Rendering engines in Kobos

[pgaunt]

Hello. I'm new around here having bought myself a Kobo Aura a couple of months ago. I'm been pretty happy with it on the whole until I tried to read one of Alex Bellos's books which contains a lot of SVGs.

Am I correct in reaching the conclusion that there are two entirely separate rendering engines used by the Kobos - one which renders kepubs and one which renders epubs? The kepub engine renders the svg images so small that they're usually impossible to read while the epub engine handles them properly.

There seem to be other differences too to do with the way fonts and page-breaks are handled. I have some sideloaded fonts which are handled properly by the epub engine which the kepub engine can't handle properly (eg it thinks the bold or italic faces are the regular face). The epub engine on the other hand sometimes generates spurious page-breaks.

Anyone know just why there are (apparently) two completely separate rendering engines?

[PeterT]

Correct there are 2 engines. EPubs are handled by an engine that uses Adobe's RMSDK technology which is compatible with Adobe's DRM scheme enabling the use of any eBook store/Library that uses Adobe DRM.

KEpubs use an engine based on NetFront's ACCESS that supports many of the features of epub3, and Kobo's own DRM scheme that is incompatible with Adobe.

[Ken Maltby]

There are also the MuPDF and CR3 based renders used in Koreader. There is also, Sergey's CoolReader port.

Luck;
Ken

[PeterT]

But Ken; those engines are not installed by default on Kobo devices; the OP is askign about that Kobo includes, not what others include.

[pgaunt]

It really is most peculiar. I downloaded the book straight into the reader from the Kobo store and found it unreadable. On a whim (and I've no idea why I had it) I redownloaded it as an Adobe DRM file and found it completely fine. If I rename the latter as a kepub.epub file it becomes unreadable again. With this particular book I think perhaps Kobo should issue a warning that it needs to be downloaded as Adobe. It's not the DRM which interests me here (I run everything through Calibre anyway to remove the DRM), it's the actual rendering of the page.

Thanks for the replies confirming there really are two separate readers installed. I thought I might be going crazy :-)

[PeterT]

What book is it?

Does it render correctly in the Kobo Desktop (which only handles the kEpub variant).

[pgaunt]

Originally Posted by PeterT

What book is it?

Does it render correctly in the Kobo Desktop (which only handles the kEpub variant).

Alex Through the Looking Glass. I originally downloaded it from Amazon, where it's a lot cheaper, and turned it into a kepub which didn't work so I bought it again from the Kobo store and found exactly the same problem. I now find that the Kindle conversion works just fine as an epub too.

I've no idea whether it works in the Kobo desktop app as I've never been able to get that to run on either of my Macs - it just crashes on start up. Works fine in iBooks if I do feel like reading it on a larger screen.

First time I've had any significant problems with the Aura. Think it's time to give Kobo some constructive feedback.