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Can you explain why it ruins the DVD encodes? I like this community to learn stuff

It all comes down to the fact that DVD is more of an analog format than a digital one. I feel like people get “CD ripping brain” which causes them to think that the most desirable thing is making the most-accurate copy of what's on the disc. For CD that's true because PCM is PCM, but for DVD the thing we really want is the program material, which is three layers deep on a DVD: inside an NTSC video signal, which is digitized following the Rec.601 standard, which is then shoved into an MPEG2 transport.

Four major things that can be done to DVD to make them look great on modern displays:

- Deinterlacing is the hardest to get right. Progressive-scan 24-frames-per-second DVDs exist but are mostly confined to movies where there will be a better BD release anyway. Interlaced DVDs where the program material is intended to be seen in 24FPS get “inverse telecine” (IVTC) instead of straight deinterlaced, but again I don't do a lot of those for the same reason. Almost any NTSC DVD that I care to encode is thus going to be 60000/1001 fields per second, which needs to be turned into 60000/1001 frames per second to avoid throwing away half of the available motion detail. If you do nothing at encode-time and produce an interlaced output, then the display or player software will end up doing it and will do a bad job. HandBrake's deinterlacing options just don't look good in my experience. I like QTGMC for this because it predicts the motion of the infill fields instead of just copying the previous field verbatim. It's very noticeable any time there's a lot of horizontal movement in the program material.

- Resolution and ratio. Most people hear “anamorphic” DVD and think of 16:9 crammed into a 4:3 image, but the truth is that all NTSC DVDs are anamorphic. They're 720x480 which if you calculate it is actually a 3:2 aspect ratio. Very clever because it ends up being about the same amount of scaling for 4:3 or for 16:9 material. They rely on PAR/DAR flags to tell the player or display how to scale it, but modern displays have terrible terrible scalers because it's purely a box-checking thing for them and not a feature they spend money or effort on. When I encode a DVD I stretch it myself at encode-time to 720x540 or 960x540. There's obviously some artifacting inherent in that vertical stretch, but it avoids throwing horizontal resolution detail away by scaling 4:3 programs down to 640x480 like most encoders do. Then the 540 pixel-doubles cleanly into 1080, 2160, etc.

- SD colorspace (Rec.601 again) is a similar issue where modern displays are just fucking terrible at it because there's no economic reason for them not to be. The chroma is already subsampled, so greens especially end up looking washed out and terrible. When I encode a DVD I convert them into HD colorspace which doesn't restore subsampled chroma but at least avoids letting the display make it worse.

- Cropping. The program-area resolution is actually 702 or 704x480 for anything transferred from tape (look up SONY D-1). If you have any "DVDrips" sitting around of an '80s or '90s TV show, does it have 8 pixels of black pillarbars on the left and right? If so then the person who encoded it didn't know what they were doing. It subtly throws off the aspect ratio for the entire program, especially noticeable in animation where they tended to use exact-circle tools. Look at the characters' eyes in The Simpsons for a great example. I crop those off before my one-time scaling so the program ratio comes out perfect.

This all applies similarly to PAL DVDs except I'm usually shrinking them down to 540px because the loss of some vertical resolution is still better than trying to get a modern display to scale 576px to panel-native res, and deinterlacing PAL is a straight 50-fields-to-50-frames without the wacky 1001 division notation that is a legacy of the backwards-compatible way that color was introduced to NTSC.


That's fascinating, thx!

Thank you! I don’t have many DVDs (and only PAL), but it’s good to hear that I would need to be careful when ripping them

As with any lossy encoding process, I also always keep my originals so I can do it over in the future if need be :)

Not necessarily the physical disc but at least an ISO. I tend to rip DVD ISOs with the encryption intact in the name of making an untouched copy, since CSS is so thoroughly broken and since I have seen some very bad “backup” tooling that corrupts the VOBs when decrypting. I use DVDfab Passkey which is free for DVD usage; “Rip to Image” → “Keep Protection”.


I just remembered that I have a non-infringing example encode I can share: PBS's “Code Rush — A Year in the Life of a Silicon Valley Supernova: Netscape” (2000)

Original PBS web page: https://web.archive.org/web/20000815055556/http://www.pbs.or...

