Mobipocket vs ePub: Why worse is better in ebook formats

anurag · 06-20-2009, 04:13 AM

A very good article with implementation overviews of Mobi, MS LIT and ePub formats and an example where an incorrect rendering decision made by the Mobi implementation works better than the 'correct' rendering approach adopted by ePub. Hopefully the ePub implementation team is listening.

http://platypope.org/blog/2009/4/3/w...e-book-formats

JSWolf · 06-20-2009, 04:32 AM

I think the author is nuts. Yes, eReader is not a nice format. But Mobipocket is not better then ePub. As he pointed out, with the Mobile ePub specifications, the issues of having to load in the entire file and render it all at once in memory is a non-issue. The author is just wrong. What he says is so good about Mobipocket is part of why Mobipocket is not so good.

HarryT · 06-20-2009, 04:35 AM

Interesting article, and I completely agree with the author.

JSWolf · 06-20-2009, 04:41 AM

Quote:

Originally Posted by HarryT

Interesting article, and I completely agree with the author.

The author needs to get a clue.

HarryT · 06-20-2009, 04:45 AM

You are entirely wrong, Jon.

anurag · 06-20-2009, 04:46 AM

Quote:

Originally Posted by JSWolf

I think the author is nuts. Yes, eReader is not a nice format. But Mobipocket is not better then ePub. As he pointed out, with the Mobile ePub specifications, the issues of having to load in the entire file and render it all at once in memory is a non-issue. The author is just wrong. What he says is so good about Mobipocket is part of why Mobipocket is not so good.

Perhaps you are being too harsh - I believe the author is saying ePub is indeed better than Mobi, but there's a reason Mobi and LIT formats still exist, and ePub can learn from them.

HarryT · 06-20-2009, 05:02 AM

ePub is completely impractical for "resource-limited" devices due to the necessity to load the entire XML parse tree into memory. As the author very rightly says, Mobi rendering is "good enough".

Jellby · 06-20-2009, 05:07 AM

Quote:

Originally Posted by HarryT

Interesting article, and I completely agree with the author.

I agree with the last paragraph, at least.

But it suffers a bit from the common "blame ePUB for ADE's faults" ailment.

HarryT · 06-20-2009, 05:11 AM

The necessity to load the entire parse tree into memory is a part of the ePub spec. ADE's 300k "flow size" restriction is a result of that requirement.

Hadrien · 06-20-2009, 05:58 AM

Quote:

Originally Posted by HarryT

The necessity to load the entire parse tree into memory is a part of the ePub spec. ADE's 300k "flow size" restriction is a result of that requirement.

No, it's not part of the specs. It's a common way to deal with XML, but you can optimize things or do it a different way.

Lbooker · 06-20-2009, 06:47 AM

Interesting article!
Some sentences could be made clearer for the non-specialist, though.
It could also be interesting to add other formats like the Russian fb2 to this analysis.

A big question for me (and an interesting test for all those formats) is which format allows the use of these free off-line versions of Wikipedia available in many languages there:
http://pinguinburg.de/wpmp

Right now they are available in mobipocket format, but most e-reader devices cannot use them because the closed-source mobipocket software reader does not handle links between several files.
The open source FBReader cannot do anything with those files for two reasons:
- it absolutely wants to load the entire book in memory (imagine a 1 GB Wikipedia file in the memory of one of our favorite devices!
- like the official mobipocket software reader, it does not allow links between several files, and those freely downloadable Wikipedia files come in the following form: a zip file decompressed into a directory containing a master index file, and the hundreds of thousands of Wikipedia articles are contained in a few dozen files.
Could epub do better? Should the epub standard be rewritten to be able to handle Wikipedia?
Could fb2 do it?

JSWolf · 06-20-2009, 07:36 AM

Quote:

Originally Posted by HarryT

The necessity to load the entire parse tree into memory is a part of the ePub spec. ADE's 300k "flow size" restriction is a result of that requirement.

But that 300k restriction does gove ePub the ability to run on resource limited devices.

netseeker · 06-20-2009, 07:44 AM

Quote:

Originally Posted by JSWolf

But that 300k restriction does gove ePub the ability to run on resource limited devices.

With a better implementation it could even work without that 300k restriction. It's a shame that Adobes/Sonys engineers didn't come up with a better solution.

=X= · 06-20-2009, 10:43 AM

Great article I completely agree with the author.

Quote:

Originally Posted by platypope.org

4 In fact, AFAIK I was the first person to even bother reverse-engineering them when I implemented LIT generation for calibre.

