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Start/stop recording based on external switch?

Posted: Sun Jul 11, 2010 10:10 am
by eprimetime
I have used Audacity for a few years off and on for various things, but now I need some help, and hopefully there are answers, even if it means that I cannot use Audacity.

I have a device similar, but about 15 years older, than this product - http://www.radioshack.com/product/index ... Id=2104040

It has a phone jack in, a phone jack out, an audio output to connect to a tape recorder, and then a smaller plug that is used to plug into an older tape recorder's record control plug. When you are using the phone, it detects that, and basically closes the switch on the record line. The audio is sent through the audio out, to the tape recorder.

Being as I am one of the dwindling number of people that have a landline phone still, and the need to record the audio at times, I was looking for a way, based on the closing of that record control switch by the box, to automatically start recording through the sound card of my computer. Preferably, when the switch is opened, the recording stops, and it automatically time and date stamped, for future reference. I can solder, and have thought of using either the serial port or parallel port to connect to the record switch. No problem on the hardware side of things. I just need to know if Audacity or another software can monitor said port, and start recording, end recording when the circuit is broken, and time and date stamp the files.


BTW, it is legal for me to record all phone conversations in my state, without having to notify the other party. Only one party has to give consent, and no notification is needed.

Thanks,

eprimetime

Re: Start/stop recording based on external switch?

Posted: Sun Jul 11, 2010 5:01 pm
by whomper
lots of similar devices for sale now
maybe even a program that timestamps which that device does not do

perhaps you could use the sound activated recordign feature of audacity - similar to vox - when the phone line is outputting a signal it would be recorded ---

dont think you are going to get time and date stamp though
but that batteryshack device did not do that either
and it was intended to go to a vox capable cassette recorder
although some of them also controlled a cassette device through the mike remote on/off plug

so
dump the old cassette
connect the audacity
turn on record when signal detected
and
you have the same capability as you do now
still without the timestamp that you do not have now

Re: Start/stop recording based on external switch?

Posted: Sun Jul 11, 2010 9:07 pm
by kozikowski
Audacity is a simple audio program with pretty simple features. There's no shortage of people trying to make it into a surveillance program and for the most part, it won't do that. For one thing, it doesn't do much in real time except capture and play back. There is one capture feature and that's Voice Activated Recording. Past that, there's nothing.

So your task is to write Windows routines that will respond to contact closures and perform System Level commands to Audacity -- and even then, you have to be running Audacity from inside the program to get some of those features.

So the short answer is no.

Koz

Re: Start/stop recording based on external switch?

Posted: Mon Jul 12, 2010 3:54 pm
by steve
The "Sound Activated Recording" feature in Audacity 1.3.12 may provide what you need http://manual.audacityteam.org/index.ph ... references

On Windows, all files are automatically "timed stamped" when they are created. When you export your recording, the audio file that you create will have a "file creation time/date" http://articles.techrepublic.com.com/51 ... 34280.html

Re: Start/stop recording based on external switch?

Posted: Mon Jul 12, 2010 7:31 pm
by eprimetime
I saw the sound-activated recording, and that almost seems like what I need. The only question is, will it create a new file every time the level changes to wheer audacity is recording or not? or if I leave it running all day, will all of my phone convos be in one large file? I can almost deal with that, and it will come close. The time/date stamp on windows is sufficient, and I think I ran across a file renamer that would rename based on file creation time, so that could handle this.

To the first reply, the box that I have does turn the recorder on/off based on the microphone or "remote" input.

I will be dedicating a computer to this task, and can probably find a program launcher that could, say, launch Audacity at 12 in the morning, and shut down Audacity at 11:55. It would then be off for 5 minutes, but I am never on the phone at midnight anyway. Or maybe even a shut-down timer program to reboot the whole computer at 11:55 at night, with Audacity in the startup folder, so it start when Windows starts. At least then, if it records all audio to a single file, I can narrow it down by day, and can search based on date of creation.

Any other ideas, I am more than happy to hear them.

Thanks

Re: Start/stop recording based on external switch?

Posted: Mon Jul 12, 2010 8:05 pm
by steve
To get a time-stamped recording for each call you would need to export the recording after each call.
(File menu > Export)
then delete the Audacity track to be ready for the next call.

If you just leave it running, you will get one long track and when you export it the entire track will have one time stamp (the time that you export it).

Alternatively you could record as one long track, then split up the track later using labels (markers) and the "Export Multiple" function, though I would think that exporting the calls as you go would be easier. (more info: http://wiki.audacityteam.org/wiki/Split ... ate_tracks )
eprimetime wrote:Or maybe even a shut-down timer program to reboot the whole computer at 11:55 at night,
That would not work. Audacity does not create "audio files" until you "Export" the recording as an audio file. Audacity works with raw data, loosely bound into a "Project". If you just shut down the computer, Audacity will effectively crash and the recorded data will probably be lost. See here for an explanation of how Audacity handles data and files: http://wiki.audacityteam.org/wiki/File_Management_Tips

Re: Start/stop recording based on external switch?

Posted: Mon Jul 12, 2010 11:19 pm
by whomper
but with one long track timestamped at teh beginning
you can see the time of any sample by adding elapsed time to start time

Re: Start/stop recording based on external switch?

Posted: Mon Jul 12, 2010 11:23 pm
by steve
whomper wrote:but with one long track timestamped at teh beginning
you can see the time of any sample by adding elapsed time to start time
It wouldn't be time stamped at the beginning.
stevethefiddle wrote:the entire track will have one time stamp (the time that you export it).

Re: Start/stop recording based on external switch?

Posted: Tue Jul 13, 2010 5:30 am
by kozikowski
Audacity doesn't create a file until you export which would be at the end of the process and not necessarily at the end of the recording. In any event, it wouldn't give you anything useful. If you only got three loud seconds of performance each hour for 12 hours, you would have one thirty six second long file for twelve hours work.

You really need a surveillance program. They automatically roll over periodically like once a month and provide abundant time and date stamps in a continuous stream. The one we have scrubs. Many provide key activation (motion, location, trigger, brightness, loudness, etc. with even more meta-data to tell you exactly what they did.

The desperation method is to shoot bad quality video of a calendar/clock along with its associated sound capture. No matter what the capture did or how it stopped and started, there's a running record. You might do something with time code, but those start over every 24 hours. Remember VHS tape? Those would record HiFi sound for six hours, longer if you jiggered a contact closure into the pause button -- or the remote.

Koz