public override void Flush()
{
if (UnderlyingIO == null)
{
throw new InvalidOperationException(
@"UnderlyingI stream missing. Tilepart headers should be
written after codestream headers");
}
if (!IsOpened)
{
throw new InvalidOperationException(String.Concat(
"Trying to flush to IO stream ",
"a closed tile-part"));
}
if (_offset == OFFSET_NOT_SET)
{
_offset = (Parent as JP2Codestream).AssignOffset(this);
}
// SOT marker includes the full tile-part length we should write the
// SOT marker after all the packets have been added, and we know in
// advance what is the full tile-part length (markers and packets).
UnderlyingIO.Seek(Position, SeekOrigin.Begin);
_sot.WriteMarkerSegment(UnderlyingIO);
foreach (var plt in _pltMarkers)
{
plt.WriteMarkerSegment(UnderlyingIO);
}
MarkerSegment.WriteMarker(MarkerType.SOD, UnderlyingIO);
// can be safely closed and reopened from the underlying stream.
IsFlushed = true;
}
internal override CodestreamNode Open()
{
if (IsOpened)
{
return(this);
}
UnderlyingIO.Seek(Position, SeekOrigin.Begin);
MarkerType marker = MarkerSegment.Peek(UnderlyingIO);
if (marker != MarkerType.SOT)
{
throw new ArgumentException(
"SOT marker expected but was not found");
}
List <PltMarker> pltMarkers = new List <PltMarker>();
int zIdx = -1; // current z-idx of plt markers
bool isZOrderConsistent = true; // true iff every consequent plt
// maintains ascending order from zero, without gaps.
long offset = 0;
while (MarkerSegment.Peek(UnderlyingIO) != MarkerType.SOD)
{
MarkerSegment ms = MarkerSegment.Open(UnderlyingIO);
switch (ms.Type)
{
case MarkerType.SOT:
_sot = ms as SotMarker;
break;
case MarkerType.PLT:
var plt = ms as PltMarker;
isZOrderConsistent &= (++zIdx) == plt.ZIndex;
pltMarkers.Add(plt);
break;
case MarkerType.COD:
case MarkerType.COC:
case MarkerType.QCD:
case MarkerType.QCC:
throw new NotSupportedException(
"Codestream and quantization markers are " +
" not supported in tile part header");
default:
break;
}
offset += MarkerSegment.MarkerLength + ms.Length;
}
_sodOffset = offset;
if (!isZOrderConsistent)
{
// needs sorting!
pltMarkers.Sort((PltMarker pltX, PltMarker pltY) =>
pltX.ZIndex.CompareTo(pltY.ZIndex));
}
if (!pltMarkers.Any() && Length > EMPTY_TILEPART_LENGTH)
{
throw new NotSupportedException(
"packet lengths are not specified in a non empty tile-part"
+ " decoding packet headers is not supported yet");
}
_pltMarkers = pltMarkers;
// flatten
uint packOffset = 0;
foreach (var plt in pltMarkers)
{
foreach (var packLength in plt)
{
packOffset += packLength;
_packetOffsets.Add(packOffset);
}
}
// read and parsed successfully.
IsOpened = true;
return(this);
}