Record audio from Landline

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Hi,
A project I wish to do using C program.
I use a LAN cable which connects to my Land line. And through which I connect to internet.
I need to record what ever I speak through my Land Line phone on my desktop which is obviously Windows xp machine.

Is there a way to do it. What aspects do I need to learn to achieve this task?

I need your help please :)

Could you please help?

Posted 13-Aug-12 8:49am

AshakiranBhatter

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Kenneth Haugland 13-Aug-12 14:53pm

Yeah, connect your program to a phone sentral or have VoiceOverIp Telephones, othervise known as bugging somebody ;)

enhzflep 13-Aug-12 15:45pm

Not in my state/country.
In my country, it's illegal to intercept the conversation at some point *in the telecommunications infrastructure* without (a) the knowledge and consent of 1 of the parties or (b) a court order to do so.

It's illegal to modify equipment attached to Telstra's lines, so your choices are limited.

But anyway, my point is that laws of this nature can vary wildly from state to state, even within the same country.

Kenneth Haugland 13-Aug-12 15:50pm

Thats not what I meant. I installed local phone sentrals, meaning in office buildings and sutch, there you can have access to a lot of information, if not exactly bugging people. As for VoiceOver IP you can ruter the conversations via a local server, and then do something with the data. As for analog phones, well that is a nother matter completley, you might as well get the house bugged. :)

PS Never calimed it was leagal, just said the way he proposed it would be difficult in any matter.

enhzflep 13-Aug-12 15:53pm

Oops, sorry.
Cool, Interesting info.
cheers :thumbsup:

With respect - you made no mention of the level of difficulty of the task. You used the word bugging, which I've extrapolated (wrongly) to mean surreptitious interception. (which is illegal unless court mandated)

Kenneth Haugland 13-Aug-12 16:01pm

I understand, but I meant both. I think it's illigal no matter what the law said. Its basically a police job :)
I suspected he wondered about taping conversations of sales and other buissiness deals.
BTW: Here is the phone sentral I was talking about:
http://enterprise.alcatel-lucent.com/?product=OmniPCXOffice&page=overview

enhzflep 13-Aug-12 16:20pm

"I think it's illegal no matter what the law said"
:laughs: And that's why we have lawmakers, judges and police - people that are qualified in the application of the law. If the law says it's legal, it doesn't make a piece of difference what I or you think....
Just like programmers are the people I want coding my stuff - not just some secretary...
Again, in my state & country I do NOT have to inform the other party that I am recording the conversation, so long as I am a party to it & I don't publish it, nor record it with the intent to publish it.
Companies are NOT legally obligated to give the usual
"This call may be recorded for training purposes. Please say so if you object" - it's both a courtesy and a a$$ covering exercise (it allows them to publish the call transcript/audio)

But anyway, that's just getting off-topic.

That looks like a reasonably nice piece of gear - It's certainly a lot smaller than the old PABX system I played with about 20 years ago - back when an ISDN connection was both expensive and something to be envious of. (3g mobile gets better speed than ISDN - for $5/week, ISDN was thousands per month)

Loved it when my last workplace moved over to Cisco Voip Phones..
You know exactly what happened when the network went down, right? Yup - dozens of people running around frantic on their mobile phones, trying to get answers - my computer wont work, my phone doesn't work to report the problem, what the hell do I do?

Think we got sent home 2 or 3 times at 1pm because of that.
Fun times indeed. :) I'd forgotten all about it till I saw the photo of the OmniPCX Office RCE.

Thanks for the memories! :-D

Kenneth Haugland 13-Aug-12 16:28pm

What I meant is I though the one that does the recording without informing others is a real a**hole, I wouldnt do that.

It is nearly 10 years since I installed this hardware, but there were always some issues with them, and I remember my boss call setting the parameters in the phone central for programming :) I understand what he means but now with .NET it's a bit wierd....

[no name] 13-Aug-12 15:02pm

are you serious ?

[no name] 13-Aug-12 15:03pm

I am not kidding but just want to know if this can be considered as a project or not ?

enhzflep 13-Aug-12 15:51pm

I'm running on the assumption that it's a ADSL modem inside your PC - though that seems strange, since phone-lines in this country are a different size than LAN cables (slightly smaller than lan - less wires too)

I suspect that you'd have to be able to write a driver for the equipment in your pc that's attached to the phone line. Surely, no mean feat! (not easy)

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Christian Graus · Answer 1 · 2012-08-13T09:38:00

Solution 1

Yes, Ken is serious. If your data is analogue, then your computer can't read it, even if the plug fits. VOIP will make it digital. It's almost certainly easier to buy a cheap microphone and stick it to your phone.

Posted 13-Aug-12 9:38am

Christian Graus

Comments

Albert Holguin 14-Aug-12 20:55pm

Actually, he should be able to digitize the analog audio with his sound card.

JackDingler · Answer 2 · 2012-08-14T07:43:00

Solution 2

The alternative is to buy a telephony card and program it to record calls.

Some phone modems may also have the capacity to do this. I haven't had much luck in getting off the shelf modem cards with audio, to work well.

Posted 14-Aug-12 7:43am

JackDingler

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Albert Holguin 14-Aug-12 20:55pm

Sound card would work for digitizing audio...

JackDingler 15-Aug-12 2:46am

If you plug it straight into a landline, it may be damaged when the 100 volt ring signal comes through.

Albert Holguin 15-Aug-12 10:18am

There's usually converters for that type of application, but I did mention the tricky part was connecting them together. It is very doable though.

JackDingler 15-Aug-12 10:48am

A telephony card is an audio card that digitizes audio... It also has controls to send and receive DTMFs, detect rings, perform flash hooks, etc....

But yeah, you could probably externalize these functions and plug them into an existing audio card.

Albert Holguin 15-Aug-12 11:00am

See my comment below to the OP... I personally think this would be a great project for an engineering student. The breadth of subjects covered by this one task covers a lot of ground.

Albert Holguin · Answer 3 · 2012-08-14T14:53:00

Solution 3

Sure there's a way to do this... if your computer has a sound card, then you have this capability already.

A few steps to achieve this:
0. Connect your phone line to your line in input (not as trivial as it sounds)
1. Digitize the data using your sound card (this will turn it into PCM audio)
2. Save your PCM data to WAV file (uncompressed audio)

The tricky part will be connecting your analog telephone line to your line in input. Reason being that you have to make sure you don't burn the input with levels that may be too high (consult your sound card manufacturer for appropriate levels).

After you've figured out the voltage levels, you can simply control your capture using the Windows API's for sound capture. Something like this[^]...

Posted 14-Aug-12 14:53pm

Albert Holguin

Comments

Kenneth Haugland 14-Aug-12 21:01pm

In norway the analog line in is about 48 V, and the ISDN line from 120 - 160 V, he would have to be careful not to blow up his computer trying to do this himself. Just a warning :)

Albert Holguin 14-Aug-12 21:04pm

Good point, in the US the levels don't go up that high (except for when the phone rings). There are converters available to remove the high voltage ring though (I believe).

[no name] 15-Aug-12 9:58am

There are a lot of politicians in this blog!!!! certainly they talk about impossibility before even talking about the possibility. I said i wanted to take it as a mini project and they talk about country rules. I was trying to explore technical things but they deny in terms of politics. :(

Albert Holguin 15-Aug-12 10:20am

Everyone is suspicious off the back, can't blame them... but I do think this type of project would be excellent for an engineering student. Why? You deal with everything from analog circuits (to tie the two systems in together) to digitization and processing within your PC (programming). It encompasses a bit of everything, so it's a real world type of scenario for an engineering student.