/// <summary>
/// Loads the children of the current instance from a
/// specified file using the internal data position and size.
/// </summary>
/// <param name="file">
/// The <see cref="TagLib.File" /> from which the current
/// instance was read and from which to read the children.
/// </param>
/// <returns>
/// A <see cref="T:System.Collections.Generic.IEnumerable`1" /> object enumerating the
/// boxes read from the file.
/// </returns>
/// <exception cref="ArgumentNullException">
/// <paramref name="file" /> is <see langref="null" />.
/// </exception>
protected IEnumerable <Box> LoadChildren(TagLib.File file)
{
if (file == null)
{
throw new ArgumentNullException("file");
}
List <Box> children = new List <Box> ();
long position = DataPosition;
long end = position + DataSize;
header.Box = this;
while (position < end)
{
Box child = BoxFactory.CreateBox(file,
position, header, handler,
children.Count);
children.Add(child);
position += child.Size;
}
header.Box = null;
return(children);
}
/// <summary>
/// Parses boxes for a specified range, looking for tags and
/// properties.
/// </summary>
/// <param name="start">
/// A <see cref="long" /> value specifying the seek position
/// at which to start reading.
/// </param>
/// <param name="end">
/// A <see cref="long" /> value specifying the seek position
/// at which to stop reading.
/// </param>
/// <param name="handler">
/// A <see cref="IsoHandlerBox" /> object that applied to the
/// range being searched.
/// </param>
private void ParseTagAndProperties(long start, long end,
IsoHandlerBox handler)
{
BoxHeader header;
for (long position = start; position < end;
position += header.TotalBoxSize)
{
header = new BoxHeader(file, position);
ByteVector type = header.BoxType;
if (type == BoxType.Moov ||
type == BoxType.Mdia ||
type == BoxType.Minf ||
type == BoxType.Stbl ||
type == BoxType.Trak)
{
ParseTagAndProperties(
header.HeaderSize + position,
header.TotalBoxSize + position,
handler);
}
else if (type == BoxType.Stsd)
{
stsd_boxes.Add(BoxFactory.CreateBox(
file, header, handler));
}
else if (type == BoxType.Hdlr)
{
handler = BoxFactory.CreateBox(file,
header, handler) as
IsoHandlerBox;
}
else if (mvhd_box == null &&
type == BoxType.Mvhd)
{
mvhd_box = BoxFactory.CreateBox(file,
header, handler) as
IsoMovieHeaderBox;
}
else if (udta_box == null &&
type == BoxType.Udta)
{
udta_box = BoxFactory.CreateBox(file,
header, handler) as
IsoUserDataBox;
}
else if (type == BoxType.Mdat)
{
mdat_start = position;
mdat_end = position + header.TotalBoxSize;
}
if (header.TotalBoxSize == 0)
{
break;
}
}
}
/// <summary>
/// Parses boxes for a specified range, looking for chunk
/// offset boxes.
/// </summary>
/// <param name="start">
/// A <see cref="long" /> value specifying the seek position
/// at which to start reading.
/// </param>
/// <param name="end">
/// A <see cref="long" /> value specifying the seek position
/// at which to stop reading.
/// </param>
private void ParseChunkOffsets(long start, long end)
{
BoxHeader header;
for (long position = start; position < end;
position += header.TotalBoxSize)
{
header = new BoxHeader(file, position);
if (header.BoxType == BoxType.Moov)
{
ParseChunkOffsets(
header.HeaderSize + position,
header.TotalBoxSize + position);
}
else if (header.BoxType == BoxType.Moov ||
header.BoxType == BoxType.Mdia ||
header.BoxType == BoxType.Minf ||
header.BoxType == BoxType.Stbl ||
header.BoxType == BoxType.Trak)
{
ParseChunkOffsets(
header.HeaderSize + position,
header.TotalBoxSize + position);
}
else if (header.BoxType == BoxType.Stco ||
header.BoxType == BoxType.Co64)
{
stco_boxes.Add(BoxFactory.CreateBox(
file, header));
}
else if (header.BoxType == BoxType.Mdat)
{
mdat_start = position;
mdat_end = position + header.TotalBoxSize;
}
if (header.TotalBoxSize == 0)
{
break;
}
}
}
/// <summary>
/// Parses boxes for a specified range, looking for tags.
/// </summary>
/// <param name="start">
/// A <see cref="long" /> value specifying the seek position
/// at which to start reading.
/// </param>
/// <param name="end">
/// A <see cref="long" /> value specifying the seek position
/// at which to stop reading.
/// </param>
private void ParseTag(long start, long end)
{
BoxHeader header;
for (long position = start; position < end;
position += header.TotalBoxSize)
{
header = new BoxHeader(file, position);
if (header.BoxType == BoxType.Moov ||
header.BoxType == BoxType.Mdia ||
header.BoxType == BoxType.Minf ||
header.BoxType == BoxType.Stbl ||
header.BoxType == BoxType.Trak)
{
ParseTag(header.HeaderSize + position,
header.TotalBoxSize + position);
}
else if (udta_box == null &&
header.BoxType == BoxType.Udta)
{
udta_box = BoxFactory.CreateBox(file,
header) as IsoUserDataBox;
}
else if (header.BoxType == BoxType.Mdat)
{
mdat_start = position;
mdat_end = position + header.TotalBoxSize;
}
if (header.TotalBoxSize == 0)
{
break;
}
}
}