Characters, Symbols and the Unicode Miracle - Computerphile

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  • čas přidán 9. 06. 2024
  • Audible free book: www.audible.com/computerphile
    Representing symbols, characters and letters that are used worldwide is no mean feat, but unicode managed it - how? Tom Scott explains how the web has settled on a standard.
    More from Tom Scott: / enyay and / tomscott
    EXTRA BITS: • EXTRA BITS - UTF-8 'ne...
    Data Security: • Security of Data on Di...
    / computerphile
    / computer_phile
    This video was filmed and edited by Sean Riley.
    Computerphile is a sister project to Brady Haran's Numberphile. See the full list of Brady's video projects at: bit.ly/bradychannels

Komentáře • 617

  • @Jivvi
    @Jivvi Před 9 lety +7785

    Which side of a napkin is the back?

  • @Computerphile
    @Computerphile  Před 10 lety +1407

    This was shot at the Marriott St Pancras Renaissance in London - kind thanks to them for allowing us to film there! >Sean

  • @AndreiZisu
    @AndreiZisu Před 10 lety +3709

    This guy just radiates enthusiasm

  • @praemdonck
    @praemdonck Před 7 lety +2237

    You forgot to mention that the great hacker behind the great hack is Ken Thompson, the genius behind unix

  • @tuberlook1
    @tuberlook1 Před 10 lety +596

    It's rare to see a person who is knowledgeable, passionate and able to explain in a linear and easy to understand manner.

  • @MikkoRantalainen
    @MikkoRantalainen Před 7 lety +4145

    There's a saying that UTF-8 was successful because USA did not need to understand it. (Explanation: they could just keep using ASCII and magically they are compatible with UTF-8).

  • @pao_lumu
    @pao_lumu Před 7 lety +209

    3 years later, still quality.
    -Well, give-or-take a few leap seconds-

  • @codeman99-dev
    @codeman99-dev Před 10 lety +746

    While designing ASCII they also chose "00110000" (48) for character zero. This is even more impressive than "a is 1" since you can then XOR any character with the value of character zero to find out if it's a decimal number (0 through 9)! :)
    In code example:
    char x = random(0, 128);
    if (x ^ '0' < 10) {
    // variable x is a decimal number character
    } else {
    // variable x is NOT a decimal number character
    }

  • @coldfire6869
    @coldfire6869 Před 9 měsíci +24

    Tom Scott explaining UTF-8 in some hotel lobby 9 years ago. Very nice!

  • @dominiquestrauss-kahn2509
    @dominiquestrauss-kahn2509 Před 9 lety +921

    Where is he presenting all this? That place looks rather pleasant.

  • @ACDCBoy62
    @ACDCBoy62 Před 9 lety +853

    Hey, this video actually helped me fix a bug! I was trying to pass an ANSI filename to a function, and it would always fail. When I looked at the variable watch, the string showed up as a bunch of Chinese characters, so I was immediately able to recognize it was being reinterpret-casted to Unicode, rather than the proper typecast I assumed would happen!

  • @UteChewb
    @UteChewb Před 3 lety +17

    Minor goof by Tom at 6:25 he writes 0110 0001 and writes 'A' when it should be 'a'. But a great video, and perhaps this is a deliberate mistake to see who was awake in class. I remember when I first read how unicode works I was blown away, but Tom's explanation is so much better than how I learnt it.

  • @amykathleen2
    @amykathleen2 Před 9 lety +294

    Just want to mention, not that people probably care, that Korean actually has a phonetic alphabet, unlike Chinese and Japanese. The letters do arrange into syllable blocks (e.g. ㅎ[h]+ㅏ[a]+ㄴ[n]+ㄱ[g]+ㅜ[u]+ㄱ[k]=한국[Hanguk, meaning Korea]), so I'm not sure if individual letters are encoded or if entire syllable blocks are encoded, but it is an alphabet nonetheless.

    • @SexyStarfleet
      @SexyStarfleet Před 9 lety +15

      I didn't know that. I remember studying Korea in world history and how it was very different from Japan and China. I guess I never thought about the language being that different. That's cool, and I'm sure it makes keyboards easy for you guys :)

    • @amykathleen2
      @amykathleen2 Před 9 lety +44

      Yeah, it's pretty cool. I'm a Korean-language learner, and I mastered Korean touch-typing (on an American keyboard, no less) in about a month. :)
      The Korean alphabet, called Hangeul, was invented by a team of scholars led by King Sejong the Great in 1443 so Koreans wouldn't have to use Chinese characters to write anymore. Whenever I talk to a Korean and the topic of Chinese characters comes up, I always tell them, "I'm very grateful for King Sejong!"

