be encoded |
| * \param[in] l2_len length of l2_data in bytes, used to determine MCS |
| * \returns 0 on success; negative on error */ |
| int gsm0503_pdtch_egprs_encode(ubit_t *bursts, |
| const uint8_t *l2_data, uint8_t l2_len) |
| { |
| ubit_t hc[EGPRS_DATA_C_MAX], dc[EGPRS_DATA_DC_MAX]; |
| ubit_t c1[EGPRS_DATA_C1], c2[EGPRS_DATA_C2]; |
| uint8_t mcs; |
| struct egprs_cps cps; |
| union gprs_rlc_dl_hdr_egprs *hdr; |
| |
| switch (l2_len) { |
| case 27: |
| mcs = EGPRS_MCS1; |
| break; |
| case 33: |
| mcs = EGPRS_MCS2; |
| break; |
| case 42: |
| mcs = EGPRS_MCS3; |
| break; |
| case 49: |
| mcs = EGPRS_MCS4; |
| break; |
| case 60: |
| mcs = EGPRS_MCS5; |
| break; |
| case 78: |
| mcs = EGPRS_MCS6; |
| break; |
| case 118: |
| mcs = EGPRS_MCS7; |
| break; |
| case 142: |
| mcs = EGPRS_MCS8; |
| break; |
| case 154: |
| mcs = EGPRS_MCS9; |
| break; |
| default: |
| return -1; |
| } |
| |
| /* Read header for USF and puncturing matrix selection. */ |
| hdr = (union gprs_rlc_dl_hdr_egprs *) l2_data; |
| |
| switch (mcs) { |
| case EGPRS_MCS1: |
| case EGPRS_MCS2: |
| case EGPRS_MCS3: |
| case EGPRS_MCS4: |
| /* Check for valid CPS and matching MCS to message size */ |
| if ((egprs_parse_dl_cps(&cps, hdr, EGPRS_HDR_TYPE3) < 0) || |
| (cps.mcs != mcs)) |
| goto bad_header; |
| |
| egprs_encode_hdr(hc, l2_data, mcs); |
| egprs_encode_data(dc, l2_data, mcs, cps.p[0], 0); |
| egprs_type3_map(bursts, hc, dc, hdr->type3.usf); |
| break; |
| case EGPRS_MCS5: |
| case EGPRS_MCS6: |
| if ((egprs_parse_dl_cps(&cps, hdr, EGPRS_HDR_TYPE2) < 0) || |
| (cps.mcs != mcs)) |
| goto bad_header; |
| |
| egprs_encode_hdr(hc, l2_data, mcs); |
| egprs_encode_data(dc, l2_data, mcs, cps.p[0], 0); |
| egprs_type2_map(bursts, hc, dc, hdr->type2.usf); |
| break; |
| case EGPRS_MCS7: |
| case EGPRS_MCS8: |
| case EGPRS_MCS9: |
| if ((egprs_parse_dl_cps(&cps, hdr, EGPRS_HDR_TYPE1) < 0) || |
| (cps.mcs != mcs)) |
| goto bad_header; |
| |
| egprs_encode_hdr(hc, l2_data, mcs); |
| egprs_encode_data(c1, l2_data, mcs, cps.p[0], 0); |
| egprs_encode_data(c2, l2_data, mcs, cps.p[1], 1); |
| egprs_type1_map(bursts, hc, c1, c2, hdr->type1.usf, mcs); |
| break; |
| } |
| |
| return mcs >= EGPRS_MCS5 ? |
| GSM0503_EGPRS_BURSTS_NBITS : GSM0503_GPRS_BURSTS_NBITS; |
| |
| bad_header: |
| /* Invalid EGPRS MCS-X header */ |
| return -1; |
| } |
| |
| /*! GPRS DL message encoding |
| * \param[out] bursts caller-allocated buffer for unpacked burst bits |
| * \param[in] l2_data L2 (MAC) block to be encoded |
| * \param[in] l2_len length of l2_data in bytes, used to determine CS |
| * \returns 0 on success; negative on error */ |
| int gsm0503_pdtch_encode(ubit_t *bursts, const uint8_t *l2_data, uint8_t l2_len) |
| { |
| ubit_t iB[456], cB[676]; |
| const ubit_t *hl_hn; |
| ubit_t conv[334]; |
| int i, j, usf; |
| |
| switch (l2_len) { |
| case 23: |
| osmo_pbit2ubit_ext(conv, 0, l2_data, 0, 184, 1); |
| |
| osmo_crc64gen_set_bits(&gsm0503_fire_crc40, conv, 184, conv + 184); |
| |
| osmo_conv_encode(&gsm0503_xcch, conv, cB); |
| |
| hl_hn = gsm0503_pdtch_hl_hn_ubit[0]; |
| |
| break; |
| case 34: |
| osmo_pbit2ubit_ext(conv, 3, l2_data, 0, 271, 1); |
| usf = l2_data[0] & 0x7; |
| |
| osmo_crc16gen_set_bits(&gsm0503_cs234_crc16, conv + 3, |
| 271, conv + 3 + 271); |
| |
| memcpy(conv, gsm0503_usf2six[usf], 6); |
| |
| osmo_conv_encode(&gsm0503_cs2_np, conv, cB); |
| |
| for (i = 0, j = 0; i < 588; i++) |
| if (!gsm0503_puncture_cs2[i]) |
| cB[j++] = cB[i]; |
| |
| hl_hn = gsm0503_pdtch_hl_hn_ubit[1]; |
| |
| break; |
| case 40: |
| osmo_pbit2ubit_ext(conv, 3, l2_data, 0, 315, 1); |
| usf = l2_data[0] & 0x7; |
| |
| osmo_crc16gen_set_bits(&gsm0503_cs234_crc16, conv + 3, |
| 315, conv + 3 + 315); |
| |
| memcpy(conv, gsm0503_usf2six[usf], 6); |
| |
| osmo_conv_encode(&gsm0503_cs3_np, conv, cB); |
| |
| for (i = 0, j = 0; i < 676; i++) |
| if (!gsm0503_puncture_cs3[i]) |
| cB[j++] = cB[i]; |
| |
| hl_hn = gsm0503_pdtch_hl_hn_ubit[2]; |
| |
| break; |
| case 54: |
| osmo_pbit2ubit_ext(cB, 9, l2_data, 0, 431, 1); |
| usf = l2_data[0] & 0x7; |
| |
| osmo_crc16gen_set_bits(&gsm0503_cs234_crc16, cB + 9, |
| 431, cB + 9 + 431); |
| |
| memcpy(cB, gsm0503_usf2twelve_ubit[usf], 12); |
| |
| hl_hn = gsm0503_pdtch_hl_hn_ubit[3]; |
| |
| break; |
| default: |
| return -1; |
| } |
| |
| gsm0503_xcch_interleave(cB, iB); |
| |
| for (i = 0; i < 4; i++) { |
| gsm0503_xcch_burst_map(&iB[i * 114], &bursts[i * 116], |
| hl_hn + i * 2, hl_hn + i * 2 + 1); |
| } |
| |
| return GSM0503_GPRS_BURSTS_NBITS; |
| } |
| |
| /* |
| * GSM TCH/F FR/EFR transcoding |
| */ |
| |
| /*! assemble a FR codec frame in format as used inside RTP |
| * \param[out] tch_data Codec frame in RTP format |
| * \param[in] b_bits Codec frame in 'native' format |
| * \param[in] net_order FIXME */ |
| static void tch_fr_reassemble(uint8_t *tch_data, |
| const ubit_t *b_bits, int net_order) |
| { |
| int i, j, k, l, o; |
| |
| tch_data[0] = 0xd << 4; |
| memset(tch_data + 1, 0, 32); |
| |
| if (net_order) { |
| for (i = 0, j = 4; i < 260; i++, j++) |
| tch_data[j >> 3] |= (b_bits[i] << (7 - (j & 7))); |
| |
| return; |
| } |
| |
| /* reassemble d-bits */ |
| i = 0; /* counts bits */ |
| j = 4; /* counts output bits */ |
| k = gsm0503_gsm_fr_map[0]-1; /* current number bit in element */ |
| l = 0; /* counts element bits */ |
| o = 0; /* offset input bits */ |
| while (i < 260) { |
| tch_data[j >> 3] |= (b_bits[k + o] << (7 - (j & 7))); |
| if (--k < 0) { |
| o += gsm0503_gsm_fr_map[l]; |
| k = gsm0503_gsm_fr_map[++l]-1; |
| } |
| i++; |
| j++; |
| } |
| } |
| |
| static void tch_fr_disassemble(ubit_t *b_bits, |
