mirror of
https://github.com/aaru-dps/Aaru.git
synced 2025-12-16 19:24:25 +00:00
114 lines
4.8 KiB
C#
114 lines
4.8 KiB
C#
// /***************************************************************************
|
|
// Aaru Data Preservation Suite
|
|
// ----------------------------------------------------------------------------
|
|
//
|
|
// Filename : HDCopy.cs
|
|
// Author(s) : Michael Drüing <michael@drueing.de>
|
|
//
|
|
// Component : Disk image plugins.
|
|
//
|
|
// --[ Description ] ----------------------------------------------------------
|
|
//
|
|
// Manages floppy disk images created with HD-Copy
|
|
//
|
|
// --[ 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 © 2017-2025 Michael Drüing
|
|
// Copyright © 2011-2025 Natalia Portillo
|
|
// ****************************************************************************/
|
|
|
|
/* Some information on the file format from Michal Necasek (www.os2museum.com):
|
|
*
|
|
* The HD-Copy diskette image format was used by the eponymous DOS utility,
|
|
* written by Oliver Fromme around 1995. The HD-Copy format is relatively
|
|
* straightforward, supporting images with 512-byte sector size and uniform
|
|
* sectors per track count. A basic form of run-length compression is also
|
|
* supported, and empty/unused tracks aren't stored in the image. Images
|
|
* with up to 82 cylinders are supported.
|
|
*
|
|
* No provision appears to be made for single-sided images. The disk image
|
|
* is stored as a sequence of compressed tracks (where a track refers to only
|
|
* one side of the disk), and individual tracks may be left out.
|
|
*
|
|
* The HD-Copy RLE compression works as follows. The image is divided into a
|
|
* number of independent blocks, one per track. Each compressed block starts
|
|
* with a header which contains the size of compressed data (16-bit little
|
|
* endian) and the escape byte. Whenever the escape byte is encountered in the
|
|
* byte stream, it is followed by a data byte and a count byte.
|
|
*
|
|
* Note that HD-Copy uses RLE compression for sequences of as few as three
|
|
* bytes, even though that provides no benefit.
|
|
*
|
|
* It would be tempting to perform in-place decompression to save memory.
|
|
* Unfortunately the simplistic RLE algorithm means the encoded data may be
|
|
* larger than the decoded version, with unknown worst case behavior. Hence
|
|
* the compressed data for a sector may not fit into a buffer the size of the
|
|
* uncompressed sector.
|
|
*
|
|
* There is no signature, hence heuristics must be used to identify a HD-Copy
|
|
* diskette image. Fortunately, the HD-Copy header is highly recognizable.
|
|
*/
|
|
|
|
// ReSharper disable NotAccessedField.Local
|
|
|
|
using System.Collections.Generic;
|
|
using Aaru.CommonTypes.Interfaces;
|
|
using Aaru.CommonTypes.Structs;
|
|
|
|
namespace Aaru.Images;
|
|
|
|
/// <inheritdoc />
|
|
/// <summary>Implements reading HD-Copy disk images</summary>
|
|
public sealed partial class HdCopy : IMediaImage
|
|
{
|
|
const string MODULE_NAME = "HDCP plugin";
|
|
/// <summary>Every track that has been read is cached here</summary>
|
|
readonly Dictionary<int, byte[]> _trackCache = new();
|
|
|
|
/// <summary>The offset in the file where each track starts, or -1 if the track is not present</summary>
|
|
readonly Dictionary<int, long> _trackOffset = new();
|
|
/// <summary>The HDCP file header after the image has been opened</summary>
|
|
FileHeader _fileHeader;
|
|
|
|
/// <summary>The ImageFilter we're reading from, after the file has been opened</summary>
|
|
IFilter _hdcpImageFilter;
|
|
ImageInfo _imageInfo;
|
|
|
|
public HdCopy() => _imageInfo = new ImageInfo
|
|
{
|
|
ReadableSectorTags = [],
|
|
ReadableMediaTags = [],
|
|
HasPartitions = false,
|
|
HasSessions = false,
|
|
Version = null,
|
|
Application = null,
|
|
ApplicationVersion = null,
|
|
Creator = null,
|
|
Comments = null,
|
|
MediaManufacturer = null,
|
|
MediaModel = null,
|
|
MediaSerialNumber = null,
|
|
MediaBarcode = null,
|
|
MediaPartNumber = null,
|
|
MediaSequence = 0,
|
|
LastMediaSequence = 0,
|
|
DriveManufacturer = null,
|
|
DriveModel = null,
|
|
DriveSerialNumber = null,
|
|
DriveFirmwareRevision = null
|
|
};
|
|
} |