    • @raizin4908
      @raizin4908 Před 9 lety +74

      amykathleen2 You might not care, but Japanese texts have a large number of phonetic "letters" as well, unlike Chinese. Although it's technically not an alphabet but a syllabary. (Each "letter" signifying a syllable, rather than a "sound")
      Japanese uses a mix of phonetic and non-phonetic characters, and for a significant number of words both phonetic and non-phonetic spellings are common. It's also entirely possible to write any Japanese sentence fully in phonetic characters, but it's practically impossible to make a proper sentence without them. (Although it should be noted most sentences, especially more complex ones, would be significantly harder to read were they written fully phonetically.)
      In a modern Japanese sentence such as this:
      これは日本語での例文である。
      all the curly characters (これは での である) are phonetic, and the more rigid/angled characters (日本語 例文) are usually non-phonetic characters, often identical to characters used in Chinese (汉语 / 漢語). Although there's also a type of angled phonetic characters (カタカナ), which is usually reserved for loan words and foreign names and such.
      It's likely you already knew this, but I felt the need to clarify for interested uninformed passersby.

    • @amykathleen2
      @amykathleen2 Před 9 lety +9

      Raizin Yes, I did know the basics. But I didn't know that the two syllabaries had different uses and different "kinds" of shapes, that's really interesting! Some of those angled phonetic characters really look a lot like Chinese characters - like 力 and 夕. I think if that syllabary was the more common one, I wouldn't be able to tell Chinese and Japanese writing apart, as my personal rule is "Japanese is the one with the squiggly characters," haha. Thank you for sharing that information! :D

    • @amykathleen2
      @amykathleen2 Před 9 lety +26

      ***** The point I was trying to make is that, since not long after the Korean war, Korean has been written almost *exclusively* using a phonetic *alphabet*. Japanese usually uses a mix of Chinese characters and syllabic characters, while Chinese usually uses Chinese characters exclusively. In modern Korean, Chinese characters are only used in high-level texts, such as medical or legal journals. Everything else is written using the Korean alphabet (which, again, is *not* a syllabary, unlike bopomofo and kana, and is *not* based on borrowed letters, unlike pinyin). Many Koreans can't even write their own names using Chinese characters. So I made my comment to correct the fact that, in the video, he listed several alphabets (English, Cyrillic, Arabic), and then said, "Japanese, Chinese, and Korean characters." This is wrong; Korean uses an alphabet and should have been listed with the alphabets if it was to be listed at all.

  • @blenderpanzi
    @blenderpanzi Před 9 lety +142

    Another nice feature: Sorting UTF-8 strings under the assumption they are ASCII strings will sort them correctly in ascending codepoint order. For proper sorting in the context of a language you need of course much more complicated methods, but having some kind of sort that somehow makes sense for some technical applications that can be performed by something that was written for ASCII is already very nice.

  • @squgeim
    @squgeim Před 9 lety +344

    Tom Scott is the James Grime of Computerphile!

  • @TheBoxOfBeats
    @TheBoxOfBeats Před 10 lety +866

    6:30 -- 01100001 is not 'A' and its not 65, its 97 / 'a' . Or am I wrong?

  • @benjaminfoo9270
    @benjaminfoo9270 Před 10 lety +88

    I've never seen a guy explaining utf8 so well and so excited like this fellow here - really great job

  • @douggwyn9656
    @douggwyn9656 Před 9 lety +257

    The original version of UTF-8 was invented by Thompson and Pike for use in Plan 9 from Bell Labs. There were already ISO standards for character encoding; ISO 10646 is the master character compendium and assigns codes throughout a 31-bit range. I was impressed enough with the Plan 9 scheme that I promoted it in my C Standards column in the Journal of C Language Translation. The advantages of UTF-8 covered in this video helped its adoption by many applications needing to support an international character set. By the way, Plan 9 only implemented the 16-bit range, although the full scheme can encode any 31-bit pattern. The current IETF RFC3629 unnecessarily constrains UTF-8 to 16 bits. I'm at the beginning of the process of trying to undo those restrictions.

    • @iemobile930
      @iemobile930 Před 9 lety +8

      This is interesting Doug. I plan to watch this later. Happy 4th to you too.

  • @Computerphile
    @Computerphile  Před 10 lety +78

    There will be more with Tom :) >Sean

  • @Computerphile
    @Computerphile  Před 10 lety +13

    See the "extra bits" film for a further explanation! (link in the description) >Sean

  • @chandragie
    @chandragie Před 6 měsíci +3

    This video showed up to me in Dec 2023, 10 years later from when this video launched. And I'm still amazed on how this guy explained it 👍👍

  • @mehrosenasir9974
    @mehrosenasir9974 Před rokem +5

    I remember when I watched this video for the first time back in 2018, didn't make any sense to me. Now I can understand how beautifully he explains the complete journey started from Ascii to UTF 8.

