void
strip(std::string &s,
bool newlines) {
const char *c = s.c_str();
int i = 0;
if (newlines)
while ((c[i] != 0) && (isblanktab(c[i]) || iscr(c[i])))
i++;
else
while ((c[i] != 0) && isblanktab(c[i]))
i++;
if (i > 0)
s.erase(0, i);
strip_back(s, newlines);
}
void
srt_parser_c::parse() {
boost::regex timecode_re(SRT_RE_TIMECODE_LINE, boost::regex::perl);
boost::regex number_re("^\\d+$", boost::regex::perl);
boost::regex coordinates_re(SRT_RE_COORDINATES, boost::regex::perl);
int64_t start = 0;
int64_t end = 0;
int64_t previous_start = 0;
bool timecode_warning_printed = false;
parser_state_e state = STATE_INITIAL;
int line_number = 0;
unsigned int subtitle_number = 0;
unsigned int timecode_number = 0;
std::string subtitles;
m_io->setFilePointer(0, seek_beginning);
while (1) {
std::string s;
if (!m_io->getline2(s))
break;
line_number++;
strip_back(s);
if (s.empty()) {
if ((STATE_INITIAL == state) || (STATE_TIME == state))
continue;
state = STATE_SUBS_OR_NUMBER;
if (!subtitles.empty())
subtitles += "\n";
subtitles += "\n";
continue;
}
if (STATE_INITIAL == state) {
if (!boost::regex_match(s, number_re)) {
mxwarn_tid(m_file_name, m_tid, boost::format(Y("Error in line %1%: expected subtitle number and found some text.\n")) % line_number);
break;
}
state = STATE_TIME;
parse_number(s, subtitle_number);
} else if (STATE_TIME == state) {
boost::smatch matches;
if (!boost::regex_search(s, matches, timecode_re)) {
mxwarn_tid(m_file_name, m_tid, boost::format(Y("Error in line %1%: expected a SRT timecode line but found something else. Aborting this file.\n")) % line_number);
break;
}
int s_h = 0, s_min = 0, s_sec = 0, e_h = 0, e_min = 0, e_sec = 0;
// 1 2 3 4 5 6 7 8
// "\\s*(-?)\\s*(\\d+):\\s(-?)*(\\d+):\\s*(-?)(\\d+)[,\\.]\\s*(-?)(\\d+)?"
parse_number(matches[ 2].str(), s_h);
parse_number(matches[ 4].str(), s_min);
parse_number(matches[ 6].str(), s_sec);
parse_number(matches[10].str(), e_h);
parse_number(matches[12].str(), e_min);
parse_number(matches[14].str(), e_sec);
std::string s_rest = matches[ 8].str();
std::string e_rest = matches[16].str();
auto neg_calculator = [&](size_t const start_idx) -> int64_t {
int64_t neg = 1;
for (size_t idx = start_idx; idx <= (start_idx + 6); idx += 2)
neg *= matches[idx].str() == "-" ? -1 : 1;
return neg;
};
int64_t s_neg = neg_calculator(1);
int64_t e_neg = neg_calculator(9);
if (boost::regex_search(s, coordinates_re) && !m_coordinates_warning_shown) {
mxwarn_tid(m_file_name, m_tid,
Y("This file contains coordinates in the timecode lines. "
"Such coordinates are not supported by the Matroska SRT subtitle format. "
"The coordinates will be removed automatically.\n"));
m_coordinates_warning_shown = true;
}
// The previous entry is done now. Append it to the list of subtitles.
if (!subtitles.empty()) {
strip_back(subtitles, true);
add(start, end, timecode_number, subtitles.c_str());
}
// Calculate the start and end time in ns precision for the following entry.
start = (int64_t)s_h * 60 * 60 + s_min * 60 + s_sec;
end = (int64_t)e_h * 60 * 60 + e_min * 60 + e_sec;
start *= 1000000000ll * s_neg;
end *= 1000000000ll * e_neg;
while (s_rest.length() < 9)
s_rest += "0";
if (s_rest.length() > 9)
s_rest.erase(9);
start += atol(s_rest.c_str());
while (e_rest.length() < 9)
e_rest += "0";
if (e_rest.length() > 9)
e_rest.erase(9);
end += atol(e_rest.c_str());
if (0 > start) {
mxwarn_tid(m_file_name, m_tid,
boost::format(Y("Line %1%: Negative timestamp encountered. The entry will be adjusted to start from 00:00:00.000.\n")) % line_number);
end -= start;
start = 0;
if (0 > end)
end *= -1;
}
// There are files for which start timecodes overlap. Matroska requires
// blocks to be sorted by their timecode. mkvmerge does this at the end
// of this function, but warn the user that the original order is being
// changed.
if (!timecode_warning_printed && (start < previous_start)) {
mxwarn_tid(m_file_name, m_tid, boost::format(Y("Warning in line %1%: The start timecode is smaller than that of the previous entry. "
"All entries from this file will be sorted by their start time.\n")) % line_number);
timecode_warning_printed = true;
}
previous_start = start;
subtitles = "";
state = STATE_SUBS;
timecode_number = subtitle_number;
} else if (STATE_SUBS == state) {
if (!subtitles.empty())
subtitles += "\n";
subtitles += s;
} else if (boost::regex_match(s, number_re)) {
state = STATE_TIME;
parse_number(s, subtitle_number);
} else {
if (!subtitles.empty())
subtitles += "\n";
subtitles += s;
}
}
if (!subtitles.empty()) {
strip_back(subtitles, true);
add(start, end, timecode_number, subtitles.c_str());
}
sort();
}
