[liberationtech] Efficient digital one-way communication

[Jens Christian Hillerup]

On Mon, Mar 4, 2013 at 7:26 PM, Don Marti <dmarti at zgp.org> wrote:
> begin Jens Christian Hillerup quotation of Mon, Mar 04, 2013 at 06:53:05PM +0100:
>
>> Whoops, we're drifting off-list. I've included the relevant parts (and
>> committed a stereo fix to the main repo that fixes the bug from my
>> second mail).
>
> DTMF uses two pitches at a time -
>   http://en.wikipedia.org/wiki/Dual-tone_multi-frequency_signaling
>
> Chords might be a way to get more information in.

Yes, and then I can scrap the stereo encoding again. I'd rather have
it optional than required. And I agree, it would make more sense to
pick eight notes and use them as a bitmap. We'd face the same problems
as we did before with the harmonies, but that problem does not get any
bigger or smaller so I don't see the point in not implementing it.

Idea: parity information in the overtones? Not applicable if we go
with Reed-Solomon codes, though.

JC