epub covers not loading on a Kobo Touch

[dank reader]

I've been scratching my head for the past few days trying to understand just why my kobo would not load covers for epub books from calibre 3.6.0 and 3.7.0 after I replaced my Kobo (long story, short version, i broke my N905C and ebayed a pair of N905's)

PDF files are fine. Same with kepub loaded through the Kobo desktop app.
At first I thought it was the rom, so I downgraded the Kobo.
No version of the rom alleviated the symptoms.
Different combinations of loading documents singly, or in groups, newly converted or downloaded from humble bundle, all had the same issue. No combination of settings in kobo touch driver, the kobo touch extended driver or kobo utilities could get covers to load for epub files.

Checking the .kobo-images and koboExtStorage/images-cache folder showed
.parsed files were not present for the epubs, but are for the pdf files.

I eventually tried side loading directly to the SD card.
That worked fine.

Downgrading Calibre to 3.1.1 fixed it.

Which is wierd.

So to confirm, I'm running N905, with rom 4.5.9587, Calibre 3.1.1 (64-bit), windows 10 (1703), Kobo Utilities v2.60 and the kobo touch extended driver 2.8.2 succesfully. Calibre 3.6.0 (64-bit) and Calibre 3.7.0 (64-bit). Rom on the Kobo is definitely not an issue.

Is this an issue with Calibre, Kobo Utilities, or the KoboTouchExtended driver?

[davidfor]

I'm not quite sure what you are saying. I think you are saying that you enabled the cover options in the KoboTouchExtended driver and the covers weren't generated and sent to the Kobo Touch when you sent an epub. But, when you sent a PDF, the cover was generated and sent.

Or are you saying that the device isn't showing and storing a cover image when you send the book? If so, what is it showing?

Now, I don't normally use the cover sending options in the driver, but have used them in the last couple of weeks while testing something else. I didn't see any problems with them. The covers where generated properly, and used by the device. And I haven't seen any problems with the device generating the covers either with any firmware version for a very long time.

Also, for the cover sending, it won't matter whether you use the KoboTouch or KoboTouchExtended drivers. The function is implemented in the KoboTouch driver and the KoboTouchExtended driver just adds other functions that do not affect this. And the cover sending function in the Kobo Utilities plugin, just uses the KoboTouch driver. If one is broken, they all are.

If the problem is with the send to the device, I will need to see a debug log. Run calibre in debug mode with the version in question and send a book with the cover options enabled. Then post the log for me to look at.

[dank reader]

I only use pdf and epub files on my kobo
PDF files work as expected. They transfer to the kobo, covers are shown on the kobo, and cover images are found in the expected directory on the kobo.
epub files transfer to the kobo. The cover images do not transfer to the kobo, so the default image is used by the kobo.

Regressing to an earlier build of calibre resolved this.

Where does calibre keep its log files? What are you looking for in them? I'll pull them for you over the weekend.

[davidfor]

Originally Posted by dank reader

I only use pdf and epub files on my kobo
PDF files work as expected. They transfer to the kobo, covers are shown on the kobo, and cover images are found in the expected directory on the kobo.
epub files transfer to the kobo. The cover images do not transfer to the kobo, so the default image is used by the kobo.

When sending the covers from calibre to the Kobo devices, there is no difference between how PDFs and epubs are handled. The cover in the calibre library is resized as needed and copied to the device. The device will then find these covers when it needed and use them instead of generating them. If there is no cover in the calibre library, I don't know what will be sent.

What is the device showing as the "default image"? I don't believe there is one. There is a text cover it uses when one cannot be generated. This has the book title and format with a couple of boxes drawn around the edge.

You are using the KoboTouchExtened driver. This means that while you are sending epubs to the device, they are converted to kepubs by the driver. The way the covers are generated by the device is different for epubs (renders first page) and kepubs (finds image in book marked as cover). If the books are sent as kepubs, the covers are not being sent, and the device cannot find a cover in the book, then the default text cover I described above will be used.

Regressing to an earlier build of calibre resolved this.

In the range of calibre versions you mentions, I can't think of any changes that would have affected the cover sending.

Where does calibre keep its log files? What are you looking for in them? I'll pull them for you over the weekend.

