public List <MatroskaSubtitle> GetSubtitle(int trackNumber, LoadMatroskaCallback progressCallback)
{
_subtitleRip.Clear();
_subtitleRipTrackNumber = trackNumber;
ReadSegmentCluster(progressCallback);
return(_subtitleRip);
}
private void ReadSegmentCluster(LoadMatroskaCallback progressCallback)
{
// go to segment
_stream.Seek(_segmentElement.DataPosition, SeekOrigin.Begin);
while (_stream.Position < _segmentElement.EndPosition)
{
var beforeReadElementIdPosition = _stream.Position;
var id = (ElementId)ReadVariableLengthUInt(false);
if (id == ElementId.None && beforeReadElementIdPosition + 1000 < _stream.Length)
{
// Error mode: search for start of next cluster, will be very slow
const int maxErrors = 5_000_000;
var errors = 0;
var max = _stream.Length;
while (id != ElementId.Cluster && beforeReadElementIdPosition + 1000 < max)
{
errors++;
if (errors > maxErrors)
{
return; // we give up
}
beforeReadElementIdPosition++;
_stream.Seek(beforeReadElementIdPosition, SeekOrigin.Begin);
id = (ElementId)ReadVariableLengthUInt(false);
}
}
var size = (long)ReadVariableLengthUInt();
var element = new Element(id, _stream.Position, size);
if (element.Id == ElementId.Cluster)
{
ReadCluster(element);
}
else
{
_stream.Seek(element.DataSize, SeekOrigin.Current);
}
progressCallback?.Invoke(element.EndPosition, _stream.Length);
}
}
private void ReadSegmentCluster(LoadMatroskaCallback progressCallback)
{
// go to segment
_stream.Seek(_segmentElement.DataPosition, SeekOrigin.Begin);
Element element;
while (_stream.Position < _segmentElement.EndPosition && (element = ReadElement()) != null)
{
if (element.Id == ElementId.Cluster)
{
ReadCluster(element);
}
else
{
_stream.Seek(element.DataSize, SeekOrigin.Current);
}
progressCallback?.Invoke(element.EndPosition, _stream.Length);
}
}
public List<SubtitleSequence> GetMatroskaSubtitle(string fileName, int trackNumber, out bool isValid, LoadMatroskaCallback callback)
{
byte b;
bool done;
UInt32 matroskaId;
int sizeOfSize;
long dataSize;
long afterPosition;
bool endOfFile;
_subtitleRipTrackNumber = trackNumber;
_f = new FileStream(fileName, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
matroskaId = GetMatroskaId();
if (matroskaId != 0x1A45DFA3) // matroska file must start with ebml header
{
isValid = false;
}
else
{
isValid = true;
b = (byte)_f.ReadByte();
sizeOfSize = GetMatroskaVariableIntLength(b);
dataSize = GetMatroskaDataSize(sizeOfSize, b);
_f.Seek(dataSize, SeekOrigin.Current);
done = false;
endOfFile = false;
while (endOfFile == false && done == false)
{
matroskaId = GetMatroskaId();
if (matroskaId == 0)
{
done = true;
}
else
{
b = (byte)_f.ReadByte();
sizeOfSize = GetMatroskaVariableIntLength(b);
dataSize = GetMatroskaDataSize(sizeOfSize, b);
if (matroskaId == 0x1549A966) // segment info
{
afterPosition = _f.Position + dataSize;
AnalyzeMatroskaSegmentInformation(afterPosition);
_f.Seek(afterPosition, SeekOrigin.Begin);
}
else if (matroskaId == 0x1654AE6B) // tracks
{
afterPosition = _f.Position + dataSize;
AnalyzeMatroskaTracks();
_f.Seek(afterPosition, SeekOrigin.Begin);
}
else if (matroskaId == 0x1F43B675) // cluster
{
afterPosition = _f.Position + dataSize;
AnalyzeMatroskaCluster();
_f.Seek(afterPosition, SeekOrigin.Begin);
}
else if (matroskaId != 0x18538067) // segment
{
_f.Seek(dataSize, SeekOrigin.Current);
}
}
if (callback != null)
callback.Invoke(_f.Position, _f.Length);
endOfFile = _f.Position >= _f.Length;
}
}
_f.Close();
_f.Dispose();
_f = null;
return _subtitleRip;
}
private void ReadSegmentCluster(LoadMatroskaCallback progressCallback)
{
// go to segment
_stream.Seek(_segmentElement.DataPosition, SeekOrigin.Begin);
Element element;
while (_stream.Position < _segmentElement.EndPosition && (element = ReadElement()) != null)
{
if (element.Id == ElementId.Cluster)
{
ReadCluster(element);
}
else
{
_stream.Seek(element.DataSize, SeekOrigin.Current);
}
if (progressCallback != null)
{
progressCallback.Invoke(element.EndPosition, _stream.Length);
}
}
}
public List<MatroskaSubtitle> GetSubtitle(int trackNumber, LoadMatroskaCallback progressCallback)
{
_subtitleRipTrackNumber = trackNumber;
ReadSegmentCluster(progressCallback);
return _subtitleRip;
}
