double WebVTTParser::collectTimeStamp(const String& line, unsigned* position)
{
// 4.8.10.13.3 Collect a WebVTT timestamp.
// 1-4 - Initial checks, let most significant units be minutes.
enum Mode { minutes, hours };
Mode mode = minutes;
if (*position >= line.length() || !isASCIIDigit(line[*position]))
return malformedTime;
// 5-6 - Collect a sequence of characters that are 0-9.
String digits1 = collectDigits(line, position);
int value1 = digits1.toInt();
// 7 - If not 2 characters or value is greater than 59, interpret as hours.
if (digits1.length() != 2 || value1 > 59)
mode = hours;
// 8-12 - Collect the next sequence of 0-9 after ':' (must be 2 chars).
if (*position >= line.length() || line[(*position)++] != ':')
return malformedTime;
if (*position >= line.length() || !isASCIIDigit(line[(*position)]))
return malformedTime;
String digits2 = collectDigits(line, position);
int value2 = digits2.toInt();
if (digits2.length() != 2)
return malformedTime;
// 13 - Detect whether this timestamp includes hours.
int value3;
if (mode == hours || (*position < line.length() && line[*position] == ':')) {
if (*position >= line.length() || line[(*position)++] != ':')
return malformedTime;
if (*position >= line.length() || !isASCIIDigit(line[*position]))
return malformedTime;
String digits3 = collectDigits(line, position);
if (digits3.length() != 2)
return malformedTime;
value3 = digits3.toInt();
} else {
value3 = value2;
value2 = value1;
value1 = 0;
}
// 14-19 - Collect next sequence of 0-9 after '.' (must be 3 chars).
if (*position >= line.length() || line[(*position)++] != '.')
return malformedTime;
if (*position >= line.length() || !isASCIIDigit(line[*position]))
return malformedTime;
String digits4 = collectDigits(line, position);
if (digits4.length() != 3)
return malformedTime;
int value4 = digits4.toInt();
if (value2 > 59 || value3 > 59)
return malformedTime;
// 20-21 - Calculate result.
return (value1 * secondsPerHour) + (value2 * secondsPerMinute) + value3 + (value4 * secondsPerMillisecond);
}
bool MediaFragmentURIParser::parseNPTTime(const LChar* timeString, unsigned length, unsigned& offset, double& time)
{
enum Mode { minutes, hours };
Mode mode = minutes;
if (offset >= length || !isASCIIDigit(timeString[offset]))
return false;
// http://www.w3.org/2008/WebVideo/Fragments/WD-media-fragments-spec/#npttimedef
// Normal Play Time can either be specified as seconds, with an optional
// fractional part to indicate miliseconds, or as colon-separated hours,
// minutes and seconds (again with an optional fraction). Minutes and
// seconds must be specified as exactly two digits, hours and fractional
// seconds can be any number of digits. The hours, minutes and seconds
// specification for NPT is a convenience only, it does not signal frame
// accuracy. The specification of the "npt:" identifier is optional since
// NPT is the default time scheme. This specification builds on the RTSP
// specification of NPT RFC 2326.
//
// ; defined in RFC 2326
// npt-sec = 1*DIGIT [ "." *DIGIT ] ; definitions taken
// npt-hhmmss = npt-hh ":" npt-mm ":" npt-ss [ "." *DIGIT] ; from RFC 2326
// npt-mmss = npt-mm ":" npt-ss [ "." *DIGIT]
// npt-hh = 1*DIGIT ; any positive number
// npt-mm = 2DIGIT ; 0-59
// npt-ss = 2DIGIT ; 0-59
String digits1 = collectDigits(timeString, length, offset);
int value1 = digits1.toInt();
if (offset >= length || timeString[offset] == ',') {
time = value1;
return true;
}
double fraction = 0;
if (timeString[offset] == '.') {
if (offset == length)
return true;
String digits = collectFraction(timeString, length, offset);
fraction = digits.toDouble();
time = value1 + fraction;
return true;
}
if (digits1.length() < 2)
return false;
if (digits1.length() > 2)
mode = hours;
// Collect the next sequence of 0-9 after ':'
if (offset >= length || timeString[offset++] != ':')
return false;
if (offset >= length || !isASCIIDigit(timeString[(offset)]))
return false;
String digits2 = collectDigits(timeString, length, offset);
int value2 = digits2.toInt();
if (digits2.length() != 2)
return false;
// Detect whether this timestamp includes hours.
int value3;
if (mode == hours || (offset < length && timeString[offset] == ':')) {
if (offset >= length || timeString[offset++] != ':')
return false;
if (offset >= length || !isASCIIDigit(timeString[offset]))
return false;
String digits3 = collectDigits(timeString, length, offset);
if (digits3.length() != 2)
return false;
value3 = digits3.toInt();
} else {
value3 = value2;
value2 = value1;
value1 = 0;
}
if (offset < length && timeString[offset] == '.')
fraction = collectFraction(timeString, length, offset).toDouble();
time = (value1 * secondsPerHour) + (value2 * secondsPerMinute) + value3 + fraction;
return true;
}
SWITCH_DECLARE(int) CoreSession::collectDigits(int abs_timeout) {
return collectDigits(0, abs_timeout);
}
