Smart Playlists

Smart playlists are rule-based: you define filters (genre, artist, album) and a track limit.

What it does

• Rules — Filter by genre, artist, or album. You can pick multiple values (e.g. Rock + Jazz).
• Track limit — Cap the number of tracks (e.g. 50) or allow all matching.
• Create — Build the playlist from the current library. Results are deterministic based on rules.

How it works

Smart playlists use the same rule engine as sync custom selection. Rules are stored as JSON. When you create or update a Smart playlist, the app queries the database for tracks matching the rules, applies the limit, and saves the track list.

Rockbox dynamic mode (per-device opt-in)

If your device runs Rockbox firmware, you can configure it to receive smart playlists as a live tag-tree view instead of static .m3u snapshots. Enable "Rockbox smart playlists (tagnavi)" on the device profile (Devices → Edit). When this is on:

• During sync, smart playlists are written to <device>/.rockbox/tagnavi_user.config as tagnavi query entries that are evaluated live against the device's tag database.
• Smart-playlist .m3u files are no longer written to the device's Playlists folder; any leftover ones from prior syncs are cleaned up under the configured Orphan Policy.
• Other playlist kinds (Custom, Genius, Savant) still write .m3u — see below for why.
• Inside Rockbox, the entries appear at the bottom of the main Database menu (one entry per smart playlist, named after the playlist).

Only artist, album, and genre rules translate cleanly. Multiple values for the same rule type are OR'd (Rockbox @ operator with pipe-separated values); different rule types are also OR'd, mirroring the desktop's smart-playlist track query.

After syncing: reboot + database init

Two device-side conditions must be met before the entries actually show tracks:

• Tag database must be built. The device's tagcache (the database_*.tcd files in .rockbox/) is what tagnavi queries against. The first time you enable this feature, run Database → Initialize Now in Rockbox. Subsequent updates happen automatically if tagcache_autoupdate: on is set, but the first build always needs a manual init. Rockbox shows progress while it scans; when the build completes, a database_unchanged.tcd marker file appears in .rockbox/.
• Reboot to reload the config. Rockbox caches tagnavi_user.config in memory and only re-reads it on boot. After a sync that changes smart playlists, reboot the iPod (hold Menu+Select for ~5 seconds) so Rockbox picks up the new entries. Without a reboot, the menu still shows the previous version of the file regardless of what was just synced.

If a smart-playlist entry appears in the menu but is empty when opened, the most likely causes are: (a) the database hasn't finished its initial build, or (b) no tracks on the device match the rules.

Why only Smart playlists become tagnavi

Tagnavi entries are live database queries, not file lists. A Smart playlist rule like "genre = Rock, limit 50" translates directly to a tagnavi expression that Rockbox evaluates against its tag database every time you open it — so if you add new Rock tracks to the device, the playlist updates automatically.

Genius, Savant, and Custom playlists are static track selections made at a point in time. Genius picks tracks based on play history and scoring; Savant uses AI and harmonic sequencing; Custom is hand-curated. None of these have a metadata expression that could reproduce the original selection on the device. The right format for a static track list is .m3u, which is an exact record of which files belong. Embedding a 50-track file list inside a tagnavi config line would be strictly worse — same data, harder to read, breaks if any path changes.

How to work with it

1. Choose By genre, By artist, or By album.
2. Pick one or more values from the dropdown (loaded from your library).
3. Set the track limit or check "No limit".
4. Click Create and give the playlist a name.
5. The playlist appears in the All tab. Re-create it to refresh when your library changes (Smart playlists are not live-updating).