Playing Radio

Playing Radio

Finding stations in Volumio

Music Library > FM/DAB Radio shows:

Section	Entry	Contents
Quick Access	Favorites	Stations you marked as favourite
	Recently Played	The stations played last
Radio Sources	FM Radio	All FM stations that are not hidden or deleted
	DAB Radio	All DAB stations, as one flat list or by ensemble
Management	Hidden Stations, Deleted Stations	Stations you hid, and the recycle bin

A station can be added to Volumio's own favourites, playlists and queue like any other item. Its address has the form rtlsdr://fm/<frequency> or rtlsdr://dab/<channel>/<service name>.

What happens when a station is played

flowchart TD
    play(["Play a station"]) --> kind{"FM or DAB?"}

    kind -- "FM" --> known{"Gain known for this<br/>station and dongle?"}
    known -- "no" --> measure["The gain is measured<br/>(about 2 seconds)"]
    known -- "yes" --> fmrx["The FM receiver starts"]
    measure --> fmrx
    fmrx --> fmsound["Sound"]
    fmrx --> fmmeta["RDS: name, text,<br/>programme code"]

    kind -- "DAB" --> dabgain["The decoder measures the gain"]
    dabgain --> lock["It finds the ensemble, following<br/>the dongle's frequency error"]
    lock --> service["It finds the service"]
    service --> dabsound["Sound<br/>(about 6 seconds after play)"]
    service --> dabmeta["Text and<br/>slideshow pictures"]

    fmmeta --> screen["Player screen:<br/>name, text, picture, reception"]
    dabmeta --> screen

    fmrx -. "no signal from the dongle" .-> stopped["Stopped, with a message"]
    lock -. "no ensemble within 30 seconds" .-> stopped

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What the player shows

• Title: the station's name, or the name you gave it.
• Artist / album line: for FM the frequency, for DAB the ensemble, and while a station sends text, what it says; where the text names a song, its artist and title.
• Picture: on DAB, the newest picture the station itself sends with its programme (slideshow), as it arrives; otherwise the cover of the song being played when one is found; otherwise the station's logo; otherwise the FM or DAB icon. See Artwork and Metadata and Station Logos.
• Reception: five dots beside "FM" or "DAB". For FM they come from how far the stereo pilot stands above the noise, or, for a station the scan listed as sending no pilot (mono), from how clear its carrier is of the noise; for DAB from the decoder's own measure of the signal. A station that sends no pilot shows MONO between "FM" and the dots, for as long as it sends none.

Play, pause and stop

A broadcast cannot be paused. Pause stops the station, and the player shows it as stopped; play starts it again from what is on air at that moment. Stop does the same.

Loudness

A DAB station plays at the level the broadcaster sends, which is about that of a music track. An FM station is brought to the same range: a fully modulated station peaks 1 dB below full scale, whatever receiver sample rate is set. Nothing is compressed or levelled over time. FM and DAB, and radio and your music, therefore need about the same volume setting.

One dongle, one station

The dongle receives one thing at a time. Starting a station stops whatever used the dongle before: another station or an antenna tool. A scan started while a station plays asks whether to stop the station first; an antenna tool stops it, and the player shows it as stopped.

When a station cannot be played

The plugin says why rather than showing a station as playing over silence:

Message	Meaning
... could not be received: no usable DAB signal on channel ...	The decoder found no ensemble it could read on that channel within 30 seconds.
The dongle is not delivering a signal. Unplug it, plug it in again, and play the station once more.	The dongle opened but sent no samples.
Failed to play station: ...	A receiver program ended by itself; the text names it.

What to do about each is on the Troubleshooting page.

Sound quality

• FM is received in mono. The settings offer four receiver sample rates: 171 kHz is best for RDS, the higher ones (200, 240, 300 kHz) give a little more audio bandwidth at the cost of RDS. De-emphasis follows the region unless another is chosen.
• DAB and DAB+ are decoded at the station's own bit rate and sample rate and resampled to 48 kHz for the player.

Using a station as an alarm or in a playlist

A station can be put in a Volumio playlist and used with the alarm clock like any other item. It needs reception at the moment it is started: with a marginal signal the start can fail, and the player then stays silent with the message above.