Hvad er XDELTA-filformatet?
En .xdelta-fil er en binær patch oprettet af xdelta, et open-source delta-komprimeringsværktøj og C-bibliotek startet af Joshua P. MacDonald. I stedet for at indeholde en hel fil, gemmer den kun forskellene mellem en original fil og en modificeret version. Da to lignende filer normalt kun adskiller sig på få steder, er patchen langt mindre end selve filerne, hvilket gør .xdelta til en kompakt måde at distribuere ændringer på.
Moderne xdelta (xdelta3-serien) skriver patches i VCDIFF-formatet defineret af RFC 3284. En VCDIFF-strøm begynder med bytene V, C, D med deres høje bits sat (hex D6 C3 C4) efterfulgt af en versions-byte. Indeni er patchen en serie af instruktioner til kopiering, tilføjelse og kørsel, der fortæller xdelta, hvordan målet skal genopbygges fra kilden. Du vil oftest støde på .xdelta-filer i forbindelse med spil-modding og ROM-oversættelser, hvor forfattere distribuerer en lille patch i stedet for en ophavsretligt beskyttet original.
Sikkerhed og tryghed
RISIKO: MEDIUMA .xdelta file is passive data and cannot run on its own. The real risk is what it patches: applying a patch produces a new file (often a game ROM, ISO, or executable) whose safety depends on the patch author. Only apply patches to the correct, expected original file and from sources you trust, since a malicious patch could turn a clean file into a modified executable. Applying a patch to the wrong source usually just fails a checksum rather than corrupting anything.
Formatdetaljer
kort fortalt- xdelta1 legacy patches - Files from the original 1997-era xdelta (version 1) also used the .xdelta name but a different, non-VCDIFF on-disk layout; they are not compatible with xdelta3.
Programmer der åbner XDELTA-filer
Windows3 apps
xdelta3 (command line)
Open-source Run xdelta3 -d -s original.bin patch.xdelta output.bin in a terminal to apply the patch against the original file.
Delta Patcher
Open-source Open the app, pick the original file and the .xdelta patch, then click Apply Patch to produce the patched file. It is self-contained and does not need a separate xdelta binary.
xdelta UI
Gratis Load the original file and the .xdelta patch in the Apply tab to generate the patched output; commonly used for ROM patches. 
macOS2 apps
xdelta3 (command line)
Open-source Install with brew install xdelta, then run xdelta3 -d -s original patch.xdelta output to apply the patch.
Delta Patcher
Open-source Use the cross-platform GUI to select the source file and .xdelta patch and apply it without touching a terminal. 
Linux2 apps
xdelta3 (command line)
Open-source Install the xdelta3 package from your distro, then run xdelta3 -d -s original patch.xdelta output to rebuild the patched file.
Delta Patcher
Open-source Run the wxWidgets GUI to apply or create .xdelta patches with a graphical interface.
Xdelta patcher (WebAssembly)
Open-source Drag the original file and the .xdelta patch into the browser page to apply the patch locally without installing anything. Tekniske detaljer
dyb specifikation| Encoding | Binary VCDIFF (RFC 3284) delta stream with COPY, ADD and RUN instructions referencing a source file |
| Byte order | Endian-independent by design; integers are stored as variable-length, byte-order-neutral values |
| Container | VCDIFF window/section layout (header, then one or more windows each with instruction, data and address sections) |
| Compression | Secondary compression selectable at encode time: djw (default in many builds), lzma, fgk, or none |
| Typical size | Small relative to the target file; often a tiny fraction of the original when the two files are similar |
| Structure | A .xdelta file stores the difference between a source file and a target file. It is not a standalone document: applying it requires the exact original (source) file, from which xdelta reconstructs the target byte-for-byte. |
| Integrity | xdelta3 can embed and verify source and output checksums (Adler-32, and BLAKE3 in recent 3.2.x builds) to confirm the correct source file and a correct reconstruction |
| Platforms | Windows, macOS, Linux, BSD |
| Notes | Created by the xdelta command-line tool and C library. Widely used to distribute game translations and mods (ROM/ISO patches) because delta encoding accounts for shifted data and avoids embedding copyrighted source bytes. |
| Udgivet | 1997 (xdelta1); xdelta3 series in the 2000s |
| Seneste version | xdelta3 3.2.x |
| Åben standard | Ja · royaltyfri |
| Specifikation | datatracker.ietf.org |
XDELTA-konverteringer
Fællesskabets Q&A
spurgt af brugereIngen spørgsmål endnu - vær den første til at spørge om XDELTA-filer.
Ofte stillede spørgsmål
Hvordan åbner jeg en .xdelta-fil?
xdelta3 (xdelta3 -d -s original patch.xdelta output) eller en GUI som Delta Patcher eller xdelta UI, som beder om kildefilen og patchen.Hvorfor kan min .xdelta-patch ikke anvendes?
Hvilket program opretter .xdelta-filer?
xdelta3 -e -s original modified patch.xdelta. GUI-værktøjer som Delta Patcher kan også generere dem ved at sammenligne to filer, du angiver.Er en .xdelta-fil det samme som en VCDIFF-fil?
.xdelta og en .vcdiff lavet af xdelta3 indeholder den samme type data. Filendelsen er blot et navngivningsvalg.Er .xdelta-filer sikre?
Kan jeg se, hvad der er inde i en .xdelta-fil?
xdelta3 printhdr patch.xdelta eller xdelta3 -v, men det meningsfulde resultat vises først, når du anvender den på kildefilen.
