void MediaSource::setDurationInternal(const MediaTime& duration)
{
// Duration Change Algorithm
// https://dvcs.w3.org/hg/html-media/raw-file/tip/media-source/media-source.html#duration-change-algorithm
// 1. If the current value of duration is equal to new duration, then return.
if (duration == m_duration)
return;
// 2. Set old duration to the current value of duration.
MediaTime oldDuration = m_duration;
// 3. Update duration to new duration.
m_duration = duration;
// 4. If the new duration is less than old duration, then call remove(new duration, old duration)
// on all objects in sourceBuffers.
if (oldDuration.isValid() && duration < oldDuration) {
for (auto& sourceBuffer : *m_sourceBuffers)
sourceBuffer->rangeRemoval(duration, oldDuration);
}
// 5. If a user agent is unable to partially render audio frames or text cues that start before and end after the
// duration, then run the following steps:
// 5.1 Update new duration to the highest end time reported by the buffered attribute across all SourceBuffer objects
// in sourceBuffers.
// 5.2 Update duration to new duration.
// NOTE: Assume UA is able to partially render audio frames.
// 6. Update the media controller duration to new duration and run the HTMLMediaElement duration change algorithm.
LOG(MediaSource, "MediaSource::setDurationInternal(%p) - duration(%g)", this, duration.toDouble());
m_private->durationChanged();
}
void MediaSource::seekToTime(const MediaTime& time)
{
// 2.4.3 Seeking
// https://dvcs.w3.org/hg/html-media/raw-file/tip/media-source/media-source.html#mediasource-seeking
m_pendingSeekTime = time;
LOG(MediaSource, "MediaSource::seekToTime(%p, %f): %lu active source buffers", this, time.toDouble(), m_activeSourceBuffers->length());
// Run the following steps as part of the "Wait until the user agent has established whether or not the
// media data for the new playback position is available, and, if it is, until it has decoded enough data
// to play back that position" step of the seek algorithm:
// 1. The media element looks for media segments containing the new playback position in each SourceBuffer
// object in activeSourceBuffers.
for (auto& sourceBuffer : *m_activeSourceBuffers) {
// ↳ If one or more of the objects in activeSourceBuffers is missing media segments for the new
// playback position
if (!sourceBuffer->buffered()->ranges().contain(time)) {
// 1.1 Set the HTMLMediaElement.readyState attribute to HAVE_METADATA.
m_private->setReadyState(MediaPlayer::HaveMetadata);
// 1.2 The media element waits until an appendBuffer() or an appendStream() call causes the coded
// frame processing algorithm to set the HTMLMediaElement.readyState attribute to a value greater
// than HAVE_METADATA.
LOG(MediaSource, "MediaSource::seekToTime(%p) - waitForSeekCompleted()", this);
m_private->waitForSeekCompleted();
return;
} else
LOG(MediaSource, "MediaSource::seekToTime(%p) - seek time buffered already.", this);
// ↳ Otherwise
// Continue
}
completeSeek();
}
