void WebVTTParser::parseBytes(const char* data, unsigned length)
{
// 4.8.10.13.3 WHATWG WebVTT Parser algorithm.
// 1-3 - Initial setup.
unsigned position = 0;
while (position < length) {
String line = collectNextLine(data, length, &position);
switch (m_state) {
case Initial:
// Buffer up at least 9 bytes before proceeding with checking for the file identifier.
m_identifierData.append(data, length);
if (m_identifierData.size() < bomLength + fileIdentifierLength)
return;
// 4-12 - Collect the first line and check for "WEBVTT".
if (!hasRequiredFileIdentifier()) {
if (m_client)
m_client->fileFailedToParse();
return;
}
m_state = Header;
m_identifierData.clear();
break;
case Header:
// 13-18 - Allow a header (comment area) under the WEBVTT line.
if (line.isEmpty())
m_state = Id;
break;
case Id:
// 19-29 - Allow any number of line terminators, then initialize new cue values.
if (line.isEmpty())
break;
resetCueValues();
// 30-39 - Check if this line contains an optional identifier or timing data.
m_state = collectCueId(line);
break;
case TimingsAndSettings:
// 40 - Collect cue timings and settings.
m_state = collectTimingsAndSettings(line);
break;
case CueText:
// 41-53 - Collect the cue text, create a cue, and add it to the output.
m_state = collectCueText(line, length, position);
break;
case BadCue:
// 54-62 - Collect and discard the remaining cue.
m_state = ignoreBadCue(line);
break;
}
}
}
void InbandTextTrackPrivateAVF::processCue(CFArrayRef attributedStrings, double time)
{
if (!m_player)
return;
if (m_havePartialCue) {
// Cues do not have an explicit duration, they are displayed until the next "cue" (which might be empty) is emitted.
m_currentCueEndTime = time;
LOG(Media, "InbandTextTrackPrivateAVF::processCue flushing cue: start=%.2f, end=%.2f, settings=\"%s\", content=\"%s\" \n",
m_currentCueStartTime, m_currentCueEndTime,
m_currentCueSettings.toString().utf8().data(), m_currentCueContent.toString().utf8().data());
m_player->flushCurrentCue(this);
resetCueValues();
}
CFIndex count = CFArrayGetCount(attributedStrings);
for (CFIndex i = 0; i < count; i++) {
CFAttributedStringRef attributedString = static_cast<CFAttributedStringRef>(CFArrayGetValueAtIndex(attributedStrings, i));
if (!attributedString || !CFAttributedStringGetLength(attributedString))
continue;
processCueAttributes(attributedString, m_currentCueContent, m_currentCueSettings);
m_currentCueStartTime = time;
m_havePartialCue = true;
}
}
void InbandTextTrackPrivateAVF::beginSeeking()
{
// Forget any partially accumulated cue data as the seek could be to a time outside of the cue's
// range, which will mean that the next cue delivered will result in the current cue getting the
// incorrect duration.
resetCueValues();
m_seeking = true;
}
VTTParser::ParseState VTTParser::recoverCue(const String& line)
{
// Step 17 and 21.
resetCueValues();
// Step 22.
return collectTimingsAndSettings(line);
}
void InbandTextTrackPrivateAVF::processCue(CFArrayRef attributedStrings, double time)
{
if (!client())
return;
if (m_havePartialCue) {
// Cues do not have an explicit duration, they are displayed until the next "cue" (which might be empty) is emitted.
m_currentCueEndTime = time;
if (m_currentCueEndTime >= m_currentCueStartTime) {
for (size_t i = 0; i < m_cues.size(); i++) {
GenericCueData* cueData = m_cues[i].get();
LOG(Media, "InbandTextTrackPrivateAVF::processCue flushing cue: start=%.2f, end=%.2f, content=\"%s\" \n",
m_currentCueStartTime, m_currentCueEndTime, cueData->content().utf8().data());
if (!cueData->content().length())
continue;
cueData->setStartTime(m_currentCueStartTime);
cueData->setEndTime(m_currentCueEndTime);
// AVFoundation cue "position" is to the center of the text so adjust relative to the edge because we will use it to
// set CSS "left".
if (cueData->position() >= 0 && cueData->size() > 0)
cueData->setPosition(cueData->position() - cueData->size() / 2);
LOG(Media, "InbandTextTrackPrivateAVF::processCue(%p) - adding cue for time = %.2f, position = %.2f, line = %.2f", this, cueData->startTime(), cueData->position(), cueData->line());
client()->addGenericCue(this, cueData);
}
} else
LOG(Media, "InbandTextTrackPrivateAVF::processCue negative length cue(s) ignored: start=%.2f, end=%.2f\n", m_currentCueStartTime, m_currentCueEndTime);
resetCueValues();
}
if (!attributedStrings)
return;
CFIndex count = CFArrayGetCount(attributedStrings);
if (!count)
return;
for (CFIndex i = 0; i < count; i++) {
CFAttributedStringRef attributedString = static_cast<CFAttributedStringRef>(CFArrayGetValueAtIndex(attributedStrings, i));
if (!attributedString || !CFAttributedStringGetLength(attributedString))
continue;
m_cues.append(adoptPtr(new GenericCueData));
processCueAttributes(attributedString, m_cues[i].get());
m_currentCueStartTime = time;
m_havePartialCue = true;
}
}
void InbandTextTrackPrivateAVF::processCue(CFArrayRef attributedStrings, double time)
{
if (!client())
return;
LOG(Media, "InbandTextTrackPrivateAVF::processCue - %li cues at time %.2f\n", attributedStrings ? CFArrayGetCount(attributedStrings) : 0, time);
if (m_pendingCueStatus != None) {
// Cues do not have an explicit duration, they are displayed until the next "cue" (which might be empty) is emitted.
