/*
* 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 "config.h"
#include "core/html/MediaFragmentURIParser.h"
#include "platform/graphics/media/MediaPlayer.h"
#include "wtf/text/CString.h"
#include "wtf/text/StringBuilder.h"
#include "wtf/text/WTFString.h"
namespace WebCore {
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();
}
double MediaFragmentURIParser::invalidTimeValue()
{
return MediaPlayer::invalidTime();
}
MediaFragmentURIParser::MediaFragmentURIParser(const KURL& url)
: m_url(url)
, m_timeFormat(None)
, m_startTime(MediaPlayer::invalidTime())
, m_endTime(MediaPlayer::invalidTime())
{
}
double MediaFragmentURIParser::startTime()
{
if (!m_url.isValid())
return MediaPlayer::invalidTime();
if (m_timeFormat == None)
parseTimeFragment();
return m_startTime;
}
double MediaFragmentURIParser::endTime()
{
if (!m_url.isValid())
return MediaPlayer::invalidTime();
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) {
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 = MediaPlayer::invalidTime();
double end = MediaPlayer::invalidTime();
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;
}
}