PRS-650 How to read a large O'Reilly epub3 book

pmcnz · 03-28-2014, 01:33 AM

Hi,
This may be useful to those of us still running the PRS-650 and using PRS+
The background is I use my Sony PRS-650 to read technical books travelling to and from work by train. I find its size, battery life (fingers crossed) and eink screen to be better for commuting reading than my larger Samsung tablet.
Now for the story:
I took advantage of a recent offer from O'Reilly Books and bought an ebook on Software Requirements. I downloaded the epub version onto my PC and then sideloaded to my Sony PRS-650.
Reading this book on the Sony was a dreadful experience - slow to load and turn pages, crashing when I tried to go back to a previous chapter or just freezing.
So I checked the file size - 20MB! and talked to one of the developers at work who said size could be a problem for a low power ereader. As a check, I uploaded the epub file onto my large Samsung tablet and read the book using the Mantano ereader software - no problems, so this pointed to the file size as the most likely cause
I then split the epub (using the ePubSplit plugin for Calibre) into 5 smaller epubs with the largest being 6MB and downloaded these to the Sony.
This improved the loading speed and page turns, but I still got some freezes and crashes. So I did some more digging on the Internet and found that from early 2013 O'Reilly Books had switched all their books to the epub3 format. I could not confirm that the PRS-650 has problems with epub3 files but it seemed a reasonable assumption.
I then checked Calibre's epub -> epub conversion and found the output would be epub2-ish. I put the 5 smaller epubs through Calibre's epub->epub conversion (targeted for Sony eReader).
The 5 epub file sizes shrank by 50% so the largest is now 3MB. The true test was downloading the new versions of the 5 smaller epubs and then reading them. Speed is good, freezes are not happening, looks good so far (1 day).
It is a nuisance having 5 files instead of 1 - However I did not have to buy a new tablet or ereader.

Cheers
Paul

rkomar · 03-28-2014, 03:04 AM

Crap! I noticed a few days ago that most of my books were updated within the last year, and re-downloaded them. I guess I have the EPUB3 versions now. Thanks for the info.

HarryT · 03-28-2014, 06:36 AM

The PRS-650 uses a rather old version of Adobe's RMSDK (mobile reading software). More modern devices will probably do a lot better with the books.

The total size of an ePub file really shouldn't matter, because only one "flow" (normally a chapter) at a time is loaded into memory.

elcreative · 03-28-2014, 09:12 PM

Quote:

Originally Posted by HarryT

The PRS-650 uses a rather old version of Adobe's RMSDK (mobile reading software). More modern devices will probably do a lot better with the books.

The total size of an ePub file really shouldn't matter, because only one "flow" (normally a chapter) at a time is loaded into memory.

True, what really counts is the internal segment size which should be <260K for Sony x50 eReaders (calibre can do this for you)...

pholy · 03-28-2014, 11:12 PM

Quote:

Originally Posted by elcreative

True, what really counts is the internal segment size which should be <260K for Sony x50 eReaders (calibre can do this for you)...

I've found that page turns really slow down towards the end of 260K files on my PRS-T1, although it doesn't crash. It becomes a real nuisance. Fortunately I was able to find reasonable section breaks to make the files smaller.

Ripplinger · 03-29-2014, 03:43 PM

Confirming what others have already said, once individual files are broken up correctly within the epub, I'm betting you can then restore the book into just one epub and your reader will handle it just fine.

I've opened up books and have seen a few where it consists of one HUGE html file. That will choke any ereader.

HarryT · 03-29-2014, 04:24 PM

More modern versions of the RMSDK (Adobe's mobile ePub reader) have far fewer problems with large flows. Unfortunately Sony still use a pretty old version of it.

pmcnz · 03-29-2014, 06:21 PM

Quote:

Originally Posted by elcreative

True, what really counts is the internal segment size which should be <260K for Sony x50 eReaders (calibre can do this for you)...

Thanks for this information. I noticed that Calibre had automatically set the file size to this limit (260K) when I told it the output for the ePub to ePub conversion would be a Sony ereader but I did not know why and this explains it.

