trx (C) Copyright 2012 Mark Hills <mark@...>
Usage: tx [<parameters>]
Real-time audio transmitter over IP

Audio device (ALSA) parameters:
  -d <dev>    Device name (default 'default')
  -m <ms>     Buffer time (default 16 milliseconds)

Network parameters:
  -h <addr>   IP address to send to (default ::)
  -p <port>   UDP port number (default 1350)

Encoding parameters:
  -r <rate>   Sample rate (default 48000Hz)
  -c <n>      Number of channels (default 2)
  -f <n>      Frame size (default 960 samples, see below)
  -b <kbps>   Bitrate (approx., default 128)

Display parameters:
  -v <n>      Verbosity level (default 1)

Allowed frame sizes (-f) are defined by the Opus codec. For example,
at 48000Hz the permitted values are 120, 240, 480 or 960.