A copy of this was released as an MPEG-4 Part 2 (not AAC/H.264!) MOV back in 2008 to commemorate the Firefox 3.0 release: https://waxy.org/2008/06/code_rush/

Then re-released and licensed under Creative Commons Attribution-NonCommercial-ShareAlike 3.0: https://waxy.org/2009/07/code_rush_in_the_creative_commons/

  mega dot nz/file/QhtHzBZD#Z8eUnBgmk3lsjRgKQsiSaGD_gAnRgNY6FCk2rzrSisM

From the name I thought this was about learning NixOS, and they found a very clever name

Maybe the author could add a small note that this is not about that, and refer to something official about NixOS?

Anyway, I like the idea of the project!


“*nix” means a Unix-like OS just generally (http://en.wikipedia.org/wiki/%2Anix), like for example in “Minix” and “Xenix”. Sticking “OS” to the end of an OS name is also commonplace. However, the title on the page is “The Learnix Operating System”, so the actual name seems to be just “Learnix”.

It’s arguably Nix and NixOS who have unnecessarily stepped into the “*nix” namespace without adding a distinguishing prefix.


Then I guess the OS part is redundant, since thr nix already implies an OS.


I feel like if I saw something just called "learn unix", I'd expect it to be teaching me how to use it generically, not implement it. Adding "OS" makes it clear to me that it's a dedicated OS for the purpose of learning (although it still wasn't clear to me that the goal was implement it so if anything I'd argue that the title is missing context, but the name of the OS isn't redundant).


No, actually Nix is a package manager/system configuration tool. NixOS uses Nix as part of its image.


No, nix clearly means a Unix-like OS and any other interpretation is wrong, as the context of this thread would suggest.


So your argument is the first usage of a word gets exclusive rights to it? Firstly, that's not how human languages work. Secondly, this would invalidate the Unix claim to "nix" as it's been a word for hundreds of years prior to Unix being invented.


It is, but in IT context the association was strong, while Unixes decline and most of the systems with derived naming are historic. But anybody with a background in sysadmin for more than 10 years probably would still have the association. In ten years Linux will probably the only one remaining with the ux-naming (and MacOS X with the single X, which also serves as ten, following MacOS 9)


My guy, most people don't even know what nix (the package manager) is.


Time to get familiar then.



LearnixOS doesn't seem to have anything to do with NixOS, afaict?


> “*nix” means a Unix-like OS just generally

"Unix-like OS" isn't a thing that has existed for two decades. Only Linux and Darwin survived, so don't do the "*nix" thing, please.


BSD would like a word.


They can't be heard over the faint booing from the Solaris crowd.


For that matter, if we're including the proprietary OSs, HP-UX is still kinda a thing and AIX is going strong. Of course, IIRC those are actual certified UNIX™ instead of unix-like... though I'd call that a subset, so still in scope IMO.


TIL AIX is still in development and they had a release this month

https://community.ibm.com/community/user/blogs/sanket-rathi1...


We don't talk about BSD here.



Very confident.

The people who do the "*nix" cargo cult thing have never seen a SunOS machine and don't even know what a HPUX is.


The linked trends suggest a revival of the term though.

> The people who do the "*nix" cargo cult thing have never seen a SunOS machine and don't even know what a HPUX is.

The meaning of words evolve over time though. Text is still broken into lines by "carriage return/line feeds" and is written on "hard disk" split up in "sectors".,. Over time people using these would not have seen a typewriter or even know what a platter is but may still use it to communicate effectively.


Illumos is still actively developed, open source, and can trace its lineage back to actual unix.

For that matter, we've had new members joining the family over the years; https://www.redox-os.org/ is, in their own words, "a complete Unix-like microkernel-based operating system written in Rust, with a focus on security, reliability and safety."


For anyone wondering, OpenSolaris -> illumos (e.g. OpenIndiana). Good times!


Not to mention that Version 4 UNIX source code was just released!


Well, yes, but that's not exactly a modern OS, just historically interesting.


Darwin is not UNIX (nor is XNU). But macOS technically is certified UNIX.


XNU literally stands for “X is Not Unix”


I had the same confusion. Even without considering NixOS, "learnix" is awkward to pronounce and somewhat pretentious.

