On 20/09/16 08:26, glen english wrote:
> He's is an experience to share... and all this I know already but when 
> you experience just how frugal codec2 is on speech bits, it is 
> enlightenment.....
> 
> I am doing a project that uses Codec2 and sends data over Si4460 
> transceiver chips.
> 
> one thing that has become apparent is there is not much data coming out...
> 
> I send a packet every 20mS so that lost packets don't matter so much.
> But.. all there is to transmit is ... 8 bytes ! :-)   there is 12 bytes 
> wrapped around it..... Ha !
> 
> which means the data rate (and BW) has to go up  to cope with the 
> overhead..... and David has worked so hard to get the bits down, and I 
> just throw 1.5x excess in radio overhead...

One option might be to use some forward erasure coding on each Codec2
frame to give you two 8-byte packets, then in each RF frame, you send
packet 2 (or zeros if it's the first packet) from the previous Codec2
frame concatenated with packet 1 from the current Codec2 frame.

You double your data rate, but if an RF frame gets lost, you can still
recover the full message with no delay or loss.
-- 
Stuart Longland (aka Redhatter, VK4MSL)

I haven't lost my mind...
  ...it's backed up on a tape somewhere.

Attachment: signature.asc
Description: OpenPGP digital signature

------------------------------------------------------------------------------
_______________________________________________
Freetel-codec2 mailing list
Freetel-codec2@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/freetel-codec2

Reply via email to