Vector<RefPtr<TimeRanges> > MediaSource::activeRanges() const
{
Vector<RefPtr<TimeRanges> > activeRanges(m_activeSourceBuffers->length());
for (size_t i = 0; i < m_activeSourceBuffers->length(); ++i)
activeRanges[i] = m_activeSourceBuffers->item(i)->buffered(ASSERT_NO_EXCEPTION);
return activeRanges;
}
std::unique_ptr<PlatformTimeRanges> MediaSource::buffered() const
{
// Implements MediaSource algorithm for HTMLMediaElement.buffered.
// https://dvcs.w3.org/hg/html-media/raw-file/default/media-source/media-source.html#htmlmediaelement-extensions
Vector<RefPtr<TimeRanges>> ranges = activeRanges();
// 1. If activeSourceBuffers.length equals 0 then return an empty TimeRanges object and abort these steps.
if (ranges.isEmpty())
return PlatformTimeRanges::create();
// 2. Let active ranges be the ranges returned by buffered for each SourceBuffer object in activeSourceBuffers.
// 3. Let highest end time be the largest range end time in the active ranges.
double highestEndTime = -1;
for (size_t i = 0; i < ranges.size(); ++i) {
unsigned length = ranges[i]->length();
if (length)
highestEndTime = std::max(highestEndTime, ranges[i]->end(length - 1, ASSERT_NO_EXCEPTION));
}
// Return an empty range if all ranges are empty.
if (highestEndTime < 0)
return PlatformTimeRanges::create();
// 4. Let intersection ranges equal a TimeRange object containing a single range from 0 to highest end time.
RefPtr<TimeRanges> intersectionRanges = TimeRanges::create(0, highestEndTime);
// 5. For each SourceBuffer object in activeSourceBuffers run the following steps:
bool ended = readyState() == endedKeyword();
for (size_t i = 0; i < ranges.size(); ++i) {
// 5.1 Let source ranges equal the ranges returned by the buffered attribute on the current SourceBuffer.
TimeRanges* sourceRanges = ranges[i].get();
// 5.2 If readyState is "ended", then set the end time on the last range in source ranges to highest end time.
if (ended && sourceRanges->length())
sourceRanges->add(sourceRanges->start(sourceRanges->length() - 1, ASSERT_NO_EXCEPTION), highestEndTime);
// 5.3 Let new intersection ranges equal the the intersection between the intersection ranges and the source ranges.
// 5.4 Replace the ranges in intersection ranges with the new intersection ranges.
intersectionRanges->intersectWith(*sourceRanges);
}
return PlatformTimeRanges::create(intersectionRanges->ranges());
}
