/// <summary>
/// Renders the current instance, including its children, to
/// a new <see cref="ByteVector" /> object, preceeding the
/// contents with a specified block of data.
/// </summary>
/// <param name="topData">
/// A <see cref="ByteVector" /> object containing box
/// specific header data to preceed the content.
/// </param>
/// <returns>
/// A <see cref="ByteVector" /> object containing the
/// rendered version of the current instance.
/// </returns>
protected virtual ByteVector Render(ByteVector topData)
{
var free_found = false;
var output = new ByteVector();
if (Children != null)
{
foreach (var box in Children)
{
if (box.GetType() == typeof(
IsoFreeSpaceBox))
{
free_found = true;
}
else
{
output.Add(box.Render());
}
}
}
else if (Data != null)
{
output.Add(Data);
}
// If there was a free, don't take it away, and let meta
// be a special case.
if (free_found || BoxType == Mpeg4.BoxType.Meta)
{
long size_difference = DataSize - output.Count;
// If we have room for free space, add it so we
// don't have to resize the file.
if (header.DataSize != 0 && size_difference >= 8)
{
output.Add(new IsoFreeSpaceBox(
size_difference).Render());
}
// If we're getting bigger, get a lot bigger so
// we might not have to again.
else
{
output.Add(new IsoFreeSpaceBox(2048
).Render());
}
}
// Adjust the header's data size to match the content.
header.DataSize = topData.Count + output.Count;
// Render the full box.
output.Insert(0, topData);
output.Insert(0, header.Render());
return(output);
}