| const uint8_t *tch_data, int net_order) |
| { |
| int i, j, k, l, o; |
| |
| if (net_order) { |
| for (i = 0, j = 4; i < 260; i++, j++) |
| b_bits[i] = (tch_data[j >> 3] >> (7 - (j & 7))) & 1; |
| |
| return; |
| } |
| |
| i = 0; /* counts bits */ |
| j = 4; /* counts input bits */ |
| k = gsm0503_gsm_fr_map[0] - 1; /* current number bit in element */ |
| l = 0; /* counts element bits */ |
| o = 0; /* offset output bits */ |
| while (i < 260) { |
| b_bits[k + o] = (tch_data[j >> 3] >> (7 - (j & 7))) & 1; |
| if (--k < 0) { |
| o += gsm0503_gsm_fr_map[l]; |
| k = gsm0503_gsm_fr_map[++l] - 1; |
| } |
| i++; |
| j++; |
| } |
| } |
| |
| /* assemble a HR codec frame in format as used inside RTP */ |
| static void tch_hr_reassemble(uint8_t *tch_data, const ubit_t *b_bits) |
| { |
| int i, j; |
| |
| tch_data[0] = 0x00; /* F = 0, FT = 000 */ |
| memset(tch_data + 1, 0, 14); |
| |
| for (i = 0, j = 8; i < 112; i++, j++) |
| tch_data[j >> 3] |= (b_bits[i] << (7 - (j & 7))); |
| } |
| |
| static void tch_hr_disassemble(ubit_t *b_bits, const uint8_t *tch_data) |
| { |
| int i, j; |
| |
| for (i = 0, j = 8; i < 112; i++, j++) |
| b_bits[i] = (tch_data[j >> 3] >> (7 - (j & 7))) & 1; |
| } |
| |
| /* assemble a EFR codec frame in format as used inside RTP */ |
| static void tch_efr_reassemble(uint8_t *tch_data, const ubit_t *b_bits) |
| { |
| int i, j; |
| |
| tch_data[0] = 0xc << 4; |
| memset(tch_data + 1, 0, 30); |
| |
| for (i = 0, j = 4; i < 244; i++, j++) |
| tch_data[j >> 3] |= (b_bits[i] << (7 - (j & 7))); |
| } |
| |
| static void tch_efr_disassemble(ubit_t *b_bits, const uint8_t *tch_data) |
| { |
| int i, j; |
| |
| for (i = 0, j = 4; i < 244; i++, j++) |
| b_bits[i] = (tch_data[j >> 3] >> (7 - (j & 7))) & 1; |
| } |
| |
| /* assemble a AMR codec frame in format as used inside RTP */ |
| static void tch_amr_reassemble(uint8_t *tch_data, const ubit_t *d_bits, int len) |
| { |
| int i, j; |
| |
| memset(tch_data, 0, (len + 7) >> 3); |
| |
| for (i = 0, j = 0; i < len; i++, j++) |
| tch_data[j >> 3] |= (d_bits[i] << (7 - (j & 7))); |
| } |
| |
| static void tch_amr_disassemble(ubit_t *d_bits, const uint8_t *tch_data, int len) |
| { |
| int i, j; |
| |
| for (i = 0, j = 0; i < len; i++, j++) |
| d_bits[i] = (tch_data[j >> 3] >> (7 - (j & 7))) & 1; |
| } |
| |
| /* re-arrange according to TS 05.03 Table 2 (receiver) */ |
| static void tch_fr_d_to_b(ubit_t *b_bits, const ubit_t *d_bits) |
| { |
| int i; |
| |
| for (i = 0; i < 260; i++) |
| b_bits[gsm610_bitorder[i]] = d_bits[i]; |
| } |
| |
| /* re-arrange according to TS 05.03 Table 2 (transmitter) */ |
| static void tch_fr_b_to_d(ubit_t *d_bits, const ubit_t *b_bits) |
| { |
| int i; |
| |
| for (i = 0; i < 260; i++) |
| d_bits[i] = b_bits[gsm610_bitorder[i]]; |
| } |
| |
| /* re-arrange according to TS 05.03 Table 3a (receiver) */ |
| static void tch_hr_d_to_b(ubit_t *b_bits, const ubit_t *d_bits) |
| { |
| int i; |
| |
| const uint16_t *map; |
| |
| if (!d_bits[93] && !d_bits[94]) |
| map = gsm620_unvoiced_bitorder; |
| else |
| map = gsm620_voiced_bitorder; |
| |
| for (i = 0; i < 112; i++) |
| b_bits[map[i]] = d_bits[i]; |
| } |
| |
| /* re-arrange according to TS 05.03 Table 3a (transmitter) */ |
| static void tch_hr_b_to_d(ubit_t *d_bits, const ubit_t *b_bits) |
| { |
| int i; |
| const uint16_t *map; |
| |
| if (!b_bits[34] && !b_bits[35]) |
| map = gsm620_unvoiced_bitorder; |
| else |
| map = gsm620_voiced_bitorder; |
| |
| for (i = 0; i < 112; i++) |
| d_bits[i] = b_bits[map[i]]; |
| } |
| |
| /* re-arrange according to TS 05.03 Table 6 (receiver) */ |
| static void tch_efr_d_to_w(ubit_t *b_bits, const ubit_t *d_bits) |
| { |
| int i; |
| |
| for (i = 0; i < 260; i++) |
| b_bits[gsm660_bitorder[i]] = d_bits[i]; |
| } |
| |
| /* re-arrange according to TS 05.03 Table 6 (transmitter) */ |
| static void tch_efr_w_to_d(ubit_t *d_bits, const ubit_t *b_bits) |
| { |
| int i; |
| |
| for (i = 0; i < 260; i++) |
| d_bits[i] = b_bits[gsm660_bitorder[i]]; |
| } |
| |
| /* extract the 65 protected class1a+1b bits */ |
| static void tch_efr_protected(const ubit_t *s_bits, ubit_t *b_bits) |
| { |
| int i; |
| |
| for (i = 0; i < 65; i++) |
| b_bits[i] = s_bits[gsm0503_gsm_efr_protected_bits[i] - 1]; |
| } |
| |
| static void tch_fr_unreorder(ubit_t *d, ubit_t *p, const ubit_t *u) |
| { |
| int i; |
| |
| for (i = 0; i < 91; i++) { |
| d[i << 1] = u[i]; |
| d[(i << 1) + 1] = u[184 - i]; |
| } |
| |
| for (i = 0; i < 3; i++) |
| p[i] = u[91 + i]; |
| } |
| |
| static void tch_fr_reorder(ubit_t *u, const ubit_t *d, const ubit_t *p) |
| { |
| int i; |
| |
| for (i = 0; i < 91; i++) { |
| u[i] = d[i << 1]; |
| u[184 - i] = d[(i << 1) + 1]; |
| } |
| |
| for (i = 0; i < 3; i++) |
| u[91 + i] = p[i]; |
| } |
| |
| static void tch_hr_unreorder(ubit_t *d, ubit_t *p, const ubit_t *u) |
| { |
| memcpy(d, u, 95); |
| memcpy(p, u + 95, 3); |
| } |
| |
| static void tch_hr_reorder(ubit_t *u, const ubit_t *d, const ubit_t *p) |
| { |
| memcpy(u, d, 95); |
| memcpy(u + 95, p, 3); |
| } |
| |
| static void tch_efr_reorder(ubit_t *w, const ubit_t *s, const ubit_t *p) |
| { |
| memcpy(w, s, 71); |
| w[71] = w[72] = s[69]; |
| memcpy(w + 73, s + 71, 50); |
| w[123] = w[124] = s[119]; |
| memcpy(w + 125, s + 121, 53); |
| w[178] = w[179] = s[172]; |
| memcpy(w + 180, s + 174, 50); |
| w[230] = w[231] = s[222]; |
| memcpy(w + 232, s + 224, 20); |
| memcpy(w + 252, p, 8); |
| } |
| |
| static void tch_efr_unreorder(ubit_t *s, ubit_t *p, const ubit_t *w) |
| { |
| int sum; |
| |
| memcpy(s, w, 71); |
| sum = s[69] + w[71] + w[72]; |
| s[69] = (sum >= 2); |
