rockbox-ffi — Clojure examples

Small, runnable programs showing each surface of the binding. Build the shared library first (cargo build --release -p rockbox-ffi from the repo root, or set ROCKBOX_FFI_LIB), then run any example with the :examples alias — it adds --enable-native-access=ALL-UNNAMED for the Foreign Function & Memory API:

mise exec -- clojure -M:examples examples/metadata.clj /path/to/song.flac
mise exec -- clojure -M:examples examples/dsp_replaygain.clj
mise exec -- clojure -M:examples examples/dsp_eq.clj
mise exec -- clojure -M:examples examples/player.clj /path/to/song.flac

File	Shows
metadata.clj	metadata/read (tags, duration, ReplayGain) and metadata/probe
dsp_replaygain.clj	A −6.02 dB track gain halving a 1 kHz sine through the DSP
dsp_eq.clj	Enabling the 10-band EQ and setting shelf bands
player.clj	Queue + transport + live player/status on the output device

The three surfaces

(require '[rockbox.ffi.metadata :as metadata]
         '[rockbox.ffi.dsp :as dsp]
         '[rockbox.ffi.player :as player])

;; metadata — parse tags without an output device
(metadata/read "/music/song.flac")      ; => {:title … :codec "FLAC" …}
(metadata/probe "song.flac")            ; => "FLAC"

;; dsp — process interleaved stereo int16 (a short-array); handle is a singleton
(dsp/with-dsp [d 44100]
  (dsp/eq-enable d true)
  (dsp/set-eq-band d 0 100 0.7 3.0)
  (dsp/process d samples))              ; => short-array

;; player — queue + transport; owns a live output device
(player/with-player [p {:volume 0.8}]
  (player/set-queue p ["/music/a.flac"])
  (player/play p)
  (:state (player/status p)))

with-dsp / with-player free the native handle on exit; every char* / int16* the ABI returns is freed inside the binding. Enum arguments accept a keyword or the raw int — note the two ReplayGain encodings: dsp-replaygain-mode (:track 0, :album 1, :shuffle 2, :off 3) for the DSP, replaygain-mode (:off 0, :track 1, :album 2) for the player.