Calibre doesn't keep logs of these sort of actions. You need to produce a debug log. Restart calibre in debug mode by right-clicking on the Preferences button and selecting the option. When calibre restarts, connect the device, send an epub to the device and close calibre when the send is finished. Calibre will then show the debug log. Post the full contents of the log or PM it to me.

[dank reader]

yeah, I think they are being converted to kepub.
The kobo utilities lets you send cover images to the N905 seperate to the epub. That just wasn't working at all.
The default image is just a blank book cover image, so you can see something is there in the gallery view. With 1200 books, thats a bit of an issue to browse.


This is happening with store bought stuff with covers in the file, not just ones I've converted from PDF or txt. It's just the epubs when they are converted.

I know its bizzarre, but reverting back a few versions has fixed the issue.

I'll see if i can get the time to post the logs over the weekend. Having a second kobo should make this a lot easier to do
Seeing as tech support is my day job, it should hopefully make a bit more sense than 2am rambling.

[davidfor]

Originally Posted by dank reader

yeah, I think they are being converted to kepub.
The kobo utilities lets you send cover images to the N905 seperate to the epub. That just wasn't working at all.

Strangely enough, I know the Kobo Utilities plugin can send covers to any Kobo device separately to sending the book. I also know it is just calling the cover sending function that is in the KoboTouch driver.

And I have tested with my N905 Touch tonight with calibre 3.7.0 and the covers were sent when I sent the book. And the Kobo Utilities cover sending went fine as well.

The default image is just a blank book cover image, so you can see something is there in the gallery view. With 1200 books, thats a bit of an issue to browse.

Now you have me baffled. As I described above, the default cover used by the Kobo devices is a the book title plus the book format. With two lines drawn around the outside. A "blank book cover image" sounds more like what calibre is using if there is no cover. Do you have a cover image in the calibre library for the books?

This is happening with store bought stuff with covers in the file, not just ones I've converted from PDF or txt. It's just the epubs when they are converted.

I know its bizzarre, but reverting back a few versions has fixed the issue.

I'll see if i can get the time to post the logs over the weekend. Having a second kobo should make this a lot easier to do
Seeing as tech support is my day job, it should hopefully make a bit more sense than 2am rambling.

Hopefully the debug log will tell me what is happening.

[Blas]

well idk why but my covers are taking REALLY long to load now.

[davidfor]

Originally Posted by Blas

well idk why but my covers are taking REALLY long to load now.

Sorry, but I don't know if that is a request for help, or just a comment.

If it is a request for help, we need more information. Such as:

- How long is "REALLY long" and compared to what?
- When did this change? What else happened at the time?
- Are you talking when sending the covers, or using the device?
- Firmware version and calibre version.
- Book format you are using.

And just about anything else you think might help.

[Blas]

oh yeah it was like some venting hahahh but here I go.

- After turning the Kobo Touch on, it goes to the home page. There shoes "My books", and some other collections that I have. All of the book covers will be with a black and the name of the book. It won't have the real image of the book. So I will have to keep pressing the Home button to refresh the page, so the covers will start to show up one by one. I have to keep pressing until all the covers show up.
- I don't really know how it started, but whenever I send a new book to my kobo, after disconnect it from my Desktop, it will start to "import the new content " and freeze in 9%.
- Its when using the device, like when I'm in the home page.
- The firmware is the latest for the Kobo Touch C - 4.6.9995
- And all of my books are Kepubs.
- I was using some patches in this firmware, but now I reinstalled the same firmware. SO I don't have any patches.

[davidfor]

Originally Posted by Blas

oh yeah it was like some venting hahahh but here I go.

And I have no problem with people venting a bit. So long as it's obvious

- After turning the Kobo Touch on, it goes to the home page. There shoes "My books", and some other collections that I have. All of the book covers will be with a black and the name of the book. It won't have the real image of the book. So I will have to keep pressing the Home button to refresh the page, so the covers will start to show up one by one. I have to keep pressing until all the covers show up.

That's a weird one. I don't think I've heard of that before. The home screen shouldn't show any titles. But,if for some reason a cover image can't be found or generated, the cover shown has the title and format of the book plus two rectangles drawn around the outside. Is that what you are seeing?

If it is keeps generating the cover image after pressing the home page, is there any space left on the device? I would recommend keeping 100MB free for rewriting the database and generated covers. It's been a while since I completely filled a Kobo device, but I seem to remember some weird behaviour when it happened.

