Epub Book Seizes When Reading

[mcgarvan]

Hi,
I have a problem with reading one particular epub book on my Sony PRS-650. There is no problem reading it in Calibre or any other of the books by the same author in the same series which I have on my Sony.
When I get to page 24 it seizes up and will not move on to the next page or jump past the problem to a later page. More often than not my Sony seizes up, so to get out of the book and read a different book I have to do a reset.
I have thought of editing the book in Calibre to remove the problem but I have no idea what I might be looking for in the html. My experience there is limited to correcting a few typos.
Can anyone help me?

As a newbie I have no idea what tags to this post might be useful. Sorry.

[eschwartz]

Possibly the individual HTML files are too large.
Some older ereaders choke on them.


If you were to convert a book in calibre to EPUB, you would see a an option in EPUB Output to
"Split files larger than: ______" (default is 260 KB)
Performing an EPUB ==> EPUB conversion should fix that kind of issue, as would manually editing in the calibre Editor.

I would prefer the calibre editor, simply because conversions are lossy in regard to future-proofing, and calibre's automatic CSS flattening makes it harder to perform targeted edits later on.

In the Editor, right-click anywhere in the text and use "Split At Multiple Locations" -- it accepts XPath, you can split on header tags (header tags are usually used for chapter headers which is a natural place to split) using the XPath Wizard.

[JSWolf]

It would help if you told us what book it is that's causing the problem.

It could be the cover is too large or too many graphics. The 650 uses an old version RMDSK to display ePub.

[Toxaris]

Could also be some CSS. There is at least one combination that will choke the PRS-3xx/PRS-6xx.

[JSWolf]

Originally Posted by Toxaris

Could also be some CSS. There is at least one combination that will choke the PRS-3xx/PRS-6xx.

What combination would that be?

[Toxaris]

Originally Posted by JSWolf

What combination would that be?

I knew you would ask that and I am sure I mentioned it several times before. Let me see if I can find it again on this site.

[theducks]

Lots of 'Validated" (EPUB+CSS) things choke older RMSDK devices

JPGs as big a apple covers (I fixed a book that had graphic Chapter numbers larger than 800x600 so it would also open on my Astak. It was scaled smaller in the CSS why ship that size )

GIFs even close to a physical screen dimension

And, as been mentioned: the 260K boundary (s/b smaller if using larger images on the page)

[Toxaris]

I looked it up. Several older Sony readers have issues with 'heighth: 100%' in the body or html tag in the stylesheets. See also: https://www.mobileread.com/forums/sho...d.php?t=178947

[JSWolf]

Originally Posted by Toxaris

I looked it up. Several older Sony readers have issues with 'heighth: 100%' in the body or html tag in the stylesheets. See also: https://www.mobileread.com/forums/sho...d.php?t=178947

I know it's not a problem on the x50 or T series. Other than that, I'm not sure if I used that code back before the x50.

[JSWolf]

Originally Posted by theducks

Lots of 'Validated" (EPUB+CSS) things choke older RMSDK devices

JPGs as big a apple covers (I fixed a book that had graphic Chapter numbers larger than 800x600 so it would also open on my Astak. It was scaled smaller in the CSS why ship that size )

GIFs even close to a physical screen dimension

And, as been mentioned: the 260K boundary (s/b smaller if using larger images on the page)

Remember, a lot of Readers these days have a screen that's higher resolution than 800x600. So what may have looked fine on an 800x600 eInk acreen, can look too small on a Hi-Res Carta screen such as those in Kindles and Kobos.

[theducks]

Originally Posted by JSWolf

Remember, a lot of Readers these days have a screen that's higher resolution than 800x600. So what may have looked fine on an 800x600 eInk acreen, can look too small on a Hi-Res Carta screen such as those in Kindles and Kobos.

It looks fine on my TAB and my 22" LCD Monitor. It's a bloody chapter number, not the Mona Lisa

I am not one who will stretch an image to FILL THE SCREEN

But then, I bought Letterbox Laser Discs to watch the film the way the director intended (just on a smaller scale). I did not whine that the was unused portions on my CRT(TV) Screen

[mcgarvan]

Thanks for the quick response everyone. I am pretty sure it isn't anything to do with graphics as the only graphic in the file, a vanilla "overdrive reader works" cover is less than 60kb. That is way smaller than many of the covers in my other books and the same as plenty other books where there is no problem.
The (5) HTML files are all under 260kb, admittedly the last three only by a few kb. However, the first one, where the problem starts, is only 136kb, well under the limit.
No sign of heighth: 100% (or 'height: 100%) in the css sheets.
I will have a go at "split at multiple locations" as suggested, once I have identified the right parameters.

[rubeus]

First of all i would run it through epubcheck and css validator. Nicely said: calibre is very tolerant ...

[mcgarvan]

Hi,

Update on progress. Thanks to the advice from eschwartz I did an epub to epub conversion, setting the file size to 70kb. There are now 16 html text files, all under 70kb and I have now nearly finished the book with no problems. I can jump to any page now and no sign of it seizing up.
I can now look at correcting some persistent typos and removing a couple of duplicate paragraphs to tidy up the book.

Many thanks, especially to eschwartz, but also to everyone else who kindly took the time to respond to my question.

[JSWolf]

70kb is too small. Leave the default at 260kb. I have a 650 and you do not need to go so small. The default works perfectly well.

What eBook is it that caused the problem?