[mythtv] Shouldn't MythTV disable the tuner between switching inputs?

[Rudy Zijlstra]

Daniel Kristjansson wrote:
> On Sat, 2008-01-05 at 15:56 -0800, Sam Logen wrote:
>   
>> --- Sam Logen <starz909 at yahoo.com> wrote:
>>     
>
>   
>>   Anyhow, when I'm attaching a device to a/v
>> connectors on a PVR-150, and I'd like to watch Livetv
>> through that, instead of the tuner, I can't seem to
>> change my inputs on the card because the tuner isn't
>> being shut off first (I have programming on the tuner,
>> so I want to keep that input source).  I'm just asking
>> if it's not better to have Mythtv shut off the tuner
>> before switching away from it to a different input.
>>     
Are you certain on this? What i do remember is that it cannot switch 
while encoding... In other words, the driver will refuse to switch 
inputs while the MPEG2 engine is active, as doing that will cause 
incorrect MPEG streams. When you switch with the MPEG engine not active, 
there should be no problem. Can you point to the relevant ivtv posting?
>
> Historically the ivtv driver has not had a problem with switching
> inputs. Do you have any information on when the driver was changed
> and do you know if this only applies to the PVR-150 or the whole
> range of ivtv cards? Turning off the tuner would introduce a channel
> changing delay for all MPEG-2 recording cards and turning on and off
> the tuner when special hardware requires it is really a job for
> the driver anyway, we shouldn't need to special case for particular
> hardware or particular V4L2 drivers in MythTV; we don't really have
> enough information, and that taking care of that stuff is the main
> reason we bother with drivers in the first place for an application
> like MythTV.
>
> FYI I'm stuck using an older ivtv since the current drivers, starting
> a little before 1.0.0, don't support 608 captions on PVR-250 cards.
>   
This is on Hans his TODO list (if you are talking about VBI as i think 
you are doing). His problem is access to a PVR250 in NTSC land, as he is 
living in PAL country. If you can get him access to a NTSC PVR250 that 
would likely help things along :)

> Until that is fixed there probably won't be many additions to MythTV
> to support newer ivtv driver revisions.
>
> -- Daniel
>
>
>   
Cheers,

Rudy