Opened 7 years ago

Last modified 3 days ago

#11482 assigned Developer Task

Implement support for LNAs through DVB API

Reported by: stuartm Owned by: Klaas de Waal
Priority: minor Milestone: 32.0
Component: MythTV - DVB Version: Master Head
Severity: low Keywords:
Cc: Stuart Auchterlonie Ticket locked: no

Description

http://linuxtv.org/downloads/v4l-dvb-apis/FE_GET_SET_PROPERTY.html#DTV-LNA

Since a lot of users have problems with drivers that default to disabling the LNA built into their tuners we should implement support for enabling the LNA when using the card with MythTV.

My experience of handling user support requests in IRC and mailing lists suggests that most users need the LNA enabled, so the simplest solution would just enable by default with a GUI option to disable it.

A better implementation would automatically the LNA if the signal strength/quality falls below a reasonable threshold. The difficulty here is that signal strength can change over time and with changes in weather, so the very best implementation would be tied to the signal monitor and work per-tune rather than be set once when scanning.

Attachments (1)

20191217-lna-on-off.patch (847 bytes) - added by Klaas de Waal 5 weeks ago.
Switch LNA on, off or auto (requires recompliing to change setting)

Download all attachments as: .zip

Change History (13)

comment:1 Changed 7 years ago by stuartm

Owner: set to stuartm
Status: newassigned

comment:2 Changed 7 years ago by paulh

Milestone: 0.270.28

comment:3 Changed 6 years ago by stuartm

Priority: minorblocker

comment:4 Changed 5 years ago by paulh

Component: MythTV - GeneralMythTV - DVB

comment:5 Changed 4 years ago by Stuart Auchterlonie

Milestone: 0.280.29

comment:6 Changed 4 years ago by Stuart Auchterlonie

Milestone: 0.2929.0

Milestone renamed

comment:7 Changed 3 years ago by Stuart Auchterlonie

I think we should do this as part of the switch to DVBv5 API (#12638)

comment:8 Changed 2 years ago by Stuart Auchterlonie

Milestone: 29.029.1

comment:9 Changed 2 years ago by Stuart Auchterlonie

Milestone: 29.10.28.2

Moving remaining open tickets to 0.28.2 milestone

comment:10 Changed 2 years ago by Stuart Auchterlonie

Milestone: 0.28.229.2

Moving remaining open tickets to 29.2 milestone

comment:11 Changed 5 weeks ago by Klaas de Waal

Cc: Stuart Auchterlonie added
Status: assignedinfoneeded

This is something that looks not too difficult to implement, although it needs a database schema update to store the LNA setting.

I have done comparative testing with "LNA off" and "LNA on" with two different DVB-T2 tuners, a MyGica? T230 USB stick and a Digital Devices PCIe card. On both tuners there is no difference whatsoever between "LNA off" and "LNA on" as shown in the Signal/Noise? and Signal Strength values in the mythtv-setup SCANNING page.

The question is whether implementing this will make a difference for anybody. If there are tuners who are documented to have an LNA then please add them to this ticket. For those willing to test their DVB-T2 tuner, the patch that I used to test this, 20191217-lna-on-off.patch is attached.

Changed 5 weeks ago by Klaas de Waal

Attachment: 20191217-lna-on-off.patch added

Switch LNA on, off or auto (requires recompliing to change setting)

comment:12 Changed 3 days ago by Klaas de Waal

Milestone: 29.232.0
Owner: changed from stuartm to Klaas de Waal
Priority: blockerminor
Severity: mediumlow
Status: infoneededassigned

As this is documented in the DVBv5 and potentially useful it is a good idea to implement this for v32.

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