/// <summary>
/// return the fragment information for the first fragment in the FRT whose fragment number
/// is greater than or equal to fragment id. special cases:
///
/// if fragmentId is in a gap, the first fragment after the gap will be returned.
/// if fragmentId is in a skip, the first fragment after the skip will be returned.
/// if fragmentId is before the first fragment-duration-pair, the first fragment will be returned.
/// if fragmentId is after the last fragment-duration-pair, it will be assumed to exist.
/// (in other words, the live point is ignored).
///
/// if there are no valid entries in the FRT, returns null. this is the only situation that returns null.
/// </summary>
public FragmentAccessInformation getFragmentWithIdGreq(uint fragmentId)
{
FragmentDurationPair desiredFdp = null;
uint desiredFragmentId = 0;
forEachInterval(delegate(FragmentDurationPair fdp, bool isLast, uint startFragmentId, uint endFragmentId, uint startTime, uint endTime) {
if (fragmentId < startFragmentId)
{
// before the given interval
desiredFdp = fdp;
desiredFragmentId = startFragmentId;
return(false); // stop iterating
}
else if (isLast)
{
// catch all in the last entry
desiredFdp = fdp;
desiredFragmentId = fragmentId;
return(false);
}
else if (fragmentId < endFragmentId)
{
// between the start and end of this interval
desiredFdp = fdp;
desiredFragmentId = fragmentId;
return(false); // stop iterating
}
else
{
// beyond this interval, but not the last entry
return(true); // keep iterating
}
});
if (desiredFdp == null)
{
// no fragment entries case
return(null);
}
if (desiredFragmentId < desiredFdp.firstFragment)
{
// probably won't ever hit this
// just make sure that we're before the start
desiredFragmentId = desiredFdp.firstFragment;
}
FragmentAccessInformation fai = new FragmentAccessInformation();
fai.fragId = desiredFragmentId;
fai.fragDuration = desiredFdp.duration;
fai.fragmentEndTime = (uint)desiredFdp.durationAccrued + (desiredFragmentId - desiredFdp.firstFragment + 1) * desiredFdp.duration;
return(fai);
}
/// <summary>
/// return the fragment information for the first fragment in the FRT that contains a time
/// greater than or equal to fragment time. special cases:
///
/// if time is in a gap, the first fragment after the gap will be returned.
/// if time is in a skip, the first fragment after the skip will be returned.
/// if time is before the first fragment-duration-pair, the first fragment will be returned.
/// if time is after the last fragment-duration-pair, it will be assumed to exist.
/// (in other words, the live point is ignored).
///
/// if there are no valid entries in the FRT, returns null. this is the only situation that returns null.
/// </summary>
public FragmentAccessInformation getFragmentWithTimeGreq(uint fragmentTime)
{
FragmentDurationPair desiredFdp = null;
uint desiredFragmentStartTime = 0;
forEachInterval(delegate(FragmentDurationPair fdp, bool isLast, uint startFragmentId, uint endFragmentId, uint startTime, uint endTime) {
if (fragmentTime < startTime)
{
// before the given interval
desiredFdp = fdp;
desiredFragmentStartTime = startTime;
return(false); // stop iterating
}
else if (isLast)
{
// catch all in the last entry
desiredFdp = fdp;
desiredFragmentStartTime = fragmentTime;
return(false);
}
else if (fragmentTime < endTime)
{
// between the start and end of this interval
desiredFdp = fdp;
desiredFragmentStartTime = fragmentTime;
return(false); // stop iterating
}
else
{
// beyond this interval, but not the last entry
return(true); // keep iterating
}
});
if (desiredFdp == null)
{
// no fragment entries case
return(null);
}
uint desiredFragmentId = calculateFragmentId(desiredFdp, desiredFragmentStartTime);
FragmentAccessInformation fai = new FragmentAccessInformation();
fai.fragId = desiredFragmentId;
fai.fragDuration = desiredFdp.duration;
fai.fragmentEndTime = (uint)desiredFdp.durationAccrued + (desiredFragmentId - desiredFdp.firstFragment + 1) * desiredFdp.duration;
return(fai);
}
private FragmentAccessInformation getNextValidFragment(int startIdx)
{
FragmentAccessInformation fai = null;
for (int i = startIdx; i < fragmentDurationPairs.Count; i++)
{
FragmentDurationPair fdp = fragmentDurationPairs[i];
if (fdp.duration > 0)
{
fai = new FragmentAccessInformation();
fai.fragId = fdp.firstFragment;
fai.fragDuration = fdp.duration;
fai.fragmentEndTime = (uint)fdp.durationAccrued + fdp.duration;
break;
}
}
return(fai);
}
/// <summary>
/// Given a fragment id, check whether the current fragment is valid or a discontinuity.
