When talking about DV hardware approaches, I have no problem with D-STAR's use of the proprietary AMBE coded that sells for about $20 per chip in small quantities. It was chosen because it was the best codec available. Most other DV systems use AMBE chips too.
But when talking about DV software approaches, the AMBE chip does limit development, not so much because it's proprietary, but because you can only get it at that inexpensive price on a chip. This greatly limits experimentation. So a couple of new codecs legally available to amateurs would be very welcome. David's codec2 web page also points out the value for amateur satellites of having open code that could be uploaded to the sats. He advocates at least two new codecs, one with better audio quality and wider bandwidth for use on VHF+, the other using narrow bandwidth (like MELP) for HF. If this really happens, there will be a lot of happy amateurs worldwide. But I am skeptical that it will happen anytime soon. We are told it is very hard to write quality, workable codecs that work in a reasonable bandwidth. David's site currently conjectures how to go about this archtecturally, but this project needs more than good plans and good intentions. But, I wish him luck. Jim - K6JM ----- Original Message ----- From: a cutler22 To: [email protected] Sent: Sunday, June 06, 2010 5:18 PM Subject: [DSTAR_DIGITAL] Codec2 development - open source vocoder Some of you may have heard of "codec2": www.codec2.org David Rowe, VK5DGR has been working on its development - it is an open source alternative to the closed AMBE chip required for the current version of the DSTAR protocol. His development site is: http://www.rowetel.com/ucasterisk/codec2.html Current development status is available here: http://www.rowetel.com/ucasterisk/codec2.html#plan He is currenty looking for assistance, either financially or coding. Because of financial obligations he's had to take a hiatus from development to pay bills with other work. His email is: [email protected] The prospect of an open-source vocoder, ham-developed would open a lot of doors in the way of experimentation, and reduce the $$$ barrier. A DSTAR protocol implementing Codec2 Digital Voice would significantly drop the entrance and appeal to a much wider audience! -73 de Anthony, KE7HQY
