Linux Phone: Alpha Testers Wanted!

Linux Phone: Alpha Testers Wanted!

Post by Max Par » Fri, 15 Nov 1996 04:00:00

Hope you'll have time to check this out..  It's free software (GNU copyright)


Digital voice using 4,800 bps modems...

     * Real Time Linear Predictive Coding (LPC) coder
     * Compression better than an astounding 97%
     * Compress either sound files from disk or real time (from /dev/dsp)

     * File player
     * Network support allows voice link (half-duplex at present) using
       standard slow-speed dial-up modems (4,800 bps or better)
     * Multicast daemon (server process) for audio distribution to
       several clients simultaneously

     * Linux (and other Un*x systems, untested)
     * Sound Card and driver supporting /dev/dsp interface
     * (Optional) For network support, you need a TCP/IP Net connection
       (4,800 bps or better)

   Future Possibilities: (This does not represent a commitment)
     * Full Duplex voice operation
     * Encryption for secure communication support
     * Audio Multiplexing
     * Integration with the Web via CGI (server) and plug-ins (client)
     * Voice Mail

   Availability: (Help Wanted: Alpha Testers)

   Free Software (GNU Public License)
   Includes public domain LPC software developed by the United States

   Further Information
   The speech coder uses approx. 25% CPU of a P5-100 for real time
   operation. The decoder uses about 12-13%. The encoder can read WAV
   format files or for real-time sampling reads /dev/dsp. The decoder can
   output audio either to the speakers or to a file. The system uses 16
   bit mono data sampled at 8,000 per sec.

   There is also a network option allowing the encoder and player to run
   on different machines. You can also have multicast servers which use
   close to zero CPU time when serving pre-coded files.

   Audio Samples
   This demo file was captured from one channel of a stereo FM broadcast
   and encoded at 8,000 sample/sec, 16 bit. The file starts with the
   voice of a male announcer (Daniel Shorr) and ends abruptly during a
   weather broadcast by a female announcer. During a portion of the
   sample there is some light jazz guitar. The compressed version of this
   file is 53,248 bytes!

   The sample sound file can be downloaded here:


   ? Copyright, 1996 Max H. Parke


Linux Phone: Alpha Testers Wanted!

Post by Paul Rub » Fri, 15 Nov 1996 04:00:00

>Hope you'll have time to check this out..  It's free software (GNU copyright)


Cool.  You might also like looking at
for a similar program that does support encryption, plus comes with
a range of voice coders.  Hopefully it will become GPL once some
issues are resolved; for now, at least the source code is there.