| /* |
| * Copyright (C) 2011, 2012 Apple Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY |
| * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR |
| * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY |
| * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include "core/html/MediaFragmentURIParser.h" |
| |
| #include "wtf/text/CString.h" |
| #include "wtf/text/StringBuilder.h" |
| #include "wtf/text/WTFString.h" |
| |
| namespace blink { |
| |
| const int secondsPerHour = 3600; |
| const int secondsPerMinute = 60; |
| const unsigned nptIdentiferLength = 4; // "npt:" |
| |
| static String collectDigits(const LChar* input, unsigned length, unsigned& position) |
| { |
| StringBuilder digits; |
| |
| // http://www.ietf.org/rfc/rfc2326.txt |
| // DIGIT ; any positive number |
| while (position < length && isASCIIDigit(input[position])) |
| digits.append(input[position++]); |
| return digits.toString(); |
| } |
| |
| static String collectFraction(const LChar* input, unsigned length, unsigned& position) |
| { |
| StringBuilder digits; |
| |
| // http://www.ietf.org/rfc/rfc2326.txt |
| // [ "." *DIGIT ] |
| if (input[position] != '.') |
| return String(); |
| |
| digits.append(input[position++]); |
| while (position < length && isASCIIDigit(input[position])) |
| digits.append(input[position++]); |
| return digits.toString(); |
| } |
| |
| MediaFragmentURIParser::MediaFragmentURIParser(const KURL& url) |
| : m_url(url) |
| , m_timeFormat(None) |
| , m_startTime(std::numeric_limits<double>::quiet_NaN()) |
| , m_endTime(std::numeric_limits<double>::quiet_NaN()) |
| { |
| } |
| |
| double MediaFragmentURIParser::startTime() |
| { |
| if (!m_url.isValid()) |
| return std::numeric_limits<double>::quiet_NaN(); |
| if (m_timeFormat == None) |
| parseTimeFragment(); |
| return m_startTime; |
| } |
| |
| double MediaFragmentURIParser::endTime() |
| { |
| if (!m_url.isValid()) |
| return std::numeric_limits<double>::quiet_NaN(); |
| if (m_timeFormat == None) |
| parseTimeFragment(); |
| return m_endTime; |
| } |
| |
| void MediaFragmentURIParser::parseFragments() |
| { |
| if (!m_url.hasFragmentIdentifier()) |
| return; |
| String fragmentString = m_url.fragmentIdentifier(); |
| if (fragmentString.isEmpty()) |
| return; |
| |
| unsigned offset = 0; |
| unsigned end = fragmentString.length(); |
| while (offset < end) { |
| // http://www.w3.org/2008/WebVideo/Fragments/WD-media-fragments-spec/#processing-name-value-components |
| // 1. Parse the octet string according to the namevalues syntax, yielding a list of |
| // name-value pairs, where name and value are both octet string. In accordance |
| // with RFC 3986, the name and value components must be parsed and separated before |
| // percent-encoded octets are decoded. |
| size_t parameterStart = offset; |
| size_t parameterEnd = fragmentString.find('&', offset); |
| if (parameterEnd == kNotFound) |
| parameterEnd = end; |
| |
| size_t equalOffset = fragmentString.find('=', offset); |
| if (equalOffset == kNotFound || equalOffset > parameterEnd) { |
| offset = parameterEnd + 1; |
| continue; |
| } |
| |
| // 2. For each name-value pair: |
| // a. Decode percent-encoded octets in name and value as defined by RFC 3986. If either |
| // name or value are not valid percent-encoded strings, then remove the name-value pair |
| // from the list. |
| String name = decodeURLEscapeSequences(fragmentString.substring(parameterStart, equalOffset - parameterStart)); |
| String value; |
| if (equalOffset != parameterEnd) |
| value = decodeURLEscapeSequences(fragmentString.substring(equalOffset + 1, parameterEnd - equalOffset - 1)); |
| |
| // b. Convert name and value to Unicode strings by interpreting them as UTF-8. If either |