| memcpy(s + 71, w + 73, 50); |
| sum = s[119] + w[123] + w[124]; |
| s[119] = (sum >= 2); |
| memcpy(s + 121, w + 125, 53); |
| sum = s[172] + w[178] + w[179]; |
| s[172] = (sum > 2); |
| memcpy(s + 174, w + 180, 50); |
| sum = s[222] + w[230] + w[231]; |
| s[222] = (sum >= 2); |
| memcpy(s + 224, w + 232, 20); |
| memcpy(p, w + 252, 8); |
| } |
| |
| static void tch_amr_merge(ubit_t *u, const ubit_t *d, const ubit_t *p, int len, int prot) |
| { |
| memcpy(u, d, prot); |
| memcpy(u + prot, p, 6); |
| memcpy(u + prot + 6, d + prot, len - prot); |
| } |
| |
| static void tch_amr_unmerge(ubit_t *d, ubit_t *p, const ubit_t *u, int len, int prot) |
| { |
| memcpy(d, u, prot); |
| memcpy(p, u + prot, 6); |
| memcpy(d + prot, u + prot + 6, len - prot); |
| } |
| |
| /*! Perform channel decoding of a FR/EFR channel according TS 05.03 |
| * \param[out] tch_data Codec frame in RTP payload format |
| * \param[in] bursts buffer containing the symbols of 8 bursts |
| * \param[in] net_order FIXME |
| * \param[in] efr Is this channel using EFR (1) or FR (0) |
| * \param[out] n_errors Number of detected bit errors |
| * \param[out] n_bits_total Total number of bits |
| * \returns length of bytes used in \a tch_data output buffer; negative on error */ |
| int gsm0503_tch_fr_decode(uint8_t *tch_data, const sbit_t *bursts, |
| int net_order, int efr, int *n_errors, int *n_bits_total) |
| { |
| sbit_t iB[912], cB[456], h; |
| ubit_t conv[185], s[244], w[260], b[65], d[260], p[8]; |
| int i, rv, len, steal = 0; |
| |
| /* map from 8 bursts to interleaved data bits (iB) */ |
| for (i = 0; i < 8; i++) { |
| gsm0503_tch_burst_unmap(&iB[i * 114], |
| &bursts[i * 116], &h, i >> 2); |
| steal -= h; |
| } |
| /* we now have the bits of the four bursts (interface 4 in |
| * Figure 1a of TS 05.03 */ |
| |
| gsm0503_tch_fr_deinterleave(cB, iB); |
| /* we now have the coded bits c(B): interface 3 in Fig. 1a */ |
| |
| if (steal > 0) { |
| rv = _xcch_decode_cB(tch_data, cB, n_errors, n_bits_total); |
| if (rv) { |
| /* Error decoding FACCH frame */ |
| return -1; |
| } |
| |
| return 23; |
| } |
| |
| osmo_conv_decode_ber(&gsm0503_tch_fr, cB, conv, n_errors, n_bits_total); |
| /* we now have the data bits 'u': interface 2 in Fig. 1a */ |
| |
| /* input: 'conv', output: d[ata] + p[arity] */ |
| tch_fr_unreorder(d, p, conv); |
| |
| for (i = 0; i < 78; i++) |
| d[i + 182] = (cB[i + 378] < 0) ? 1 : 0; |
| |
| /* check if parity of first 50 (class 1) 'd'-bits match 'p' */ |
| rv = osmo_crc8gen_check_bits(&gsm0503_tch_fr_crc3, d, 50, p); |
| if (rv) { |
| /* Error checking CRC8 for the FR part of an EFR/FR frame */ |
| return -1; |
| } |
| |
| if (efr) { |
| tch_efr_d_to_w(w, d); |
| /* we now have the preliminary-coded bits w(k) */ |
| |
| tch_efr_unreorder(s, p, w); |
| /* we now have the data delivered to the preliminary |
| * channel encoding unit s(k) */ |
| |
| /* extract the 65 most important bits according TS 05.03 3.1.1.1 */ |
| tch_efr_protected(s, b); |
| |
| /* perform CRC-8 on 65 most important bits (50 bits of |
| * class 1a + 15 bits of class 1b) */ |
| rv = osmo_crc8gen_check_bits(&gsm0503_tch_efr_crc8, b, 65, p); |
| if (rv) { |
| /* Error checking CRC8 for the EFR part of an EFR frame */ |
| return -1; |
| } |
| |
| tch_efr_reassemble(tch_data, s); |
| |
| len = GSM_EFR_BYTES; |
| } else { |
| tch_fr_d_to_b(w, d); |
| |
| tch_fr_reassemble(tch_data, w, net_order); |
| |
| len = GSM_FR_BYTES; |
| } |
| |
| return len; |
| } |
| |
| /*! Perform channel encoding on a TCH/FS channel according to TS 05.03 |
| * \param[out] bursts caller-allocated output buffer for bursts bits |
| * \param[in] tch_data Codec input data in RTP payload format |
| * \param[in] len Length of \a tch_data in bytes |
| * \param[in] net_order FIXME |
| * \returns 0 in case of success; negative on error */ |
| int gsm0503_tch_fr_encode(ubit_t *bursts, const uint8_t *tch_data, |
| int len, int net_order) |
| { |
| ubit_t iB[912], cB[456], h; |
| ubit_t conv[185], w[260], b[65], s[244], d[260], p[8]; |
| int i; |
| |
| switch (len) { |
| case GSM_EFR_BYTES: /* TCH EFR */ |
| |
| tch_efr_disassemble(s, tch_data); |
| |
| tch_efr_protected(s, b); |
| |
| osmo_crc8gen_set_bits(&gsm0503_tch_efr_crc8, b, 65, p); |
| |
| tch_efr_reorder(w, s, p); |
| |
| tch_efr_w_to_d(d, w); |
| |
| goto coding_efr_fr; |
| case GSM_FR_BYTES: /* TCH FR */ |
| tch_fr_disassemble(w, tch_data, net_order); |
| |
| tch_fr_b_to_d(d, w); |
| |
| coding_efr_fr: |
| osmo_crc8gen_set_bits(&gsm0503_tch_fr_crc3, d, 50, p); |
| |
| tch_fr_reorder(conv, d, p); |
| |
| memcpy(cB + 378, d + 182, 78); |
| |
| osmo_conv_encode(&gsm0503_tch_fr, conv, cB); |
| |
| h = 0; |
| |
| break; |
| case GSM_MACBLOCK_LEN: /* FACCH */ |
| _xcch_encode_cB(cB, tch_data); |
| |
| h = 1; |
| |
| break; |
| default: |
| return -1; |
| } |
| |
| gsm0503_tch_fr_interleave(cB, iB); |
| |
| for (i = 0; i < 8; i++) { |
| gsm0503_tch_burst_map(&iB[i * 114], |
| &bursts[i * 116], &h, i >> 2); |
| } |
| |
| return 0; |
| } |
| |
| /*! Perform channel decoding of a HR(v1) channel according TS 05.03 |
| * \param[out] tch_data Codec frame in RTP payload format |
| * \param[in] bursts buffer containing the symbols of 8 bursts |
| * \param[in] odd Odd (1) or even (0) frame number |
| * \param[out] n_errors Number of detected bit errors |
| * \param[out] n_bits_total Total number of bits |
| * \returns length of bytes used in \a tch_data output buffer; negative on error */ |
| int gsm0503_tch_hr_decode(uint8_t *tch_data, const sbit_t *bursts, int odd, |
| int *n_errors, int *n_bits_total) |
| { |
| sbit_t iB[912], cB[456], h; |
