Register Guidelines E-Books Search Today's Posts Mark Forums Read

Go Back   MobileRead Forums > E-Book Formats > Kindle Formats

Notices

Reply
 
Thread Tools Search this Thread
Old 06-15-2011, 04:33 AM   #1
comet
Connoisseur
comet began at the beginning.
 
Posts: 62
Karma: 10
Join Date: Feb 2010
Location: Germany
Device: Sony PRS 350, PRS 650, Kindle Keyboard 3G, Kindle Touch Wlan
Size of mobi much larger than epub?

Hallo,

I buy books at o'reilly, and there I get the same title in different formats. I observed that for one book I bought the epub for my Sony has a size of 4.7MB, the mobi for my kindle 17.1MB! What is the reason of this large difference?
comet is offline   Reply With Quote
Old 06-15-2011, 05:41 AM   #2
pdurrant
The Grand Mouse
pdurrant ought to be getting tired of karma fortunes by now.pdurrant ought to be getting tired of karma fortunes by now.pdurrant ought to be getting tired of karma fortunes by now.pdurrant ought to be getting tired of karma fortunes by now.pdurrant ought to be getting tired of karma fortunes by now.pdurrant ought to be getting tired of karma fortunes by now.pdurrant ought to be getting tired of karma fortunes by now.pdurrant ought to be getting tired of karma fortunes by now.pdurrant ought to be getting tired of karma fortunes by now.pdurrant ought to be getting tired of karma fortunes by now.pdurrant ought to be getting tired of karma fortunes by now.
 
pdurrant's Avatar
 
Posts: 30,764
Karma: 85457880
Join Date: Jul 2007
Location: Norfolk, England
Device: NOOK ST GlowLight
Quote:
Originally Posted by comet View Post
Hallo,

I buy books at o'reilly, and there I get the same title in different formats. I observed that for one book I bought the epub for my Sony has a size of 4.7MB, the mobi for my kindle 17.1MB! What is the reason of this large difference?
Unpack them both and find out. It's probably due to images, although I don't really see why.

It's also just possible that the Mobi also has a copy of the ePub stuffed at the end of it.

The ePub you can unpack just by unzipping it. The Mobi you'll need the Mobipocket Unpack script from here: http://www.mobileread.com/forums/sho...36&postcount=5
pdurrant is online now   Reply With Quote
Old 06-15-2011, 06:14 AM   #3
HarryT
eBook Enthusiast
HarryT ought to be getting tired of karma fortunes by now.HarryT ought to be getting tired of karma fortunes by now.HarryT ought to be getting tired of karma fortunes by now.HarryT ought to be getting tired of karma fortunes by now.HarryT ought to be getting tired of karma fortunes by now.HarryT ought to be getting tired of karma fortunes by now.HarryT ought to be getting tired of karma fortunes by now.HarryT ought to be getting tired of karma fortunes by now.HarryT ought to be getting tired of karma fortunes by now.HarryT ought to be getting tired of karma fortunes by now.HarryT ought to be getting tired of karma fortunes by now.
 
HarryT's Avatar
 
Posts: 62,466
Karma: 39919465
Join Date: Nov 2006
Location: UK
Device: PW2, iPad Retina Mini, iPhone 4, MS Surface Pro, Onyx T68, N7,
There are two probable reasons:

1. Most Kindle books are created using Amazon's "Kindlegen" tool. This includes a copy of the complete HTML source into the book, which increases the size considerably.

2. ePub files use a much more efficient compression method than Mobipocket format does.

As Paul notes, if the book is illustrated it's possible that the Kindle version has higher-resolution images than the ePub version does.
HarryT is offline   Reply With Quote
Old 06-15-2011, 07:59 AM   #4
dwig
Guru
dwig ought to be getting tired of karma fortunes by now.dwig ought to be getting tired of karma fortunes by now.dwig ought to be getting tired of karma fortunes by now.dwig ought to be getting tired of karma fortunes by now.dwig ought to be getting tired of karma fortunes by now.dwig ought to be getting tired of karma fortunes by now.dwig ought to be getting tired of karma fortunes by now.dwig ought to be getting tired of karma fortunes by now.dwig ought to be getting tired of karma fortunes by now.dwig ought to be getting tired of karma fortunes by now.dwig ought to be getting tired of karma fortunes by now.
 
dwig's Avatar
 
Posts: 951
Karma: 1351860
Join Date: Dec 2004
Location: Paradise (Key West, FL)
Device: Current:Kindle 3/WiFi Retired:Clie - UX50, T415, ...
The other thing that can happen occurs when a ePub with inefficient CSS usage is converted to MOBI. If the CSS for, say, the <p> tag contains 40 characters the bulk of that can get moved to each and every <p> tag in the html that is integrated into the MOBI adding bulk to the MOBI.

It more efficient to put the style in a <DIV> that spans all of the matching <P>'s leaving the <P> tags unstyled. This will reduce bloat in the MOBI conversion.

