On Sat, 2011-04-23 at 20:00 +1000, Tony Langdon wrote:
At 07:33 PM 4/23/2011, you wrote:
The chips are "readily available" at a few hundred dollars apiece, and if you attempt to implement your own AMBE codec then you're going to have DVSI's lawyers jumping on you.
More like $20 apiece in small (possible 1 off) quantities.
I'd love to know where you're seeing them for that much in onesy-twoesy quantities
Proprietary software has no place in Amateur Radio.
It's hardware with firmware. So let's throw out all the other proprietary bits (processors with embedded code, etc) and go back to soldering valves?
Yes, throw out the proprietary bits. Write your own, it's easy.
The simple fact of the matter was back around 2000 when the D-STAR spec was developed, there weren't a lot of choices for how to compress speech into 2.4kbps and have FEC. AND have it available in a suitable form for implementation into mobile and handheld radios. While the proprietary codec is a minor inconvenience in some situations, it's proved to be no impediment to home brew enhancements to D-STAR. The number of ham developed D-STAR projects is significant, so that one chip hasn't proved to be an impediment to ham experimentation in practice.
Yes, "back around 2000". It's over ten years old. We have better codecs and better modulation schemes now. Why are we crippling digital comms with a single-source proprietary codec that sounds like an angry duck in a tin outhouse?
The commercial world is no better - just look at DMR, which uses the same awful AMBE codec!
Gordon MM0YEQ