| ubit_t conv[98], b[112], d[112], p[3]; |
| int i, rv, steal = 0; |
| |
| /* Only unmap the stealing bits */ |
| if (!odd) { |
| for (i = 0; i < 4; i++) { |
| gsm0503_tch_burst_unmap(NULL, &bursts[i * 116], &h, 0); |
| steal -= h; |
| } |
| |
| for (i = 2; i < 5; i++) { |
| gsm0503_tch_burst_unmap(NULL, &bursts[i * 116], &h, 1); |
| steal -= h; |
| } |
| } |
| |
| /* If we found a stole FACCH, but only at correct alignment */ |
| if (steal > 0) { |
| for (i = 0; i < 6; i++) { |
| gsm0503_tch_burst_unmap(&iB[i * 114], |
| &bursts[i * 116], NULL, i >> 2); |
| } |
| |
| for (i = 2; i < 4; i++) { |
| gsm0503_tch_burst_unmap(&iB[i * 114 + 456], |
| &bursts[i * 116], NULL, 1); |
| } |
| |
| gsm0503_tch_fr_deinterleave(cB, iB); |
| |
| rv = _xcch_decode_cB(tch_data, cB, n_errors, n_bits_total); |
| if (rv) { |
| /* Error decoding FACCH frame */ |
| return -1; |
| } |
| |
| return GSM_MACBLOCK_LEN; |
| } |
| |
| for (i = 0; i < 4; i++) { |
| gsm0503_tch_burst_unmap(&iB[i * 114], |
| &bursts[i * 116], NULL, i >> 1); |
| } |
| |
| gsm0503_tch_hr_deinterleave(cB, iB); |
| |
| osmo_conv_decode_ber(&gsm0503_tch_hr, cB, conv, n_errors, n_bits_total); |
| |
| tch_hr_unreorder(d, p, conv); |
| |
| for (i = 0; i < 17; i++) |
| d[i + 95] = (cB[i + 211] < 0) ? 1 : 0; |
| |
| rv = osmo_crc8gen_check_bits(&gsm0503_tch_fr_crc3, d + 73, 22, p); |
| if (rv) { |
| /* Error checking CRC8 for an HR frame */ |
| return -1; |
| } |
| |
| tch_hr_d_to_b(b, d); |
| |
| tch_hr_reassemble(tch_data, b); |
| |
| return 15; |
| } |
| |
| /*! Perform channel encoding on a TCH/HS channel according to TS 05.03 |
| * \param[out] bursts caller-allocated output buffer for bursts bits |
| * \param[in] tch_data Codec input data in RTP payload format |
| * \param[in] len Length of \a tch_data in bytes |
| * \returns 0 in case of success; negative on error */ |
| int gsm0503_tch_hr_encode(ubit_t *bursts, const uint8_t *tch_data, int len) |
| { |
| ubit_t iB[912], cB[456], h; |
| ubit_t conv[98], b[112], d[112], p[3]; |
| int i; |
| |
| switch (len) { |
| case 15: /* TCH HR */ |
| tch_hr_disassemble(b, tch_data); |
| |
| tch_hr_b_to_d(d, b); |
| |
| osmo_crc8gen_set_bits(&gsm0503_tch_fr_crc3, d + 73, 22, p); |
| |
| tch_hr_reorder(conv, d, p); |
| |
| osmo_conv_encode(&gsm0503_tch_hr, conv, cB); |
| |
| memcpy(cB + 211, d + 95, 17); |
| |
| h = 0; |
| |
| gsm0503_tch_hr_interleave(cB, iB); |
| |
| for (i = 0; i < 4; i++) { |
| gsm0503_tch_burst_map(&iB[i * 114], |
| &bursts[i * 116], &h, i >> 1); |
| } |
| |
| break; |
| case GSM_MACBLOCK_LEN: /* FACCH */ |
| _xcch_encode_cB(cB, tch_data); |
| |
| h = 1; |
| |
| gsm0503_tch_fr_interleave(cB, iB); |
| |
| for (i = 0; i < 6; i++) { |
| gsm0503_tch_burst_map(&iB[i * 114], |
| &bursts[i * 116], &h, i >> 2); |
| } |
| |
| for (i = 2; i < 4; i++) { |
| gsm0503_tch_burst_map(&iB[i * 114 + 456], |
| &bursts[i * 116], &h, 1); |
| } |
| |
| break; |
| default: |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| /*! Perform channel decoding of a TCH/AFS channel according TS 05.03 |
| * \param[out] tch_data Codec frame in RTP payload format |
| * \param[in] bursts buffer containing the symbols of 8 bursts |
| * \param[in] codec_mode_req is this CMR (1) or CMC (0) |
| * \param[in] codec array of active codecs (active codec set) |
| * \param[in] codecs number of codecs in \a codec |
| * \param ft Frame Type; Input if \a codec_mode_req = 1, Output * otherwise |
| * \param[out] cmr Output in \a codec_mode_req = 1 |
| * \param[out] n_errors Number of detected bit errors |
| * \param[out] n_bits_total Total number of bits |
| * \returns (>=4) length of bytes used in \a tch_data output buffer; ([0,3]) |
| * codec out of range; negative on error |
| */ |
| int gsm0503_tch_afs_decode(uint8_t *tch_data, const 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) |
| { |
| sbit_t iB[912], cB[456], h; |
| ubit_t d[244], p[6], conv[250]; |
| int i, j, k, best = 0, rv, len, steal = 0, id = 0; |
| *n_errors = 0; *n_bits_total = 0; |
| |
| for (i=0; i<8; i++) { |
| gsm0503_tch_burst_unmap(&iB[i * 114], &bursts[i * 116], &h, i >> 2); |
| steal -= h; |
| } |
| |
| gsm0503_tch_fr_deinterleave(cB, iB); |
| |
| if (steal > 0) { |
| rv = _xcch_decode_cB(tch_data, cB, n_errors, n_bits_total); |
| if (rv) { |
| /* Error decoding FACCH frame */ |
| return -1; |
| } |
| |
| return GSM_MACBLOCK_LEN; |
| } |
| |
| for (i = 0; i < 4; i++) { |
| for (j = 0, k = 0; j < 8; j++) |
| k += abs(((int)gsm0503_afs_ic_sbit[i][j]) - ((int)cB[j])); |
| |
| if (i == 0 || k < best) { |
| best = k; |
| id = i; |
| } |
| } |
| |
| /* Check if indicated codec fits into range of codecs */ |
| if (id >= codecs) { |
| /* Codec mode out of range, return id */ |
| return id; |
| } |
| |
| switch ((codec_mode_req) ? codec[*ft] : codec[id]) { |
| case 7: /* TCH/AFS12.2 */ |
| osmo_conv_decode_ber(&gsm0503_tch_afs_12_2, cB + 8, |
| conv, n_errors, n_bits_total); |
| |
| tch_amr_unmerge(d, p, conv, 244, 81); |
| |
| rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 81, p); |
| if (rv) { |
| /* Error checking CRC8 for an AMR 12.2 frame */ |
| return -1; |
| } |
| |
| tch_amr_reassemble(tch_data, d, 244); |
| |
| len = 31; |
| |
| break; |
| case 6: /* TCH/AFS10.2 */ |
| osmo_conv_decode_ber(&gsm0503_tch_afs_10_2, cB + 8, |
| conv, n_errors, n_bits_total); |
| |
| tch_amr_unmerge(d, p, conv, 204, 65); |
| |
| rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 65, p); |
| if (rv) { |
| /* Error checking CRC8 for an AMR 10.2 frame */ |
| return -1; |
| } |
| |
| tch_amr_reassemble(tch_data, d, 204); |
| |
| len = 26; |
| |
| break; |
