VOCP System - Vgetty - Test

Once it is installed, you need to test vgetty. Use the pvf tools to convert a wav file (or whatever, but if you use wav, try to get a mono file sampled at 8000 Hz) to pvf format (portable voice format) and then from that resulting file, create an rmd file (Raw Modem Data) that you can play through your modem.

The sequence goes something like:

wavtopvf file.wav file.pvf
pvftormd [OPTIONS] file.pvf file.rmd

The OPTIONS depend on the type of modem you've got, so you'll probably need to do some experimenting to get it right. IMPORTANT: make a note of the options used with pvftormd for the VOCP installation. Do a

pvftormd -L
to see the available choices. For my GVC modem with a Cirrus MD56xx chipset, I use
pvftormd MT_2834 4 file.pvf file.rmd
while for my 33.6 USR, I use
pvftormd US_Robotics 1 file.pvf file.rmd

The options you use should will probably be different and may be determined as described in the vgetty installation page.

Once you have created an rmd file, try it out. First we'll try to hear the file. Use:

rmdtopvf file.rmd | pvfspeed -s 8000 | pvftobasic > /dev/audio

which should play the file in your speakers. Now we try to play it through the modem. You probably need to be root to execute this:

vm play -s -v /path/to/file.rmd

which asks vm to play the file to your modem's internal speaker (you could also try -t instead of -s to play the file through the phone, just make sure you actually have a phone hooked into your modem's phone extension jack - NOT the line jack)

If you're lucky and you're modem is compatible you will hear the file played with that deep, rich sound that emanates from modem speakers. If you don't hear anything it's either that

  • your modem cannot digest the data
  • vgetty does not recognize your modem

Find out which is the case by going through the logs (which you can probably find in /var/log/vm.log and /var/log/vgetty.ttySX).

If it seems like all is ok with your modem initialization but that it has problems when trying to play the file, then your life is good: just use a different set of options with pvftormd and try until you hit one that works (IMPORTANT: make a note of the options used with pvftormd for the VOCP installation). When you do, configure vgetty.

If instead vgetty just stops trying at some point, saying stuff like no voice modem found then you've got compatibility issues: take the easy way out and get a modem the documentation says is supported, check the vgetty installation section to find out how to use our voice.conf force_detect patch or go the harder way - hack and recompile (as described in the VOCP doc/vgetty.txt file) vgetty.

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