/* * Copyright (C) 2014 Jared Boone, ShareBrained Technology, Inc. * Copyright (C) 2016 Furrtek * * This file is part of PortaPack. * * 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, 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; see the file COPYING. If not, write to * the Free Software Foundation, Inc., 51 Franklin Street, * Boston, MA 02110-1301, USA. */ #include "rds.hpp" #include "portapack_shared_memory.hpp" // RDS infos: // One frame = X groups (as necessary) // One group = 4 blocks = 4 * 26 bits // One block = 26 bits (16 bits data + 10 bits checkword) // Sent MSB first namespace rds { uint32_t make_block(uint32_t data, uint16_t offset) { uint16_t CRC = 0; uint8_t bit; for (uint8_t i = 0; i < 16; i++) { bit = (((data << i) & 0x8000) >> 15) ^ (CRC >> 9); if (bit) CRC ^= 0b0011011100; CRC = ((CRC << 1) | bit) & 0x3FF; } return (data << 10) | (CRC ^ offset); } // Boolean to binary uint8_t b2b(const bool in) { if (in) return 1; else return 0; } // Type 0B groups are like 0A groups but without alternative frequency data RDSGroup make_0B_group(const uint16_t PI_code, const bool TP, const uint8_t PTY, const bool TA, const bool MS, const bool DI, const uint8_t C, const std::string chars) { RDSGroup group; group.block[0] = PI_code; group.block[1] = (0x0 << 12) | (1 << 11) | (b2b(TP) << 10) | ((PTY & 0x1F) << 5) | (b2b(TA) << 4) | (b2b(MS) << 3) | (b2b(DI) << 2) | (C & 3); group.block[2] = PI_code; group.block[3] = (chars[0] << 8) | chars[1]; return group; } // For RadioText, up to 64 chars with 2A, 32 chars with 2B RDSGroup make_2A_group(const uint16_t PI_code, const bool TP, const uint8_t PTY, const bool AB, const uint8_t segment, const std::string chars) { RDSGroup group; group.block[0] = PI_code; group.block[1] = (0x2 << 12) | (0 << 11) | (b2b(TP) << 10) | ((PTY & 0x1F) << 5) | (b2b(AB) << 4) | (segment & 15); group.block[2] = (chars[0] << 8) | chars[1]; group.block[3] = (chars[2] << 8) | chars[3]; return group; } // Time and date - usually one message per minute - Month: 1~12 - Day: 1~31 - Hour/Minute: 0~59 - Local offset: -12/+12 from UTC RDSGroup make_4A_group(const uint16_t PI_code, const bool TP, const uint8_t PTY, const uint16_t year, const uint8_t month, const uint8_t day, const uint8_t hour, const uint8_t minute, const int8_t local_offset) { RDSGroup group; uint32_t L = 0; uint32_t day_code; if ((month == 1) || (month == 2)) L = 1; day_code = 14956 + day + (uint32_t)((float)(year - 1900 - L) * 365.25) + uint16_t((float)((month + 1) + L * 12) * 30.6001); group.block[0] = PI_code; group.block[1] = (0x4 << 12) | (0 << 11) | (b2b(TP) << 10) | ((PTY & 0x1F) << 5) | ((day_code & 0x18000) >> 15); group.block[2] = ((day_code & 0x7FFF) << 1) | (hour >> 4); group.block[3] = ((hour & 15) << 12) | ((minute & 0x3F) << 6) | (local_offset & 0x3F); return group; } void gen_PSN(std::vector<RDSGroup>& frame, const std::string& psname, const RDS_flags* rds_flags) { uint8_t c; RDSGroup group; frame.clear(); // 4 groups with 2 PSN characters in each for (c = 0; c < 4; c++) { group = make_0B_group(rds_flags->PI_code, rds_flags->TP, rds_flags->PTY, rds_flags->TA, rds_flags->MS, rds_flags->DI, c, psname.substr(c * 2, 2)); group.block[0] = make_block(group.block[0], RDS_OFFSET_A); group.block[1] = make_block(group.block[1], RDS_OFFSET_B); group.block[2] = make_block(group.block[2], RDS_OFFSET_Cp); // C' ! group.block[3] = make_block(group.block[3], RDS_OFFSET_D); frame.emplace_back(group); } } void gen_RadioText(std::vector<RDSGroup>& frame, const std::string& text, const bool AB, const RDS_flags* rds_flags) { size_t c; // RDSGroup * groups_ptr; std::string radiotext_buffer = text; size_t rt_length, group_count; RDSGroup group; radiotext_buffer += 0x0D; rt_length = radiotext_buffer.length(); rt_length = (rt_length + 3) & 0xFC; group_count = rt_length >> 2; // 4 characters per group // groups_ptr = (RDSGroup*)chHeapAlloc(0, group_count * sizeof(RDSGroup)); frame.clear(); for (c = 0; c < group_count; c++) { group = make_2A_group(rds_flags->PI_code, rds_flags->TP, rds_flags->PTY, AB, c, radiotext_buffer.substr(c * 4, 4)); group.block[0] = make_block(group.block[0], RDS_OFFSET_A); group.block[1] = make_block(group.block[1], RDS_OFFSET_B); group.block[2] = make_block(group.block[2], RDS_OFFSET_C); group.block[3] = make_block(group.block[3], RDS_OFFSET_D); frame.emplace_back(group); } } void gen_ClockTime(std::vector<RDSGroup>& frame, const RDS_flags* rds_flags, const uint16_t year, const uint8_t month, const uint8_t day, const uint8_t hour, const uint8_t minute, const int8_t local_offset) { RDSGroup group; group = make_4A_group(rds_flags->PI_code, rds_flags->TP, rds_flags->PTY, year, month, day, hour, minute, local_offset); // Generate checkbits for each block group.block[0] = make_block(group.block[0], RDS_OFFSET_A); group.block[1] = make_block(group.block[1], RDS_OFFSET_B); group.block[2] = make_block(group.block[2], RDS_OFFSET_C); group.block[3] = make_block(group.block[3], RDS_OFFSET_D); frame.clear(); frame.emplace_back(group); } } /* namespace rds */