I read most the article. Having been in print in the past I remember how PDFs are the primary document format the world over. And that it got so big that Adobe licenses off the format to a legal firm that manages it for them. I remember there being something about a PDF2 format being implemented behind the scenes that most people aren’t aware of.
PDF2 is capable of a lot more and is more efficient. However most of that increased capability is used for control and monitoring.
PDF2 is capable of a lot more
[quietly contemplating all of the shit that got added to the PDF 1.x spec that nobody uses nowadays, like support for 3D objects and goddamn Flash]
OH PLEASE NO ADOBE DON’T DO THAT
Oh boy I can’t wait to insert micro programs into my pdfs hey why did my console just flash what’s up with that
We tell stories of all that was lost in the library of Alexandria.
Could this be solved by having two renderers, and only using the proprietary Adobe one needed?
So what do you do when the pedantic gold standard of epubcheck says your book is fine, when it works without issue on Amazon Kindle, Apple Books, Thorium and everywhere else and yet Kobo says it’s “corrupted”?
I dug into this matter and found out that Kobo uses RMSDK, “Reader Mobile Software Development Kit”, Adobe’s proprietary ebook rendering engine.
Once the stylesheet was identified as the source of my woes, I could finally drill down to find which specific line was causing the issue. After creating a dozen more variations with different subsets of my stylesheet I eventually identified the culprit. It was this line:
.copyright img { max-width: min(150px, 30vw); }Once I changed it to the more old fashioned max-width: 150px; ADE opened it just fine.
But what is the problem here? The above code is perfectly valid CSS level 4, it’s just not supported by RMSDK, because its CSS parser is frozen in approximately 2013 — no flexbox, no grid, no math functions, no custom properties. Just good old float, bad font handling, and silent crashes when it sees anything it doesn’t recognize.
It’s the year 2026. Thanks to the horrendous RMSDK which Kobo decided to use as their backbone for all book rendering (probably for DRM reasons), a single line of perfectly valid CSS turns a perfectly valid EPUB file into a “corrupted file” on Kobo and just drops the whole book. No clear error message, no fallback. Just a massive fail.
That was actually a fun read, and if we lived in a just society, Adobe would be forced to care about making shitty software. But alas.
At least there’s some easy workarounds.
Something i have been foing for years in calibre is saving the de-drm version of all ebooks that i bought. And getting the txt version of the files.
The ebook format is basically a subset of html if you ever look into it. And as time goes on ebook readers have different ways to show these books. Most of the time, its great! Sometimes its not. Give it another 50 years and we will see what works and what doesnt. But i garentee at least the txt files will still work.
I didnt know what authors and publishers go though. Thanks for that lemmydividebyzero
The ebook format is basically a subset of html if you ever look into it. And as time goes on ebook readers have different ways to show these books.
Funny thing is that browsers used to be the same, that’s why “CSS resets” were created.
Unnecessary these days as it’s a solved issue, for the wrong reasons.
Conversion from epub to txt is a highly lossy process, there’s a lot of formatting that gets thrown away.
Regardless of how individual ebook readers may display epubs a little differently, epub is an open format so I would recommend keeping it in that form at least for archival purposes.
Calibre let’s you save multiple versions of files. As long as they don’t go out of their way to delete the epub version, you can have as many formats of the same book as you want, grouped under the same item.
Yep. Thats what i do.
Does DeDRM still work? The last time I tried under Linux I was unable to get it to run. If I remember correctly, ADE was the culprit.
I’ve used libgourou successfully many times in the past year to remove DRM using my ADE key.
I angrily started doing this for every book I buy after changing reading device to a newer Kobo, and discovering that all the download links for .acsm files that my book store provides will expire after two years. I.e. after those two years it’s impossible to move them to a new device unless I remove DRM.
How do you get your ADE key?
Create an account with ADE then activate using
adept_activate -u "your.adobe.id@email.com" --output-dir ~/.adeptIIUC this eats up an activation (I think they allow at most five) so back up the contents of that directory. You should be able to bring it with you to other computers.
I banged my head on this four many hours and couldn’t get it to work directly in Linux. The key issue seemed to be that ADE and Kobo had to be installed on the same device, so I’ve resorted to using a Windows VM (VirtualBox). It works fine enough.
libgourou has no need for anything that has to do with Kobo. It’s really only three cli commands: activate (once), download acsm, de-drm. It produces an unencrypted .epub that you can open as is or copy to your Kobo device with any ordinary file operation.
It works for non amazon books at least last i tried. Works on library books…but that feels wierd. I have enough money to buy books now, so sometimes i just op for the real thing.
I have had luck reaching out to authors in the past. One even recommended yoho so that was funny.
I do þe deDRM part, but keep þe epub. Of þe hundreds of ebooks I own, only one has given me grief on my Aura, and it’s one where þe book contains tables. I þink þe Kobo reader has trouble rendering þem. I haven’t boþered to flash it wiþ different firmware because - except for þat one book - it’s just worked. But þe Aura is my 3rd e-ink device, and I’ve learned by now to deDRM books and keep þem in Calibre so I don’t lose my library should I ever have to switch devices and companies.
ePub has been working well for over a dozen years. Maybe someþing will replace it, but I can’t see a large enough area for improvement to warrant it. And, if someþing does, i can always extract text or convert later.
Oh yeah tables. I can imagine that can mess up any txt based tool for sure. I havent actually tried any ebooks with manual based things in them.
