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Decimen Optical Transfer: fountain-coded QR file transfer

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Re: Decimen Optical Transfer: fountain-coded QR file transfer

#21

Post by myself248 »

legulere wrote: post #15

The actual article explaining the use for fountain codes in this use case: https://divan.dev/posts/fountaincodes/

Oooooooooooo.

I bet that's how satellite radios get their firmware updates and stuff.

Actually I bet it's how they get almost everything aside from the audio streams themselves. Metadata. Channel art. Subscription info. Traffic data. Weather maps. Receiver firmware... The satellite is a textbook-perfect fountain, and the receiver may tune in at any time during the stream, and may miss any random number of packets, but fairly quickly it has what it needs.

I believe the various categories of metadata are sent at different rates according to how promptly a newly-awakened receiver should be able to update itself, so what's actually on the air is an interleaved collection of fountain streams, yeah? Hmm.

Re: Decimen Optical Transfer: fountain-coded QR file transfer

#22

Post by inigyou »

_joel wrote: post #19
inigyou wrote: post #16

Earlier quoted context omitted.

Listen, you do not want your firmware to be updated by playing a FLAC file.

FLAC? That shows some degree of advanced technology that I would assume the original device in question does not have.

It's "digital audio gear". It receives uncompressed PCM, which could come from your computer playing a FLAC.

Re: Decimen Optical Transfer: fountain-coded QR file transfer

#23

Post by bschwindHN »

elric wrote: post #2

Neat, finally an easy way of transferring files between devices that doesn't rely on online services -- no clue why we didn't solve that ages ago. Adding encryption shouldn't be hard, as long as you can communicate the keys out of band. Could probably achieve the same result using audio instead of video, but maybe that would be too annoying?

Encryption is a toilet paper roll.

Re: Decimen Optical Transfer: fountain-coded QR file transfer

#25

Post by _joel »

inigyou wrote: post #22
_joel wrote: post #19

Earlier quoted context omitted.

FLAC? That shows some degree of advanced technology that I would assume the original device in question does not have.

It's "digital audio gear". It receives uncompressed PCM, which could come from your computer playing a FLAC.

right, so a very specific case of playing FLAC via an external device, not on the system itself. Ok, that makes more sense. Still don't get what the issue is. Put the device in the correct mode and play from whatever digital input or playback (CD, DAT etc) the system already has.

Re: Decimen Optical Transfer: fountain-coded QR file transfer

#26

Post by inigyou »

_joel wrote: post #25
inigyou wrote: post #22

Earlier quoted context omitted.

It's "digital audio gear". It receives uncompressed PCM, which could come from your computer playing a FLAC.

right, so a very specific case of playing FLAC via an external device, not on the system itself. Ok, that makes more sense. Still don't get what the issue is. Put the device in the correct mode and play from whatever digital input or playback (CD, DAT etc) the system already has.

Okay, if there's a button you have to hold to enable firmware update then it's more sensible.

Probably still wouldn't want to use digital audio input though. Although it's a perfect digital stream, it's been processed in analog-like ways before it gets to the device - such as filtering and volume changes. So you'd still want to use a modem protocol over it.

Re: Decimen Optical Transfer: fountain-coded QR file transfer

#27

Post by sunrunner »

inigyou wrote: post #16
_joel wrote: post #10

Earlier quoted context omitted.

If only they had a clean digital way of getting data into the system.

Listen, you do not want your firmware to be updated by playing a FLAC file.

Especially if it's a recording of Rhythm Nation.

Re: Decimen Optical Transfer: fountain-coded QR file transfer

#28

Post by smalltorch »

legulere wrote: post #15

The actual article explaining the use for fountain codes in this use case: https://divan.dev/posts/fountaincodes/

> The receiver can start receiving blocks from any point, receive blocks in any order, with any erasure probability – fountain codes will work as soon as you received K+ different blocks.

Thats just cool.

Re: Decimen Optical Transfer: fountain-coded QR file transfer

#29

Post by pjc50 »

elric wrote: post #2

Neat, finally an easy way of transferring files between devices that doesn't rely on online services -- no clue why we didn't solve that ages ago. Adding encryption shouldn't be hard, as long as you can communicate the keys out of band. Could probably achieve the same result using audio instead of video, but maybe that would be too annoying?

> between devices that doesn't rely on online services -- no clue why we didn't solve that ages ago

Airdrop is a thing, but remember that Android phones are controlled by the online services company that wants you to use online services.

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