Kobo Device Driver Update

[Caribou007]

Originally Posted by JSWolf

Seeing as you are now coming up to the limits of your hardware, my suggestion is to start saving to get new hardware that will allow you to easily run the software you want.

[NiLuJe]

Another RFC regarding the patch in #255 now that I have more free time... .

I've been using this for quite a while now without any issues, and I've since confirmed that ShouldDither, while great, doesn't affect the sleep screens, even those processed by nickel itself, so it doesn't deprecate this patch.

@davidfor: Do you have any further comments, or should I go ahead and send a PR to Kovid?

[davidfor]

@NiLuJe: I have to admit I completely forgot about this until last week. And that was only because when I was adding support for the Glo HD I picked the wrong book to test with. And that caused me to realise there is a little problem with the cover generation.

I think I'm OK with it, but, I need to look at it again. I now have a Aura H2O and a Glo HD so have been a little more conscious of the image display.

One issue is that I don't have a C environment to build the magick. Do the samples images you posted before cover all the different circumstances? I think that if I put them in a CBZ, I can scroll through them on the device. That's assuming the same rendering/display engine is used there as for the screensaver. Otherwise, I can to manually replace the covers images for a few books.

The other thing is the letterboxing. That is OK for people who display the covers full screen, but for the non-full screen display, I think it will mean black rectangles down the size. I'll have to try it to see. But, doing the resizing is what I was thinking about last week. I think I was being to smart when I originally did this.

I'll try and do something this week or over the weekend. But, there's something else related to calibre and Kobo I promised to do for someone first. Of course, it has completely slipped my mind what it is, so I'll probably do this first. Unless I decide to read a book. Or we get weather like last week.

[NiLuJe]

@davidfor: Heh, no worries, take your time .

I have no idea how the CBZ renderer behaves, so the most accurate way (that I can think of) of testing the set of images I posted (in #215) are the raw ones to feed to pickel, not the PNGs.
(Granted, swapping the cover of a book manually is also a very roundabout way of going at it, but I've seen some weird caching behavior when I checked the shouldDither stuff on that front, so that might take a reboot).

As for the letterboxing/full-screen thingy, do you mean that when the "Show information popup" (or whatever it's actually called ^^) checkbox in the power settings is enabled, the covers are handled differently? AFAICT, nickel itself always builds full-size images when syncing stuff. Or did I completely misunderstood what you were talking about?

EDIT: Or did you mean the thumbnails that are shown on the homescreen & Library? In which case I think I disabled letterboxing in these cases to avoid just such an issue.

[davidfor]

Originally Posted by NiLuJe

@davidfor: Heh, no worries, take your time .

I have no idea how the CBZ renderer behaves, so the most accurate way (that I can think of) of testing the set of images I posted (in #215) are the raw ones to feed to pickel, not the PNGs.

What I want is the version as generated by calibre as it is, calibre as you suggest and what the device would generate. Then I can compare those on the device and see what the difference is.

(Granted, swapping the cover of a book manually is also a very roundabout way of going at it, but I've seen some weird caching behavior when I checked the shouldDither stuff on that front, so that might take a reboot).

Been there, done that, reconnected and sent it again several times until I remembered

As for the letterboxing/full-screen thingy, do you mean that when the "Show information popup" (or whatever it's actually called ^^) checkbox in the power settings is enabled, the covers are handled differently? AFAICT, nickel itself always builds full-size images when syncing stuff. Or did I completely misunderstood what you were talking about?

EDIT: Or did you mean the thumbnails that are shown on the homescreen & Library? In which case I think I disabled letterboxing in these cases to avoid just such an issue.

No, the "Show book covers full screen" option. Turning that off displays the cover in a box centred on the screen with with the state above and below the cover.

Also, the patch you created before doesn't want to apply. I can do it manually, but I need the "eink_colors.gif" file. Could you post that?

[NiLuJe]

@davidfor:

Okay, I'll try to get you a set of those three cases, need to swap stuff around between OS X/Linux, might take a while .

I'll take a look at what happens with the "Show book covers full screen" option disabled on my end, I'd completely forgotten that this even existed ^^.

I updated #255 w/ the gif.

