What is the DDB file format?
A .ddb file is a proprietary binary database automatically generated by Avid Pro Tools' DigiBase media browser engine. DigiBase is the media-management component built into Pro Tools that indexes all audio and video files visible to the application.
Each volume or folder that Pro Tools has scanned receives its own .ddb file, stored inside a hidden folder named Digidesign Databases at the root of that volume. The database records file and clip metadata - names, sample rates, channel counts, timestamps, waveform overview data, and search indexes - so that DigiBase can display, search, and sort media assets quickly without re-reading every audio file.
.ddb files grow with the number of indexed media files, ranging from a few kilobytes on a small project folder up to several megabytes on a large sample library drive. Because they are automatically regenerated whenever Pro Tools scans a volume, they can be safely deleted if they become corrupted or oversized; no audio data is stored inside them.
The format is tied to .ptx Pro Tools sessions and is not documented publicly by Avid. Renaming or manually editing a .ddb file will corrupt it; Pro Tools simply rebuilds it on the next launch. These files are analogous in purpose to the thumbnail cache databases macOS and Windows create for media folders.
Security & safety
RISK: LOWDDB is an auto-generated index with no executable code. No security risk. Do not confuse with .ddb (DebugDiag database) or other coincidental uses of this extension.
Format details
in a nutshell- Device Dependent Bitmap - Legacy graphics format (Windows 3.x era); rare today and not associated with current users of this extension.
Programs that open DDB files
Windows1 app
Avid Pro Tools
Paid Pro Tools reads DDB automatically; no need to open manually. File > Open Session to work with a PT session. 
macOS1 app
Avid Pro Tools
Paid DDB is managed automatically by Pro Tools on macOS. Delete it to force a DigiBase rescan. Technical details
deep spec| Developer | Avid Technology (formerly Digidesign) |
| Application | Avid Pro Tools DigiBase media browser |
| Encoding | Proprietary binary; internal structure not publicly documented |
| Typical size | 10 KB-5 MB, growing with the number of indexed media files |
| Storage location | Hidden Digidesign Databases folder at the root of each indexed volume |
| Content | File and clip metadata: names, sample rates, timestamps, waveform overviews, and search indexes |
| Scope | One .ddb file per indexed volume or folder |
| Regeneration | Automatically rebuilt by Pro Tools if deleted or corrupted; no audio data is lost |
| Operating systems | Windows, macOS |
| Format dependency | Tied to Pro Tools version; internal structure not publicly documented by Avid |
| Relation to sessions | Supports Pro Tools session files (.ptx) but is stored separately from the session itself |
| Released | Late 1990s, with Digidesign Pro Tools DigiBase (Pro Tools 6.x era, ~2003) |
| Specification | duc.avid.com |
Community Q&A
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