I would suggest the name "Leanix" if the author is willing to rename.

It rhymes with Minix which is the OG curriculum for a POSIX kernel, and is "lean" in many senses of the word.

In any case an excellent writeup. It's detailed enough to implement in any programming language.


> I would suggest the name "Leanix"

Then people would complain that it sounds too much like “Linux”.


Particularly if you have learned to pronounce Linus’s name correctly.


What's pretentious about learnix?


I like the current name and already have the domain :|


I think that it's supposed to be a portmanteau of Unix and Learn.


I don't find it awkward to pronounce in the least, and not in any way pretentious.

I think the name is fine as is.


I mean, it is about learning. It threw me for a loop too but I think it's actually reasonably appropriate.


Thought the same! Was a bit interested in learning Nix for a moment.


Will do!


[flagged]


> Others think someone from the Rust (programming language, not video game) development community was responsible due to how critical René has been of that project, but those claims are entirely unsubstantiated.


Yes, although not as much. But I still keep my TI Nspire CX CAS charged for when I need it (needed it during my CS studies for adjacent topics). Specifically the CAS version is nice because it can simplify algebra for you, and even solve/rewrite an expression for a specific variable. There’s probably something I can use on my computer, I do like the ergonomics of the calculator though


They are actually of the same age, the iPhone 8 and X came out at the same time (yes it’s still confusing now)


Just for reference: if you need Subtitles on an OLED, e.g. on Netflix you can set the subtitles to grey (only in the Web app, but is used on all other apps). Had that same problem with the OLED


In Switzerland, most instructor cars are Diesels, since they have higher torque and are very hard to stall. Then you go home and drive your parent's petrol engine car and you stall it all the time


This is a really interesting comment for me. I’m a mechanical/aerospace engineer, I size motors by their stall torque all the time, I’ve owned/driven many manual cars over the last 25 years, I’ve done a few clutch jobs in cars, including upgrading a sports car (so I learned about and experienced some of the parameters that make a performant clutch perform). I’ve even had to replace a magnetic clutch on an industrial lathe when I did an automation upgrade on it and it exposed the fact that the clutch was worn beyond its spec - before it was manually operated and the operators just compensated for the wear over time although I forget how. Yet I’ve never put 2+2 together and thought about the torque in a car when starting out and how that relates to how easy/hard it is to stall a particular car.


Huh. That's completely the wrong way round. My instructor's car had a petrol engine that would have been appropriate for a skateboard, so I had to get the clutch just right and learnt properly.


Nonsense. The goal of a driving instructor is to teach how to behave on the road, not how to cajole your car into not giving up on you.

The pupil can do that on their on time, on the first shitbox they acquire. If you want to learn how to start an 037 without stripping the gear feel free to do that.


In German it's called the Kaufmanns-Und (roughly merchant's/salesman's And). I think it may be related to advertising, if you advertise a product name (or a producer name) with an "and" in it, the ampersand is much shorter and more visually appealing


Which is consistent with many Romance languages, where it's called a variation of “commercial and”. Including the Italian “e commerciale”, Portuguese “e comercial”, and Spanish “y comercial”.


And French "Et commercial". It's sometimes written as a form closer to "et", corresponding to the ligature outlined in the article


That's like how the symbol @ used to be called "commercial at" (this is its Unicode name). This is because of how sales were listed on receipts and such, think "4 apples @ 50¢ each".


"@" has a lot of interesting names - monkey, herring, pig's tail, strudel, mouse, elephant's trunk, and "arroba" (a unit of weight, like a bushel).


Yeah, in Dutch it's "apenstaartje" (little monkey's tail), although the last decades, it's becoming far more common to use the English "at".


it's "Klammeraffe" in German, spider monkey, and figuratively a small monkey clinging to / clasping someone or something.


It's "zavináč" in Czech -- pickled herring. If you buy them in a jar, they're rolled up, looking a lot like that symbol.


I kept a collection of names for @ on my first website: https://web.archive.org/web/19981202002949/www.student.nada....


My favorite name for “@“ is “rogue”


I prefer ”tourist”


What languages or cultures or regions use this form?


It's particularly popular in Yendor, I believe.


