> ## Documentation Index
> Fetch the complete documentation index at: https://rockboxzig.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Snapcast

> Synchronised multi-room playback through Snapserver — TCP or FIFO.

Rockbox can feed [Snapcast](https://github.com/badaix/snapcast) two ways.
Both write raw **S16LE stereo PCM at 44 100 Hz** to snapserver; pick the
transport that fits your setup.

|                           | TCP sink                      | FIFO sink                  |
| ------------------------- | ----------------------------- | -------------------------- |
| Filesystem entry required | No                            | Yes (`/tmp/snapfifo`)      |
| Snapserver source type    | `tcp://`                      | `pipe://`                  |
| Startup order             | Snapserver first              | Rockbox first              |
| Auto-reconnect            | Yes (next play call)          | n/a — FIFO stays open      |
| Auto-discovery in UI      | Yes (`_snapcast._tcp.local.`) | No — static virtual device |
| stdout pipe support       | No                            | Yes (`fifo_path = "-"`)    |

**Use TCP** for auto-discovery, multiple snapservers, or no filesystem
dependency. **Use FIFO** for stdout piping or the traditional pipe model.

## TCP (recommended)

```toml theme={"theme":{"light":"catppuccin-latte","dark":"min-dark"}}
music_dir         = "/path/to/Music"
audio_output      = "snapcast_tcp"
snapcast_tcp_host = "192.168.1.x"   # IP of the snapserver host
snapcast_tcp_port = 4953            # default snapserver TCP source port
```

Snapserver:

```ini theme={"theme":{"light":"catppuccin-latte","dark":"min-dark"}}
# /etc/snapserver.conf  (or /usr/local/etc/snapserver.conf on macOS)
[stream]
source = tcp://0.0.0.0:4953?name=default&sampleformat=44100:16:2
```

<Tip>
  **Auto-discovery**: rockboxd scans `_snapcast._tcp.local.` at startup;
  discovered servers appear in the web UI device picker. Click to connect —
  no config file editing required.
</Tip>

<Note>
  **Startup order**: start `snapserver` first so it is already listening when
  rockboxd begins playback. If the connection drops (e.g. snapserver
  restarts), it is re-established automatically on the next play call.
</Note>

## FIFO / pipe

```toml theme={"theme":{"light":"catppuccin-latte","dark":"min-dark"}}
music_dir    = "/path/to/Music"
audio_output = "fifo"
fifo_path    = "/tmp/snapfifo"   # named FIFO for snapserver; "-" = stdout
```

Snapserver:

```ini theme={"theme":{"light":"catppuccin-latte","dark":"min-dark"}}
[stream]
source = pipe:///tmp/snapfifo?name=default&sampleformat=44100:16:2
```

<Warning>
  **Startup order matters**: start `rockboxd` before `snapserver`. Rockbox
  holds a permanent write reference on the FIFO so snapserver never sees a
  premature EOF between tracks. If snapserver opens the FIFO first it may get
  EOF and stop reading.
</Warning>

### stdout mode

`fifo_path = "-"` writes raw PCM to stdout — useful for piping into any
consumer:

```sh theme={"theme":{"light":"catppuccin-latte","dark":"min-dark"}}
rockboxd | ffplay -f s16le -ar 44100 -ac 2 -
```

```sh theme={"theme":{"light":"catppuccin-latte","dark":"min-dark"}}
rockboxd | sox -t raw -r 44100 -e signed -b 16 -c 2 - -d
```

## macOS quirk

Snapserver v0.35.0 on macOS ignores the `-s` sample-format CLI flag. Use the
config file at `/usr/local/etc/snapserver.conf` instead:

```ini theme={"theme":{"light":"catppuccin-latte","dark":"min-dark"}}
[stream]
source = pipe:///tmp/snapfifo?name=default&sampleformat=44100:16:2
```

## Verifying it works

```sh theme={"theme":{"light":"catppuccin-latte","dark":"min-dark"}}
# In one terminal
snapserver --logging.filter "*:debug"

# In another
rockboxd
```

You should see `Stream: 'default' connected` in the snapserver logs within
a second of starting playback. From a snapclient host:

```sh theme={"theme":{"light":"catppuccin-latte","dark":"min-dark"}}
snapclient -h <snapserver-ip>
```