CDP File

What are CDP files and how to open them

Are you having problems opening a CDP file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your CDP files.

What is a CDP file?

CDP files have multiple uses, and CD Architect Project is one of them. Read more about the other uses further down the page.

CD Architect Project

CD Architect Project files are used by the audio CD mastering and burning program CD Architect (originally by Sonic Foundry, later owned by Sony) to store all the settings for assembling and preparing an audio CD. The project file holds information about which audio source files are included, how they are edited (cuts, trims, fade-ins/outs), where tracks and indices begin, and how the CD layout should be burned. It does not itself contain the audio data; instead edits are applied non-destructively by referencing the source files until a final CD is produced.

The project file is created and maintained by CD Architect software whenever a user starts or works on a CD layout: saving under the "project" command produces the file. Because edits are stored in the project file rather than modifying the source media, multiple experiments or revisions can be saved without altering original audio files. When burning or exporting the CD, CD Architect consults this file to render/copy the audio, apply effects, cross-fades and write the physical disc. Temporary files named AUTOSAVE.CDP are used for recovery - autosaves happen regularly and are deleted when the program closes.

Project files of version 4 begin with a RIFF container header: the first four bytes are ASCII "RIFF", followed by four bytes and then the ASCII "SFPJ". This pattern occurs at the very start of the file (offset zero) and identifies version 4 of the CD Architect Project file format.

How to open CDP files

Important: Different programs may use files with the CDP file extension for different purposes, so unless you are sure which format your CDP file is, you may need to try a few different programs.

While we have not verified the apps ourselves yet, our users have suggested ten different CDP openers which you will find listed below.

Last updated: August 31, 2026

All known file formats using extension .CDP

While CD Architect Project is a popular type of CDP-file, we know of 3 different uses of the .CDP file extension. Different software may use files with the same extension for different types of data.

Chess Assistant Database

Chess Assistant Database format is a proprietary binary database used by the Chess Assistant program (also known as ChessOK) to store large collections of chess games, player and tournament metadata, opening trees, classifiers, and related structures. It is used when "Chess Assistant" saves its native format; it supports advanced features such as rapid searching, filtering by material distributions, player ratings, classification, comments, variations and game analysis, all optimized for this software.

The format is created and maintained by Convekta Ltd (makers of Chess Assistant). Databases are written in this format when the user saves or converts a collection of games into the native format to gain speed and full access to features. These database files can be read by Chess Assistant itself (and by compatible programs such as Aquarium, subject to limitations). Typical operations include filtering or searching games by player, year, opening, position; storing and using classifier tags ("classes"); and building opening trees ("Direct Tree", "CAP evaluations", etc.).

The file type is known as "Chess Assistant Database" (import format name: "Chess Assistant DB (v3.0) - Chess Data Pro (v1.1)") and uses the extension CDP. At the start of the file is an ASCII header beginning with "Chess Assistant 3.0 database" and also "Chess Data Pro format. Version 1.1", followed by metadata sections containing keywords such as USER FOLDERS, CLASSES, PLAYERS, GAMEID. These internal strings and byte signatures are part of version 3.0 / format version 1.1 identifying this exact binary layout.

Trainz Content Dispatcher Pack

Files with the .cdp file extension are most commonly used by the Trainz Simulator railroad games.

These games allow players to create train simulations, including train routes and locomotive designs. The CDP files contain add-on content that can be used in the game, providing players with additional routes, scenery, train designs, and other game components.

Various apps that use files with this extension

These apps are known to open certain types of CDP files. Remember, different programs may use CDP files for different purposes, so you may need to try out a few of them to be able to open your specific file.

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