  • @devjock
    @devjock Před 10 lety +1245

    Are you listening to me Neo, or are you distracted by "Woman in the red jeans" 5:40
    Great explanation!

  • @manogilissen
    @manogilissen Před 10 lety +25

    7:17 Why does he say 4096? You can use 5+6 = 11 bits so wouldn't that be 2^11 = 2048?

  • @taserianAlephNull
    @taserianAlephNull Před 8 lety +121

    This was an excellent presentation. Thank you for making it so understandable!
    I do have a very minor quibble. At 7:18, there's an error; in a 2 byte Unicode character, having 11 bits available (5 from the header, and 6 from the continuation) will only allow you to get values up to 2048, not 4096.

  • @DaChilla1
    @DaChilla1 Před 8 lety +170

    Holy shit, this guy is freaking enthusiastic about it. But he has a point.... I only recently learned the way UTF-8 works and I gotta say, this is some freaking genius hack.

  • @megaelliott
    @megaelliott Před 10 lety +218

    UTF-8 is love, UTF-8 is life.

  • @nameredacted1242
    @nameredacted1242 Před 2 lety +3

    For a restaurant setup, this is BIZARRELY informational and useful. So strange!!!

  • @diogoj95
    @diogoj95 Před 10 lety +90

    5:38 i see what you did there xD

  • @lcdvasrm
    @lcdvasrm Před 8 lety +238

    cameraman, please take a seat

  • @torlack
    @torlack Před 10 lety +14

    There are problems with UTF8. For languages that aren't latin1 based, UTF8 can often take more space than UTF16 or ucs2. When we localize our games for Asian languages, we usually use ucs2 instead of UTF8. We have so much dialog that we have to be careful. Also, for those who said UTF16 is the same as ucs2, it isn't,. Ucs2 is a character set while UTF16 is an encoding. UTF16 supports many more code points that aren't in ucs2

  • @rlamacraft
    @rlamacraft Před 10 lety +3

    Love this guy's enthusiasm and this type of video converting the odd bits of computing like how number phill covers the odd bits of maths rather than teach a full course in those subjects

  • @samuvisser
    @samuvisser Před 5 lety +3

    I watched this video like 5 times over a long period now. Keep coming back to it, I so love the explanation and the storytelling!

  • @another-person-on-youtube
    @another-person-on-youtube Před 4 lety +13

    This was unironically riveting for me. I'm amazed at the incredibly clever solutions that make up the foundations of mundane computer operation.

  • @user-bd5ln2ex6r
    @user-bd5ln2ex6r Před rokem +3

    Thank you for providing Korean subtitles. You explained it so well that I could understand it well. Thank you.

  • @Dinoguy1000
    @Dinoguy1000 Před 10 lety +28

    This makes me think of the error-checking header used in PNG files, really a quite clever piece of work that I'd love to see a video on. =)

  • @joeserneem853
    @joeserneem853 Před 10 lety +16

    I really like Tom Scott's way of explaining.

  • @RedPandad
    @RedPandad Před 5 lety +11

    For the people wanting to know where this vid was taken it in a cafe called the booking office in St Pancras station I know because I have been there once it's pretty popular

  • @Niki_0001
    @Niki_0001 Před 10 lety +7

    It's always interesting to listen to someone who's that passionate, or at least sounds passionate. Even if you don't care about the subject at hand, it somehow becomes interesting when person speaking is passionate about it!

  • @bulman07
    @bulman07 Před 8 lety +203

    Was this filmed in the St Pancras Hotel?

    • @Computerphile
      @Computerphile  Před 8 lety +148

      Yep

    • @Computerphile
      @Computerphile  Před 7 lety +94

      ***** actually this is just their public bar, our filming location fell through and they were kind enough to let us film there. Anyone can go in >Sean

  • @dunx125
    @dunx125 Před 10 lety +5

    This guy is brilliant at explaining things, please feature him more often!

  • @chridal
    @chridal Před 10 lety +11

    This guy is a LOT of fun. He's so enthusiastic! Please have him on again!

  • @arzenn_
    @arzenn_ Před 7 lety +22

    I learn more here than my software lessons

  • @joedeshon
    @joedeshon Před 4 lety +1

    Definitely one of my favorite Tom Scott videos!

