public EBMLElement(Matroska.File _file, ulong position)
{
if (_file == null)
{
throw new ArgumentNullException("file");
}
if (position > (ulong)(_file.Length - 4))
{
throw new ArgumentOutOfRangeException("position");
}
file = _file;
file.Seek((long)position);
ByteVector vector = file.ReadBlock(1);
Byte header_byte = vector[0];
Byte mask = 0x80, id_length = 1;
while (id_length <= 4 && (header_byte & mask) == 0)
{
id_length++;
mask >>= 1;
}
if (id_length > 4)
{
throw new CorruptFileException("invalid EBML id size");
}
if (id_length > 1)
{
vector.Add(file.ReadBlock(id_length - 1));
}
ebml_id = vector.ToUInt();
vector.Clear();
vector = file.ReadBlock(1);
header_byte = vector[0];
mask = 0x80;
Byte size_length = 1;
while (size_length <= 8 && (header_byte & mask) == 0)
{
size_length++;
mask >>= 1;
}
if (size_length > 8)
{
throw new CorruptFileException("invalid EBML element size");
}
vector[0] &= (Byte)(mask - 1);
if (size_length > 1)
{
vector.Add(file.ReadBlock(size_length - 1));
}
ebml_size = vector.ToULong();
offset = position;
data_offset = offset + id_length + size_length;
}
/// <summary>
/// Write the EMBL (and all its data/content) to a file.
/// </summary>
/// <param name="file">A <see cref="File"/> representing the file to write to.</param>
/// <param name="position">The byte-position in the file to write the EBML to.</param>
/// <param name="reserved">The reserved size in bytes that the EBML may overwrite from the given position. (Default: 0, insert)</param>
public void Write(Matroska.File file, long position, long reserved = 0)
{
if (file == null)
{
throw new ArgumentNullException("file");
}
if (position > file.Length || position < 0)
{
throw new ArgumentOutOfRangeException("position");
}
if (Data != null && Children != null)
{
throw new UnsupportedFormatException("EBML element cannot contain both Data and Children");
}
// Reserve required size upfront to speed up writing
var size = Size;
if (size > reserved)
{
// Extend reserved size
file.Insert(size - reserved, position + reserved);
reserved = size;
}
// Write the Header
var header = Header;
file.Insert(header, position, header.Count);
position += header.Count;
reserved -= header.Count;
// Write the data/content
if (Data != null)
{
file.Insert(Data, position, Data.Count);
}
else if (Children != null)
{
foreach (var child in Children)
{
child.Write(file, position, reserved);
var csize = child.Size;
position += csize;
reserved -= csize;
}
}
}
/// <summary>
/// Remove the EBML element from the file
/// </summary>
/// <returns>Size difference compare to previous EBML size</returns>
public long Remove()
{
long ret = -(long)Size;
file.RemoveBlock((long)Offset, (long)Size);
// Invalidate this object
ebml_id = 0;
data_offset = offset;
ebml_size = 0;
file = null;
return(ret);
}
/// <summary>
/// Constructs a root <see cref="EBMLreader" /> instance, by reading from
/// the provided file position.
/// </summary>
/// <param name="_file"><see cref="File" /> File instance to read from.</param>
/// <param name="position">Position in the file to start reading from.</param>
public EBMLreader(Matroska.File _file, ulong position)
{
// Keep a reference to the file
file = _file;
parent = null;
// Initialize attributes
offset = position;
data_offset = position;
ebml_id = 0;
ebml_size = 0;
// Actually read the EBML on the file
Read(true);
}
/// <summary>
/// Create a new abstract <see cref="EBMLreader" /> with arbitrary attributes,
/// without reading its information on the file.
/// </summary>
/// <param name="parent">The <see cref="EBMLreader" /> that contains the instance to be described.</param>
/// <param name="position">Position in the file.</param>
/// <param name="ebmlid">EBML ID of the element</param>
/// <param name="size">Total size of the EBML, in bytes</param>
public EBMLreader(EBMLreader parent, ulong position, MatroskaID ebmlid, ulong size = 0)
{
// Keep a reference to the file
if (parent != null)
{
file = parent.file;
}
this.parent = parent;
// Initialize attributes
offset = position;
data_offset = offset;
ebml_id = (uint)ebmlid;
ebml_size = size;
}
/// <summary>
/// Constructs a child <see cref="EBMLreader" /> reading the data from the
/// EBML parent at the provided file position.
