Advice on Terrestrial Digital (DVB) TV

[Airw0lf]

Hi all,

A terrestrial (i.e., not satellite) digital TV (DVB) trial has started up in my area recently, and I've been trying to figure out what kind of hardware and software I would need to make use of it.

Firstly, I understand that all you need to get a signal is a UHF antenna. I have a roof-mounted UHF antenna that works pretty well. In general, how resilient is the signal to poor reception? Since it is a digital signal, does it mean that it is "all or nothing" - i.e., you either get a perfect reception, or nothing at all, or just some dropped frames? The major attraction for me is the fact that a DVB tuner card will allow me to record the signal in its original MPEG-2 format...no lossy analog to digital conversion like with traditional tuner cards. I am just wondering if you need absolute perfect conditions to get any decent performance, in which case I don't think it will be worth the effort.

I have been looking at some tuner cards that are available, such as this one from AVerMedia - http://www.avermedia.com/cgi-bin/products_digitvtuner_dvbt777.asp?show=2. They all seem to have similar features, but I think they all work through software that is proprietary to the manufacturer. Most of the interfaces all seem to be unnecessarily bloated too.

Is there any free or open source software that can dump the DVB streams to disk, or will I have to rely on what my card provides? As far as watching TV, I assume that the manufacturers usually provide a directshow driver that most third party programs can access. Currently I use DScaler with my Bt8x8 analog card, so I don't even need to bother with DirectShow...

[Video Dude]

Since it is a digital signal, does it mean that it is "all or nothing" - i.e., you either get a perfect reception, or nothing at all, or just some dropped frames?
You will get dropped frames or it will appear that the picture will freeze.

[SeeMoreDigital]

All DVB signals rely on the quality of the received signal over the signal strength. Poor signal quality will result in either total loss of picture and sound or very annoying on-screen intermittent picture freezing and/or squeaking sounds emanating from your speakers...... Horrible!

Most DVB-T cards are capable of offering reliable digital TV reception. And once the cards drivers have been installed, many cards can be run using third party software.

When it comes to capturing the MPEG-2 DVB-T signal, most card softwares offer "direct" stream capture (ie: no re-compression). So your captures have the capability of looking every bit as good as the source.

As for the perceived quality of any digital image (and sound), it all depends on the bit-rate of the transmission, not to mention the source. DVB-T signals in the UK can look pretty crap, especially when displayed on a big screen. Depending on the time of day and the amount of channels sharing the multiplex they often look very (very) pixellated.


Cheers

[Airw0lf]

Thanks for the responses guys. I think I might just give it a go and see what happens.

[*.mp4 guy]

Not to Hijack the thread, but would that card work in the united states (I know nothing about HDTV cards), and if not what cards do?

[Edit]
whats the difference betwene ATSC tv and DVBT?

[jggimi]

Might I suggest perusing our HTDV/DVB/TiVO forum? There's lots of information there.

[*.mp4 guy]

That sounds like a good idea. :p

[reepa]

This is what digital ice hockey looks like :^)

http://img387.imageshack.us/img387/3417/dikitv23xh.th.jpg (http://img387.imageshack.us/my.php?image=dikitv23xh.jpg)

[*.mp4 guy]

...No I beleive thats what an over compressed Mpeg4-AVC stream without inloop deblocking enabled looks like. :sly: