Koreader running on Kobos (all of them, hopefully!)

[NiLuJe]

Helpful reminder: don't cross-post, it's more likely to get you ignored that anything else.

(Also, it's highly frowned upon in general).

xref: https://www.mobileread.com/forums/sh...&postcount=204

Which, bonus points, happened to have an actually useful log excerpt, unlike this one .

[serdar0020]

another pdf problem not encountered before: I OCR'd the pdf myself with Adobe Acrobat DC2019 (60 MB, with pictures). The pages are too wide to read them even in landscape, so I switched to text reflow. Every 20 page or so a paragraph's font turns minuscule, and sometimes even lines are mixed up. Could this be due to low RAM or processor of my Kobo? I'm on KoReader 2019.12 - screenshots

Spoiler:

[Frenzie]

That's definitely a curious effect, but the cause seems fairly straightforward. Due to the way the text lines up perfectly the algorithm seems to have misinterpreted it as two columns. By default it scans the middle third of the page for column gaps, and within that zone it seems to have found some.

If you're already using tools on your computer it's more expedient to just throw https://www.willus.com/k2pdfopt/help/overview.shtml into the mix. The same program provides functionality for KOReader, but by using the GUI or the command line you can tailor it in much more detail and much faster. (Use max columns: 1.)

[serdar0020]

edit: the column is gone, but the minuscule text remains

Spoiler:

after running my entire 573 pp. pdf through it, the processed output pdf is now 169 MB, 1460 pp. This is not what I want for my book archive. Rather a perfectly OCR'd pdf, book layout, 1 column, correct font sizes, that is faithfully transmitted in KOReader reflow. K2pdfopt is good if you want to quickly read a text on your reader and then delete it. But thanks for the tip

[Frenzie]

If you select native PDF output it might be smaller, which may also load faster on a device.

I'm not really sure what the deal might be with the small text. Maybe @NiLuJe knows?

[NiLuJe]

No idea, I kind of have a hate/hate relationship with PDF ^^.

[serdar0020]

I ran the two pages through AbbyFineReader12 and now it's ok in K2pdfopt.

Spoiler:

my only problem is, AbbyFinereader compresses the pdf too much (I think it's MRC compression) and then my Kobo has trouble opening the file, I've posted something about it earlier.

edit: I've been experimenting a bit more with the OCR functions of Abby and K2pdfopt, but I couldn't manage to get a proper reflow text of the book on my Kobo

[Frenzie]

I suspect the small text might indicate that k2pdfopt interprets that block as an image. But I don't see an obvious reason for it like with the columns. A lot of noise/speckling might cause that, for example, but there is none. There's some minor warping but nothing that seems like it should be problematic. Nevertheless it might be worthwhile to quickly try the autostraighten option in k2pdfopt.

[serdar0020]

auto-straighten didn't help either, unfortunately

[Biep]

Since October or so the update feature in KOReader (on Kobo Aura One with KSM) no longer works for me. Whenever I try to update, I get "Update information unavailable on XX channel" (or rather the Dutch equivalent of that). I just dumped the latest version of KOReader in .adds/KOReader, but the problem persists.
Any ideas how to solve that?

Thanks a lot in advance, and thanks for a wonderful reader!

I can't post a reply, so let me try here:

Before updating manually, no channel/server combination worked - trying from many different WiFi hotspots. Nickel updated without problems.
After manually updating I had tried both channels, but only the vislab server, which didn't work.
Both links you give are intermittently accessible - sometimes I get there; sometimes I get "server not found". (You call them 'mirror', but the visual lay-out is not the same, BTW.)
With ota.koreader.rocks I got somewhere - the update was consistently offered, but then failed, with first a three-way option (retry, delete temporal files, keep temporal files), and upon retrying a two-way offer (keep or delete temporal files).
With koreader.ak-team.com I finally was able to update - though it took a > 15 min zsync delta computation.

Thanks!

P.S.: Almost 100% of the attempts lead to a "torn screen", a triangular white area, often covering the pop-up window with the failure message/update offer.

[NiLuJe]

@Biep: On which channel, and on which server?

Can you actually access any of them from the same network? (master: http://ota.koreader.rocks/ // mirror: http://koreader.ak-team.com/)

[Biep]

See above.

For some reason I kept getting "Cannot post message because you have logged in since accessing the page" or something along those lines. I now find I can post a very short message, and then edit it.
@NiLuJe - I answered you below my original message above.

[NiLuJe]

The vislab mirror is in China, and I've personally never ever been able to access it .

(Even when @chrox was still active, I could only extremely rarely access it, and with downright terrible transfer rates (i.e., sub kB)).

I've vaguely considered commenting it out, but it may still be kept up to date, in which case it's useful for Chinese users. But I have no way to check that .

TL;DR: Don't use that one .

----

http://ota.koreader.rocks is the master, but it's behind a CloudFlare CDN, which has been known to screw with zsync in some circumstances.

http://koreader.ak-team.com is my own mirror, it's a physical dedicated server, hosted in France, but with somewhat limited bandwidth. Provided you have decent peering to it from your current location, it should behave okay w/ zsync.

----

I've almost never seen refresh glitches on the OTA popups, but I did saw a couple recently in a very specific range of versions, for some mysterious reasons. Haven't seen any since.
As usual, it's pretty sensitive to timing and ambient temperature, so, eh, who knows ;p.

----

I also keep a couple ObjectStorage-backed mirrors in sync:

http://koreader-fr.ak-team.com in France
http://koreader-pl.ak-team.com in Poland
http://koreader-na.ak-team.com in Canada

But those are commented out, because zsync can't handle the quirks of an OpenStack HTTP frontend.

[Frenzie]

As an aside, https://perfops.net/ping-from-china can't ping vislab.bjmu.edu.cn and it tries from Beijing, Hohhot, and Shanghai. In the past I was able to access it (albeit slowly; I think traffic from China is throttled at 30 kB/s or something :P) so I wouldn't bet on it.

[makara]

On the latest version 2020.01, the menu items "Autosuspend timeout" and "Autoshutdown timeout" disappeared. Version for Kobo and for Kindle.