MobileRead Forums - View Single Post - PRS-300 How long should a page turn take?

chaley · 03-26-2010, 07:01 AM

There are several reasons that page turn times can be slow. One is that the book is using special fonts. The second is that their are images on the pages. A third is segmentation. There are probably more.

Regarding segmentation, EPUB ebooks are split internally into segments. The ebook is really a ZIP archive, and segments are stored as individual files within the archive. Sometimes the segments are by chapter, sometimes by size, or sometimes as the publisher felt like.

My experience on my Sony 300 is that page turn time seems to depends on how far into the file segment I am. It starts at around 1 second. The further in, the longer it takes. If the segment is very long (some publishers don't segment at all), it can take several seconds. In one case I had it take up to 10.

You can test whether this is what you are seeing by noting whether the page turn time slows down as you progress through the book. When you cross a segment boundary, it will slow down once to open the segment (an extra second or two), then get faster, then start to slow down as you advance through the segment. This slowdown will be even more apparent when paging backwards.

My '10-second' book was in one segment. Around half way in, the page turn times because intolerable. Fortunately the book was DRM-free, so I could use Calibre to convert it from EPUB to EPUB. Calibre resegmented the book (and possibly did some other things) and the problem went away.

03-26-2010, 07:01 AM	#4
chaley Grand Sorcerer Posts: 11,742 Karma: 6997045 Join Date: Jan 2010 Location: Notts, England Device: Kobo Libra 2	There are several reasons that page turn times can be slow. One is that the book is using special fonts. The second is that their are images on the pages. A third is segmentation. There are probably more. Regarding segmentation, EPUB ebooks are split internally into segments. The ebook is really a ZIP archive, and segments are stored as individual files within the archive. Sometimes the segments are by chapter, sometimes by size, or sometimes as the publisher felt like. My experience on my Sony 300 is that page turn time seems to depends on how far into the file segment I am. It starts at around 1 second. The further in, the longer it takes. If the segment is very long (some publishers don't segment at all), it can take several seconds. In one case I had it take up to 10. You can test whether this is what you are seeing by noting whether the page turn time slows down as you progress through the book. When you cross a segment boundary, it will slow down once to open the segment (an extra second or two), then get faster, then start to slow down as you advance through the segment. This slowdown will be even more apparent when paging backwards. My '10-second' book was in one segment. Around half way in, the page turn times because intolerable. Fortunately the book was DRM-free, so I could use Calibre to convert it from EPUB to EPUB. Calibre resegmented the book (and possibly did some other things) and the problem went away.