[mythtv-users] LiveTV on HVR-4000 not working- 0.22/F12

[Mike Perkins]

Michael PARKER wrote:
> All,
> 
> Having spent the last five evenings trying unsuccessfully to get LiveTV 
> working on my F12/0.22 platform, I've now run out of ideas and need to ask 
> for help.
> 
> I'm trying to watch LiveTV in Myth, fed from my VirginMedia STB via the RF 
> input of the analogue tuner of my Hauppauge HVR-4000 card. Mplayer works 
> fine, finding the STB output on channel 21/471.25MHz. Both of the following 
> mplayer command lines allow me to watch TV, albeit without sound:
> 
> mplayer -v tv:// -tv driver=v4l2:device=/dev/video0:normid=4:channel=21 
> mplayer -v tv:// -tv driver=v4l2:device=/dev/video0:normid=4:freq=471.25
> 
> When I try to watch LiveTV in Myth, I setup the capture card up as a V4L 
> analogue capture card, a dummy "no grabber" video source and the input 
> connection is setup to preset the tuner to channel 21. Since I've yet to sort
>  out any channel change script, I just use /bin/echo to see what Myth thinks 
> it's changing the STB channel to. My MythTV default video format/normid is 
> PAL-I which corresponds to the "4" used by mplayer.
> 
> When I try to watch LiveTV in mythfrontend, I get "snow" with a green 
> vertical line to the RHS of the screen (see screenshot below). This looks 
> distinctly similar to the output I see when I deliberately mis-tune mplayer 
> to the wrong channel/frequency.
> 
> Reviewing the FE/BE logs (with all debug verbose logging options enabled, see
>  below for URLs), nothing seems amiss - Myth seems to believe that everything
>  is fine and that I'm happily watching TV. Likewise the output of lspci,
> lsmod & dmesg (see below for URLs) all look OK - albeit to my untrained eye.
> 
> So in summary - everything looks fine, except I can't watch TV!
> 
> NB. I also can't record TV. Having seen reports of people being able to 
> record but not watch LiveTV, I thought I'd try recording. No luck - I just 
> get 5mins of snow with a vertical green line :o(
> 
> FWIW, I've installed firmware v1.23.86.1 for the HVR-4000's cx24116 DVB-S2 
> demod, which is successfully picks up. I also tried compiling up the latest 
> v4l-dvb drivers to no effect. Since I experienced the same problem I reverted
>  back to the kernel-supplied drivers.
> 
> My best guess is some form of driver issue - given the similarity of what I'm
>  seeing to a mis-tuned mplayer, could Myth be passing the incorrect frequency
>  to the tuner? Maybe a factor of 1e3/1e6 out? (I notice that mplayer talks in
>  terms of MHz, MythTV initially in terms of KHz with a subsequent conversion 
> to Hz).
> 
> Is there any way of seeing exactly what Myth passes to the tuner in the way 
> of parameters?
> 
> Should I be concerned that mplayer uses the v4l2 driver whilst Myth seems to 
> use the cx8800 driver? (A review of lsmod appears to suggest that cx8800 
> calls v4l2 anyway, but I thought I'd mention it).
> 
> I'm really at the end of my tether with this one. I've passed it by another 
> guy here at work who has extensive personal experience of Myth but, other 
> than supporting my theory of some form of driver issue, he can't suggest much
>  else to try.
> 
> Any help (very) gratefully received,
> 
> Mike
> 
> PS. I started seeing this issue on 0.23RC2. Thinking that colelctive 
> experience of 0.23RC was likely to be limited, I reverted back to 0.22 
> secretly hoping the issue was down to 0.23. No such luck - both 0.22 and 
> 0.23RC2 repeatably show the same bahaviour.
> 
Couple of minor things. Your dummy channel change script should end with
/bin/true so that Myth thinks it worked correctly, and I understood the default 
output channel from a Virgin box to be channel 60. That's what mine was set at 
when I had it to replace my original NTL box, and I had to ask the engineer to 
move it because one of my local broadcast muxes is also channel 60, so there was 
a conflict.

-- 

Mike Perkins