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Diffstat (limited to 'src/bitcomp.c')
| -rw-r--r-- | src/bitcomp.c | 354 |
1 files changed, 0 insertions, 354 deletions
diff --git a/src/bitcomp.c b/src/bitcomp.c deleted file mode 100644 index 6f2fb62b..00000000 --- a/src/bitcomp.c +++ /dev/null @@ -1,354 +0,0 @@ -/*! \file bitcomp.c - * Osmocom bit compression routines */ -/* - * (C) 2016 by sysmocom - s.f.m.c. GmbH - * Author: Max Suraev <msuraev@sysmocom.de> - * - * 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. - * - */ - -/*! \defgroup bitcomp Bit compression - * @{ - * \file bitcomp.c */ - -#include <stdint.h> -#include <stdbool.h> -#include <errno.h> -#include <string.h> - -#include <osmocom/core/bitvec.h> -#include <osmocom/core/bitcomp.h> - -/* - * Terminating codes for uninterrupted sequences of 0 and 1 up to 64 bit length - * according to TS 44.060 9.1.10 - */ -static const unsigned t4_term[2][64] = { - { - 0b0000110111, - 0b10, - 0b11, - 0b010, - 0b011, - 0b0011, - 0b0010, - 0b00011, - 0b000101, - 0b000100, - 0b0000100, - 0b0000101, - 0b0000111, - 0b00000100, - 0b00000111, - 0b000011000, - 0b0000010111, - 0b0000011000, - 0b0000001000, - 0b00001100111, - 0b00001101000, - 0b00001101100, - 0b00000110111, - 0b00000101000, - 0b00000010111, - 0b00000011000, - 0b000011001010, - 0b000011001011, - 0b000011001100, - 0b000011001101, - 0b000001101000, - 0b000001101001, - 0b000001101010, - 0b000001101011, - 0b000011010010, - 0b000011010011, - 0b000011010100, - 0b000011010101, - 0b000011010110, - 0b000011010111, - 0b000001101100, - 0b000001101101, - 0b000011011010, - 0b000011011011, - 0b000001010100, - 0b000001010101, - 0b000001010110, - 0b000001010111, - 0b000001100100, - 0b000001100101, - 0b000001010010, - 0b000001010011, - 0b000000100100, - 0b000000110111, - 0b000000111000, - 0b000000100111, - 0b000000101000, - 0b000001011000, - 0b000001011001, - 0b000000101011, - 0b000000101100, - 0b000001011010, - 0b000001100110, - 0b000001100111 - }, - { - 0b00110101, - 0b000111, - 0b0111, - 0b1000, - 0b1011, - 0b1100, - 0b1110, - 0b1111, - 0b10011, - 0b10100, - 0b00111, - 0b01000, - 0b001000, - 0b000011, - 0b110100, - 0b110101, - 0b101010, - 0b101011, - 0b0100111, - 0b0001100, - 0b0001000, - 0b0010111, - 0b0000011, - 0b0000100, - 0b0101000, - 0b0101011, - 0b0010011, - 0b0100100, - 0b0011000, - 0b00000010, - 0b00000011, - 0b00011010, - 0b00011011, - 0b00010010, - 0b00010011, - 0b00010100, - 0b00010101, - 0b00010110, - 0b00010111, - 0b00101000, - 0b00101001, - 0b00101010, - 0b00101011, - 0b00101100, - 0b00101101, - 0b00000100, - 0b00000101, - 0b00001010, - 0b00001011, - 0b01010010, - 0b01010011, - 0b01010100, - 0b01010101, - 0b00100100, - 0b00100101, - 0b01011000, - 0b01011001, - 0b01011010, - 0b01011011, - 0b01001010, - 0b01001011, - 0b00110010, - 0b00110011, - 0b00110100 - } -}; - -static const unsigned t4_term_length[2][64] = { - {10, 2, 2, 3, 3, 4, 4, 5, 6, 6, 7, 7, 7, 8, 8, 9, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12}, - {8, 6, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8} -}; - -static const unsigned t4_make_up_length[2][15] = { - {10, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 13, 13}, - {5, 5, 6, 7, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9} -}; - -static const unsigned t4_make_up[2][15] = { - { - 0b0000001111, - 0b000011001000, - 0b000011001001, - 0b000001011011, - 0b000000110011, - 0b000000110100, - 0b000000110101, - 0b0000001101100, - 0b0000001101101, - 0b0000001001010, - 0b0000001001011, - 0b0000001001100, - 0b0000001001101, - 0b0000001110010, - 0b0000001110011 - }, - { - 0b11011, - 0b10010, - 0b010111, - 0b0110111, - 0b00110110, - 0b00110111, - 0b01100100, - 0b01100101, - 0b01101000, - 0b01100111, - 0b011001100, - 0b011001101, - 0b011010010, - 0b011010011, - 0b011010100 - } -}; - -/*! Make-up codes for a given length - * - * \return Return proper make-up code word for an uninterrupted - * sequence of b bits of length len according to modified ITU-T T.4 - * from TS 44.060 Table 9.1.10.2 */ -static inline