  • @TheBreadCatt
    @TheBreadCatt Před 10 lety +1

    If you could do more with Tom Scott that would be amazing. I love his videos and these videos, so combining them is just awesome!

  • @lpatrasco
    @lpatrasco Před 4 lety +9

    Such an incredible enthusiasm just for UTF-8! I’d like to hear you speaking about quantum entanglement 🥴

  • @GunjanBagayatkar
    @GunjanBagayatkar Před 10 lety +6

    Very interesting & informative video.
    Explained in detail and still very easy to understand.
    Thanks for uploading.
    Keep up the good work guys...

  • @LIES666
    @LIES666 Před 10 lety +1

    It's always nice when you're watching one of Brady's channels and someone from a completely unrelated channel you subscribe to turns up.

  • @endermannull4420
    @endermannull4420 Před rokem +1

    bingeing computerphile on halloween is a mood

  • @ButzPunk
    @ButzPunk Před 10 lety +4

    Finally, someone who loves UTF-8 and Unicode as much as me!

  • @ronanderson1023
    @ronanderson1023 Před 9 lety +2

    Thank you so much for sharing so much detailed information!
    I always thought of bits and bytes to be something i'll never be interester in, but frankly, this stuff is getting really interesting the more you into it.
    Greetings and all the best!

  • @m_jacko12
    @m_jacko12 Před 10 lety

    this was one of the best videos on this channel, i loved it

  • @Carutsu
    @Carutsu Před 10 lety

    UTF has to be one o the most beautiful solutions I´ve ever seen. Loved it since I translated the unicode page.

  • @ElectricFury
    @ElectricFury Před 7 lety +59

    homework is to watch this

  • @jlamothe2
    @jlamothe2 Před 4 lety +36

    Another advantage of UTF-8 that wasn't mentioned is that if you want to sort strings by Unicode value, you can just treat it as though each byte were a separate character, and it'll just work.
    The only real downside to UTF-8 is that you can't seek out a character at a specific index without walking the entire string character by character.

  • @iabervon
    @iabervon Před 10 lety +2

    Another tiny correction: at 1:53, he says a space is all zeros; actually, a space is 0100000 = 32 = 0x20. As he mentions later, all zeros is "end of string".

  • @lexbailey
    @lexbailey Před 10 lety

    This is one of the best computerphile videos. This is the sort of topic explained at the right level to be interesting to most people who (I suspect) subscribe here. Good work!

  • @aatheus
    @aatheus Před 10 lety

    That is actually a very good explanation of UTF-8! I had wondered how the continuation bytes worked for a long time.

  • @DarrylCollins
    @DarrylCollins Před 10 lety +55

    Very interesting video explainer. I learnt something new today! (Particularly like the crash zoom at 5:42 to see girl in red pants!)

  • @policello1980
    @policello1980 Před 4 lety

    Great video, I really like the close-discussion format !

  • @blindshiva2826
    @blindshiva2826 Před 5 lety +10

    Thanks for the history lesson. It is always interesting to remember how we got to where we are today.

  • @fabioampe
    @fabioampe Před 10 lety

    You talk with so much passion about the subject. I think that's really beautifull. I bet Even someone who doesn't understand a sh** about computers will know how important it was.

  • @BGroothedde
    @BGroothedde Před 10 lety

    Man... I love these videos, I love all the videos by you.

  • @glitchsmasher
    @glitchsmasher Před 8 lety +68

    All 0s in ASCII is Nul. 32 (01 00000) is Space.

  • @jamesmax
    @jamesmax Před 10 lety +33

    Why dose UTF-8 go up to 1111110X and not 11111110?

  • @puncheex2
    @puncheex2 Před 10 lety +2

    historical note: Before ASCII there was 5 bit teletype code (upper case only), binary coded decimal (BCD), which was a 6 bit code, and extended BCD interchange code (EBCDIC), an 8 bit code. BCD and EBCDIC were IBM standards adopted by the industry. All used the "trick" of having the letters in collating order; it was the basis for punch card computing.

  • @KeianhhnaieK
    @KeianhhnaieK Před rokem +1

    Nothing short of amazing.

  • @eduardobcastro14
    @eduardobcastro14 Před 2 lety +1

    These videos are great contributions to human knowledge

  • @Cathal1992edition
    @Cathal1992edition Před 9 lety +73

    Love the enthusiasm! :)

  • @ZestyCrunchy
    @ZestyCrunchy Před 10 lety +1

    I've never seen someone that passionate about encoding characters.

  • @raditz2488
    @raditz2488 Před 4 lety

    In depth explanation. He also shares a cool way to remember what A's and a's codepoints are.

