[mythtv-users] HVR-950q analog/NTSC capture has no sound

James Miller gajs-f0el at dea.spamcon.org
Fri Feb 10 21:33:11 UTC 2017

On Fri, 10 Feb 2017, R. G. Newbury wrote:

> It's a little off the wall, but try plugging the two units into USB sockets 
> *which are on different hubs*. Say, one on a rear socket and one on the front 
> of the box. It is quite possible that the usb sub-system is getting confused 
> about the number of units actually available *on one hub*, since they 
> obviously have the same usb identifier.

Thanks for the suggestion, Geoff. Sounds worth a try, though I'll have to 
do some strategizing to implement it. First, I'm not sure this box has 
more than one hub built in: this is a Liva X with only 3 USB ports. I 
suppose it might nonetheless be worthwhile checking whether plugging one 
or other of the HVR-950q's into a different USB port might have an effect.

One USB port is home to the system's recording storage drive connector, so 
I don't want to mess with that one. Another port has my flirc plugged into 
it which, apart from the fact that it is currently in the optimum 
orientation to receive signals from my remote, could otherwise be plugged 
into my external USB hub (in place of the errant HVR-950q). The third port 
is where I connect the external hub into which the two HVR-950q's are 
currently plugged.

> Have you determined whether the *same* unit is always recognized on reboot? 
> If that changes it would point to an initialization "lottery" condition 
> (which is probably worse than a race condition)

I've so far tested it only about a dozen times but, yes, so far each time 
I've rebooted/power-cycled it has been the same HVR-950q's analog 
component that gets recognized and that shows up under /dev/video0. The 
other seems invisible to the system (and thus to MythTV) until I 
unplug/re-plug it, after which it shows up and--subsequent to killing and 
restarting MythTV--works fine for live viewing or recording.

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