int t4_rle(struct bitvec *bv, unsigned len, bool b) -{ - if (len >= 960) { - bitvec_set_uint(bv, t4_make_up[b][14], t4_make_up_length[b][14]); - return bitvec_set_uint(bv, t4_term[b][len - 960], t4_term_length[b][len - 960]); - } - - if (len >= 896) { - bitvec_set_uint(bv, t4_make_up[b][13], t4_make_up_length[b][13]); - return bitvec_set_uint(bv, t4_term[b][len - 896], t4_term_length[b][len - 896]); - } - - if (len >= 832) { - bitvec_set_uint(bv, t4_make_up[b][12], t4_make_up_length[b][12]); - return bitvec_set_uint(bv, t4_term[b][len - 832], t4_term_length[b][len - 832]); - } - - if (len >= 768) { - bitvec_set_uint(bv, t4_make_up[b][11], t4_make_up_length[b][11]); - return bitvec_set_uint(bv, t4_term[b][len - 768], t4_term_length[b][len - 768]); - } - - if (len >= 704) { - bitvec_set_uint(bv, t4_make_up[b][10], t4_make_up_length[b][10]); - return bitvec_set_uint(bv, t4_term[b][len - 704], t4_term_length[b][len - 704]); - } - - if (len >= 640) { - bitvec_set_uint(bv, t4_make_up[b][9], t4_make_up_length[b][9]); - return bitvec_set_uint(bv, t4_term[b][len - 640], t4_term_length[b][len - 640]); - } - - if (len >= 576) { - bitvec_set_uint(bv, t4_make_up[b][8], t4_make_up_length[b][8]); - return bitvec_set_uint(bv, t4_term[b][len - 576], t4_term_length[b][len - 576]); - } - - if (len >= 512) { - bitvec_set_uint(bv, t4_make_up[b][7], t4_make_up_length[b][7]); - return bitvec_set_uint(bv, t4_term[b][len - 512], t4_term_length[b][len - 512]); - } - - if (len >= 448) { - bitvec_set_uint(bv, t4_make_up[b][6], t4_make_up_length[b][6]); - return bitvec_set_uint(bv, t4_term[b][len - 448], t4_term_length[b][len - 448]); - } - - if (len >= 384) { - bitvec_set_uint(bv, t4_make_up[b][5], t4_make_up_length[b][5]); - return bitvec_set_uint(bv, t4_term[b][len - 384], t4_term_length[b][len - 384]); - } - - if (len >= 320) { - bitvec_set_uint(bv, t4_make_up[b][4], t4_make_up_length[b][4]); - return bitvec_set_uint(bv, t4_term[b][len - 320], t4_term_length[b][len - 320]); - } - - if (len >= 256) { - bitvec_set_uint(bv, t4_make_up[b][3], t4_make_up_length[b][3]); - return bitvec_set_uint(bv, t4_term[b][len - 256], t4_term_length[b][len - 256]); - } - - if (len >= 192) { - bitvec_set_uint(bv, t4_make_up[b][2], t4_make_up_length[b][2]); - return bitvec_set_uint(bv, t4_term[b][len - 192], t4_term_length[b][len - 192]); - } - - if (len >= 128) { - bitvec_set_uint(bv, t4_make_up[b][1], t4_make_up_length[b][1]); - return bitvec_set_uint(bv, t4_term[b][len - 128], t4_term_length[b][len - 128]); - } - - if (len >= 64) { - bitvec_set_uint(bv, t4_make_up[b][0], t4_make_up_length[b][0]); - return bitvec_set_uint(bv, t4_term[b][len - 64], t4_term_length[b][len - 64]); - } - - return bitvec_set_uint(bv, t4_term[b][len], t4_term_length[b][len]); -} - -/*! encode bit vector in-place using T4 encoding - * Assumes MSB first encoding. - * \param[in] bv bit vector to be encoded - * \return color code (if the encoding started with 0 or 1) or -1 on - * failure (encoded is bigger than original) - */ -int osmo_t4_encode(struct bitvec *bv) -{ - unsigned rl0 = bitvec_rl(bv, false), rl1 = bitvec_rl(bv, true); - int r = (rl0 > rl1) ? 0 : 1; - uint8_t orig[bv->data_len], tmp[bv->data_len * 2]; /* FIXME: better estimate max possible encoding overhead */ - struct bitvec comp, vec; - comp.data = tmp; - comp.data_len = bv->data_len * 2; - bitvec_zero(&comp); - vec.data = orig; - vec.data_len = bv->data_len; - bitvec_zero(&vec); - memcpy(vec.data, bv->data, bv->data_len); - vec.cur_bit = bv->cur_bit; - - while (vec.cur_bit > 0) { - if (rl0 > rl1) { - bitvec_shiftl(&vec, rl0); - t4_rle(&comp, rl0, false); - } else { - bitvec_shiftl(&vec, rl1); - t4_rle(&comp, rl1, true); - } - /* - TODO: implement backtracking for optimal encoding - printf(" -> [%d/%d]", comp.cur_bit + vec.cur_bit, bv->cur_bit); - */ - rl0 = bitvec_rl(&vec, false); - rl1 = bitvec_rl(&vec, true); - } - if (comp.cur_bit < bv->cur_bit) { - memcpy(bv->data, tmp, bv->data_len); - bv->cur_bit = comp.cur_bit; - return r; - } - return -1; -} - -/*! @} */ |