Spread from there to Ancardia and Moria as well, though.


touché


In the 90s/00s it was often referred to as 'miukumauku' in Finnish, roughly translates as 'meowmeow', as in the sound a cat makes, since it somewhat looks like a sleeping cat.


In Russian, it's usually called `dog`. No idea why.


A dog will always perform a certain spiral inwards walk pattern before it comes to rest on bedding.


I forget the exact details, but I've seen it called a snail in some programming language or other - I remember getting an error message along the lines of 'unexpected snail at line x'! I wish I could recall what language it was - perhaps something verilog related?


In italian we call it "chiocciola", which translates to snail.


@ "Princess Leia hair"


In the subcontinent, almost everybody pronounces this "at-the-rate-of". I guess they learn this in school or something. Makes you do a double take the first couple of times someone reads you an email adress :)


Very briefly worked in a metal fabrication shop in the last gasp of pre-CAD and electronic records. Writing out the bill of materials (by hand, to be typed up) involved a lot of numbers - measurements, quantities, and prices.

Using symbols like # before a quantity, @ before a unit price, or ⌀ before a diameter was considered critical for minimizing confusion. I think it was meant to work like a sort of Hungarian notation for numbers, so if someone’s transcribing them into an order form or something, and they find themselves copying a diameter into a price column, they catch themselves on the type mismatch.

It never seemed like there was much room for ambiguity in any of the lists I wrote up, but I guess when you screw up an order to a steel supplier and get the quantity mixed up with the length, that can be a pretty expensive mistake.


In Spanish the @ is used, mainly in text chat, as both an "a" and an "o" at the same time. Saves time when you want to address both males and females: "amig@s" instead of "amigos y amigas"


Smart, maybe can displace the harder to read latinx term.


as an accountant, i feel that cringe feeling whenever someone says their email john at the rate of gmail.com lol.....


The @ is sometimes used like "apples, 50¢ @" in which it is read as "each" rather than "at". This may have faded out once email addresses popularized it as "at", but it always made more sense to me since @ looks like an "ea" ligature.


Ah, I wasn’t aware of this, but it makes a lot of sense! It even looks like it could be a ligature of “eac”, and it’s very natural to imagine a cursive each being abbreviated first to @h and eventually to just @ by a busy clerk.


German uses à for this purpose, there is probably a shared history behind that.


Its html code is "@".


I always thought it's "amper's and" for that reason, and "amper" must mean "Kaufmann".


as opposed to the appealing German scharfes (ß)


Don’t believe them! ß is not sharp! Do you see any sharp edges there? Me neither! It’s as blunt it can get!


The curve is a convex edge. The shape provides lower surface area at the point of impact, increasing the surface pressure with the same impact force compared to a straight edge.


the baseline looks close to being a "sharp edge"...

really though, with the "New Book called "What if? 2" by the XKCD creator, can I get him to sign it? given the previous books suggestion: a cure for the common cold, "If everyone on the planet stayed away from each other for a couple of weeks, wouldn't the common cold be wiped out?"? https://news.ycombinator.com/item?id=30139925


German class teacher told us once that this particular letter can be called scharfes S and eszett

Was kinda amusing when the "less involved" classmates were trying to read it as B


it's from (serif-like) handwriting really... it's easy to see that given people "describe" the as being scharfes of the entity `ß`


To be honest, when I was very young, there was always the thrill something unexpected might happen on TV, and crashes were part of that. But this has quickly faded. I only dimly remember the Bianchi incident, at the time watching I didn't think too much of it. The Grosjean incident though was really something, and I got similar vibes a few weeks ago with the Schumacher (Mick) incident where he wasn't shown for a short time


The Bianchi incident was so odd and I've only (accidentally) saw one video of it since as far as I know, no broadcast camera captured the incident. But F1 learned and red flags seem more common now and they don't race with reduced visibility.

Agreed about Mick as well, its always terrible when they don't show replays for a while. But I also think that fact alone contradicts the OP, they won't broadcast a serious crash.


Has there been an attempt at doing a shell?



(to GP) I really have to say, this is not how you should ask someone else to fix a problem. Going at the developers on a personal level is NEVER a good thing. If it was my project, I probably would have closed the issue completely after you insulted me this personally.


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