- I don't really know how it started, but whenever I send a new book to my kobo, after disconnect it from my Desktop, it will start to "import the new content " and freeze in 9%.

How do you get out of that? If you are pressing the reset button, then it probably isn't importing some of your books. And this is usually a sign that a book you have sent to the device has some bad errors causing the import to fail. In these cases, you need to find the book and remove it. Then the rest of the books should be OK.

- Its when using the device, like when I'm in the home page.

Do you see any problems on the book lists? Or when reading?

- The firmware is the latest for the Kobo Touch C - 4.6.9995

Actually, it isn't. Kobo did release 4.6.9995 to the three versions of the Touch. But, some problems were found and they removed it. The problems were with the display when reading books. The margins and the top and bottom of the screen could be filled with black. The current version of the firmware for the three models of the Touch is 4.5.9587. You might want to try going back to this.

If you do go back to 4.5.9587, you are fairly safe to install it over 4.6.9995. But, what I do when I want to try this, is to take a full copy of the book partition of the device. If anything goes wrong, I can recover to this state without much trouble.

- And all of my books are Kepubs.

Are you are sending them to the device using the KoboTouchExtended driver? Or are you doing a conversion first? Are the books you have seen this for large or complex?

- I was using some patches in this firmware, but now I reinstalled the same firmware. SO I don't have any patches.

It's good to eliminate that as a source.

[Blas]

Originally Posted by davidfor

And I have no problem with people venting a bit. So long as it's obvious

That's a weird one. I don't think I've heard of that before. The home screen shouldn't show any titles. But,if for some reason a cover image can't be found or generated, the cover shown has the title and format of the book plus two rectangles drawn around the outside. Is that what you are seeing?

If it is keeps generating the cover image after pressing the home page, is there any space left on the device? I would recommend keeping 100MB free for rewriting the database and generated covers. It's been a while since I completely filled a Kobo device, but I seem to remember some weird behaviour when it happened.

Yeah that's what I see when they are not loaded.
All of my books are saved in my sdCard that is 32GBG. On my Kobo it shows that I have 28.3 GB of 28.8GB avaible on the sdCard.
My database has 56MB.

How do you get out of that? If you are pressing the reset button, then it probably isn't importing some of your books. And this is usually a sign that a book you have sent to the device has some bad errors causing the import to fail. In these cases, you need to find the book and remove it. Then the rest of the books should be OK.
Do you see any problems on the book lists? Or when reading?

I always try to wait a bit to see if it will keep frozen, then I just press the home button and it goes to the home screen. It adds the books normally. I never had any problem to load a book to read or change pages.

The current version of the firmware for the three models of the Touch is 4.5.9587. You might want to try going back to this.

I will give a try and reinstall this firmware version "4.5.9587" and try to find the book that has an issue. Thx for the advice.

[EDIT]I reinstalled the firmware and the problem persists.

Are you are sending them to the device using the KoboTouchExtended driver?

And yes I use this Kobo extension which I think that already covert the epub to Kepub before sending it to the device right.

[EDIT] I think that the problem is that I have a book that has some error which is affecting the importing content. And is affecting the covers loading too.

[Blas]

Which errors on a book can freeze the "importing content"?

[davidfor]

Originally Posted by Blas

Yeah that's what I see when they are not loaded.
All of my books are saved in my sdCard that is 32GBG. On my Kobo it shows that I have 28.3 GB of 28.8GB avaible on the sdCard.
My database has 56MB.

With that amount of space taken, and that small a database, the books have to be huge. Are we talking comics? Large PDFs? Or lots of books on the card that have not been imported. And if the book or images in them are large, then the time taken to generate the cover image could be noticeable. Especially on the Touch as it has the slowest CPU and least RAM of touch based Kobo devices.

And the card could be exacerbating this. The speed of the card will have an affect. Plus, the device doesn't store the generated images for books on the card. For books on the main memory, the cover images are generated and stored, which makes them faster. But, for the card the covers images are generated. Restarting the device will mean the images are generated each time. The images are cached in memory for a while, but the cache will be limited. If you scroll through the lists, you will see them constantly being generated.

You can use the driver in calibre to generate and send the covers. While the device isn't saving them to the SD card, it does look for them and use them if they exist. The driver has an option to send them. And you can use my Kobo Utilities plugin to send or replace the covers for books already on the device.