m_currentCueEndTime = time;
if (m_currentCueEndTime >= m_currentCueStartTime) {
for (size_t i = 0; i < m_cues.size(); i++) {
GenericCueData* cueData = m_cues[i].get();
if (m_pendingCueStatus == Valid) {
cueData->setEndTime(m_currentCueEndTime);
cueData->setStatus(GenericCueData::Complete);
LOG(Media, "InbandTextTrackPrivateAVF::processCue(%p) - updating cue: start=%.2f, end=%.2f, content=\"%s\"", this, cueData->startTime(), m_currentCueEndTime, cueData->content().utf8().data());
client()->updateGenericCue(this, cueData);
} else {
// We have to assume that the implicit duration is invalid for cues delivered during a seek because the AVF decode pipeline may not
// see every cue, so DO NOT update cue duration while seeking.
LOG(Media, "InbandTextTrackPrivateAVF::processCue(%p) - ignoring cue delivered during seek: start=%.2f, end=%.2f, content=\"%s\"", this, cueData->startTime(), m_currentCueEndTime, cueData->content().utf8().data());
}
}
} else
LOG(Media, "InbandTextTrackPrivateAVF::processCue negative length cue(s) ignored: start=%.2f, end=%.2f\n", m_currentCueStartTime, m_currentCueEndTime);
resetCueValues();
}
if (!attributedStrings)
return;
CFIndex count = CFArrayGetCount(attributedStrings);
if (!count)
return;
for (CFIndex i = 0; i < count; i++) {
CFAttributedStringRef attributedString = static_cast<CFAttributedStringRef>(CFArrayGetValueAtIndex(attributedStrings, i));
if (!attributedString || !CFAttributedStringGetLength(attributedString))
continue;
RefPtr<GenericCueData> cueData = GenericCueData::create();
processCueAttributes(attributedString, cueData.get());
if (!cueData->content().length())
continue;
m_cues.append(cueData);
m_currentCueStartTime = time;
cueData->setStartTime(m_currentCueStartTime);
cueData->setEndTime(numeric_limits<double>::infinity());
// AVFoundation cue "position" is to the center of the text so adjust relative to the edge because we will use it to
// set CSS "left".
if (cueData->position() >= 0 && cueData->size() > 0)
cueData->setPosition(cueData->position() - cueData->size() / 2);
LOG(Media, "InbandTextTrackPrivateAVF::processCue(%p) - adding cue for time = %.2f, position = %.2f, line = %.2f", this, cueData->startTime(), cueData->position(), cueData->line());
cueData->setStatus(GenericCueData::Partial);
client()->addGenericCue(this, cueData.release());
m_pendingCueStatus = seeking() ? DeliveredDuringSeek : Valid;
}
}
void VTTParser::parse()
{
// WebVTT parser algorithm. (5.1 WebVTT file parsing.)
// Steps 1 - 3 - Initial setup.
String line;
while (m_lineReader.getLine(line)) {
switch (m_state) {
case Initial:
// Steps 4 - 9 - Check for a valid WebVTT signature.
if (!hasRequiredFileIdentifier(line)) {
if (m_client)
m_client->fileFailedToParse();
return;
}
m_state = Header;
break;
case Header:
// Steps 10 - 14 - Allow a header (comment area) under the WEBVTT line.
collectMetadataHeader(line);
if (line.isEmpty()) {
if (m_client && m_regionList.size())
m_client->newRegionsParsed();
m_state = Id;
break;
}
// Step 15 - Break out of header loop if the line could be a timestamp line.
if (line.contains("-->"))
m_state = recoverCue(line);
// Step 16 - Line is not the empty string and does not contain "-->".
break;
case Id:
// Steps 17 - 20 - Allow any number of line terminators, then initialize new cue values.
if (line.isEmpty())
break;
// Step 21 - Cue creation (start a new cue).
resetCueValues();
// Steps 22 - 25 - Check if this line contains an optional identifier or timing data.
m_state = collectCueId(line);
break;
case TimingsAndSettings:
// Steps 26 - 27 - Discard current cue if the line is empty.
if (line.isEmpty()) {
m_state = Id;
break;
}
// Steps 28 - 29 - Collect cue timings and settings.
m_state = collectTimingsAndSettings(line);
break;
case CueText:
// Steps 31 - 41 - Collect the cue text, create a cue, and add it to the output.
m_state = collectCueText(line);
break;
case BadCue:
// Steps 42 - 48 - Discard lines until an empty line or a potential timing line is seen.
m_state = ignoreBadCue(line);
break;
}
}
}