| case 5: /* TCH/AFS7.95 */ |
| osmo_conv_decode_ber(&gsm0503_tch_afs_7_95, cB + 8, |
| conv, n_errors, n_bits_total); |
| |
| tch_amr_unmerge(d, p, conv, 159, 75); |
| |
| rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 75, p); |
| if (rv) { |
| /* Error checking CRC8 for an AMR 7.95 frame */ |
| return -1; |
| } |
| |
| tch_amr_reassemble(tch_data, d, 159); |
| |
| len = 20; |
| |
| break; |
| case 4: /* TCH/AFS7.4 */ |
| osmo_conv_decode_ber(&gsm0503_tch_afs_7_4, cB + 8, |
| conv, n_errors, n_bits_total); |
| |
| tch_amr_unmerge(d, p, conv, 148, 61); |
| |
| rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 61, p); |
| if (rv) { |
| /* Error checking CRC8 for an AMR 7.4 frame */ |
| return -1; |
| } |
| |
| tch_amr_reassemble(tch_data, d, 148); |
| |
| len = 19; |
| |
| break; |
| case 3: /* TCH/AFS6.7 */ |
| osmo_conv_decode_ber(&gsm0503_tch_afs_6_7, cB + 8, |
| conv, n_errors, n_bits_total); |
| |
| tch_amr_unmerge(d, p, conv, 134, 55); |
| |
| rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 55, p); |
| if (rv) { |
| /* Error checking CRC8 for an AMR 6.7 frame */ |
| return -1; |
| } |
| |
| tch_amr_reassemble(tch_data, d, 134); |
| |
| len = 17; |
| |
| break; |
| case 2: /* TCH/AFS5.9 */ |
| osmo_conv_decode_ber(&gsm0503_tch_afs_5_9, cB + 8, |
| conv, n_errors, n_bits_total); |
| |
| tch_amr_unmerge(d, p, conv, 118, 55); |
| |
| rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 55, p); |
| if (rv) { |
| /* Error checking CRC8 for an AMR 5.9 frame */ |
| return -1; |
| } |
| |
| tch_amr_reassemble(tch_data, d, 118); |
| |
| len = 15; |
| |
| break; |
| case 1: /* TCH/AFS5.15 */ |
| osmo_conv_decode_ber(&gsm0503_tch_afs_5_15, cB + 8, |
| conv, n_errors, n_bits_total); |
| |
| tch_amr_unmerge(d, p, conv, 103, 49); |
| |
| rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 49, p); |
| if (rv) { |
| /* Error checking CRC8 for an AMR 5.15 frame */ |
| return -1; |
| } |
| |
| tch_amr_reassemble(tch_data, d, 103); |
| |
| len = 13; |
| |
| break; |
| case 0: /* TCH/AFS4.75 */ |
| osmo_conv_decode_ber(&gsm0503_tch_afs_4_75, cB + 8, |
| conv, n_errors, n_bits_total); |
| |
| tch_amr_unmerge(d, p, conv, 95, 39); |
| |
| rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 39, p); |
| if (rv) { |
| /* Error checking CRC8 for an AMR 4.75 frame */ |
| return -1; |
| } |
| |
| tch_amr_reassemble(tch_data, d, 95); |
| |
| len = 12; |
| |
| break; |
| default: |
| /* Unknown frame type */ |
| *n_bits_total = 448; |
| *n_errors = *n_bits_total; |
| return -1; |
| } |
| |
| /* Change codec request / indication, if frame is valid */ |
| if (codec_mode_req) |
| *cmr = id; |
| else |
| *ft = id; |
| |
| return len; |
| } |
| |
| /*! Perform channel encoding on a TCH/AFS channel according to TS 05.03 |
| * \param[out] bursts caller-allocated output buffer for bursts bits |
| * \param[in] tch_data Codec input data in RTP payload format |
| * \param[in] len Length of \a tch_data in bytes |
| * \param[in] codec_mode_req Use CMR (1) or FT (0) |
| * \param[in] codec Array of codecs (active codec set) |
| * \param[in] codecs Number of entries in \a codec |
| * \param[in] ft Frame Type to be used for encoding (index to \a codec) |
| * \param[in] cmr Codec Mode Request (used in codec_mode_req = 1 only) |
| * \returns 0 in case of success; negative on error */ |
| int gsm0503_tch_afs_encode(ubit_t *bursts, const uint8_t *tch_data, int len, |
| int codec_mode_req, uint8_t *codec, int codecs, uint8_t ft, |
| uint8_t cmr) |
| { |
| ubit_t iB[912], cB[456], h; |
| ubit_t d[244], p[6], conv[250]; |
| int i; |
| uint8_t id; |
| |
| if (len == GSM_MACBLOCK_LEN) { /* FACCH */ |
| _xcch_encode_cB(cB, tch_data); |
| |
| h = 1; |
| |
| goto facch; |
| } |
| |
| h = 0; |
| |
| if (codec_mode_req) { |
| if (cmr >= codecs) { |
| /* FIXME: CMR ID is not in codec list! */ |
| return -1; |
| } |
| id = cmr; |
| } else { |
| if (ft >= codecs) { |
| /* FIXME: FT ID is not in codec list! */ |
| return -1; |
| } |
| id = ft; |
| } |
| |
| switch (codec[ft]) { |
| case 7: /* TCH/AFS12.2 */ |
| if (len != 31) |
| goto invalid_length; |
| |
| tch_amr_disassemble(d, tch_data, 244); |
| |
| osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 81, p); |
| |
| tch_amr_merge(conv, d, p, 244, 81); |
| |
| osmo_conv_encode(&gsm0503_tch_afs_12_2, conv, cB + 8); |
| |
| break; |
| case 6: /* TCH/AFS10.2 */ |
| if (len != 26) |
| goto invalid_length; |
| |
| tch_amr_disassemble(d, tch_data, 204); |
| |
| osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 65, p); |
| |
| tch_amr_merge(conv, d, p, 204, 65); |
| |
| osmo_conv_encode(&gsm0503_tch_afs_10_2, conv, cB + 8); |
| |
| break; |
| case 5: /* TCH/AFS7.95 */ |
| if (len != 20) |
| goto invalid_length; |
| |
| tch_amr_disassemble(d, tch_data, 159); |
| |
| osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 75, p); |
| |
| tch_amr_merge(conv, d, p, 159, 75); |
| |
| osmo_conv_encode(&gsm0503_tch_afs_7_95, conv, cB + 8); |
| |
| break; |
| case 4: /* TCH/AFS7.4 */ |
| if (len != 19) |
| goto invalid_length; |
| |
| tch_amr_disassemble(d, tch_data, 148); |
| |
| osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 61, p); |
| |
| tch_amr_merge(conv, d, p, 148, 61); |
| |
| osmo_conv_encode(&gsm0503_tch_afs_7_4, conv, cB + 8); |
| |
| break; |
| case 3: /* TCH/AFS6.7 */ |
| if (len != 17) |
| goto invalid_length; |
| |
| tch_amr_disassemble(d, tch_data, 134); |
| |
| osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 55, p); |
| |
| tch_amr_merge(conv, d, p, 134, 55); |
| |
| osmo_conv_encode(&gsm0503_tch_afs_6_7, conv, cB + 8); |
| |
| break; |
