Digital TV Transmitter Using a VGA card

An anonymous reader writes "Yet Another Project from Fabrice Bellard : with any PC and a standard VGA card, you can build a real Analog or DVB-T Digital TV transmitter by directly generating the VHF signal. The provided example shows a Lena picture transmitted as a real Digital TV channel."

Comments

Re:ANOTHER one!!

[gg3po]

I know he's the guy behind ffmpeg (used by most *nix media players) and the excellent qemu emulator that I use every day.

It Won't Be Long

[geomon]

Until this project is rendered illegal in the US under some DMCA-style bullshit. After all, you might be able to (gasp!) record something off of your incoming television signal.

Of course, only pirates and pedophiles will have a use for this project.

(The last part of this post is a JOKE, gawddammit!)

NSFW?!?

[natron 2.0]

Hey editors, how about a NSFW warning on stories such as this!

Guys, this is no small feat

[o'reor]

and yes, I am a (former) DVB-T engineer (and a consultant in digital video broadcasting at large -- yes, I know a bit about the US and Japanese standards too).

What Fabrice is telling us here is that he has managed to produce a real-time (or close-to-real-time) DVB-T/DVB-H software COFDM modulator, the output of which may be broadcast via the DAC converters of the video board. Given the complexity of the generated signal (more than 6000 subcarriers, not including pilot subcarriers which are used as beacons for the demodulator, and paying respect to the guard interval -- sorry for the technical gobbledygook), this usually requires a dedicated ASIC. Don't forget to include the preliminary phases of the encoding : creating an MPEG-2 video channel, an MEPG-2 transport stream (OK, he did it using a modified MPEG library), then encapsulate this into MPEG-2/DVB frames, add the Reed-Solomon code, perform the interleaving procedure, pour in some Viterbi encoding for redundancy, and feed it to the input of the DVB-T modulator, phew ! you're done.

I want to say hats off, ladies and gentlemen, to this outstanding performance. The Free Software movement definitely needs more guys like Fabrice, and we all need to encourage him into publishing more of his code.

Chapeau bas, mon cher Fabrice !

Re:crap ..

[Bishop]

a naked shoulder will get you fired? Where the hell do you work?

Re:Guerrilla television in 2007

[modecx]

Let's assume that it does happen. All the middle-class people won't notice it because they are paying monthly cable fees and cable TV will not be affected by the VHF/UHF shutdown. However, let's assume that in poor neighborhoods the convertor boxes don't work well, or are prohibitively expensive, or are too technically complex for the general population. Suddenly there's no television.

That's a joke, in my experience. My family rents out many (small) appartments, and several houses. Many of the tenants certianly qualify as poor, certianly they're on fixed incomes... And the overwhelming majority have cable today, and always have had it in the past. You can't blame it on poor reception, either. It's fine.

A couple of tenants have even gone as far as losing their water service, but they still had to have their $60/month cable service. It's like goddamned crack. They'll do anything, as long as they have a roof over their heads, food in their bellies, and America's Funniest Home Videos on the TV.

My family dosn't belive in much TV. We're too busy managing our small corner of the universe, and actually having fun when we're not doing that. I only got cable a year ago when Qwest pissed me off to the point where I had to ditch DSL through them.

For $3 extra than the cable internet service I get basic, anaglog cable, and that's fine because I get a few chanels that I do enjoy. Discovery (love them motorcycles!), Food Network, and I think TBS. There's some others but they mostly have crap/reruns(crap).

I think many Middle Class Americans hold off on overly superfluous things like pay-TV. Not to sound clichéd, but do people really need more than 64 channels? Unless you spend all day in front of the boobtube, you can't remotely hope to watch enough to justify it--if you don't have money to throw away, that is.

I suspect that this phenomenon echos throught our country. I think many lower-class people (from the Blacks in the ghetto, to the whites in the trailer courts) are either too lazy to do anything else, unable (by injury, or illness, including mental--including TV addiction), or they just don't know what the hell else to do.

Having that said, I doubt pirate broadcasts will pop up all over. There's the thing about the price of the equipment (unless they steal it that is), the knowledge of how to hook it up, and, well, it takes effort. People don't like effort.