  • @freeman1884
    @freeman1884 Před 4 lety

    Patiently watched twice and understood it very well, thanks!

  • @plutoniumseller
    @plutoniumseller Před 10 lety

    I have been waiting for something on Unicode/UTF-8. THANK YOU, COMPUTERPHILE!

  • @CBaggers
    @CBaggers Před 10 lety +1

    Love this guy's passion, great video

  • @MixedTacticsGamer
    @MixedTacticsGamer Před 10 lety

    More of this guy please! He's awesome, really great speaker!

  • @xway2
    @xway2 Před 10 lety

    This guy's personal channel is in the description. I just checked it out and it's really amazing. You should too.

  • @cmroosen
    @cmroosen Před 7 měsíci

    Great explanation, love his enthusiasm

  • @veloxsouth
    @veloxsouth Před 10 lety

    This is the first computerphile video I didn't hate. Well done.

  • @BorealSelfReliance
    @BorealSelfReliance Před 10 lety

    Great Vid! one of my most fave vids from this channel.

  • @ChrisDuncanCodeCow
    @ChrisDuncanCodeCow Před 10 lety +1

    Thanks for this! Character encoding always confused me; this video explained UTF pretty well to me.

  • @rastajedi420
    @rastajedi420 Před 9 lety +5

    I'm still not sure I understand how a UTF-8 encoded file (with characters *other* than ASCII characters) would show up in something that is only ASCII compatible?

  • @marty34534
    @marty34534 Před 10 lety +3

    You explained that so clearly, well done! I agree its brilliant

  • @_wouter52
    @_wouter52 Před 10 lety

    This was great! I like this guy and the episodes become better and better!

  • @dospy1
    @dospy1 Před 10 lety

    i love this guy's enthusiasm. great video

  • @svartholstjornuson6215
    @svartholstjornuson6215 Před 11 měsíci +5

    5:39: Zoom out. Pan right.

  • @Jessassin
    @Jessassin Před 10 lety +2

    This is the sort if thing I subbed for. Thank you :)

  • @lierdakil
    @lierdakil Před 7 lety +1

    "[...] we don't have mojibake, [...] we have something that nearly works" - Tom Scott, 2013.
    I absolutely adore this "nearly" thing.

  • @coreyaudet8574
    @coreyaudet8574 Před 4 lety +1

    This schooled me. Great information. Thank you! I just subbed.

  • @ominousplatypus380
    @ominousplatypus380 Před 2 lety +2

    Am I misunderstanding something or is there an error at 6:30? Shouldn't that be 97 or a lower case 'a'?

  • @resonance2001
    @resonance2001 Před 10 lety +2

    I like UTF-8 too. It's very useful. I quite like UTF-16 for encoding foreign words in RAM. I wrote a special text editor for writing in different languages and I found UTF-8 to be perfect for saving the text files.

  • @DamoonBlu
    @DamoonBlu Před rokem

    I don't even want to think about the stress of allocating every symbol with a number, but great video!

  • @kelvinmburu2698
    @kelvinmburu2698 Před 7 měsíci

    Beautiful explanation, Thank you

  • @harrytaller9403
    @harrytaller9403 Před 6 lety

    thanx Computerphile for explaining utf8 , user tried to understand from wiki but could not do it, u make everything simple

  • @mathiasbynens
    @mathiasbynens Před 10 lety +2

    In practice, you’ll never really encounter UTF-8 byte sequences with 4 or 5 continuation bytes. In November 2003, UTF-8 was restricted by RFC 3629 to end at U+10FFFF, in order to match the constraints of the UTF-16 character encoding. This removed all 5- and 6-byte sequences, and about half of the 4-byte sequences, but it’s still enough to represent every possible Unicode symbol ever.

  • @MrJekyllDrHyde1
    @MrJekyllDrHyde1 Před 10 lety

    If you asked me to watch a UTF-8, I would have given it a pass... but with this guy, I could not stop watching.

  • @sonodrome
    @sonodrome Před 10 lety

    Hey Tom! Fancy seeing you here :) Great to see you on ye olde Computerphile.
    Maybe catch you at the next TDC! Loving the video empire Brady, thanks for bringing us a slice of Tom - Jim.

  • @lambar0
    @lambar0 Před rokem +1

    Simply Elegant … clear explanation

  • @theroztube
    @theroztube Před 10 lety +1

    perfect explanation! Thanks for that.

  • @ltericdavis2237
    @ltericdavis2237 Před 10 lety

    Finally I get an explanation! I've been wondering about this.

  • @hansvetter8653
    @hansvetter8653 Před 7 měsíci

    Great explanation of UTF-8! Thanks!