mobi2epub:how much time?

comet · 02-12-2012, 03:37 AM

Hallo,

I just converted a mobi of 50MB to an epub. Of course calibre did a good job, but it needs 13 hours. What's the reason for such a long time?

speakingtohe · 02-12-2012, 07:50 AM

Most ebooks are under 3kb so that is part of it.
50 MB is unusually large and posibly made up of images which generally takes longer.

Helen

comet · 02-12-2012, 08:27 AM

Yes, there were pictures, but the html-part of the book had a size of 50MB, so this part of the book was much larger than the images!

theducks · 02-12-2012, 09:16 AM

Quote:

Originally Posted by comet

Yes, there were pictures, but the html-part of the book had a size of 50MB, so this part of the book was much larger than the images!

Pictures can get converted (scaled) as part of the process.
That eats CPU cycles (time). Code complexity (not what you see as 'the book') can cause long convert times.

comet · 02-12-2012, 09:55 AM

Does there exist a relation between size of the mobi and the time needed to convert it to an epub that can be used to estimate the time of convertion?

theducks · 02-12-2012, 10:25 AM

Quote:

Originally Posted by comet

Does there exist a relation between size of the mobi and the time needed to convert it to an epub that can be used to estimate the time of convertion?

No
It is the contents being rendered.

A straight text (no other styling. No bold,Italics or size changes...) should process briskly.

frostschutz · 02-12-2012, 11:16 AM

3kb is a bit small even for ebooks... A 800 pages book (printed) may easily go into 1-2MB range even with simplest HTML (just <p>text</p>) and next to no unnecessary whitespace. And Calibre might take a minute to convert it which is a relatively long time.

Calibre does a lot of things that might not be efficient, so the time it takes might grow exponentially with size. It reformats the entire HTML, and consolidates styles, and at the same time it tries to fix stuff in the text such as punctuation and chapter detection etc.

These things just take time esp. if developed with a primary focus on functionality rather than efficience, since people rarely convert a hundred books at a time and a size of 50MB for a single book is really a bit unusual.

02-12-2012, 03:37 AM	#1
comet Connoisseur Posts: 66 Karma: 10 Join Date: Feb 2010 Location: Germany Device: Kindle Voyage, Kindle Oasis , Kindle Oasis 2, Tolino Epos	mobi2epub:how much time? Hallo, I just converted a mobi of 50MB to an epub. Of course calibre did a good job, but it needs 13 hours. What's the reason for such a long time?

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02-12-2012, 07:50 AM	#2
speakingtohe Wizard Posts: 4,812 Karma: 26912940 Join Date: Apr 2010 Device: sony PRS-T1 and T3, Kobo Mini and Aura HD, Tablet	Most ebooks are under 3kb so that is part of it. 50 MB is unusually large and posibly made up of images which generally takes longer. Helen

02-12-2012, 08:27 AM	#3
comet Connoisseur Posts: 66 Karma: 10 Join Date: Feb 2010 Location: Germany Device: Kindle Voyage, Kindle Oasis , Kindle Oasis 2, Tolino Epos	Yes, there were pictures, but the html-part of the book had a size of 50MB, so this part of the book was much larger than the images!

02-12-2012, 09:55 AM	#5
comet Connoisseur Posts: 66 Karma: 10 Join Date: Feb 2010 Location: Germany Device: Kindle Voyage, Kindle Oasis , Kindle Oasis 2, Tolino Epos	Does there exist a relation between size of the mobi and the time needed to convert it to an epub that can be used to estimate the time of convertion?

02-12-2012, 11:16 AM	#7
frostschutz Linux User Posts: 2,279 Karma: 6123806 Join Date: Sep 2010 Location: Heidelberg, Germany Device: none	3kb is a bit small even for ebooks... A 800 pages book (printed) may easily go into 1-2MB range even with simplest HTML (just <p>text</p>) and next to no unnecessary whitespace. And Calibre might take a minute to convert it which is a relatively long time. Calibre does a lot of things that might not be efficient, so the time it takes might grow exponentially with size. It reformats the entire HTML, and consolidates styles, and at the same time it tries to fix stuff in the text such as punctuation and chapter detection etc. These things just take time esp. if developed with a primary focus on functionality rather than efficience, since people rarely convert a hundred books at a time and a size of 50MB for a single book is really a bit unusual.