Television decoding

[Chankama]

I want to get started on a new project. Any of you know where I can get some details about how Cable television signals are encoded before being delivered to houses?

I want to pipe these to my computer. decode them (if necessary), and then pipe them back out to a television set or something. Obviously, it's only for personal use..

 

[Elbatrop1]

I think your first stop will be here:
http://electronics.howstuffworks.com/cable-tv.htm

I think the easiest way to do this is to get a PCI TV Tuner, and connect your cable into that.

Cable signals are broadband. Thus there are all the channels being transmitted on the cable at once. They are all transmitted simultaneously by making each channel a different frequency. You have to be able to tune into each frequency to get the channel there.

 

[Chankama]

Hey Elbatrop1. Cool. You are the Cable Guy ..

What about all those specialty channels and such that we are "not" subscribed to?.. Are they typically transmistted, and if so how are they typically "protected" from non-subscribers?.. That was the original motivation behind this thread actually. A tv tuner doesn't give u the channels u are not subscribed to. I just wanted to do some signal processing to bypass this, and then ouput the post-processed signal to a TV or whatever.

This is strictly for education/personal purposes.

Thx..

 

[Elbatrop1]

Actually, you are not able to get those channels back that you arent subscribed to. On you cable line, a filter is actually installed according to what service you subscribe to. For example, if you only want cable internet, then the cable guy will put a filter on your line that gets rid of all signals except for the internet (which is kinda on a channel, itself).

So, the filtered channels dont actually reach your house, and you have no way of bringing them back.

Digital cable is a different story. If you have digital cable, filters are still used. But, for filtering digital channels, your digital terminal is actually programmed from the cable companies office. And, again, there is no way to get around it.

 

[Chankama]

So, the filtered channels dont actually reach your house, and you have no way of bringing them back.

Ah damn. Where is this filter located man? Inside the house or what?.. And can the cable company tell remotely, if the filter is "tampered" with?..

I am only asking b/c "phone companies" can tell if u screw around with the phone line on your end. This dude I used to hang with tapped the phone lines in our residence, from just inside his room, and got caught by the phone company's scanners. lol

 

[Elbatrop1]

The filter is located in a pedestal or aerial line. They are locked so that people cant remove the filters inside. Also, the filters themselves are also locked onto the lines so that they cant be removed.

I dont know about the cable company where you are, but the one I work for will actually audit the pedestals and make sure no one is getting more than what they pay for.