Thread: Mobi format limitations
View Single Post
Old 01-08-2009, 09:41 PM   #4
delphidb96
Wizard
delphidb96 ought to be getting tired of karma fortunes by now.delphidb96 ought to be getting tired of karma fortunes by now.delphidb96 ought to be getting tired of karma fortunes by now.delphidb96 ought to be getting tired of karma fortunes by now.delphidb96 ought to be getting tired of karma fortunes by now.delphidb96 ought to be getting tired of karma fortunes by now.delphidb96 ought to be getting tired of karma fortunes by now.delphidb96 ought to be getting tired of karma fortunes by now.delphidb96 ought to be getting tired of karma fortunes by now.delphidb96 ought to be getting tired of karma fortunes by now.delphidb96 ought to be getting tired of karma fortunes by now.
 
Posts: 2,999
Karma: 300001
Join Date: Jan 2007
Location: Citrus Heights, California
Device: TWO Kindle 2s, one each Bookeen Cybook Gen3, Sony PRS-500, Axim X51V
Quote:
Originally Posted by llasram View Post
I'm currently working on Mobipocket generation for Calibre, and oh yeah -- it's utterly abysmal. The problem is two-fold:

First, the actual capabilities have many and frequently eccentric limitations. Text may only be displayed in seven different font-sizes, only two of which are smaller than normal text. Blocks of text can never have a greater than normal margin on their right side. Left margins can only be specified in 1em increments. Text can only have a hanging indent if it has no left margin. Text cannot flow around images taller than one line of text. Image sizes cannot be scaled with font size. In some -- but not all -- Mobipocket renderers, text with a left margin changes that margin value per line based upon the font-size at which point the preceding line-break occurred. Many measures, such as the indent of a hanging indent, cannot be specified in ems. Text cannot be displayed in a monospace font. Tables display wildly differently on different Mobipocket renderers, especially tables which cross more than one screen. And I'm sure I'll find many more once I finish oeb2mobi and people start submitting bugs.

Second, you only get the full range of Mobipocket's formatting capabilities if you have markup written to use Mobipocket's non-standard, extended, and under-documented implementation of HTML 3.2. The rest of the world -- including the Microsoft LIT format -- has moved on, and is using some form of HTML 4.0 or XHTML 1.x along with CSS. Converting standards-compliant markup to Mobipocket's markup is a difficult process. This problem is not simplified by the state of the Mobipocket-provided tooling (mobigen) which frankly does an abysmal job of converting even reasonably complexly formatted HTML+CSS into something presentable in Mobipocket. Anything like a complex table, side notes, side bars etc will pretty much need to be converted manually to a linear flow in order to be legible.



If the books you want are sold in other formats, you can always buy them in those formats and convert yourself. Calibre should have Mobipocket-generation in the next month or so and there are several other existing tools which will do the job.

The font size limitation must be a limitation on the Sony because I've got (only one font or size selectable at any time) FOURTEEN installed fonts and EACH font supports TWELVE sizes from about 6pt to 36pt on my Cybook. Now I'll grant that the Mobi implementation on the Cybook doesn't support multiple fonts or multiple sizes within an ebook, but one still has the ability to use bold and italics.

Derek
delphidb96 is offline   Reply With Quote