[mythtv-users] DVB-T Cards - Comparisons or experiences

[Dan Seddon]

Stephen Kitchener wrote:

>On Friday 03 Feb 2006 16:50, Dan Seddon wrote:
>  
>
>>Stephen Kitchener wrote:
>>    
>>
>>>Hi List,
>>>
>>>I need some expert advice please.
>>>
>>>I am trying to decide as to which DVB-T card to buy, I have a list (though
>>>there are probably more) to select from, but I need someone who has had
>>>the experience, to answer a simple question....(the answer might not be
>>>simple however)
>>>
>>>The list is :-
>>>the list comes from " "http://pvrhw.goldfish.org/tiki-pvrhwdb.php"
>>>
>>>Twinhan Visionplus DVB-T
>>>Wintv Nova-T
>>>Technotrend Budget DVB-T
>>>Kworld DVB-T Xpert PCI
>>>
>>>(these are the ones that I could identify as DVB-T)
>>>
>>>Now I think that the Technotrend Budget DVB-T is the same as the Wintv
>>>Nova-T, which I already have, and isn't very good at decoding.
>>>
>>>The question is, which card is better at reception, I'm not talking about
>>>speed of tuning, I can compensate for that in the recording profiles if
>>>needed, what I am asking is which card is more sensitive or better at
>>>decoding the digital stream ??
>>>      
>>>
>>I'm a bit confused here, though you might be answering some questions
>>which I've wondered. When you mean decoded - I'm guessing you're talking
>>about turning the recieved transmission in to an Mpeg stream? As, the
>>actual decoding of the mpeg is done in software or hardware (which ever
>>you use). So, by saying some cards are better than others at decoding,
>>do you mean that some a more reliable/faster at converting the signal
>>(so you have fewer artifacts and quicker channel changes on Live TV) -
>>as the actual image quality would be determined by the mpeg decoder? I
>>have 2 Nova-T cards,  as they seem to be the best supported, and
>>sometimes get freezing and artifacts (which I guess could be down to the
>>card), but they are definietly very slow at changing channels. You seem
>>to be saying this varies from card to card - or are you hoping it might
>>do? I would certainly like my channels to change quicker (though perhaps
>>that will be improved in 19.0), I hadn't thought of these issues being
>>card dependent before.
>>    
>>
>
>Sorry I wasn't specific enough...what I meant was that some cards seem to be 
>better at getting a usable signal from the transmitter before it gets decoded 
>into a digital stream and that is down to the sensitivity of the tuner on the 
>card, its ability to get a signal from the transmitter and not down to the 
>ability of the encoders on the card. 
>
>If the signal isn't good enough as it leaves the tuner, you will get artifacts 
>and there isn't anything that you can do about it.....Unless someone knows 
>better, I would like to know.
>
>As to card switching speeds, I would suggest that is down to the hardware, and 
>not at all down to Mythtv, maybe the firmware, but then that has to talk to 
>the hardware anyway...
>
>  
>
Thanks that's very useful - it help me think about where to look when 
looking for some way of speeding up my card in future. Unfortunately I'm 
not the only one using my Mythtv setup, so although I'm not bothered 
about Channel change speed I'm not the only one who matters......

Cheers

Dan