Conversion Methods

Conversion Methods

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Installation	Conversion Methods	XDVDFS Technical Docs	Building from Source
	XISO Explorer	Troubleshooting & FAQ

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The application offers three conversion methods, each using a different approach to convert Redump ISOs into XISO format. All three remove the same wasted content; they differ in how the remaining data is laid out and how safe/fast the process is.

Method Comparison

Feature	extract-xiso	xdvdfs	Built-in (Modified Deterous Logic)
Approach	Repack	Repack	Trim
Output Size	Smallest	Smallest	Slightly larger
Safety	High	High	Highest
Preserves Layout	No	No	Yes
External Tool	Required	Required	Built-in
Speed	Fast	Fast	Fastest (selective sector copy only)

What Gets Removed

All three methods remove these parts from Redump ISOs:

• Video Partition (DVD movie/demonstration content) — ~7–387 MB removed
• End Padding (empty sectors after the last file) — variable
• System Update (optional, when Skip $SystemUpdate is enabled) — ~100–300 MB removed

Visual Comparison

Redump ISO (Original):
[Video Partition][XDVDFS: Header][Dir][File A][gap][File B][gap][File C][Padding]

extract-xiso / xdvdfs Output:
[XDVDFS: Header][Dir][File A][File B][File C]   (gaps removed, tightly packed)
                      ^    ^    ^
                 Files repositioned for maximum compression

Built-in (Trim) Output:
[XDVDFS: Header][Dir][File A][gap][File B][gap][File C]
                      ^         ^
                 Original layout preserved; only video/padding removed

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extract-xiso (External Tool)

• Developed by: the XboxDev team
• Approach: reads the entire ISO and creates a new optimized XISO with files packed tightly together.
• Pros: smallest output size; long-standing, well-tested tool.
• Cons: requires an external executable (extract-xiso.exe, bundled with the application).
• Best for: maximum storage savings with a battle-tested tool.

xdvdfs (External Tool)

• Developed by: antangelo
• Approach: modern Rust implementation that rebuilds the XISO from scratch.
• Pros: smallest output size; modern, actively maintained implementation.
• Cons: requires an external executable (xdvdfs.exe, bundled with the application).
• Best for: maximum compatibility and storage savings.

Built-in Method (Modified Deterous Logic)

• Original source: based on the XboxKit by Deterous XDVDFS.cs implementation for traversing the XDVDFS filesystem.
• Approach: trims the ISO by identifying and copying only valid sectors (header, directory tree, file data) while preserving the original file layout and the gaps between files.

Key Modifications Compared to the Original

• Converted recursive directory traversal to an iterative stack-based approach, avoiding stack overflows on deep directory structures.
• Added cycle detection using a HashSet to prevent infinite loops on malformed images.
• Enhanced signature detection supporting multiple known XGD1/XGD2/XGD3 partition offsets, robust validation, and fallback sector scanning for non-standard/Redump variants.
• Optional $SystemUpdate skipping for extra space savings.
• Improved directory-entry parsing, name reading, attribute handling, and comprehensive error handling and validation.
• Modern C# implementation integrated with the application's progress reporting, cancellation, and disk monitoring.

Pros and Cons

• Pros:

  • Fastest — no repacking, just selective sector copying.
  • Safest — preserves the exact original XDVDFS structure and layout.
  • No external dependencies — pure C# implementation.

• Cons: output is larger (gaps between files from the original ISO are preserved).

• Best for: preserving the original structure, debugging, and maximum safety/compatibility.

The algorithm behind this method is documented in depth on the XDVDFS Technical Documentation page.

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Which Should You Choose?

Use Case	Recommended Method
Maximum storage savings	xdvdfs or extract-xiso
Preserving exact game structure	Built-in (Modified Deterous Logic)
Debugging / development	Built-in (Modified Deterous Logic)
FTP transfer to Xbox	xdvdfs or extract-xiso

For most users: if storage space is critical, use xdvdfs or extract-xiso for maximum compression. Use the built-in logic when you want to preserve the original file layout and structure from the source ISO.

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CUE/BIN Support

Classic disc images distributed as a .cue + .bin pair are handled automatically:

1. The bundled bchunk tool converts the pair into a standard ISO.
2. The ISO is then converted with your selected method.

Both files must be present in the same folder with matching names.

Archive Support

.zip, .7z, and .rar archives are processed transparently:

1. The archive is extracted to a temporary folder (SharpCompress is used first; the bundled 7-Zip CLI handles complex .7z archives).
2. Any ISO inside is converted with your selected method.
3. Temporary files are cleaned up.

Encrypted or password-protected archives are detected up front and skipped with a clear message.