Aaru/DVD/Spare.cs

// /***************************************************************************
// The Disc Image Chef
// ----------------------------------------------------------------------------
//
// Filename       : Spare.cs
// Author(s)      : Natalia Portillo <claunia@claunia.com>
//
// Component      : Device structures decoders.
//
// --[ Description ] ----------------------------------------------------------
//
//     Decodes DVD spare area information.
//
// --[ License ] --------------------------------------------------------------
//
//     This library is free software; you can redistribute it and/or modify
//     it under the terms of the GNU Lesser General Public License as
//     published by the Free Software Foundation; either version 2.1 of the
//     License, or (at your option) any later version.
//
//     This library is distributed in the hope that it will be useful, but
//     WITHOUT ANY WARRANTY; without even the implied warranty of
//     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
//     Lesser General Public License for more details.
//
//     You should have received a copy of the GNU Lesser General Public
//     License along with this library; if not, see <http://www.gnu.org/licenses/>.
//
// ----------------------------------------------------------------------------
// Copyright © 2011-2018 Natalia Portillo
// ****************************************************************************/

using System.Text;

namespace DiscImageChef.Decoders.DVD
{
    /// <summary>
    /// Information from the following standards:
    /// ANSI X3.304-1997
    /// T10/1048-D revision 9.0
    /// T10/1048-D revision 10a
    /// T10/1228-D revision 7.0c
    /// T10/1228-D revision 11a
    /// T10/1363-D revision 10g
    /// T10/1545-D revision 1d
    /// T10/1545-D revision 5
    /// T10/1545-D revision 5a
    /// T10/1675-D revision 2c
    /// T10/1675-D revision 4
    /// T10/1836-D revision 2g
    /// </summary>
    public static class Spare
    {
        public struct SpareAreaInformation
        {
            /// <summary>
            /// Bytes 0 to 1
            /// Data length
            /// </summary>
            public ushort DataLength;
            /// <summary>
            /// Byte 2
            /// Reserved
            /// </summary>
            public byte Reserved1;
            /// <summary>
            /// Byte 3
            /// Reserved
            /// </summary>
            public byte Reserved2;
            /// <summary>
            /// Bytes 4 to 7
            /// Data length
            /// </summary>
            public uint UnusedPrimaryBlocks;
            /// <summary>
            /// Bytes 8 to 11
            /// Data length
            /// </summary>
            public uint UnusedSupplementaryBlocks;
            /// <summary>
            /// Bytes 12 to 15
            /// Data length
            /// </summary>
            public uint AllocatedSupplementaryBlocks;
        }

        public static SpareAreaInformation? Decode(byte[] response)
        {
            if(response == null)
                return null;

            if(response.Length != 16)
                return null;

            SpareAreaInformation sai = new SpareAreaInformation();

            sai.DataLength = (ushort)((response[0] << 8) + response[1]);
            sai.Reserved1 = response[2];
            sai.Reserved2 = response[3];
            sai.UnusedPrimaryBlocks = (uint)((response[4] << 24) + (response[5] << 16) + (response[6] << 8) + response[7]);
            sai.UnusedSupplementaryBlocks = (uint)((response[8] << 24) + (response[9] << 16) + (response[10] << 8) + response[11]);
            sai.AllocatedSupplementaryBlocks = (uint)((response[12] << 24) + (response[13] << 16) + (response[14] << 8) + response[15]);

            return sai;
        }

        public static string Prettify(SpareAreaInformation? sai)
        {
            if(sai == null)
                return null;

            SpareAreaInformation decoded = sai.Value;
            StringBuilder sb = new StringBuilder();

            sb.AppendFormat("{0} unused primary spare blocks", decoded.UnusedPrimaryBlocks).AppendLine();
            sb.AppendFormat("{0} unused supplementary spare blocks", decoded.UnusedSupplementaryBlocks).AppendLine();
            sb.AppendFormat("{0} allocated supplementary spare blocks", decoded.AllocatedSupplementaryBlocks).AppendLine();

            return sb.ToString();
        }

        public static string Prettify(byte[] response)
        {
            return Prettify(Decode(response));
        }
    }
}