/// </summary>
/// <param name="parent">The <see cref="EBMLreader" /> that contains the instance to be created.</param>
/// <param name="position">Position in the file to start reading from.</param>
public EBMLreader(EBMLreader parent, ulong position)
{
if (parent == null)
{
throw new ArgumentNullException("file");
}
// Keep a reference to the file
file = parent.file;
this.parent = parent;
// Initialize attributes
offset = position;
data_offset = position;
ebml_id = 0;
ebml_size = 0;
// Actually read the EBML on the file
Read(true);
}
/// <summary>
/// Constructs a <see cref="EBMLElement" /> parsing from provided
/// file data.
/// </summary>
/// <param name="_file"><see cref="File" /> instance to read from.</param>
/// <param name="position">Position to start reading from.</param>
public EBMLElement(Matroska.File _file, ulong position)
{
if (_file == null)
{
throw new ArgumentNullException("file");
}
if (position > (ulong)(_file.Length - 4))
{
throw new ArgumentOutOfRangeException("position");
}
// Keep a reference to the file
file = _file;
file.Seek((long)position);
// Get the header byte
ByteVector vector = file.ReadBlock(1);
Byte header_byte = vector [0];
// Define a mask
Byte mask = 0x80, id_length = 1;
// Figure out the size in bytes
while (id_length <= 4 && (header_byte & mask) == 0)
{
id_length++;
mask >>= 1;
}
if (id_length > 4)
{
throw new CorruptFileException("invalid EBML id size");
}
// Now read the rest of the EBML ID
if (id_length > 1)
{
vector.Add(file.ReadBlock(id_length - 1));
}
ebml_id = vector.ToUInt();
vector.Clear();
// Get the size length
vector = file.ReadBlock(1);
header_byte = vector [0];
mask = 0x80;
Byte size_length = 1;
// Iterate through various possibilities
while (size_length <= 8 && (header_byte & mask) == 0)
{
size_length++;
mask >>= 1;
}
if (size_length > 8)
{
throw new CorruptFileException("invalid EBML element size");
}
// Clear the marker bit
vector [0] &= (Byte)(mask - 1);
// Now read the rest of the EBML element size
if (size_length > 1)
{
vector.Add(file.ReadBlock(size_length - 1));
}
ebml_size = vector.ToULong();
offset = position;
data_offset = offset + id_length + size_length;
}
/// <summary>
/// Constructs a <see cref="EBMLElement" /> parsing from provided
/// file data.
/// </summary>
/// <param name="_file"><see cref="File" /> instance to read from.</param>
/// <param name="position">Position to start reading from.</param>
public EBMLElement (Matroska.File _file, ulong position)
{
if (_file == null)
throw new ArgumentNullException ("file");
if (position > (ulong) (_file.Length - 4))
throw new ArgumentOutOfRangeException ("position");
// Keep a reference to the file
file = _file;
file.Seek ((long) position);
// Get the header byte
ByteVector vector = file.ReadBlock (1);
Byte header_byte = vector [0];
// Define a mask
Byte mask = 0x80, id_length = 1;
// Figure out the size in bytes
while (id_length <= 4 && (header_byte & mask) == 0) {
id_length++;
mask >>= 1;
}
if (id_length > 4) {
throw new CorruptFileException ("invalid EBML id size");
}
// Now read the rest of the EBML ID
if (id_length > 1) {
vector.Add (file.ReadBlock (id_length -1));
}
ebml_id = vector.ToUInt ();
vector.Clear ();
// Get the size length
vector = file.ReadBlock (1);
header_byte = vector [0];
mask = 0x80;
Byte size_length = 1;
// Iterate through various possibilities
while (size_length <= 8 && (header_byte & mask) == 0) {
size_length++;
mask >>= 1;
}
if (size_length > 8) {
throw new CorruptFileException ("invalid EBML element size");
}
// Clear the marker bit
vector [0] &= (Byte) (mask - 1);
// Now read the rest of the EBML element size
if (size_length > 1) {
vector.Add (file.ReadBlock (size_length - 1));
}
ebml_size = vector.ToULong ();
offset = position;
data_offset = offset + id_length + size_length;
}
