/**
* Returns true if aValue is inside a range of aRanges, and put the range
* index in aIntervalIndex if it is not null.
* If aValue is not inside a range, false is returned, and aIntervalIndex, if
* not null, is set to the index of the range which ends immediately before aValue
* (and can be -1 if aValue is before aRanges.Start(0)).
*/
static bool
IsInRanges(TimeRanges& aRanges, double aValue, int32_t& aIntervalIndex)
{
uint32_t length;
aRanges.GetLength(&length);
for (uint32_t i = 0; i < length; i++) {
double start, end;
aRanges.Start(i, &start);
if (start > aValue) {
aIntervalIndex = i - 1;
return false;
}
aRanges.End(i, &end);
if (aValue <= end) {
aIntervalIndex = i;
return true;
}
}
aIntervalIndex = length - 1;
return false;
}
nsresult MediaDecoder::Seek(double aTime)
{
MOZ_ASSERT(NS_IsMainThread());
ReentrantMonitorAutoEnter mon(GetReentrantMonitor());
NS_ABORT_IF_FALSE(aTime >= 0.0, "Cannot seek to a negative value.");
TimeRanges seekable;
nsresult res;
uint32_t length = 0;
res = GetSeekable(&seekable);
NS_ENSURE_SUCCESS(res, NS_OK);
seekable.GetLength(&length);
if (!length) {
return NS_OK;
}
// If the position we want to seek to is not in a seekable range, we seek
// to the closest position in the seekable ranges instead. If two positions
// are equally close, we seek to the closest position from the currentTime.
// See seeking spec, point 7 :
// http://www.whatwg.org/specs/web-apps/current-work/multipage/the-video-element.html#seeking
int32_t range = 0;
if (!IsInRanges(seekable, aTime, range)) {
if (range != -1) {
// |range + 1| can't be negative, because the only possible negative value
// for |range| is -1.
if (uint32_t(range + 1) < length) {
double leftBound, rightBound;
res = seekable.End(range, &leftBound);
NS_ENSURE_SUCCESS(res, NS_OK);
res = seekable.Start(range + 1, &rightBound);
NS_ENSURE_SUCCESS(res, NS_OK);
double distanceLeft = Abs(leftBound - aTime);
double distanceRight = Abs(rightBound - aTime);
if (distanceLeft == distanceRight) {
distanceLeft = Abs(leftBound - mCurrentTime);
distanceRight = Abs(rightBound - mCurrentTime);
}
aTime = (distanceLeft < distanceRight) ? leftBound : rightBound;
} else {
// Seek target is after the end last range in seekable data.
// Clamp the seek target to the end of the last seekable range.
res = seekable.End(length - 1, &aTime);
NS_ENSURE_SUCCESS(res, NS_OK);
}
} else {
// aTime is before the first range in |seekable|, the closest point we can
// seek to is the start of the first range.
seekable.Start(0, &aTime);
}
}
mRequestedSeekTime = aTime;
mCurrentTime = aTime;
// If we are already in the seeking state, then setting mRequestedSeekTime
// above will result in the new seek occurring when the current seek
// completes.
if (mPlayState != PLAY_STATE_SEEKING) {
bool paused = false;
if (mOwner) {
paused = mOwner->GetPaused();
}
mNextState = paused ? PLAY_STATE_PAUSED : PLAY_STATE_PLAYING;
PinForSeek();
ChangeState(PLAY_STATE_SEEKING);
}
return ScheduleStateMachineThread();
}