ePub books are supposed to have a unique identifier: the Dublin Core identifier found in the OPF file. Unfortunately, the ePub spec doesn’t have any mechanism to enforce the uniqueness of the ID, so we live in a world where in fact many many epubs don’t have truly unique identifiers (or indeed, any identifiers [...]
This was an experiment and is a bit of a hack. Most people seeking to embed video in ePub should use the Flash method described earlier.
I wanted to see if could construct a valid ePub file using HTML5 (in this case, employing the HTML5 <video> element). The problem is that ePub only supports one kind [...]
Since Bookworm has support for video you may want to experiment with creating your own video ebooks. Here’s how to do it and still create a valid XHTML 1.1/ePub.
Assuming you have a Flash movie called Creative_Commons_-_Get_Creative.swf and a containing XHTML page called chapter-1.html, put this in your OPF:
<!– Flash video [...]
This is an experimental new feature but of course a very cool one: Bookworm can now display and play ePub books with embedded video.
Whether the video will actually play depends on the epub file’s formatting and the capability of your web browser. Bookworm also needs to register the particular file type.
Supported video formats:
MP4
OGV
SWF
In later [...]
This is the first in a series of posts describing some of the lesser-known features in the ePub spec. Many of them aren’t implemented by any readers, yet, but can provide some interesting functionality.
The first is “fallbacks.” As ePub developers know, only a small handful of content types are supported by the spec: [...]
Most of the time, command-line users will be able to run the epubcheck Java binary without issues. But sometimes mysterious problems occur — this happened to me on OS X before upgrading to Snow Leopard. So while it’s a bit awkward, you can use the remote epubcheck API combined with some XSLT to [...]
Our web tool for using the open-source epubcheck validator got a quick refresh:
Now includes epubpreflight results
EpubCheck’s lesser-known companion checks for additional issues like content documents that exceed 300K, which can’t be loaded on the Sony Reader. The complete (short!) list:
Content files that are empty or are >300k
Image files that are empty or are >10MB [...]
I was extremely pleased to participate in the Internet Archive’s BookServer announcement and press event. (The Register has the best coverage, but also see CNET and ReadWriteWeb).
Our part of this open ecosystem is Ibis Reader, an in-development digital reading system for a range of internet devices that provides access to books both online and offline. [...]
(You may be interested in the earlier article, When to embed fonts in ePub files.)
Font selection
Font formats and licensing are complicated. The ePub specification recommends that book designers and reading system implementers use OpenType fonts when possible (although TrueType fonts remain more common). If your font ends in a .otf extension, it’s an OpenType font. [...]
First, let’s be perfectly clear:
The ePub specification supports embedded fonts.
Embedded fonts are supported through use of the CSS2 @font-face rule.
Reading system support
As of September 2009, the following readers do support @font-face:
Adobe Digital Editions
Sony Reader
Implicitly, any reading device which uses the Adobe reading SDK should have the same behavior, though [...]