diff options
Diffstat (limited to 'src/charset.cpp')
| -rw-r--r-- | src/charset.cpp | 80 |
1 files changed, 76 insertions, 4 deletions
diff --git a/src/charset.cpp b/src/charset.cpp index 2ee14f8..1abc097 100644 --- a/src/charset.cpp +++ b/src/charset.cpp @@ -1,5 +1,5 @@ /* - Copyright (C) 2015 Matthias P. Braendli (http://opendigitalradio.org) + Copyright (C) 2018 Matthias P. Braendli (http://opendigitalradio.org) 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 @@ -16,13 +16,15 @@ */ /*! \file charset.cpp - \brief Define the EBU charset according to ETSI TS 101 756v1.8.1 for DLS encoding + \brief A converter for UTF-8 to EBU Latin charset according to + ETSI TS 101 756 Annex C, used for DLS and Labels. - \author Matthias P. Braendli <matthias@mpb.li> + \author Matthias P. Braendli \author Lindsay Cornell */ #include "charset.h" +#include <algorithm> /**********************************************/ /************* BIG FAT WARNING ****************/ @@ -34,8 +36,10 @@ /********* END OF BIG FAT WARNING *************/ /**********************************************/ +#define CHARSET_TABLE_OFFSET 1 // NUL at index 0 cannot be represented +#define CHARSET_TABLE_ENTRIES (256 - CHARSET_TABLE_OFFSET) -const char* utf8_encoded_EBU_Latin[CHARSET_TABLE_ENTRIES] = { +static const char* utf8_encoded_EBU_Latin[CHARSET_TABLE_ENTRIES] = { "Ę", "Į", "Ų", "Ă", "Ė", "Ď", "Ș", "Ț", "Ċ", "\n","\v","Ġ", "Ĺ", "Ż", "Ń", "ą", "ę", "į", "ų", "ă", "ė", "ď", "ș", "ț", "ċ", "Ň", "Ě", "ġ", "ĺ", "ż", "\u0082", " ", "!", "\"","#", "ł", "%", "&", "'", "(", ")", "*", "+", ",", "-", ".", "/", @@ -52,3 +56,71 @@ const char* utf8_encoded_EBU_Latin[CHARSET_TABLE_ENTRIES] = { "Â", "Ä", "Ê", "Ë", "Î", "Ï", "Ô", "Ö", "Û", "Ü", "ř", "č", "š", "ž", "đ", "ŀ", "Ã", "Å", "Æ", "Œ", "ŷ", "Ý", "Õ", "Ø", "Þ", "Ŋ", "Ŕ", "Ć", "Ś", "Ź", "Ť", "ð", "ã", "å", "æ", "œ", "ŵ", "ý", "õ", "ø", "þ", "ŋ", "ŕ", "ć", "ś", "ź", "ť", "ħ"}; + +using namespace std; + +CharsetConverter::CharsetConverter() +{ + /*! Build the converstion table that contains the known code points, + * at the indices corresponding to the EBU Latin table + */ + using namespace std; + for (size_t i = 0; i < CHARSET_TABLE_ENTRIES; i++) { + string table_entry(utf8_encoded_EBU_Latin[i]); + string::iterator it = table_entry.begin(); + uint32_t code_point = utf8::next(it, table_entry.end()); + m_conversion_table.push_back(code_point); + } +} + +std::string CharsetConverter::convert(std::string line_utf8, bool up_to_first_error) +{ + string::iterator end_it; + + if (up_to_first_error) { + // check for invalid utf-8, we only convert up to the first error + end_it = utf8::find_invalid(line_utf8.begin(), line_utf8.end()); + } + else { + end_it = line_utf8.end(); + } + + // Convert it to utf-32 + vector<uint32_t> utf32line; + utf8::utf8to32(line_utf8.begin(), end_it, back_inserter(utf32line)); + + string encoded_line(utf32line.size(), '0'); + + // Try to convert each codepoint + for (size_t i = 0; i < utf32line.size(); i++) { + vector<uint32_t>::iterator iter = find(m_conversion_table.begin(), + m_conversion_table.end(), utf32line[i]); + if (iter != m_conversion_table.end()) { + size_t index = std::distance(m_conversion_table.begin(), iter); + + encoded_line[i] = (char)(index + CHARSET_TABLE_OFFSET); + } + else { + encoded_line[i] = ' '; + } + } + return encoded_line; +} + +std::string CharsetConverter::convert_ebu_to_utf8(const std::string& str) +{ + string utf8_str; + for (const uint8_t c : str) { + // Table offset because NUL is not represented + if (c >= CHARSET_TABLE_OFFSET) { + string utf8_char(utf8_encoded_EBU_Latin[c - CHARSET_TABLE_OFFSET]); + utf8_str += utf8_char; + } + else { + utf8_str += "⁇"; + } + } + + return utf8_str; +} + |