Reed Solomon Encoding - Computerphile

A high level look at Reed Solomon - Professor Brailsford explains the basics of this complicated encoding technique.

This video was filmed and edited by Sean Riley.

[cybercat]

I learned about Reed Solomon Encoding a long time ago at University and used it several times since then in some code.
But really Professor Brailsford's explanation so far is one of the best, he truly has a unique way of explaining things. Even better when it's put together with those graphics.
I particularly appreciate the historical context he gives, really sells the story.

[dmsanct]

"so how can CD's continue to work afterr they've been scratched?"

me: oh boy, you're in for a treat. So it was late 50's and there was this guy called Richard Hamming

[Izzyizzy]

"Checksum from hell" is the sickest math-rock band name out there

[BuysDB]

Now I still don't know how it works :'(

[willsi]

Man's a treasure. Always enjoy it, Professor.

[bborkzilla]

Good old Évariste Galois. Came up with all his amazing mathematical theories by the age of 20, at which point he got himself killed in a duel.

[MrDaanjanssen]

5:56 "Yes, but..." *dramatic zoom in*

[mishasawangwan]

this guy and his encoding videos, as well as that one dude who does all the encryption videos (sorry name escapes me at the moment) are the best types of computerphile vids, hands down

[LucasHartmann]

DVDisaster is a piece of software that auguments empty DVD-iso space with error correction codes. I tested it working by intentionally scratching a disk, and it saved me quite a few times later. Awesome extra protection for backup disks.

[ZeroUltimax]

When starting my degree in CS, I got interested in QR codes and their uses of Reed Solomon Encoding. It was the first time I went "Nope" so hard. This bring back nightmares.

[InakaGames]

Incredible explanation of all of this. Absolutely a godsend that you are sharing these kinds of explanations online for others to learn from.

[SardarNL]

All videos of Computerphile are brilliant. However, this one has a misleading title. There is literally almost no information on Reed Solomon encoding, only emotional opinion on how complicated it is. A little example would help. Or a title like "Before your consider implementing Reed Solomon encoding...".

[lawrencedoliveiro]

5:19 Isn’t this also where the “CIRC” (“Cross-Interleave Redundancy Checking”) comes in? The bits are arranged in a pseudorandom scrambled pattern (which is unscrambled as part of the decoding process), so that any contiguous run of errors on the disc is spread across a larger area after unscrambling and affects a smaller proportion of bits within that area.

[ArumesYT]

In the 60's MIT was already deeply involved in computer tech, as was Berkeley. I think CalTech was only a couple of years behind those two as well. And Silicon Valley (although not known by that name yet) was already becoming a distinct high-tech area. Remember one of SV's most legendary companies, Fairchild Semiconductor, was already founded in 1957. So no, certainly not everybody was at Bell Labs anymore by then.

[iabervon]

Yay! It's the video I was asking for! 4-bit symbols aren't too bad, because your times table is only 256 symbols, with a 15-symbol 1/n table. The thing you didn't mention is that the long division is long division of polynomials, although that's kind of a weird math hack, because you never evaluate the polynomial for a value of x, so it's effectively just multi-digit numbers where the digits don't overflow or carry into each other. I like to say that GF(2^n) is arithmetic for people who can't count to 10, but can multiply by 2 repeatedly to 10.

[Earthcomputer]

Main thing I learnt from this is the definition of "syndrome" lol

[BoydWaters]

This seriously helps me, even after 35 years I have been arguing with computers.
"Checksum from Hell" :-)

[vjeraturk]

Please enable auto-generated English subtitles on your videos.
It is easier for me ( non-native English speaker) to follow what someone is saying if I see it written on screen, even if it is just an approximation. Your channel is the best!

[DrGreenGiant]

Yet another awesome video from David and produced so well. Great job again computerphile.
I can see this leading sweetly onto 2D barcodes!

[CoolJoshk]

I recognise Reed-Solomon due to my use of that for archival recovery records. I also notice how long it takes for a few GBs on an i7 8086k.