Built-in (SDL)

The default. SDL2 audio to your OS default device.

The built-in sink uses SDL2 to play audio through your operating system’s default audio device. This is the default and needs no setup beyond installing Rockbox.

music_dir    = "/path/to/Music"
audio_output = "builtin"

Selecting the output device

SDL plays through whichever device the OS reports as default. To change it, use your platform’s audio settings:

• macOS — System Settings › Sound › Output
• Linux (PipeWire / PulseAudio) — pavucontrol or your DE’s sound applet
• Windows — Sound settings › Output

There is no per-application device picker built into Rockbox for the SDL sink. If you need multi-device routing on Linux, point Rockbox at a PulseAudio null sink and route from there.

macOS-specific notes

SDL_InitSubSystem(SDL_INIT_AUDIO) is called explicitly on macOS. On other platforms the SDL event thread initialises audio; Apple’s event thread doesn’t, so Rockbox compensates. You shouldn’t have to do anything — but if you ever see “no audio output” on macOS only, this is the code path to look at.

Format

Output is S16LE stereo at 44 100 Hz. Higher-resolution sources are dithered down by the rbcodec DSP pipeline before they reach SDL. To change the output sample rate, set play_frequency in settings.toml (auto, 44100, 48000, 88200, 96000).

Switching to another sink

Edit audio_output in settings.toml and rockbox restart, or call:

mutation { connectDevice(id: "<device-id>") }

…with a device discovered via mDNS — see Audio output › Overview.