| case 2: /* TCH/AFS5.9 */ |
| if (len != 15) |
| goto invalid_length; |
| |
| tch_amr_disassemble(d, tch_data, 118); |
| |
| osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 55, p); |
| |
| tch_amr_merge(conv, d, p, 118, 55); |
| |
| osmo_conv_encode(&gsm0503_tch_afs_5_9, conv, cB + 8); |
| |
| break; |
| case 1: /* TCH/AFS5.15 */ |
| if (len != 13) |
| goto invalid_length; |
| |
| tch_amr_disassemble(d, tch_data, 103); |
| |
| osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 49, p); |
| |
| tch_amr_merge(conv, d, p, 103, 49); |
| |
| osmo_conv_encode(&gsm0503_tch_afs_5_15, conv, cB + 8); |
| |
| break; |
| case 0: /* TCH/AFS4.75 */ |
| if (len != 12) |
| goto invalid_length; |
| |
| tch_amr_disassemble(d, tch_data, 95); |
| |
| osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 39, p); |
| |
| tch_amr_merge(conv, d, p, 95, 39); |
| |
| osmo_conv_encode(&gsm0503_tch_afs_4_75, conv, cB + 8); |
| |
| break; |
| default: |
| /* FIXME: FT %ft is not supported */ |
| return -1; |
| } |
| |
| memcpy(cB, gsm0503_afs_ic_ubit[id], 8); |
| |
| facch: |
| gsm0503_tch_fr_interleave(cB, iB); |
| |
| for (i = 0; i < 8; i++) { |
| gsm0503_tch_burst_map(&iB[i * 114], |
| &bursts[i * 116], &h, i >> 2); |
| } |
| |
| return 0; |
| |
| invalid_length: |
| /* FIXME: payload length %len does not comply with codec type %ft */ |
| return -1; |
| } |
| |
| /*! Perform channel decoding of a TCH/AFS channel according TS 05.03 |
| * \param[out] tch_data Codec frame in RTP payload format |
| * \param[in] bursts buffer containing the symbols of 8 bursts |
| * \param[in] odd Is this an odd (1) or even (0) frame number? |
| * \param[in] codec_mode_req is this CMR (1) or CMC (0) |
| * \param[in] codec array of active codecs (active codec set) |
| * \param[in] codecs number of codecs in \a codec |
| * \param ft Frame Type; Input if \a codec_mode_req = 1, Output * otherwise |
| * \param[out] cmr Output in \a codec_mode_req = 1 |
| * \param[out] n_errors Number of detected bit errors |
| * \param[out] n_bits_total Total number of bits |
| * \returns (>=4) length of bytes used in \a tch_data output buffer; ([0,3]) |
| * codec out of range; negative on error |
| */ |
| int gsm0503_tch_ahs_decode(uint8_t *tch_data, const 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) |
| { |
| sbit_t iB[912], cB[456], h; |
| ubit_t d[244], p[6], conv[135]; |
| int i, j, k, best = 0, rv, len, steal = 0, id = 0; |
| |
| /* only unmap the stealing bits */ |
| if (!odd) { |
| for (i = 0; i < 4; i++) { |
| gsm0503_tch_burst_unmap(NULL, &bursts[i * 116], &h, 0); |
| steal -= h; |
| } |
| for (i = 2; i < 5; i++) { |
| gsm0503_tch_burst_unmap(NULL, &bursts[i * 116], &h, 1); |
| steal -= h; |
| } |
| } |
| |
| /* if we found a stole FACCH, but only at correct alignment */ |
| if (steal > 0) { |
| for (i = 0; i < 6; i++) { |
| gsm0503_tch_burst_unmap(&iB[i * 114], |
| &bursts[i * 116], NULL, i >> 2); |
| } |
| |
| for (i = 2; i < 4; i++) { |
| gsm0503_tch_burst_unmap(&iB[i * 114 + 456], |
| &bursts[i * 116], NULL, 1); |
| } |
| |
| gsm0503_tch_fr_deinterleave(cB, iB); |
| |
| rv = _xcch_decode_cB(tch_data, cB, n_errors, n_bits_total); |
| if (rv) { |
| /* Error decoding FACCH frame */ |
| return -1; |
| } |
| |
| return GSM_MACBLOCK_LEN; |
| } |
| |
| for (i = 0; i < 4; i++) { |
| gsm0503_tch_burst_unmap(&iB[i * 114], |
| &bursts[i * 116], NULL, i >> 1); |
| } |
| |
| gsm0503_tch_hr_deinterleave(cB, iB); |
| |
| for (i = 0; i < 4; i++) { |
| for (j = 0, k = 0; j < 4; j++) |
| k += abs(((int)gsm0503_ahs_ic_sbit[i][j]) - ((int)cB[j])); |
| |
| if (i == 0 || k < best) { |
| best = k; |
| id = i; |
| } |
| } |
| |
| /* Check if indicated codec fits into range of codecs */ |
| if (id >= codecs) { |
| /* Codec mode out of range, return id */ |
| return id; |
| } |
| |
| switch ((codec_mode_req) ? codec[*ft] : codec[id]) { |
| case 5: /* TCH/AHS7.95 */ |
| osmo_conv_decode_ber(&gsm0503_tch_ahs_7_95, cB + 4, |
| conv, n_errors, n_bits_total); |
| |
| tch_amr_unmerge(d, p, conv, 123, 67); |
| |
| rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 67, p); |
| if (rv) { |
| /* Error checking CRC8 for an AMR 7.95 frame */ |
| return -1; |
| } |
| |
| for (i = 0; i < 36; i++) |
| d[i + 123] = (cB[i + 192] < 0) ? 1 : 0; |
| |
| tch_amr_reassemble(tch_data, d, 159); |
| |
| len = 20; |
| |
| break; |
| case 4: /* TCH/AHS7.4 */ |
| osmo_conv_decode_ber(&gsm0503_tch_ahs_7_4, cB + 4, |
| conv, n_errors, n_bits_total); |
| |
| tch_amr_unmerge(d, p, conv, 120, 61); |
| |
| rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 61, p); |
| if (rv) { |
| /* Error checking CRC8 for an AMR 7.4 frame */ |
| return -1; |
| } |
| |
| for (i = 0; i < 28; i++) |
| d[i + 120] = (cB[i + 200] < 0) ? 1 : 0; |
| |
| tch_amr_reassemble(tch_data, d, 148); |
| |
| len = 19; |
| |
| break; |
| case 3: /* TCH/AHS6.7 */ |
| osmo_conv_decode_ber(&gsm0503_tch_ahs_6_7, cB + 4, |
| conv, n_errors, n_bits_total); |
| |
| tch_amr_unmerge(d, p, conv, 110, 55); |
| |
| rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 55, p); |
| if (rv) { |
| /* Error checking CRC8 for an AMR 6.7 frame */ |
| return -1; |
| } |
| |
| for (i = 0; i < 24; i++) |
| d[i + 110] = (cB[i + 204] < 0) ? 1 : 0; |
| |
| tch_amr_reassemble(tch_data, d, 134); |
| |
| len = 17; |
| |
| break; |
| case 2: /* TCH/AHS5.9 */ |
| osmo_conv_decode_ber(&gsm0503_tch_ahs_5_9, cB + 4, |
| conv, n_errors, n_bits_total); |
| |
| tch_amr_unmerge(d, p, conv, 102, 55); |
| |
| rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 55, p); |
| if (rv) { |
| /* Error checking CRC8 for an AMR 5.9 frame */ |
