Getting encrypted pages on a premium purchased epub.
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I purchased the premium epub for "Mapping: The Trash-Tier Skill That Got Me Into a Top-Tier Party" vol3 and downloaded it to my tablet. When I opened it in FBreader I occasionally get pages that just display "Encrypted" at the top.
I've purchased a lot of premium epubs from J-Novel club and this is the first time I'm seeing this.
Any help would be appreciated.
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@wildstars Have you tried it in a different epub reader to see if the same thing happens? If the problem is something specific to FBreader it could be difficult for anyone to provide assistance.
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I downloaded it on my PC and Calibre read it. Calibre took longer to open the book than I'm used to it taking. It even had a message about preparing the book, which was new (to me).
I open up the file with 7zip and figured out it's the images that FBreader is having a problem. It's not showing the cover or the other images.
As a test, I downloaded a new copy of By the Grace of the Gods v4 that purchased a while back. I still have the original epub I downloaded for that. The new one has the slow loading and FBReader won't display the images. The old one works just fine. The file sizes are different by .2 MB and the internal files sizes seem to be the same except for the images which have slightly different packed sizes.
Not sure what's going on.
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I noticed that the images are not compressed on the new versions of the epubs that I checked. I think that has something to do with it, but I can't figure out what.
I'm just going to rebuild the epub in Calibre. That's going to be such a pain if I have to do it for every new J-Novel premium epub just so I can read it on my tablet.
Not exactly a premium level of service.
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@wildstars It's a long weekend in the US, it's unlikely anyone from the company's technical team has even seen your inquiry and likely won't until at least tomorrow morning.
Bear in mind that if the problem is something to do with FBreader, you'll need to contact their devs for a fix. If the program JNC uses to publish their epubs is just using a newer epub standard now than it used to, it's not something that can really be fixed on this side.
That said, the more information you can provide about the issue the better the chance someone will be able to do something. There's been people in the past who had issues with their readers that were able to identify what specifically was causing the issue with their reader of choice, and while some of these things should not have caused issues (new line characters at the end of files, commented out text, etc), it was something that JNC was able to adjust in their ebook while people contacted the app developer for a more permanent fix.
I downloaded the newer version of grace of the gods 4 and was able to open it with no issues on both Calibre and Google Play Books so it seems like other epub reader software is able to read the epubs fine.
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@wildstars Hello!
We've done some testing and we can see what you are seeing on FB Reader's android edition. Note that FB Reader on windows works fine, and the epubs pass epubcheck.
We think this might be a new bug added in the latest Android release of FB Reader, I suggest sending a bug report to them to get it fixed.
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I think this is the same or a related problem to https://forums.j-novel.club/post/261982 because I also got some error about encrypted content on the occasion I was able to get one of the problematic files to load at all. So far I haven't heard any updates from the FBReader dev about fixing the problem though, but if it is the same issue, it's only triggered by new j-novel epub files and rolling back to a previous FBReader release won't help.
I was able to read the files with another app (LibreraFD) but that app is otherwise much worse than FBReader.
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@mDuo13 Any idea around when exactly the files started doing that? It does seem like something changed at some point, because grace of the gods 4 is now 0.2MB larger than before, but there's definitely not that much change in the content, so it seems like the compression algorithm must have changed slightly.
I can only guess that if JNC hasn't changed software from Sigil, maybe a software update to the program did something at some point.
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There may be occasional minor updates to the file processing on the software/server side to improve file delivery or something, but the EPUBs themselves should always be EPUBcheck compliant. If there are any errors only with third-party readers (as far as I'm aware, no Kindle, Kobo, Apple Books, Google Play Books, etc. readers have reported any issues, and our files pass their upload checks as well), those need to be addressed by the third-party developer.
J-Novel Club is simply unable to guarantee that our ebooks will be 100% compatible with every possible reader out there. If we need to change any formatting or file structures in the future in order to comply to new standards in efficiency or security, we need to be able to do that, and third-party reader developers will also need to stay on top of changes like those as well.
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@myskaros said in Getting encrypted pages on a premium purchased epub.:
J-Novel Club is simply unable to guarantee that our ebooks will be 100% compatible with every possible reader out there.
I get that, but it these epubs worked just fine up until recently. Counterpoint tho: they have to adhere to the epub standards, and I don't think they do.
There is definitely a change in the files I tested, they are no longer compressing the images. Which makes sense, there is little to gain by compressing an already compressed jpeg.
I think there is something in an xml file from before that tells the software that "these files need to be decompressed" and when FB Reader tries, it can't, and defaults to saying it's encrypted. I've run comparisons on the xml files on a few of the epubs that I have old version and new versions, and it didn't find any differences. Why some other readers deal with it fine is probably due to error correction to deal with files that don't adhere to the standard.
