DTMF tones over IP

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DTMF tones over IP

Byron Klippert
Hello,


Is there a way to generate DTMF tones using the tools in base?


I am trying to open a "live" audio path over IP from one node to
another. The audio path is fed into a controlling device which
interfaces with a VHF radio. In order to key-up the radio, the
controlling device needs to see a DTMF code (1 to key, 0 to unkey). Any
audio sent to the device between keying and unkeying, is sent to the
radio and over air.


I'm guessing an ssh-tunnel will server as the "path", just not sure
which framework can be used to record and play audio, let alone generate
DTMF.


Any pointers?



--
Byron Klippert      
  [hidden email]
  c. 867-336-1306

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Re: DTMF tones over IP

Kent Fritz
Not sure about playing remotely, but if you add the "sox" package, you
get tools to generate files or directly to audio out.  The following
play the tones to your audio output:

DTMF 1:
play -n synth 0.5 sine 697 sine 1209 channels 1
DTMF 0:
play -n synth 0.5 sine 941 sine 1336 channels 1



On Tue, Mar 25, 2014 at 3:24 PM, Byron Klippert <[hidden email]> wrote:

> Hello,
>
>
> Is there a way to generate DTMF tones using the tools in base?
>
>
> I am trying to open a "live" audio path over IP from one node to
> another. The audio path is fed into a controlling device which
> interfaces with a VHF radio. In order to key-up the radio, the
> controlling device needs to see a DTMF code (1 to key, 0 to unkey). Any
> audio sent to the device between keying and unkeying, is sent to the
> radio and over air.
>
>
> I'm guessing an ssh-tunnel will server as the "path", just not sure
> which framework can be used to record and play audio, let alone generate
> DTMF.
>
>
> Any pointers?
>
>
>
> --
> Byron Klippert
>   [hidden email]
>   c. 867-336-1306

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Re: DTMF tones over IP

Jan Stary
On Mar 25 15:24:03, [hidden email] wrote:

> Is there a way to generate DTMF tones using the tools in base?
>
> I am trying to open a "live" audio path over IP from one node to
> another. The audio path is fed into a controlling device which
> interfaces with a VHF radio. In order to key-up the radio, the
> controlling device needs to see a DTMF code (1 to key, 0 to unkey). Any
> audio sent to the device between keying and unkeying, is sent to the
> radio and over air.
>
> I'm guessing an ssh-tunnel will server as the "path", just not sure
> which framework can be used to record and play audio,

See aucat(1) for general audio work.
It also works nicely over ssh (see
http://marc.info/?l=openbsd-misc&m=136500465604928&w=3
for inspiration).

> let alone generate DTMF.

I would use the SoX package for this ...

On Mar 25 17:06:50, [hidden email] wrote:
> play -n synth 0.5 sine 697 sine 1209 channels 1
> play -n synth 0.5 sine 941 sine 1336 channels 1

... but only slightly differently:

play -c 1 -n synth 0.5 sine 697 sine 1209 gain -6
play -c 1 -n synth 0.5 sine 941 sine 1336 gain -6