| return -1; |
| } |
| |
| for (i = 0; i < 16; i++) |
| d[i + 102] = (cB[i + 212] < 0) ? 1 : 0; |
| |
| tch_amr_reassemble(tch_data, d, 118); |
| |
| len = 15; |
| |
| break; |
| case 1: /* TCH/AHS5.15 */ |
| osmo_conv_decode_ber(&gsm0503_tch_ahs_5_15, cB + 4, |
| conv, n_errors, n_bits_total); |
| |
| tch_amr_unmerge(d, p, conv, 91, 49); |
| |
| rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 49, p); |
| if (rv) { |
| /* Error checking CRC8 for an AMR 5.15 frame */ |
| return -1; |
| } |
| |
| for (i = 0; i < 12; i++) |
| d[i + 91] = (cB[i + 216] < 0) ? 1 : 0; |
| |
| tch_amr_reassemble(tch_data, d, 103); |
| |
| len = 13; |
| |
| break; |
| case 0: /* TCH/AHS4.75 */ |
| osmo_conv_decode_ber(&gsm0503_tch_ahs_4_75, cB + 4, |
| conv, n_errors, n_bits_total); |
| |
| tch_amr_unmerge(d, p, conv, 83, 39); |
| |
| rv = osmo_crc8gen_check_bits(&gsm0503_amr_crc6, d, 39, p); |
| if (rv) { |
| /* Error checking CRC8 for an AMR 4.75 frame */ |
| return -1; |
| } |
| |
| for (i = 0; i < 12; i++) |
| d[i + 83] = (cB[i + 216] < 0) ? 1 : 0; |
| |
| tch_amr_reassemble(tch_data, d, 95); |
| |
| len = 12; |
| |
| break; |
| default: |
| /* Unknown frame type */ |
| *n_bits_total = 159; |
| *n_errors = *n_bits_total; |
| return -1; |
| } |
| |
| /* Change codec request / indication, if frame is valid */ |
| if (codec_mode_req) |
| *cmr = id; |
| else |
| *ft = id; |
| |
| return len; |
| } |
| |
| /*! Perform channel encoding on a TCH/AHS channel according to TS 05.03 |
| * \param[out] bursts caller-allocated output buffer for bursts bits |
| * \param[in] tch_data Codec input data in RTP payload format |
| * \param[in] len Length of \a tch_data in bytes |
| * \param[in] codec_mode_req Use CMR (1) or FT (0) |
| * \param[in] codec Array of codecs (active codec set) |
| * \param[in] codecs Number of entries in \a codec |
| * \param[in] ft Frame Type to be used for encoding (index to \a codec) |
| * \param[in] cmr Codec Mode Request (used in codec_mode_req = 1 only) |
| * \returns 0 in case of success; negative on error */ |
| int gsm0503_tch_ahs_encode(ubit_t *bursts, const uint8_t *tch_data, int len, |
| int codec_mode_req, uint8_t *codec, int codecs, uint8_t ft, |
| uint8_t cmr) |
| { |
| ubit_t iB[912], cB[456], h; |
| ubit_t d[244], p[6], conv[135]; |
| int i; |
| uint8_t id; |
| |
| if (len == GSM_MACBLOCK_LEN) { /* FACCH */ |
| _xcch_encode_cB(cB, tch_data); |
| |
| h = 1; |
| |
| gsm0503_tch_fr_interleave(cB, iB); |
| |
| for (i = 0; i < 6; i++) |
| gsm0503_tch_burst_map(&iB[i * 114], &bursts[i * 116], |
| &h, i >> 2); |
| for (i = 2; i < 4; i++) |
| gsm0503_tch_burst_map(&iB[i * 114 + 456], |
| &bursts[i * 116], &h, 1); |
| |
| return 0; |
| } |
| |
| h = 0; |
| |
| if (codec_mode_req) { |
| if (cmr >= codecs) { |
| /* FIXME: CMR ID %d not in codec list */ |
| return -1; |
| } |
| id = cmr; |
| } else { |
| if (ft >= codecs) { |
| /* FIXME: FT ID %d not in codec list */ |
| return -1; |
| } |
| id = ft; |
| } |
| |
| switch (codec[ft]) { |
| case 5: /* TCH/AHS7.95 */ |
| if (len != 20) |
| goto invalid_length; |
| |
| tch_amr_disassemble(d, tch_data, 159); |
| |
| osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 67, p); |
| |
| tch_amr_merge(conv, d, p, 123, 67); |
| |
| osmo_conv_encode(&gsm0503_tch_ahs_7_95, conv, cB + 4); |
| |
| memcpy(cB + 192, d + 123, 36); |
| |
| break; |
| case 4: /* TCH/AHS7.4 */ |
| if (len != 19) |
| goto invalid_length; |
| |
| tch_amr_disassemble(d, tch_data, 148); |
| |
| osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 61, p); |
| |
| tch_amr_merge(conv, d, p, 120, 61); |
| |
| osmo_conv_encode(&gsm0503_tch_ahs_7_4, conv, cB + 4); |
| |
| memcpy(cB + 200, d + 120, 28); |
| |
| break; |
| case 3: /* TCH/AHS6.7 */ |
| if (len != 17) |
| goto invalid_length; |
| |
| tch_amr_disassemble(d, tch_data, 134); |
| |
| osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 55, p); |
| |
| tch_amr_merge(conv, d, p, 110, 55); |
| |
| osmo_conv_encode(&gsm0503_tch_ahs_6_7, conv, cB + 4); |
| |
| memcpy(cB + 204, d + 110, 24); |
| |
| break; |
| case 2: /* TCH/AHS5.9 */ |
| if (len != 15) |
| goto invalid_length; |
| |
| tch_amr_disassemble(d, tch_data, 118); |
| |
| osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 55, p); |
| |
| tch_amr_merge(conv, d, p, 102, 55); |
| |
| osmo_conv_encode(&gsm0503_tch_ahs_5_9, conv, cB + 4); |
| |
| memcpy(cB + 212, d + 102, 16); |
| |
| break; |
| case 1: /* TCH/AHS5.15 */ |
| if (len != 13) |
| goto invalid_length; |
| |
| tch_amr_disassemble(d, tch_data, 103); |
| |
| osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 49, p); |
| |
| tch_amr_merge(conv, d, p, 91, 49); |
| |
| osmo_conv_encode(&gsm0503_tch_ahs_5_15, conv, cB + 4); |
| |
| memcpy(cB + 216, d + 91, 12); |
| |
| break; |
| case 0: /* TCH/AHS4.75 */ |
| if (len != 12) |
| goto invalid_length; |
| |
| tch_amr_disassemble(d, tch_data, 95); |
| |
| osmo_crc8gen_set_bits(&gsm0503_amr_crc6, d, 39, p); |
| |
| tch_amr_merge(conv, d, p, 83, 39); |
| |
| osmo_conv_encode(&gsm0503_tch_ahs_4_75, conv, cB + 4); |
| |
| memcpy(cB + 216, d + 83, 12); |
| |
| break; |
| default: |
| /* FIXME: FT %ft is not supported */ |
| return -1; |
| } |
| |
| memcpy(cB, gsm0503_afs_ic_ubit[id], 4); |
| |
| gsm0503_tch_hr_interleave(cB, iB); |
| |
| for (i = 0; i < 4; i++) |
| gsm0503_tch_burst_map(&iB[i * 114], &bursts[i * 116], &h, i >> 1); |
| |
| return 0; |
| |
| invalid_length: |
| /* FIXME: payload length %len does not comply with codec type %ft */ |
| return -1; |
| } |
| |
| /* |
| * GSM RACH transcoding |
| */ |
| |
| /* |
| * GSM RACH apply BSIC to parity |
| * |