EDIT: Oookay, indeed, w/ "Show book covers full screen", the letterboxing is not that great (it's not eye-gougingly awful either, but, still). Am I right in assuming that nickel simply takes the full-screen image and resizes it? Of that's the case, I'm not terribly hopeful for a solution that handles both cases properly :/.

[NiLuJe]

Okay, here's the set:

sync: straight from the Kobo store.
The pngs are fbgrabs from what's actually shown on screen when sleeping, with/without the fullscreen cover setting.

vanilla: vanilla Calibre 2.26.0 (OS X, binary release)

patched: patched Calibre 2.26.0 (Linux x86, fully source built)

patched_v2: patched Calibre 2.27.0, with the -v5 version of the patch, letterboxing disabled (Linux x86, fully source built)

Both Calibre instances have the exact same library (rsync'ed between the two boxes).

[Grady Cole]

Realized this is best posted in a different thread.

[NiLuJe]

@davidfor: After thinking a bit more about the letterboxing thing, I updated the patch in #225 to make the letterboxing optional, because it turns out it's not that critical (especially on the H2O, where nickel does an unavoidable extra rescaling pass because of the whole top 11 px behind the bezel thing), the key point was mainly to rescale to the bounding-box of the screen instead of throwing the cover image untouched at nickel.

I also updated the image sets in #247, which are now complete.

And I also pushed this on GH.

[Bernardo]

Originally Posted by davidfor

With calibre 0.9.42, there is a new function added to the KoboTouch driver. This is to modify the stylesheets in an ePub during the send. The idea is to add CSS rules to the existing stylesheets in the ePubs to change the way a book is displayed.

• Check the new option "Modify CSS" on the driver options. Note: if you have previously had the "Attempt to support new firmware" option selected, this might already be selected.

a complete Kobo hacking and Calibre newbie here - trying to follow this recipe;
would you be able to clarify the bit "check the new option 'Modify CSS' on the driver options"?
where can this be found? running Calibre 2.5 here and the closest thing i could find is "Extra CSS" in "Look and Feel" tab when performing conversion (which didn't work when i specified kobo_extra.css (nor /kobo_extra.css); Dark Courier fonts are installed and they otherwise work fine.
Is a specific Kobo firmware required for this (mine is 2.4.0) or is this entirely handled by Calibre?

Thanks

[Bernardo]

Originally Posted by Bernardo

a complete Kobo hacking and Calibre newbie here - trying to follow this recipe;
would you be able to clarify the bit "check the new option 'Modify CSS' on the driver options"?
where can this be found? running Calibre 2.5 here and the closest thing i could find is "Extra CSS" in "Look and Feel" tab when performing conversion (which didn't work when i specified kobo_extra.css (nor /kobo_extra.css); Dark Courier fonts are installed and they otherwise work fine.
Is a specific Kobo firmware required for this (mine is 2.4.0) or is this entirely handled by Calibre?

Thanks

ok, answering my own question - found the "Modify CSS" check box under Device menu once the Kobo was connected to the PC;

works fine now;
(BTW a very interesting forum, i was blissfully unaware of it; a Google search (or more precisely Duckduckgo) unearthed it)

[davidfor]

Originally Posted by Bernardo

ok, answering my own question - found the "Modify CSS" check box under Device menu once the Kobo was connected to the PC;

I'm glad you found it. It is also access from the "Plugins" page of the preferences. You can search for "kobo" or look in the "Device interface plugins".

works fine now;
(BTW a very interesting forum, i was blissfully unaware of it; a Google search (or more precisely Duckduckgo) unearthed it)

Welcome. And if you are interested in that option, you probably should look at my Kobo Utilities plugin and some of the other Kobo related plugins.

[Bonex]

Hi there!
Was the idea of applying dithering to the b/w covers abandoned?
I'd like to have that functionality, but I see Kovid's GH repository doesn't have that modification yet.
Is there a way I can apply the patch myself to my installation?

[NiLuJe]

@Bonex: https://github.com/NiLuJe/calibre/co...99014ac60d9d13

Note that Kovid appears to currently be excising IM stuff all over the place, so this may need some massive rethinking in the next version, .

[kovidgoyal]

IM is going away, being replaced by QImage. But QImage has a convertToFormat method that accepts a color table, so it should not be too hard to implement.