/// If the latter, skip to the nearest fragment and return the new fragment id.
///
/// return the Id of the fragment that is valid.
/// </summary>
public FragmentAccessInformation validateFragment(uint fragId, ulong totalDuration, bool live = false)
{
int size = fragmentDurationPairs.Count - 1;
FragmentAccessInformation fai = null;
uint timeResidue, timeDistance, fragStartTime;
for (int i = 0; i < size; i++)
{
FragmentDurationPair curFdp = fragmentDurationPairs[i];
FragmentDurationPair nextFdp = fragmentDurationPairs[i + 1];
if ((curFdp.firstFragment <= fragId) && (fragId < nextFdp.firstFragment))
{
if (curFdp.duration <= 0)
{
fai = getNextValidFragment(i + 1);
}
else
{
fai = new FragmentAccessInformation();
fai.fragId = fragId;
fai.fragDuration = curFdp.duration;
fai.fragmentEndTime = (uint)curFdp.durationAccrued + curFdp.duration * (fragId - curFdp.firstFragment + 1);
}
break;
}
else if ((curFdp.firstFragment <= fragId) && endOfStreamEntry(nextFdp))
{
if (curFdp.duration > 0)
{
timeResidue = (uint)(totalDuration - curFdp.durationAccrued);
timeDistance = (fragId - curFdp.firstFragment + 1) * curFdp.duration;
fragStartTime = (fragId - curFdp.firstFragment) * curFdp.duration;
if (timeResidue > fragStartTime)
{
if (!live || ((fragStartTime + curFdp.duration + curFdp.durationAccrued) <= totalDuration))
{
fai = new FragmentAccessInformation();
fai.fragId = fragId;
fai.fragDuration = curFdp.duration;
if (timeResidue >= timeDistance)
{
fai.fragmentEndTime = (uint)curFdp.durationAccrued + timeDistance;
}
else
{
fai.fragmentEndTime = (uint)curFdp.durationAccrued + timeResidue;
}
break;
}
}
}
}
}
if (fai == null)
{
FragmentDurationPair lastFdp = fragmentDurationPairs[size];
if (lastFdp.duration > 0 && fragId >= lastFdp.firstFragment)
{
timeResidue = (uint)(totalDuration - lastFdp.durationAccrued);
timeDistance = (fragId - lastFdp.firstFragment + 1) * lastFdp.duration;
fragStartTime = (fragId - lastFdp.firstFragment) * lastFdp.duration;
if (timeResidue > fragStartTime)
{
if (!live || ((fragStartTime + lastFdp.duration + lastFdp.durationAccrued) <= totalDuration))
{
fai = new FragmentAccessInformation();
fai.fragId = fragId;
fai.fragDuration = lastFdp.duration;
if (timeResidue >= timeDistance)
{
fai.fragmentEndTime = (uint)lastFdp.durationAccrued + timeDistance;
}
else
{
fai.fragmentEndTime = (uint)lastFdp.durationAccrued + timeResidue;
}
}
}
}
}
return(fai);
}
