On Mon, 28 Jun 2021 09:18:59 -0500 Roger Heflin rogerheflin@gmail.com wrote:
It looks like the prior udev rule put the dvb adapters in video. Since their are both video and radio devices maybe "video" should really be renamed as "dvb" and/or maybe the rtl package should simply add itself to video and not use its own group.
udev uses the video group by default for dvb and other video devices. Many of these devices also support audio radio. I do not know why rtl-sdr chose to override this, but it seems problematic.
It seems like the packagers of the RPM did not really consider that dvb includes both video and radio devices. It is probably almost impossible for any udev rule to know which devices are radio and which are video to separate the devices.
The RTL-SDR dongle is a DVB (TV) receiver that uses the computer’s CPU to decode the video. Other software can decode the data stream in other ways, thus its application to software-defined radio. My dongle claims to support DVB-T, DAB, and FM. North America uses ATSC for digital TV, so here it does not matter, but it matters where DVB-T is the TV broadcast standard. The OP is having problems using the device to receive TV.
I think the best workaround is to copy /usr/lib/udev/rules.d/10-rtl-sdr.rules to /etc/udev/rules.d/ and change the group to video. It might also work to create an empty /etc/udev/rules.d/10-rtl-sdr.rules file, but I have not tested it.
File a bug against rtl-sdr since the package interferes with the intended use of the device.
Maybe also file a bug against rng-tools asking them to remove the dependency on rtl-sdr.
I don't have an SDR dongle, I was thinking about getting one, and mine would also be on my mythtv machine. If it is a DVB device I don't see any other way except both using a shared group of some name.
It depends on your local TV broadcast standards.
Since mythtv is using the system default "video" it probably means the rtl rpm packagers should either suggest that all use a new group of dvb, or just use the already defined "video" group for their package.
Right, I see no reason not to use the well-known video group.
On your machine the crude fix would be to change the rtlsdr group to have the same GID as video and find + chgrp all files that currently have the old gid to the new gid.
Far too ugly, IMHO.
question about SDR: How well does it work and which one do you have? And how well does it work?
I have an older generic dongle, currently about $20 online. I used it some with gqrx and had no problems. I pulled in commercial FM and 2-meter ham.
Jim
On Sun, Jun 27, 2021 at 7:52 PM Eyal Lebedinsky fedora@eyal.emu.id.au wrote:
After a recent update which installed rtl-sdr-0.6.0-9.fc34.x86_64 mythbackend failed to see the tuners. This was caused by these permissions: crw-rw----+ 1 root rtlsdr 212, 3 Jun 20 23:10 /dev/dvb/adapter0/frontend0 set by /usr/lib/udev/rules.d/10-rtl-sdr.rules and mythbackend is not a member of rtlsdr group.
There seems to be a conflict between mythtv-backend and rtl-sdr. How should this be resolved? Is it proper for one package (rtl-sdr) to take ownership of these devices?
ATM I just change the permissions of dvb tuners from rc.local but this is not ideal. Or I could add mythtv user to rtlsdr group.
TIA
-- Eyal Lebedinsky (fedora@eyal.emu.id.au)