Guglielmo implements a simple FM and DAB receiver based on Qt and the Qt-dab and sdr-j-fm packages.
The primary reason it is being developed is there is a lack of media centre quality Open Source Software Defined Radios: most of the packages out there focus more on hobbyist features, such as signal and content monitoring, leaving out media features like a volume slider or MPRIS control.
Yes, I have blown the ribbon tweeter fuses on my maggies because my previous go to SDR DAB receiver started at full blast, and I run my media centre headless: I don't really want to scramble for a VNC session when I want to stop the music, when I could simply use KDE connect on my phone.
There is also a distinct lack of FM SDR receivers, which is disappointing, since, at least in the UK, for reasons of cost, most stations transmit at a fairly poor bitRate, if not downright in mono, and FM stations seem to still be a better proposition in terms of sound quality.
The main window is divided in two: the right side changes depending on the mode, DAB or FM, the left side being common to both.
In DAB mode, top to bottom, there's the channel name, a list of all the services (AKA stations) in the current channel, a channel selector, and the previous and next buttons.
Previous and next switch to the previous or next service, if there's a previous or next service to select, or the previous or next channel if already at either end of the service list.
Or you can switch service or channel using the appropriate selectors.
The central display can switch between the services list for the current channel and the slide show for the current service using the "stations" and "slides" menus accessible from the burger menu.
FM mode sports a frequency display, and a large, old style, frequency knob.
Turn it either way to select the frequency.
The knob turns several times, much like in the analog days of old.
Below there's a scan down, scan up and stop scan buttons, which can be used to find the previous or next FM station.
The preset controls are at the bottom of the right widget.
The central selector is used to choose the next preset.
Provided that there's a DAB service selected, or in FM mode, M+ adds the current service or frequency to the presets, whileM- removes the current station from the presets, if it had been previously added.
On the top left, find the stereo, signal strength and signal quality indicators.
Green is good, red is bad, and blank, no station is playing.
Below, find the DAB or FM station name, and whatever text the station is currently choosing to display.
On the bottom you have the volume and squelch knobs, the DAB and FM buttons, and the play/stop and record/stop recording buttons.
The squelch is a control that silences the sound when the signal is poor.
The higher the value, the better the signal quality has to be for any sound to be played. It's only active in FM mode.
The burger menu button at the top right activates the about and settings windows.
Currently there are 6 tabs, controlling
- presets
- the UI interface
- remote control settings
- the sound output
- FM settings
- device settings
There's no tweakable DAB settings on offer.
The presets tab sports a presets editor (rearrange, delete or sort presets) and a station scan facility.
Once a DAB or FM scan has been completed, even partially, stations can be dragged directly to the preset list, or moved there by selecting them and using the move (<) button.
Scan lists can be added to with a new scan, are preserved across settings usages, and can be cleared.
They are not preserved across runs.
The actual themes depend on the platform and the build.