/// <summary>Copy a number of frames into a temporary stream</summary>
/// <param name="start">First frame to copy</param>
/// <param name="length">Count of frames to copy</param>
/// <returns>Pointer to the unmanaged temporary stream</returns>
public IntPtr Copy(int start, int length)
{
IntPtr copyPointer = IntPtr.Zero;
int result = Avi.EditStreamCopy(this.editableStream, ref start, ref length, ref copyPointer);
if (result != 0)
{
throw new Exception("Exception in Copy: " + result.ToString());
}
return(copyPointer);
}