| // name or value are not valid UTF-8 strings, then remove the name-value pair from the list. |
| bool validUTF8 = true; |
| if (!name.isEmpty()) { |
| name = name.utf8(StrictUTF8Conversion).data(); |
| validUTF8 = !name.isEmpty(); |
| } |
| if (validUTF8 && !value.isEmpty()) { |
| value = value.utf8(StrictUTF8Conversion).data(); |
| validUTF8 = !value.isEmpty(); |
| } |
| |
| if (validUTF8) |
| m_fragments.append(std::make_pair(name, value)); |
| |
| offset = parameterEnd + 1; |
| } |
| } |
| |
| void MediaFragmentURIParser::parseTimeFragment() |
| { |
| ASSERT(m_timeFormat == None); |
| |
| if (m_fragments.isEmpty()) |
| parseFragments(); |
| |
| m_timeFormat = Invalid; |
| |
| for (unsigned i = 0; i < m_fragments.size(); ++i) { |
| std::pair<String, String>& fragment = m_fragments[i]; |
| |
| ASSERT(fragment.first.is8Bit()); |
| ASSERT(fragment.second.is8Bit()); |
| |
| // http://www.w3.org/2008/WebVideo/Fragments/WD-media-fragments-spec/#naming-time |
| // Temporal clipping is denoted by the name t, and specified as an interval with a begin |
| // time and an end time |
| if (fragment.first != "t") |
| continue; |
| |
| // http://www.w3.org/2008/WebVideo/Fragments/WD-media-fragments-spec/#npt-time |
| // Temporal clipping can be specified either as Normal Play Time (npt) RFC 2326, as SMPTE timecodes, |
| // SMPTE, or as real-world clock time (clock) RFC 2326. Begin and end times are always specified |
| // in the same format. The format is specified by name, followed by a colon (:), with npt: being |
| // the default. |
| |
| double start = std::numeric_limits<double>::quiet_NaN(); |
| double end = std::numeric_limits<double>::quiet_NaN(); |
| if (parseNPTFragment(fragment.second.characters8(), fragment.second.length(), start, end)) { |
| m_startTime = start; |
| m_endTime = end; |
| m_timeFormat = NormalPlayTime; |
| |
| // Although we have a valid fragment, don't return yet because when a fragment dimensions |
| // occurs multiple times, only the last occurrence of that dimension is used: |
| // http://www.w3.org/2008/WebVideo/Fragments/WD-media-fragments-spec/#error-uri-general |
| // Multiple occurrences of the same dimension: only the last valid occurrence of a dimension |
| // (e.g., t=10 in #t=2&t=10) is interpreted, all previous occurrences (valid or invalid) |
| // SHOULD be ignored by the UA. |
| } |
| } |
| m_fragments.clear(); |
| } |
| |
| bool MediaFragmentURIParser::parseNPTFragment(const LChar* timeString, unsigned length, double& startTime, double& endTime) |
| { |
| unsigned offset = 0; |
| if (length >= nptIdentiferLength && timeString[0] == 'n' && timeString[1] == 'p' && timeString[2] == 't' && timeString[3] == ':') |
| offset += nptIdentiferLength; |
| |
| if (offset == length) |
| return false; |
| |
| // http://www.w3.org/2008/WebVideo/Fragments/WD-media-fragments-spec/#naming-time |
| // If a single number only is given, this corresponds to the begin time except if it is preceded |
| // by a comma that would in this case indicate the end time. |
| if (timeString[offset] == ',') { |
| startTime = 0; |
| } else { |
| if (!parseNPTTime(timeString, length, offset, startTime)) |
| return false; |
| } |
| |
| if (offset == length) |
| return true; |
| |
| if (timeString[offset] != ',') |
| return false; |
| if (++offset == length) |
| return false; |
| |
| if (!parseNPTTime(timeString, length, offset, endTime)) |
| return false; |
| |
| if (offset != length) |
| return false; |
| |
| if (startTime >= endTime) |
| return false; |
| |
| return true; |
| } |
| |
| 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; |
| } |
| |
| } // namespace blink |