I like FB Reader enough to have paid for the upgrade some time ago, and I have it tweaked to exactly how I like it. It runs on my old tablet with kitkat and my newer one with Android 11.
I found another android reader (AIReader) that processes the new files fine and runs on both tablets, but it has a page turning animation that brings my old tablet to its knees. I'm just a little butthurt by the inconvenience of having to invest time into tweaking a new software package to get my recreational reading experience back to what it was prior to this unannounced change or mistake.
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@wildstars said in Getting encrypted pages on a premium purchased epub.:
I'm just a little butthurt by the inconvenience of having to invest time into tweaking a new software package to get my recreational reading experience back to what it was prior to this unannounced change or mistake.
We understand the frustration, but to reiterate, we need to be able to make updates to our ebook structure if/when necessary, and as long as we are still compliant with EPUB publishing standards, then the issue should be addressed by the developers of the e-reader.
In this case, JNC ebooks just apparently happen to be the first to have made this change, but if/when other publishers/retailers follow suit, then they will have to address this issue anyway even if we were to roll back the change just for you.
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I don't think this is a FBReader problem. I've spent more time on this than I really wanted too for a recreational hobby.
Just to simplify things... Old epub works. New epub crashes. How is that a FBReader issue?
Everytime I D/L a new epub from y'all I throw it in an j-novel epub folder on my NAS so I can read it on either of my tablets across the network. So I've got a historical archive of every J-novel epub I've downloaded. And it's not a small number. So I've got a bunch of "old" versions of the epubs I can check against.
Here are side by side screen shots of "by the grace of the gods V4" images subfolders in the epub. New download on the left, old download on the right. Notice the new is all "store" (uncompressed) and old is all deflate (compressed).
The old files that work (of the same exact epub) use deflate method on the images. The new epub files use store for images. I ran a bash compare script on the files in the two different epubs and all the files in both epubs are identical, except the store vs deflate methods for the images. I skimmed thru the epub standards docs and from what I gather you have to specify if you are using deflate or store on files. That may only apply to encrypted epubs, I am not sure.
All the text based files (xml, etc) are using deflate in both files. What I suspect is happening is that these updated epubs are not adhering to the standard. FB Reader is trying to decompress files that are not compressed (because somewhere something is saying it's compressed) and throwing an error and saying the images are actually encrypted and crashing.
I suspect newer or more robust software packages have error checking & correction that deal with this on the fly. For example, Calibre will let you error check unencrypted epub files to ensure they adhere to the standards. But Calibre ain't exactly portable since it requires a PC.
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@wildstars said in Getting encrypted pages on a premium purchased epub.:
Just to simplify things... Old epub works. New epub crashes. How is that a FBReader issue?
Just to reply to this point specifically, we have seen issues with other third-party readers that crash when there's an extraneous line break at the end of a file. That's a problem with the reader and not the epub, because the reader should be able to handle cases like that. Is it something the epub creator could fix? Yes, but if the epub is considered EPUBcheck compliant, then it's not really incumbent on the epub creator to fix it.
Anyway, I'm sorry I misunderstood the issue you tried to explain. I will forward this information to our developers to see if the store/deflate issue is something we can resolve on our end.
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@myskaros said in Getting encrypted pages on a premium purchased epub.:
even if we were to roll back the change just for you.
Dude, I already moved on. I got AI reader. The only person who is going to do anything "just for me" is me. Or my wife.
I was just trying to help y'all out what what appears to be a larger issue that y'all might not know about. But, message received. I'll keep it to myself in the future.
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@wildstars Thanks for doing the comparison. As for what you said about deflate vs. store (no compression):
We don't compress images in our EPUBs now because it provides a performance improvement when loading the EPUB in e-readers. JPEG is already optimally compressed, and adding deflate compression on top of it serves no good purpose. If you store an image without compressing it, the e-reader has to spend less work and memory loading the resource.
Regarding the EPUB spec, first of all, the EPUBs you download are 100% compliant with EPUBCheck, the EPUB compliance checker, which I have double-checked for Mapping V3. You are correct that if a resource in an EPUB is encrypted, you need to specify whether or not it was compressed in a metadata file in the EPUB, but our EPUBs are DRM-free, and as such the compression flag is natively available in the ZIP format for any e-reader. If you check section 4.2 of the EPUB3 container format spec you'll see
OCF ZIP Containers MUST include only stored (uncompressed) and Deflate-compressed ZIP entries within the ZIP archive.. Therefore, storing without compression is perfectly valid, and I am inclined to say the ball is in FBReader's court, assuming there is nothing else wrong with the EPUB. -
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