? Are there LDPC error code lib in Ada ? thanks.

? Are there LDPC error code lib in Ada ? thanks.

[Daniel Norte Moraes]

  Hi!

  Are there LDPC error code lib in Ada ?

  Any bind or raw Ada ?

  My main uses are for: 
    1)files and chunks inside files,
    2) in memory streams code e decoder
    3) network

  p.s.: LDPC => Low-Density Parity-Check.

  Very Very Very Thanks in Advance! :-)

Re: ? Are there LDPC error code lib in Ada ? thanks.

[Dmitry A. Kazakov]

On 2019-02-22 21:35, Daniel Norte Moraes wrote:

>    Are there LDPC error code lib in Ada ?

Isn't it more a hardware thing?

>    Any bind or raw Ada ?

Not that I know. It could be implemented of course, e.g. using a simple 
look-up table, but the purpose is not clear.

>    My main uses are for:
>      1)files and chunks inside files,
>      2) in memory streams code e decoder
>      3) network

These do not fall into the category of "noisy transmission channel". 
Files, memory, network transports have integrated error correction 
already. On top of these you would use none or something rather simple, 
e.g. a checksum xor or Fletcher.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de

Re: ? Are there LDPC error code lib in Ada ? thanks.

[Daniel Norte Moraes]

Em sexta-feira, 22 de fevereiro de 2019 18:45:49 UTC-3, Dmitry A. Kazakov  escreveu:
> On 2019-02-22 21:35, Daniel Norte Moraes wrote:
> 
> >    Are there LDPC error code lib in Ada ?
> 
> Isn't it more a hardware thing?
> 
> >    Any bind or raw Ada ?
> 
> Not that I know. It could be implemented of course, e.g. using a simple 
> look-up table, but the purpose is not clear.

 via software. from personal computer passing by powefull servers to
mobily.

> 
> >    My main uses are for:
> >      1)files and chunks inside files,
> >      2) in memory streams code e decoder
> >      3) network
> 
> These do not fall into the category of "noisy transmission channel". 

   You are Correct. :-)

> Files, memory, network transports have integrated error correction 
> already. On top of these you would use none or something rather simple, 
> e.g. a checksum xor or Fletcher.

  Main objective is "forward error recover" e.g:
  1) try automatic recover data in engine of distributed database before
need to ask for retransmission data from nodes
  2) and auto-recover for data received.

  Fletcher ? :-)

> 
> -- 
> Regards,
> Dmitry A. Kazakov
> http://www.dmitry-kazakov.de

Really Thanks! :-)

[]'s Dani.

Re: ? Are there LDPC error code lib in Ada ? thanks.

[Dmitry A. Kazakov]

On 2019-02-22 23:22, Daniel Norte Moraes wrote:

>    Main objective is "forward error recover" e.g:
>    1) try automatic recover data in engine of distributed database before
> need to ask for retransmission data from nodes

If transmission errors occur they do not manifest themselves as 
corrupted data, because the transports already correct these. They do as 
undelivered data, dropped connections, missed deadlines, lost integrity etc.

>    2) and auto-recover for data received.

There is no recovery from non-delivery. You can improve situation using 
redundant nodes and some sort of consensus in the scenario when some 
nodes might go offline. Error correcting codes is no help at this level 
of abstraction (application's OSI).

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de

Re: ? Are there LDPC error code lib in Ada ? thanks.

[Daniel Norte Moraes]

Em sábado, 23 de fevereiro de 2019 04:49:41 UTC-3, Dmitry A. Kazakov  escreveu:
> On 2019-02-22 23:22, Daniel Norte Moraes wrote:
> 
> >    Main objective is "forward error recover" e.g:
> >    1) try automatic recover data in engine of distributed database before
> > need to ask for retransmission data from nodes
> 
> If transmission errors occur they do not manifest themselves as 
> corrupted data, because the transports already correct these. They do as 
> undelivered data, dropped connections, missed deadlines, lost integrity etc.
> 
> >    2) and auto-recover for data received.
> 
> There is no recovery from non-delivery. You can improve situation using 
> redundant nodes and some sort of consensus in the scenario when some 
> nodes might go offline. Error correcting codes is no help at this level 
> of abstraction (application's OSI).
> 
> -- 
> Regards,
> Dmitry A. Kazakov
> http://www.dmitry-kazakov.de

  Hi! :-)

  Just to heal my doubt:  
  Is Better double the data and verify crc and if one is corrupted (and the other is ok) substitute the corrupted with the good one ?
  It is ok for me, too. I remmenber CouchDb use this aproach. this will simplifly my code, too. :-)

 []'s Grateful, Dani. :-) 

Re: ? Are there LDPC error code lib in Ada ? thanks.

[Dmitry A. Kazakov]

On 2019-02-28 21:18, Daniel Norte Moraes wrote:

>    Is Better double the data and verify crc and if one is corrupted (and the other is ok) substitute the corrupted with the good one ?

No. It would be useful only if errors had stochastic nature. That is 
simply not the case when you are using transports like sockets. You 
cannot have corruption of this sort, I leave aside intentional data 
mangling.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de

Re: ? Are there LDPC error code lib in Ada ? thanks.

[Daniel Norte Moraes]

Hi!

Really Thanks for the hints. :-) 

Another question: someone had a Ada
Fletcher and can shared with me? 

()'s Gratefully, Dani.:-) 

Re: ? Are there LDPC error code lib in Ada ? thanks.

[darkestkhan]

On Friday, March 1, 2019 at 5:55:31 PM UTC, Daniel Norte Moraes wrote:
> Hi!
> 
> Really Thanks for the hints. :-) 
> 
> Another question: someone had a Ada
> Fletcher and can shared with me? 
> 
> ()'s Gratefully, Dani.:-)

16 bit fletcher. Only sum computation.

https://github.com/darkestkhan/fletcher

Re: ? Are there LDPC error code lib in Ada ? thanks.

[Daniel Norte Moraes]

Em sábado, 2 de março de 2019 18:57:10 UTC-3, darkestkhan  escreveu:
> On Friday, March 1, 2019 at 5:55:31 PM UTC, Daniel Norte Moraes wrote:
> > Hi!
> > 
> > Really Thanks for the hints. :-) 
> > 
> > Another question: someone had a Ada
> > Fletcher and can shared with me? 
> > 
> > ()'s Gratefully, Dani.:-)
> 
> 16 bit fletcher. Only sum computation.
> 
> https://github.com/darkestkhan/fletcher

Yahoo!!! :-)

Very Very Very Thanks! :-)

[]'s Gretefull, Dani. :-)