When converting ePub to MOBI with calibre, which doesn't embed the source in the output MOBI, the resulting MOBI files are sometimes slightly smaller, often slightly larger (~10%) and only occasional substantially larger. The latter generally being cases of poor CSS usage.
dwig is offline   Reply With Quote
Old 06-23-2011, 05:43 AM   #5
bfollowell
Fanatic
bfollowell ought to be getting tired of karma fortunes by now.bfollowell ought to be getting tired of karma fortunes by now.bfollowell ought to be getting tired of karma fortunes by now.bfollowell ought to be getting tired of karma fortunes by now.bfollowell ought to be getting tired of karma fortunes by now.bfollowell ought to be getting tired of karma fortunes by now.bfollowell ought to be getting tired of karma fortunes by now.bfollowell ought to be getting tired of karma fortunes by now.bfollowell ought to be getting tired of karma fortunes by now.bfollowell ought to be getting tired of karma fortunes by now.bfollowell ought to be getting tired of karma fortunes by now.
 
Posts: 510
Karma: 1152752
Join Date: Aug 2010
Location: Evansville, IN, USA
Device: Amazon Kindle 3 Wi-Fi & B&N Nook Tablet & B&N Nook HD+
Assuming the epub doesn't have large embedded fonts or the like, I've noticed that a typical mobi version of an ebook tends to run anywhere from 10%-25% larger than it's epub cousin. That's just been my experience though. Your mileage may vary.

- Byron
bfollowell is offline   Reply With Quote
Old 07-09-2011, 02:37 AM   #6
lenz117
Creative
lenz117 began at the beginning.
 
Posts: 2
Karma: 10
Join Date: Jul 2011
Device: kindle
HI there guys - I have a similar and slightly alarming issue:

I have an epub file that at 0.7mb that when converted jumps to 3mb. I have played with calibre 0.8.8 with varying results. I am using optimised gif files.
-
If I do a straight epub -> mobi conversion then the size increases 4 fold.

I just changed the mobi output settings to generic rather than Kindle and this then created a mobi at 1.5mb - but now cant replicate that on other book files (I have 5 I am trying to publish)

I beleive that when you convert to mobi - epub also gets bundled hence some increase in file size - but 4 times?

I know there was a script to remove the epub aspect from a mobi - but the script I have has no effect with these new files.

Has anyone else had any experience of optimising mobi files - naturally to try and reduce delivery charges for books
lenz117 is offline   Reply With Quote
Old 07-09-2011, 03:56 AM   #7
pdurrant
The Grand Mouse
pdurrant ought to be getting tired of karma fortunes by now.pdurrant ought to be getting tired of karma fortunes by now.pdurrant ought to be getting tired of karma fortunes by now.pdurrant ought to be getting tired of karma fortunes by now.pdurrant ought to be getting tired of karma fortunes by now.pdurrant ought to be getting tired of karma fortunes by now.pdurrant ought to be getting tired of karma fortunes by now.pdurrant ought to be getting tired of karma fortunes by now.pdurrant ought to be getting tired of karma fortunes by now.pdurrant ought to be getting tired of karma fortunes by now.pdurrant ought to be getting tired of karma fortunes by now.
 
pdurrant's Avatar
 
Posts: 30,764
Karma: 85457880
Join Date: Jul 2007
Location: Norfolk, England
Device: NOOK ST GlowLight
Quote:
Originally Posted by lenz117 View Post
HI there guys - I have a similar and slightly alarming issue:

I have an epub file that at 0.7mb that when converted jumps to 3mb. I have played with calibre 0.8.8 with varying results. I am using optimised gif files.
-
If I do a straight epub -> mobi conversion then the size increases 4 fold.

I just changed the mobi output settings to generic rather than Kindle and this then created a mobi at 1.5mb - but now cant replicate that on other book files (I have 5 I am trying to publish)

I beleive that when you convert to mobi - epub also gets bundled hence some increase in file size - but 4 times?

I know there was a script to remove the epub aspect from a mobi - but the script I have has no effect with these new files.

Has anyone else had any experience of optimising mobi files - naturally to try and reduce delivery charges for books
If you're converting with Calibre, the ePub does not get added to the end. That's purely if the conversion is done with Kindlegen.

If you want to know where the extra is coming from, unpack the Mobipocket and see. My guess is that Calibre is doing something to the pictures to make them larger (in bytes). But that's only a guess.
pdurrant is online now   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
0.7.58 Mobi Font Size problem Blossom Conversion 15 04-30-2011 09:27 PM
MOBI size, uploading to Amazon yuxi_kelly Kindle Formats 9 01-08-2011 06:06 PM
Smallest font size in Mobi hkdorama Kindle Formats 0 07-26-2010 04:07 AM
.mobi doesn't increase/decrease font size vidgej Astak EZReader 3 01-13-2010 10:39 AM
How to increase teh size of images in .mobi files nvr Kindle Formats 2 01-12-2010 11:23 AM


All times are GMT -4. The time now is 07:38 AM.


MobileRead.com is a privately owned, operated and funded community.