Re: [Discuss-gnuradio] DV Dongle - AMBE USB Device

[Eric Blossom]

On Wed, Mar 19, 2008 at 07:02:08AM -0600, Jeff Brower wrote:
> Rick-
> 
> > > I am also thinking of writing a APCO P25 Voice to AMBE2000 frame 
> > > converter and see
> > > if the device can decode P25 as well.  This may be a general IMBE and
> > > AMBE codec.
> > >
> > 
> > I hope so. I looked at this a while back. What concerned me most was the
> > AMBE2000/2020 documentation seemed to omit P25 style IMBE compatibility.
> > Compare the docs to another DVSI product - the VC55 - to see what I mean.
> 
> If you're looking at low bitrate codecs for GNU radio, why use a hardware 
> (dongle)
> dependent solution?  You might look at MELPe, which provides 600, 1200, and 
> 2400 bps,
> and can be implemented as a software solution.  MELPe is a US/NATO standard 
> (STANAG
> 4591).  Common applications are HF radio and L band satellite apps where 
> bandwidth is
> very limited.
> 
> -Jeff

Unless something has changed, MELP is also encumbered.  How about a
free codec, such as speex?  http://www.speex.org/

Eric