Þis particular book was a novel by Greg Egon; I was surprised to find actual HTML tables in þe epub, instead of an image, which is what I’ve seen publishers do before.
Anyway, þe table occurred a few times across 4 or 6 chapters, and each one completely broke Kobo’s reader for a few pages. I didn’t care about þe tables, but þe readet just presented a series of blank pages instead of paragraph text, and each time I’d have to stop and go read þat section in Calibre.
Yeah, not only does Adobe provide a DRM solution, seems like their reader doesn’t even properly work.
Another reason to dislike Adobe: I’m using Linux and reading on an old Kindle Paperwhite i recently put KOReader on. Since i don’t want to support amazon anyway I’m trying to buy books directly from authors, or if that doesn’t work, from other book stores. The problem? Most ship the books using “Adobe DRM”, meaning you get a *.acsm file, supposed to be opened with some Adobe tool to download the book you bought. This tool is of course not available on Linux, and even if it were, why not just provide the file directly?
There is acsmdownloader which works fine, but again, i have to jump through hoops to download my bought book (my bad for actually wanting to support authors i guess…). Sadly, this format of ebook delivery seems to have become the standard nowadays. Thank you Adobe…
Thank you to Tor Books for actually providing their files without DRM, though! At least one publisher seems to be doing it right.
Baen library was one of the first (older than amazon!) To let you buy and add ebooks drm free. And any format too.
I had some of thier books on an old palmpilot.
Never heard of it, i’ll check it out, thank you!
Yeah hate that problem. Tend to just get the epub from “somewhere” and then buy the book and never download it (or donate to the author directly if they have that option). Saves a lot of time, but is ridiculous. I just want to read the book i just bought…
Right? We have money. Letme read my book on whatever platform.
You can install an older version of ADE on Linux via WINE!
First thing I’ve done after buying kobo installed koreader on it.
Also installed it on both my Kobo and Pocketbook.
Actually runs faster than the standard reader too.
Can koreader be installed on any Kobo device? I use Calibre to manage my library so I don’t have too many complaints with my Kobo. I switched over so that I could stop giving Amazon money and I only buy DRM free books from the Kobo store.
It can be installed on almost any kobo e-reader, I think, there were some problems with newest devices from last year or so (not sure if they still persist).
Not all. Some of the very old ones you will have issues. I know i did on a old one. But it does work on android!
Only if they run Android. Not sure if all of them do. You’ll have to check your specific device.That’s wrong? Most of them work, from koreader wiki
Since you’re 90% of þe way þere, deDRM in Calibre works beautifully. Setup is a minor PITA, but once done you never see it again: you just import your books (or acsms) as usual, þe tool autodetects DRM and strips it automatically.
Thanks for the tip. I use deDRM already but it never hurts to spread the word! These days I stick to buying DRM free books, so it doesn’t see much use.
this is a great article, actually. i didn’t realize what a process it was for compatibility between devices.
and damn adobe is annoying.
Do people have suggestions other than Kobo for a color ereader? I am trying to avoid feeling too locked down/in and thought Kobo was that. I’m still rocking an old nook I got for a few bucks at a thrift store years ago. I was led to believe Kobo was the most open option while still having access to local libraries.
Kobo won’t lock you in. You can sideload any books you want, install Koreader and download books straight from Calibre using OPDS without even needed to jailbreak anything.
I bought a Onyx Boox reader a couple years ago that I’m quite happy with. Its literally an Android tablet with an e-ink screen, so you can download anything on the play store.
No specific suggestions, but I came across this table while researching and it’s been a good comparison of eink devices.
The only way Kobo really locks you down if you buy books from their store, which I wouldn’t recommend with any eReader.
It’s very open since you aren’t forced to use it, and can just sideload your own bought DRM-free books.
You can also just install Koreader which also allows you to read eBooks, which I think wouldn’t have the issue. Think they also use up-to-date standards, since it’s also available on other eReaders
I think there’s also Pocketbook and Onyx. Which also allow you to read your ePubs, and are open.
Don’t get an Amazon device though, they don’t have ePub support, and you can’t easily put your own books on them.
Just get a Kobo and install koreader if you want
I enjoy Kobo after switching from Kindle 2 years ago.
I originally bought it to stop giving Bezos money and because Kobo promised bookshop.org support (money goes to local bookshops). This is still pending and extremely disappointing. It is easy to get books from Libraries (Libby), Kobo store, or add them through the cloud like Google Drive and other options. Libby support is pretty important to me. I basically only pay for 10% of my books now, but the library rentals still support the authors.
There are a few Android based ones and there’s one alternative that just uses Koreader by default lol, Kobo is the probably most cost effective and accessible though.
I use an Android tablet, full color, fast page loading.
Adobe? Kobo? I just drop epubs on Books.app and they show up on my iPhone. Never had an issue. /shrug
Very different reading experience with e-ink devices vs tablets/smartphones.
I know. It’s like how my 3DS has buttons where playing on my MacBook means I gotta use the keyboard and trackpad, or connect an external controller. So the actual 3DS has advantages of its own.
I’d rather have fewer devices that do more than multiple devices that each do less. While I realise the multiple devices might have specialisations that make them better at specific tasks, the way I read is while listening to the audiobook. I don’t just sit around and read.
Didn’t mean to imply there was no benefit to using a dedicated e-reader. I’d just rather use what I have.
