tcd

tcd is a hybrid digital voice transcoder for ham radio used by the new URF reflector.

Introduction

This will build a new kind of hybrid transcoder that uses AMBE DVSI-based hardware for vocoding digital voice streams used in DStar/DMR/YSF and David Rowe's open-source Codec2 used in M17. At a minimum, you need a USB-based DVSI device (or multiple devices) based on the DVSI-3003 vocoder. For proper interfacing, each 3003 chip (internally containing three AMBE vocoders) will be detected by your system and assigned a unique /dev/ttyUSBX device. As each ttyUSBX device is assigned to one of the two AMBE codecs, you need at least two 3003 devices.

This software is loosely based on LX3JL's ambed, but is easily different enough to be considered an entirely original work. Here are some major differences:

• tcd mixes both hardware-based and software-based vocoders, providing a bridge between the closed source vocoders used in DStar, DMR and YSF and open-source vocoders used in M17.
• tcd uses the standard /dev/ttyUSBX for interfacing with the DVSI hardware. At lease two 3003-based devices are required.
• UNIX Sockets are used to communicate between the reflector and this transcoder. This greatly simplifies the code and significantly improves transcoding performance.
• tcd only supports DVSI-3003-based devices that use the ttyUSBX interface.

Only systemd-based operating systems are supported. Debian or Ubuntu is recommended. If you want to install this on a non-systemd based OS, you are on your own. Also, by default, tcd is built without gdb support.

Download the repository

In the same directory where you urfd repository is located:

git clone https://github.com/n7tae/tcd.git

To be perfectly clear, the urfd reflector repository clone and this clone must be in the same directory.

Configuring, compiling, installing and other activities

All other activities will be performed by the ./rconfig and ./radmin scripts in your urfd repo.

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DE N7TAE