I always try to wait a bit to see if it will keep frozen, then I just press the home button and it goes to the home screen. It adds the books normally. I never had any problem to load a book to read or change pages.

OK. I get that occasionally. And I think it only happens with a problem book. Though I usually get further than 9%.

I will give a try and reinstall this firmware version "4.5.9587" and try to find the book that has an issue. Thx for the advice.

[EDIT]I reinstalled the firmware and the problem persists.



And yes I use this Kobo extension which I think that already covert the epub to Kepub before sending it to the device right.

OK, you are using the KoboTouchExtended driver

[EDIT] I think that the problem is that I have a book that has some error which is affecting the importing content. And is affecting the covers loading too.

Originally Posted by Blas

Which errors on a book can freeze the "importing content"?

That I don't know. I've never been able to find a consistent cause. I do know that if I clean the books using either the calibre editor or Sigil, or do a conversion in calibre, they rarely fail. The problem should be in the metadata or the ToC. The import on the device reads these and puts them into the database. It doesn't look at other parts of the book, but parts of the internal file structure could cause problems.

Another possibility is if the book is very large, it could cause problems importing the book. The firmware does watch processes in case they hang. Unfortunately, it can't really tell the difference between a process that has truly hung or one that is taking longer than usual. But, I don't think this is the case as the device usually is rebooted when the process watcher kicks in.

[Blas]

Originally Posted by davidfor

You can use the driver in calibre to generate and send the covers. While the device isn't saving them to the SD card, it does look for them and use them if they exist. The driver has an option to send them. And you can use my Kobo Utilities plugin to send or replace the covers for books already on the device.

I only have books, no pdfs or comics. All of them were imported by the Kobo Touch extension on Calibre. They are not that big, they have the average size you know. I really think that I have a lot of books with issues which I don't really know how to fix.

What do you mean about "generate and send the covers"? By updating the metadata?

My sdCard is class 10. So I think it's not the problem. I must be the books cuz when I remove a certain amount till October, it starts to load the covers normally.

[EDIT] I forgot to ask, what tool can I use to automatically check and fix my books? I don't have any knowledge about fixing it tbh.

[davidfor]

Originally Posted by Blas

I only have books, no pdfs or comics. All of them were imported by the Kobo Touch extension on Calibre. They are not that big, they have the average size you know. I really think that I have a lot of books with issues which I don't really know how to fix.

My mistake. I misread your post about space. I read it as 28.3GB used, not free. That's a lot more like it.

What do you mean about "generate and send the covers"? By updating the metadata?

The driver, in your case the KoboTouchExtended driver, has a lot of options. Some of these will mean sending the cover images with the books rather than letting the device generate them. Once you turn the option on, it is all automatic.

To turn the option on, while the device is connected, right-click on the device button and select "Configure this device". The configuration dialog will open. Select the "Collections, covers & uploads" tab. In the middle, select the "Upload covers" and then the other options you like the look of. Save the changes and restart calibre. After this, when you send a book to a Kobo device, the cover will be generated by the driver and put onto the device. I think this will probably solve the problem you are seeing.

My sdCard is class 10. So I think it's not the problem. I must be the books cuz when I remove a certain amount till October, it starts to load the covers normally.

There has been some discussion about the best card to use in the Kobo forums. I think it comes down to quality of the card more than the class.

[EDIT] I forgot to ask, what tool can I use to automatically check and fix my books? I don't have any knowledge about fixing it tbh.

I don't have a good answer to that. I spend far to much time editing my books to be how I want. I use the calibre editor, but I could also use Sigil. Both are good epub editors and both have functions to check for errors and help you fix them. But, in most cases this is overkill.

A simpler method is to do an epub-to-epub conversion. This will nearly always produce a book the Kobo devices will handle with no problems. Some people will say not to do this as it messes with the internals of books in ways they don't like. But, unless you start editing the books, that doesn't really matter. The conversion can change the look of a book, and there are options to change some things. But, you can also use this to make the books how you like. For example, if you want a gap between the paragraphs instead of an indent at the start, you can do this on the "Look & feel" page of the conversion.

My suggestion is to only do something if there seems to be a problem. If the book isn't imported, then you can either do the conversion or open it in the editor and run the check function (press the button that looks like a bug). This give some help on fixing any problems or and there is an option to automatically fix some.