int track_PrepareMediaHeaders(int sliceIndex)
{
StreamDataBlockInfo lastData = null;
if (sliceIndex == 0)
{
// hypothesize a BlockSize (we don't know it at this point)
BlockSize = 8;
return(0);
}
else if (CurrentSliceList.Count >= BlockSize)
{
if (BlockSize == 8)
{
CalculateBlockSizeFromInitialSlices();
if (BlockSize > 8) // if less than or equal to 8, process it
{
return(0);
}
}
int i = CurrentSliceList.Count - 1;
if (CurrentSliceList[i].SliceType == SliceType.IFrame)
{
lastData = CurrentSliceList[i];
CurrentSliceList.RemoveAt(i);
}
else if (CurrentSliceList[i].SliceType == SliceType.DFrame)
{
return(0); // extend current block until next IFrame is found
}
}
else
{
return(0); // don't set lists (see below) for any other values of sliceIndex
}
ulong localCurrMDatOffset = track.ParentStream.CurrMDatOffset;
track.TrackFormat.PrepareSampleWriting(CurrentSliceList, ref localCurrMDatOffset);
track.ParentStream.CurrMDatOffset = localCurrMDatOffset;
track.ParentStream.WriteSamples(CurrentSliceList.Cast <Slice>(), track.Codec.CodecType); // second param is ineffective (unnecessary)
// when writing to destination file, we only need and use one cache buffer
cache[readCache].SampleStreamLocations = new List <StreamDataBlockInfo>();
// last IFrame should be part of next block
if (lastData != null)
{
CurrentSliceList.Add(lastData);
return(sliceIndex);
}
return(sliceIndex + 1); // we only get here if sliceIndex == 0 or slice is not video
}
/// <summary>
/// UpdateRelevancyScores (with ulong time parameter)
/// When this method is called, we have already found the requested slice, and
/// readCache is now set to the correct buf.
/// </summary>
/// <param name="sliceTime"></param>
void UpdateRelevancyScores(ulong sliceTime)
{
if (sliceTime == 0UL)
{
UpdateRelevancyScores(0);
return;
}
// first, look for the slice in order to get its index
StreamDataBlockInfo sliceInfo = CurrentSliceList[0]; // get any slice
uint halfOfDuration = (uint)(sliceInfo.SliceDuration / 2); // shift to the right by one
sliceInfo = CurrentSliceList.First(
s => s.TimeStampNew.HasValue && ((s.TimeStampNew.Value > sliceTime - halfOfDuration) && (s.TimeStampNew.Value < sliceTime + halfOfDuration)));
UpdateRelevancyScores(sliceInfo.index);
}
