USB export (CDJ / rekordbox-compatible)

You can export playlists and folders to a rekordbox-compatible USB stick that CDJ / XDJ players read: audio files, analysis (beat grid / waveforms / key), cue points, playlists and artwork. An export works as a sync: from the second time on, only the tracks that changed are rewritten.

Screenshots to be added

Experimental feature

rekordbox, CDJ and XDJ are trademarks of AlphaTheta Corporation. Crateforge and rbx-cli are not affiliated with or endorsed by AlphaTheta. This feature has not yet been tested on real CDJ / XDJ hardware by the developers. Before relying on it at a gig, check loading, cue positions and grids on your own players.

Exporting

1. In the sidebar, right-click a playlist or folder → “USB に書き出し…” (Export to USB), or use “USB に書き出し” in the toolbar (inside the ⋯ menu when the window is narrow).
2. Choose the playlists to export. Selecting a folder exports its playlists with the hierarchy. Smart playlists are exported with their contents at the time of the export.
3. Choose the destination: pick a USB stick from the list of mounted volumes, or any folder with “フォルダ…” (Folder…). The last destination is remembered.
4. Set the options (below).
5. “計画を確認” (Review plan) builds a plan without writing anything to the stick: tracks to copy / reuse, where analysis comes from (new / cache / reused from the stick), bytes to copy and free space (checked against the drive holding the destination, whether it is a USB stick or any folder), Traktor matching, tracks whose cues/grids changed on a CDJ and will be kept, missing files and warnings.
6. “書き出す” (Export) starts it. Progress is shown per stage (prepare → analysis & tags → change check → copy to USB → databases → verify → publish).
7. When it finishes, “取り出し” (Eject) safely ejects the stick (listed volumes only; never forced).

You can close the dialog while it runs. Progress is shown on a card at the bottom right (above the player bar); click it to return to the dialog. “中止” (Cancel) stops at the next track boundary. Whether cancelled, failed or unplugged, the stick keeps its previous contents (the new contents are staged and switched over in one step). If Crateforge is force-quit or crashes during an export, rbx-cli notices and cancels the export too (it does not keep writing to the stick unattended).

Options

Option	Meaning
Traktor のキュー/グリッドを使う (Use Traktor cues/grids)	See “Traktor cues and grids” below. Off by default
アートワークを書き出す (Export artwork)	Exports the image embedded in each audio file, resized for the players
USB から消す (Remove from USB)	Removes tracks an earlier export wrote that this export no longer contains (playlists always match this export)
CDJ で変更したキュー/グリッドを優先する (Prefer cues/grids changed on a CDJ)	Tracks whose cues or grid were changed on a CDJ since the last export keep the stick’s cues/grid (see “Conflicts with cues/grids changed on a CDJ” below). Off by default (the export stops and tells you)
デバイス名 (Device name)	The name players show. Leave empty to keep the current one
詳細設定 (Advanced)	Location of Traktor’s collection.nml, MP3 offset (ms)

What is written

• Title, artist, album, genre, comment, year, track number, disc number, play count, date added and rating (0–5 stars; half stars round up) come from the Crateforge library.
• The key is Crateforge’s effective key (your manual override, else the analysed key), written in rekordbox notation (Am, F#m, …). Tracks without one use the key analysed during the export.
• BPM, beat grid and waveforms are analysed during the export (or taken from Traktor’s grid when that option is on). The displayed BPM matches the grid’s tempo.
• Tracks whose file is missing (an external drive or NAS not connected, for example) are listed in the plan with a count and examples. They are still handed to rbx-cli and stay in their playlists:
  • a track never exported to this stick before is skipped;
  • if the stick already holds such a track from an earlier export, the export stops without changing the stick, so its copy is not deleted. Connect the drive (or fix the track’s location) and export again. Even with “USB から消す” (Remove from USB) on, a track whose file is merely missing is never deleted from the stick.

Traktor cues and grids

Crateforge itself does not store cues or beat grids. With “Traktor のキュー/グリッドを使う” on, every export reads Traktor’s collection.nml, matches tracks by file path, and writes Traktor’s cues and grids to the stick (nothing is saved to the Crateforge library).

