public static Box FromStream(Stream stream, BaseMediaOptions options = BaseMediaOptions.LoadChildren)
{
Box box = null;
try
{
ulong offset = (ulong)stream.Position;
uint size = stream.ReadBEUInt32();
uint type = stream.ReadBEUInt32();
ulong?largeSize = null;
if (size == 1)
{
largeSize = stream.ReadBEUInt64();
}
BoxType boxType = (type == uuidType)
? new BoxType(new Guid(stream.ReadBytes(16)))
: new BoxType(type);
AvailableBoxTypes.TryGetValue(boxType, out Type t);
box = t != null ? (Box)Activator.CreateInstance(t) : new Boxes.UnknownBox(boxType);
box.Size = size;
box.LargeSize = largeSize;
box.Offset = offset;
box.Initialize(ConstrainedStream.WrapStream(stream), options);
}
catch (EndOfStreamException) { }
return(box);
}
public Stream GetContentStream()
{
Stream source = ConstrainedStream.UnwrapStream(_SourceStream);
if (!source.CanSeek)
{
throw new FileNotFoundException("Invalid Source Stream in Box.GetContentStream()");
}
source.Seek((long)ContentOffset, SeekOrigin.Begin);
ConstrainedStream contentStream = ConstrainedStream.WrapStream(source);
contentStream.PushConstraint((long)ContentOffset, (long)ContentSize);
return(contentStream);
}
internal void Initialize(Stream stream, BaseMediaOptions options = BaseMediaOptions.LoadChildren)
{
Trace.WriteLine(Type, "Loading");
_SourceStream = stream;
ConstrainedStream constrainedStream = ConstrainedStream.WrapStream(stream);
constrainedStream.PushConstraint((long)Offset.Value, (long)EffectiveSize);
LoadFromStream(stream);
ContentOffset = (ulong)stream.Position;
if (((options & BaseMediaOptions.LoadChildren) == BaseMediaOptions.LoadChildren) && this is ISuperBox)
{
LoadChildrenFromStream(stream);
}
Sync(stream, !(this is IContentBox));
constrainedStream.PopConstraint();
}
public void ToStream(Stream stream)
{
Trace.WriteLine(Type, "Saving");
ConstrainedStream constrainedStream = ConstrainedStream.WrapStream(stream);
long offset = constrainedStream.Position;
ulong calculatedLength = CalculateSize() + (ulong)(Size == 1 ? 0 : 8);
uint size = 1;
ulong largeSize = 0;
if (calculatedLength > uint.MaxValue)
{
largeSize = (ulong)calculatedLength;
}
else
{
size = (uint)calculatedLength - 8;
}
constrainedStream.PushConstraint(size);
constrainedStream.WriteBEUInt32(size);
constrainedStream.WriteBEUInt32(Type.FourCC);
if (Size == 1)
{
constrainedStream.WriteBEUInt64(largeSize);
}
if (Type.FourCC == uuidType)
{
constrainedStream.WriteBytes(Type.UserType.ToByteArray());
}
SaveToStream(constrainedStream);
if (this is ISuperBox)
{
SaveChildrenToStream(constrainedStream);
}
// TODO: Handle IContentBox properly
if (this is IContentBox && this.HasContent)
{
// TODO: Support unseekable streams for the case of Size=0
if (_sourceStream != null && _sourceStream.CanSeek)
{
ConstrainedStream source = new ConstrainedStream(_sourceStream);
source.PushConstraint((long)this.ContentOffset.Value, (long)this.ContentSize.Value);
source.Seek((long)this.ContentOffset.Value, SeekOrigin.Begin);
ulong remaining = this.ContentSize.Value;
byte[] buffer = ArrayPool <byte> .Shared.Rent(4096);
int len = 0;
do
{
len = source.Read(buffer, 0, (ulong)buffer.Length < remaining ? buffer.Length : (int)remaining);
remaining -= (ulong)len;
constrainedStream.Write(buffer, 0, len);
}while (len == buffer.Length);
ArrayPool <byte> .Shared.Return(buffer);
}
}
long remainder = offset + (size == 1 ? (long)largeSize : size) - constrainedStream.Position;
if (remainder > 0)
{
Trace.WriteLine("Undershot by " + remainder + " bytes. Padding with 0s.", "WARNING");
for (long i = 0; i < remainder; i++)
{
constrainedStream.WriteByte(0);
}
}
constrainedStream.PopConstraint();
}