Paul

rkomar · 03-29-2014, 06:45 PM

Quote:

Originally Posted by HarryT

More modern versions of the RMSDK (Adobe's mobile ePub reader) have far fewer problems with large flows. Unfortunately Sony still use a pretty old version of it.

The same is true of my PocketBook 902 9.7" reader. It's my preferred device for technical reading, and it's not going to be updated again. If these new versions feel slow, I'll have to dig through my backups to maybe find the old versions of the EPUBs (or just read the PDFs).

03-28-2014, 01:33 AM	#1
pmcnz Enthusiast Posts: 32 Karma: 97970 Join Date: Nov 2011 Location: Auckland, NZ Device: PRS-650, Kindle DXG	How to read a large O'Reilly epub3 book Hi, This may be useful to those of us still running the PRS-650 and using PRS+ The background is I use my Sony PRS-650 to read technical books travelling to and from work by train. I find its size, battery life (fingers crossed) and eink screen to be better for commuting reading than my larger Samsung tablet. Now for the story: I took advantage of a recent offer from O'Reilly Books and bought an ebook on Software Requirements. I downloaded the epub version onto my PC and then sideloaded to my Sony PRS-650. Reading this book on the Sony was a dreadful experience - slow to load and turn pages, crashing when I tried to go back to a previous chapter or just freezing. So I checked the file size - 20MB! and talked to one of the developers at work who said size could be a problem for a low power ereader. As a check, I uploaded the epub file onto my large Samsung tablet and read the book using the Mantano ereader software - no problems, so this pointed to the file size as the most likely cause I then split the epub (using the ePubSplit plugin for Calibre) into 5 smaller epubs with the largest being 6MB and downloaded these to the Sony. This improved the loading speed and page turns, but I still got some freezes and crashes. So I did some more digging on the Internet and found that from early 2013 O'Reilly Books had switched all their books to the epub3 format. I could not confirm that the PRS-650 has problems with epub3 files but it seemed a reasonable assumption. I then checked Calibre's epub -> epub conversion and found the output would be epub2-ish. I put the 5 smaller epubs through Calibre's epub->epub conversion (targeted for Sony eReader). The 5 epub file sizes shrank by 50% so the largest is now 3MB. The true test was downloading the new versions of the 5 smaller epubs and then reading them. Speed is good, freezes are not happening, looks good so far (1 day). It is a nuisance having 5 files instead of 1 - However I did not have to buy a new tablet or ereader. Cheers Paul

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03-28-2014, 03:04 AM	#2
rkomar Wizard Posts: 2,986 Karma: 18343081 Join Date: Oct 2010 Location: Sudbury, ON, Canada Device: PRS-505, PB 902, PRS-T1, PB 623, PB 840, PB 633	Crap! I noticed a few days ago that most of my books were updated within the last year, and re-downloaded them. I guess I have the EPUB3 versions now. Thanks for the info.

03-28-2014, 06:36 AM	#3
HarryT eBook Enthusiast Posts: 85,544 Karma: 93383043 Join Date: Nov 2006 Location: UK Device: Kindle Oasis 2, iPad Pro 10.5", iPhone 6	The PRS-650 uses a rather old version of Adobe's RMSDK (mobile reading software). More modern devices will probably do a lot better with the books. The total size of an ePub file really shouldn't matter, because only one "flow" (normally a chapter) at a time is loaded into memory.

03-29-2014, 03:43 PM	#6
Ripplinger 350 Hoarder Posts: 3,574 Karma: 8281267 Join Date: Dec 2010 Location: Midwest USA Device: Sony PRS-350, Kobo Glo & Glo HD, PW2	Confirming what others have already said, once individual files are broken up correctly within the epub, I'm betting you can then restore the book into just one epub and your reader will handle it just fine. I've opened up books and have seen a few where it consists of one HUGE html file. That will choke any ereader.

03-29-2014, 04:24 PM	#7
HarryT eBook Enthusiast Posts: 85,544 Karma: 93383043 Join Date: Nov 2006 Location: UK Device: Kindle Oasis 2, iPad Pro 10.5", iPhone 6	More modern versions of the RMSDK (Adobe's mobile ePub reader) have far fewer problems with large flows. Unfortunately Sony still use a pretty old version of it.