pci hdtv tuner questions - Page 2

theheel · 05-25-2005, 03:26 PM

Quote: Originally Posted by HHdesign

I have one of the Wonder cards in my computer, and I cant take my eyes off the screen. (Not meaning to de-rail) the topic.

Whats the point of having HDTV in a car when normally its only being seen on a 7 inch screen or so?

i was hoping to get good picture quality tv, since i read in other threads that analog tv was real crappy in the car, even standing still

HHdesign · 05-25-2005, 03:31 PM

If you want good TV quality and have a surplus of cash... http://www.kvh.com/Products/Product.asp?id=79

I've seen it, its like Direct TV or Dish Direct in your car, really neat thing to have, and the picture (I only saw it on a 19 inch screen) was very good.

FiSKARZ · 05-25-2005, 03:34 PM

HDTV simply means High Defenition. Just by having an HDTV antenna and card does not make you immune to the factors that affect the signal itself. Basically what I mean is that HDTV is still succeptable to "inteference", just like the fuzz we used to see when we had those rabbit ear antennas on TVs. If you take a look at any HDTV with built in tuner, and you view an OTA hd channel, you can usually view the signal strength as well.

Jahntassa · 05-25-2005, 05:19 PM

Agreed..you won't get 'good' OTA tv unless you're right near the transmitters. There's a lot of stuff going against you (buildings, ground..etc). The HD card might not be a good idea, but a standard PCTV card with a good amplified in-car antenna might work.

kevinbr100 · 05-25-2005, 08:19 PM

why i would be interested in hdtv in the car, because it you can get a lock on signal the picture will be perfect. with hdtv its either perfect picture or no picture. I thought maybe in certain areas with good hdtv coverage u would have a better chance at a reliable tv signal, no static, lines.

I've read a lot of comments about it probably being difficult in a mobile application, but still I would like to hear from people that actually tried it, some environments dont have tall buildings blocking/boucing signals around like new york city, so it may actually work pretty good in other areas. I did find this interesting article about mobile hdtv,

http://broadcastengineering.com/aps/...x_electronics/

basically saying the current standard is more difficult to lock on to and demodulate in a mobile application

FiSKARZ · 05-27-2005, 01:41 AM

Quote: Originally Posted by kevinbr100

with hdtv its either perfect picture or no picture.

Thats not true, Ive seen distorted hdtv images, similar to the way you would see fuzz with a regular TV antenna. Horizontal lines across the image, with the sync off, and the signal strength reported at 35%. Although it is hi-def, OTA HD is not digital like XM or Sirius, therefore a weak signal can be noticed in the image.

Curiosity · 05-27-2005, 05:43 AM

HD is always digital. That's what makes it high def. If you ever see noise in the picture, it's coming from somewhere before the MPEG-2 stream is encoded, like if the broadcaster is taking an NTSC signal, encoding it for pseudo-HD, and transmitting an ATSC signal to you. The only thing you'll see from a low SNR is errors in the stream which look just like a corrupt MPEG or JPEG - Little 8x8 blocks of garbage starting somewhere in the middle going to the right, or even rows all the way down to the bottom.

bimmerpc · 06-16-2006, 11:57 AM

Help me out here...
I am experimenting with these usb digital-tv dongles on my laptop to get some kind of tv in my car. I have tested the freecom usb dongle with dvb-t and a crappy 2dm tall antenna (looks like a black pencil with cord). anyway, putting the antenna temporary on top of my car roof, makes the signal to be good when standing still. So I´ll just look around for some antenna-booster so that I can have the antenna hidden inside my car. Probably that will result in ok picture at least when not moving.

I have a digital tv-box inside my summerhouse and the signal was way better with a antenna-booster than before so I guess that matters.

What I wonder is.. the freecom usb does not say anything about hdtv-reception. Most other dongles brag about being hdtv ready. I dont care because the picture on my 7" screen was ok enough with the digital reception. BUT what happens when a program is broadcasted with hdtv on the "air-broadcasted tv-stations"? Will there be NO picture at all or will there be autoscaled to normal digital tv or do every usb digital dongle on the market recieve hdtv if its digital???

bimmerpc · 06-17-2006, 10:27 AM

..

dyne · 06-24-2006, 05:39 PM

OTA hdtv and SD signals are broadcasted simultaneously. If you have a tuner that doesn't do hdtv, then it'll just ignore the hdtv broadcast.

mgithens · 06-26-2006, 03:19 PM

HDTV signals are broadcast from a local radio tower (referred to as OTA - over the air)... you can receive the signal with an omnidirectional antenna - provided that the tower is close - different channels come from different towers, if the range is too far then you will need a directional antenna and it is very sensitive as to where it is pointed... the downside to an omni is that it can pick up reflected signals at the same time, so it can "double up" the image and you get a REALLY crappy picture... so a rooftop directional is the best idea, but absolutely much be adjusted for every parking spot...

another issue is that most people here are running a 480x800 display which essentially is an EDTV... which is 480p resolution, most high def channels are broadcasting at 720p and 1080i - essentially 720x1280 and 1080x1920... so the signal is a bit overkill - but I guess it is better to have too much res than not enough...

and then the true limitation of the setup... computing power... I own the ATI HDTV in my HTPC and when recording a HD show it only takes about 4 to 6% of my AMD 64 3400+... playback takes 60 to 70%... my AMD XP2000+ totally choked with this setup... watching the live stream is the same as playback... so the VIA boards are out, you need a P4 2.4 or somewhere around a 2800+...

HD in the car... desireable? YES... attainable? not really... spend the money on a larger hard drive and keep TONS of movies/tv shows on hand... voila...

setite · 07-17-2006, 01:46 AM

this is too bad... i wanted to do this but ya, to pict up digital OTA signals you need a directional antenna... having a huge rotating dish like the ones on people roofs would look funny... it would make a neat whistle in the wind though

bimmerpc · 07-17-2006, 04:39 AM

I just wonder... since the big boss boom expensive factory fiitted navigation/stereosurround/tv entertainment systems that comes with the expensive cars around always has tv (maybe though analog). Are they satisfied with no reception after paying $$$$$ for it?

setite · 07-17-2006, 01:07 PM

from what ive seen the analog isn't too bad... i assume its like the improved radio reception in the car vs at home. I live in las vegas and there is a little town called Indian Springs thats quite a bit away... i can pick it up on car stereos with good tuner modules, but none of the stereos i have tried in home work... except for one cheap clock radio my buddy had... but he was in a paper thing walled apartment.... wondering what antennas to use in car pc though... my wintv pvr500 or somethign other uses coax... car antenas seem to use 3.5 mm mini plugs

MobiTekLink · 07-17-2006, 01:14 PM

www.slingmedia.com great product! I use it over my EVDO connection in NYC