• collection.nml is auto-detected as the newest Documents/Native Instruments/Traktor <version>/collection.nml. If yours is elsewhere, set it under Advanced (or Settings → USB 書き出し).
• Tracks whose path differs are matched only when file name and file size match exactly one Traktor track. The plan shows matched / unmatched counts with examples.
• On macOS, a clone or backup volume holding the same path can make it unclear which Traktor track is meant. Then the one on the startup volume is used; if none is on the startup volume, that track gets no Traktor cues or grid (the plan lists it under “候補が複数” — several candidates).
• Mapping:
  • Grid markers → beat grid (constant tempo at Traktor’s BPM; several markers become several anchors)
  • Cue / fade-in / fade-out / load → cue points; loops → loops
  • Hot cues 1–8 → hot cues A–H; cues not on a hot cue → memory cues
  • Cue names → cue comments
• For tracks not found in Traktor, or when the option is off, no cues or grids are sent: cues already on the stick are kept, and the grid comes from analysis.
• Tracks that match follow Traktor: if a track has no cues in Traktor, its cues on the stick are removed.

MP3 offset

Traktor and rekordbox / CDJ treat the start of MP3 decoding differently, so MP3 cues and grids can be off by tens of milliseconds. “MP3 オフセット (ms)” (MP3 offset) under Advanced shifts the cues/grids imported from Traktor for MP3 files (positive = later, negative = earlier). The default is 0 ms. Because the shift can depend on the file and encoder, calibrate the value on real hardware; Crateforge does not ship a guessed value.

Conflicts with cues/grids changed on a CDJ

When you save cues to the stick or change a beat grid on a CDJ, the analysis files on the stick change. Sending Traktor’s cues/grids afterwards would lose those changes, so by default the export is stopped without changing the stick, with an explanation and the tracks concerned. Then:

• “CDJ の変更を優先して再試行” (Retry, preferring the CDJ changes) exports the same thing again (same playlists, destination and options; Traktor’s cues and grids are still sent), but the tracks changed on the CDJ keep the stick’s cues and grid. The other tracks get Traktor’s cues/grids. The result shows “CDJ で変更されたキュー/グリッドを保持した曲: N” (tracks whose CDJ cues/grid were kept) and lists them.
• To export like this every time, turn on the option “CDJ で変更したキュー/グリッドを優先する” (the plan also shows how many tracks will be kept).
• If you do not need the CDJ changes, export to another (empty) stick.

CDJ changes are kept for that one export only

Preferring the CDJ changes keeps them for that export only. On the next export, unless the tracks are changed on the CDJ again, Traktor’s cues/grids are written again. To keep the CDJ changes for good, make the same edits in Traktor (or import them from the stick with rekordbox or similar).

Cue changes that newer players recorded only in OneLibrary (exportLibrary.db) cannot be kept this way: the export still stops even when preferring the CDJ changes. Import them from the stick with rekordbox, or export to another stick.

With “Traktor のキュー/グリッドを使う” off, cues saved on a CDJ are always kept.

When an export stops for other reasons

So that nothing on the stick is lost, an export also stops without changing the stick in cases like these, and shows the reason (and the tracks concerned when known):

• track information, playlists or My Tags on the stick were changed or deleted in rekordbox or on a CDJ since the last export;
• the stick holds tracks or playlists exported by something other than Crateforge (rekordbox, for example), or belongs to another library;
• a track that “USB から消す” (Remove from USB) would delete is still in the stick’s play history (turn “USB から消す” off and export again);
• the file of a track exported earlier is missing (see “What is written” above);
• another app changed the stick during the export (export again).

Speed and caching

• The first export is slow: every track has to be analysed and written to the stick.
• Later exports reuse the analysis cache (on your computer; reused while a track’s content and the analysis settings are unchanged) and the files already on the stick, and only copy / analyse what changed.
• To detect changes reliably, though, rbx-cli still reads every audio file on both the source and the stick each time. With many tracks this takes a while even when nothing changed.
• You cannot export while rekordbox is running (it may write the same stick).

About rbx-cli

The export itself is done by the external tool rbx-cli (built on rbxport).

• Crateforge only starts rbx-cli as a separate process and talks to it in JSON. It is not built into Crateforge and not bundled with it.
• If rbx-cli is not installed yet, download it from the export dialog (or Settings → USB 書き出し (rbx-cli)). It is fetched from the upstream GitHub release, its SHA-256 checksum is verified, and it is saved in the app’s data folder.
• rbx-cli 0.1.1 or newer is required (if you downloaded 0.1.0 before, download it again when the dialog asks).
• rbx-cli is looked up as “path set in Settings → downloaded copy”, and only a version speaking a supported protocol with the required features is used (for safety, an rbx-cli on PATH is never picked up on its own). To use your own build, set it via “パスを指定…” (Set path…) in Settings.
• Release binaries exist for Windows (x86-64), macOS (Apple silicon / Intel) and Linux (x86-64, glibc 2.39 or newer).

Note

rbx-cli is GPL-2.0-or-later software (its release binaries include an LGPL-3.0 component, so they are effectively GPL-3.0). Crateforge (MIT) does not link it; it only runs it as an external command.