Is this article written by MobileRead's very own llahsram (aka Marshall)? .... I think so

=X=

TallMomof2 · 06-20-2009, 10:48 AM

Good discussion. ITA agree that Mobipocket is "good enough". I can still pull out an old Palm and read MobiPocket and eReader books on it. The only way I can use ePub is to convert it and honestly that's how I view the current implementation of ePub. Not really all that usable for me but convertable.

06-20-2009, 04:13 AM	#1
anurag Addict Posts: 236 Karma: 4066 Join Date: Feb 2009 Location: California Device: Kindle 1 and DX, iPhone	Mobipocket vs ePub: Why worse is better in ebook formats A very good article with implementation overviews of Mobi, MS LIT and ePub formats and an example where an incorrect rendering decision made by the Mobi implementation works better than the 'correct' rendering approach adopted by ePub. Hopefully the ePub implementation team is listening. http://platypope.org/blog/2009/4/3/w...e-book-formats

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06-20-2009, 04:32 AM	#2
JSWolf Resident Curmudgeon Posts: 80,718 Karma: 150249619 Join Date: Nov 2006 Location: Roslindale, Massachusetts Device: Kobo Libra 2, Kobo Aura H2O, PRS-650, PRS-T1, nook STR, PW3	I think the author is nuts. Yes, eReader is not a nice format. But Mobipocket is not better then ePub. As he pointed out, with the Mobile ePub specifications, the issues of having to load in the entire file and render it all at once in memory is a non-issue. The author is just wrong. What he says is so good about Mobipocket is part of why Mobipocket is not so good.

06-20-2009, 04:35 AM	#3
HarryT eBook Enthusiast Posts: 85,560 Karma: 93980341 Join Date: Nov 2006 Location: UK Device: Kindle Oasis 2, iPad Pro 10.5", iPhone 6	Interesting article, and I completely agree with the author.

06-20-2009, 04:45 AM	#5
HarryT eBook Enthusiast Posts: 85,560 Karma: 93980341 Join Date: Nov 2006 Location: UK Device: Kindle Oasis 2, iPad Pro 10.5", iPhone 6	You are entirely wrong, Jon.

06-20-2009, 05:02 AM	#7
HarryT eBook Enthusiast Posts: 85,560 Karma: 93980341 Join Date: Nov 2006 Location: UK Device: Kindle Oasis 2, iPad Pro 10.5", iPhone 6	ePub is completely impractical for "resource-limited" devices due to the necessity to load the entire XML parse tree into memory. As the author very rightly says, Mobi rendering is "good enough".

06-20-2009, 05:11 AM	#9
HarryT eBook Enthusiast Posts: 85,560 Karma: 93980341 Join Date: Nov 2006 Location: UK Device: Kindle Oasis 2, iPad Pro 10.5", iPhone 6	The necessity to load the entire parse tree into memory is a part of the ePub spec. ADE's 300k "flow size" restriction is a result of that requirement.

06-20-2009, 06:47 AM	#11
Lbooker Addict Posts: 316 Karma: 1021312 Join Date: Jun 2009 Device: Sony PRS-T1	Interesting article! Some sentences could be made clearer for the non-specialist, though. It could also be interesting to add other formats like the Russian fb2 to this analysis. A big question for me (and an interesting test for all those formats) is which format allows the use of these free off-line versions of Wikipedia available in many languages there: http://pinguinburg.de/wpmp Right now they are available in mobipocket format, but most e-reader devices cannot use them because the closed-source mobipocket software reader does not handle links between several files. The open source FBReader cannot do anything with those files for two reasons: - it absolutely wants to load the entire book in memory (imagine a 1 GB Wikipedia file in the memory of one of our favorite devices! - like the official mobipocket software reader, it does not allow links between several files, and those freely downloadable Wikipedia files come in the following form: a zip file decompressed into a directory containing a master index file, and the hundreds of thousands of Wikipedia articles are contained in a few dozen files. Could epub do better? Should the epub standard be rewritten to be able to handle Wikipedia? Could fb2 do it?

06-20-2009, 10:48 AM	#15
TallMomof2 Kindlephilia Posts: 2,017 Karma: 1139255 Join Date: Nov 2007 Location: Snowpacolypse 2010 Device: Too many to count	Good discussion. ITA agree that Mobipocket is "good enough". I can still pull out an old Palm and read MobiPocket and eReader books on it. The only way I can use ePub is to convert it and honestly that's how I view the current implementation of ePub. Not really all that usable for me but convertable.