[mythtv-users] Ideas to diagnose one faulty DVB-T adapter (on a dual adapter USB stick)

[John Pilkington]

On 31/10/12 14:06, Dan Gravell wrote:
> Thanks for your advice.
>
> Going back to your first response, I did originally try the MythTV tools
> (via mythtv-setup) but scanning the first adapter failed with no
> channels, the second worked. So similar to using scan, and it's easier
> to copy+paste the output from scan so I referenced that...
>
> I'm pretty sure both worked a few months back. What I didn't say
> previously is that at one point in between then and now my young puppy
> managed to get behind my home server, toppling it. One of the USB
> sockets was ripped out but otherwise the server seemed to work fine. I
> didn't check the tuner, so maybe this was a casualty. I guess I'm
> wondering if some sort of physical damage might cause these errors.
>
> Currently I have removed the first adapter from Input Cards and that
> seems to work for now. Shame I'm missing extra recording capability though.
>
> Dan
>
>     ------------------------------------------------------------------------
>     *From:* John Pilkington <J.Pilk at tesco.net>
>     *To:* mythtv-users at mythtv.org
>     *Sent:* Tuesday, 30 October 2012, 20:33
>     *Subject:* Re: [mythtv-users] Ideas to diagnose one faulty DVB-T
>     adapter (on a dual adapter USB stick)
>
>     On 30/10/12 19:48, John Pilkington wrote:
>      > On 30/10/12 19:19, John Pilkington wrote:
>      >
>      >> Ok, maybe slightly inappropriate.  If it wasn't helpful I'm sorry.
>      >> People do get into unnecessary difficulties with DVB tuning and the
>      >> choice of tool looked perhaps a little old-school.  Do you have
>     a more
>      >> useful suggestion?
>      >>
>      >> If one section is dead it should perhaps be disabled.  If it has  a
>      >> faulty PID filter, or, more likely, one with a numerically small
>      >> hardware limit, it's unlikely to be fully satisfactory today.
>     Perhaps
>      >> consult the linuxtv list of devices to see if it does have a known
>      >> hardware limit, quite likely on an oldish device.  I doubt that
>     tools
>      >> would be available to cure the problem, and new near-equivalents
>     aren't
>      >> expensive.
>      >>
>      >
>      > After Googling the device I see it is claimed to pass the entire
>     stream;
>      > no filtering.  No further suggestions.
>      >
>
>     There was a report on the linux-media list in July about being able
>     to get one or other but not both tuners working, followed by a
>     statement that it was working using 'twoflower' - whatever that is.
>     You may be able to follow that up.
>
>     I would be inclined to use the card setup page in mythtvsetup and
>     see if it still recognises the two dvb-t devices.  If it does,
>     delete all tuners, re-install them, define them as inputs and rescan
>     using the technique I linked earlier.  Googling  some more about the
>     specific device, or asking here with it in the subject line, might
>     be helpful too.
>
>     http://comments.gmane.org/gmane.linux.drivers.video-input-infrastructure/50597
>

It seems twoflower is VLC version 2.  I just tried it with my DVB-T USB 
device, having quit mythtv.  Media > Open capture device > Capture mode 
TV(Digital) lets you select the adapter number and specify mux frequency 
and Bandwidth (8 kHz).  Mine worked first time on both adapters of this:
dmesg | grep usb

  9.888261] dvb-usb: TwinHan AzureWave AD-TU700(704J)

I didn't try hard to see if I could receive two muxes simultaneously, 
though.

If you were able to try that it might provide another datapoint. Since 
the above post dates from July it might reflect a fairly recent update.