Playing a sound file over a voice modem

[WhitetailAni]

I may have already posted this, but I couldn't find it so shrug. Anyway.

 

I'm trying to work out how to play an audio file over a voice modem. My iMac G5 has one, I verified - it supports AT+FCLASS=8.

Querying it for supported types of audio gives something, and then 4-bit IMA ADPCM at 8000 Hz. I did create a 4-bit IMA ADPCM 8000 Hz audio file with Audacity, but I'm not sure how to play it over the voice modem.

I know you're supposed to set the mode, set the audio type, and then enable transmit mode with AT+VTX, but I'm not sure what to do past that point - do I just direct the file at the voice modem with >? Or do I have to read it procedurally? I couldn't find any info...

I don't work with serial ports much... any advice is appreciated!

 

I did test that my phone line setup can support audio - I took a handset cable and modified it to have the microphone port instead convert to a 3.5mm aux jack. Plugging it into my iPod resulted in working audio, though I did have to convert some songs so they didn't clip. The iMac is running 10.4 Tiger. I do have MacPorts and Python 3.11 installed, though I'm really not a fan of python and I'd like to avoid it if possible. I do have some skill in Objective-C.

 

It is connected to an Avaya Partner system which provides a dialtone, though it's not a standard one. It has no access to the wider phone network, only the phone network localized entirely within my house - it can dial two-digit phone numbers only.