| * p(j) = p(j) xor b(j) j = 0, ..., 5 |
| * b(0) = MSB of PLMN colour code |
| * b(5) = LSB of BS colour code |
| */ |
| static inline void rach_apply_bsic(ubit_t *d, uint8_t bsic, uint8_t start) |
| { |
| int i; |
| |
| /* Apply it */ |
| for (i = 0; i < 6; i++) |
| d[start + i] ^= ((bsic >> (5 - i)) & 1); |
| } |
| |
| static inline int16_t rach_decode_ber(const sbit_t *burst, uint8_t bsic, bool is_11bit, |
| int *n_errors, int *n_bits_total) |
| { |
| ubit_t conv[17]; |
| uint8_t ra[2] = { 0 }, nbits = is_11bit ? 11 : 8; |
| int rv; |
| |
| osmo_conv_decode_ber(is_11bit ? &gsm0503_rach_ext : &gsm0503_rach, burst, conv, |
| n_errors, n_bits_total); |
| |
| rach_apply_bsic(conv, bsic, nbits); |
| |
| rv = osmo_crc8gen_check_bits(&gsm0503_rach_crc6, conv, nbits, conv + nbits); |
| if (rv) |
| return -1; |
| |
| osmo_ubit2pbit_ext(ra, 0, conv, 0, nbits, 1); |
| |
| return is_11bit ? osmo_load16le(ra) : ra[0]; |
| } |
| |
| /*! Decode the Extended (11-bit) RACH according to 3GPP TS 45.003 |
| * \param[out] ra output buffer for RACH data |
| * \param[in] burst Input burst data |
| * \param[in] bsic BSIC used in this cell |
| * \returns 0 on success; negative on error (e.g. CRC error) */ |
| int gsm0503_rach_ext_decode(uint16_t *ra, const sbit_t *burst, uint8_t bsic) |
| { |
| int16_t r = rach_decode_ber(burst, bsic, true, NULL, NULL); |
| |
| if (r < 0) |
| return r; |
| |
| *ra = r; |
| |
| return 0; |
| } |
| |
| /*! Decode the (8-bit) RACH according to TS 05.03 |
| * \param[out] ra output buffer for RACH data |
| * \param[in] burst Input burst data |
| * \param[in] bsic BSIC used in this cell |
| * \returns 0 on success; negative on error (e.g. CRC error) */ |
| int gsm0503_rach_decode(uint8_t *ra, const sbit_t *burst, uint8_t bsic) |
| { |
| int16_t r = rach_decode_ber(burst, bsic, false, NULL, NULL); |
| if (r < 0) |
| return r; |
| |
| *ra = r; |
| return 0; |
| } |
| |
| /*! Decode the Extended (11-bit) RACH according to 3GPP TS 45.003 |
| * \param[out] ra output buffer for RACH data |
| * \param[in] burst Input burst data |
| * \param[in] bsic BSIC used in this cell |
| * \param[out] n_errors Number of detected bit errors |
| * \param[out] n_bits_total Total number of bits |
| * \returns 0 on success; negative on error (e.g. CRC error) */ |
| int gsm0503_rach_ext_decode_ber(uint16_t *ra, const sbit_t *burst, uint8_t bsic, |
| int *n_errors, int *n_bits_total) |
| { |
| int16_t r = rach_decode_ber(burst, bsic, true, n_errors, n_bits_total); |
| if (r < 0) |
| return r; |
| |
| *ra = r; |
| return 0; |
| } |
| |
| /*! Decode the (8-bit) RACH according to TS 05.03 |
| * \param[out] ra output buffer for RACH data |
| * \param[in] burst Input burst data |
| * \param[in] bsic BSIC used in this cell |
| * \param[out] n_errors Number of detected bit errors |
| * \param[out] n_bits_total Total number of bits |
| * \returns 0 on success; negative on error (e.g. CRC error) */ |
| int gsm0503_rach_decode_ber(uint8_t *ra, const sbit_t *burst, uint8_t bsic, |
| int *n_errors, int *n_bits_total) |
| { |
| int16_t r = rach_decode_ber(burst, bsic, false, n_errors, n_bits_total); |
| |
| if (r < 0) |
| return r; |
| |
| *ra = r; |
| |
| return 0; |
| } |
| |
| /*! Encode the (8-bit) RACH according to TS 05.03 |
| * \param[out] burst Caller-allocated output burst buffer |
| * \param[in] ra Input RACH data |
| * \param[in] bsic BSIC used in this cell |
| * \returns 0 on success; negative on error */ |
| int gsm0503_rach_encode(ubit_t *burst, const uint8_t *ra, uint8_t bsic) |
| { |
| return gsm0503_rach_ext_encode(burst, *ra, bsic, false); |
| } |
| |
| /*! Encode the Extended (11-bit) or regular (8-bit) RACH according to 3GPP TS 45.003 |
| * \param[out] burst Caller-allocated output burst buffer |
| * \param[in] ra11 Input RACH data |
| * \param[in] bsic BSIC used in this cell |
| * \param[in] is_11bit whether given RA is 11 bit or not |
| * \returns 0 on success; negative on error */ |
| int gsm0503_rach_ext_encode(ubit_t *burst, uint16_t ra11, uint8_t bsic, bool is_11bit) |
| { |
| ubit_t conv[17]; |
| uint8_t ra[2] = { 0 }, nbits = 8; |
| |
| if (is_11bit) { |
| osmo_store16le(ra11, ra); |
| nbits = 11; |
| } else |
| ra[0] = (uint8_t)ra11; |
| |
| osmo_pbit2ubit_ext(conv, 0, ra, 0, nbits, 1); |
| |
| osmo_crc8gen_set_bits(&gsm0503_rach_crc6, conv, nbits, conv + nbits); |
| |
| rach_apply_bsic(conv, bsic, nbits); |
| |
| osmo_conv_encode(is_11bit ? &gsm0503_rach_ext : &gsm0503_rach, conv, burst); |
| |
| return 0; |
| } |
| |
| /* |
| * GSM SCH transcoding |
| */ |
| |
| /*! Decode the SCH according to TS 05.03 |
| * \param[out] sb_info output buffer for SCH data |
| * \param[in] burst Input burst data |
| * \returns 0 on success; negative on error (e.g. CRC error) */ |
| int gsm0503_sch_decode(uint8_t *sb_info, const sbit_t *burst) |
| { |
| ubit_t conv[35]; |
| int rv; |
| |
| osmo_conv_decode(&gsm0503_sch, burst, conv); |
| |
| rv = osmo_crc16gen_check_bits(&gsm0503_sch_crc10, conv, 25, conv + 25); |
| if (rv) |
| return -1; |
| |
| osmo_ubit2pbit_ext(sb_info, 0, conv, 0, 25, 1); |
| |
| return 0; |
| } |
| |
| /*! Encode the SCH according to TS 05.03 |
| * \param[out] burst Caller-allocated output burst buffer |
| * \param[in] sb_info Input SCH data |
| * \returns 0 on success; negative on error */ |
| int gsm0503_sch_encode(ubit_t *burst, const uint8_t *sb_info) |
| { |
| ubit_t conv[35]; |
| |
| osmo_pbit2ubit_ext(conv, 0, sb_info, 0, 25, 1); |
| |
| osmo_crc16gen_set_bits(&gsm0503_sch_crc10, conv, 25, conv + 25); |
| |
| osmo_conv_encode(&gsm0503_sch, conv, burst); |
| |
| return 0; |
| } |
| |
| /*! @} */ |