About recording a call every x seconds

Hi,

I tried to configure to have a record every 5 seconds but I only get one. Can someone help me to troubleshoot where the misconfiguration is?

exten => 7200,1,Answer() 
same => n,Set(MONITOR_BASE_FILENAME=${STRFTIME(${EPOCH},,%Y%m%d-%H%M%S)})
same => n(start_loop),NoOp(Starting loop iteration)
same => n,Set(MONITOR_FILENAME=${MONITOR_BASE_FILENAME}-${STRFTIME(${EPOCH},,%S)}.wav)
same => n,MixMonitor(/tmp/${MONITOR_FILENAME}) 
same => n,Dial(PJSIP/7200) 
same => n,Wait(5) 
same => n,GotoIf($[${DIALSTATUS} = "ANSWER"]?start_loop:end_loop) 
same => n(end_loop),Hangup()

With all regards,
Tuan

Simple - as soon as the Dial() command executes, the dialplan will:

a) stop processing, because the call is getting connected and is then in
progress

b) not continue after the call completes, because you have not used the ‘g’
parameter to the Dial() command.

Aside from that, though, what you want is simply not possible in the dialplan

  • you would have to send the audio stream outside of Asterisk and chop it up
    into 5 second segments using some other utility.

Please enlighten me, though - why do you want to record a call in 5 second
segments?

Antony.

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Dial supervises the call, so the Wait(5) will not be executed until the call is over.

The easiest approach is probably to post-process the file, but you could probably do it with AMI, or by replacing Dial by an ARI application.

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Tks Antony. I want to see if I can stream the audio of the call to an external voice-2-text (V2T) service but I think we can’t do that with Asterisk. So I leverage the recording feature and will have the external service to translate the call content in real-time. That’s why I can’t wait until the call completes to have entire recorded file.

Please let me know if you are aware of any solution as “sampling” seems to be not an optimal solution.

Hi David551,

Tks for your support and your time. As I mentioned in my reply to Pooh, my goal is to stream the SIP call to an external service to convert it to text in real-time manner. So i am looking for a solution other than post-process the record.

As I am new to Asterisk, I think I have to check ARI to see if I can handle the SIP call while recording (or streaming would be ideal).

Tuan

Do not forget to stream the two channels (inbound / outbound or A / B or local
/ remote - call them what you will) independently, so that the speech-to-text
system can work with two streams of fairly clear text (with gaps in them when
the other person speaks, usually) and isn’t trying to understand a single
audio channel of two people in different voices speaking across each other’s
words.

Antony.

Would ‘eagi()’ be an option?

It makes audio available on file descriptor 3, which you can read and then send to your STT provider.

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Tks Pooh for the note. Definitely useful especically as a newbie. Just looking for a solution to stream now :slight_smile:

I’d question the idea of transcribing the two sides separately. Large language model based transcribers don’t translate word by word, but take in large amounts of surrounding context, and giving them only half the conversation could easily make it impossible for them to establish the correct context. They are going to get better at separating two speakers, and if it is necessary to split the two sides, one really requires a recognizer that takes both sides and decodes them in parallel.

You don’t mean sampling, but that’s what I originally thought you wanted.

It seems to me that feeding isolated 5 second slices to a transcriber is pretty much the worst thing you could do. Ideally you should feed the whole call, after it is complete, but failing that, you need a transcriber that can take a stream and maybe back track up to five seconds.

As I suggested in my other reply, what is making AI speech to text increasingly effective is the ability to make use of a large amount of preceding context, but you also need a few seconds of following context.

I think all the standard methods of capturing audio for recognizers capture a stream.

Hi David,

Tks a lot for your info and your opinion. There are still a lot of things to do at AI side to improve, I believe. But atm, my objective is to obtain the input for that AI.

According to your suggestion, i.e. replacing Dial with ARI, I am not sure if we would be able to handle the call without using SIP. I conduct some initial steps and suddenly just having that concern in mind. Can you elaborate your last sentence a bit, i.e. “standard methods of capturing audio”?

It seems that there are not many tutorial/examples for streaming a call even though it is a common topic IMHO. Please correct me if I am wrong.

Anyway, tks again for your support and your time.

why record every 5 seconds but not record continuously ?

you still can read temp wav file even this file is not complete.

What disqualifies ‘eagi()’ from consideration?

It was not a good solution for a recent client because they expanded scope and decided they wanted bi-directional audio, but for a STT application it should suffice.

I think what they are trying to do is to do near real time speech to text by breaking up the audio into short files and feeding them to a recognizer designed to transcribe whole files.

However, you can’t read .wav files that are only half written as they contain meta data that is not filled in until the file is closed. This meta data is about size and location of chunks. Whilst it could be updated after every write, that would involve seeking backwards and forwards, which isn’t otherwise necessary.

Hi Sedwards,

I saw your reply and sorry for not getting back with my thanks. I tried to avoid this one as I could not imagine how to work it out at the beginning. Here is what I did:

exten = 7100,1,Answer()
same = n,eagi(/var/lib/asterisk/agi-bin/test.eagi)
same = n,Dial(PJSIP/7100,60)
same = n,Hangup()

And I get test.eagi from here: Perl EAGI - VoIP-Info

I can see the raw file but I think it does not work because the script executes before the Dial performs. So i am not sure how to have both Dial and eagi running in parallel.

With all regards,
Tuan

My bad. All (99.99%) of my production calls are incoming which colors my mindset a bit.

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