I'm sorry if this is one of those questions that is asked repeatedly - I did do a search and could not find anything.
Am I correct that Adobe Digital Editions uses whatever is set as the first page in the spine section of content.opf as the cover, even if an image on a different page is set as the cover image using a metatag?
In content.opf I have
<meta name="cover" content="coverimage" />
(The values for "name" and "content" are correct, I checked, and it works when viewed on an iPad)
A different page is set to open first in the spine section - that also works.
But when viewed in ADE, the first page in spine is chosen as the cover. That's normal, right?
09-27-2012, 05:45 AM
No, not really. Although it is common practice to use the first page as the cover, it is not required. Are you sure you have all the semantics correct?
I'm pretty sure that I have the semantics correct, Toxaris. I double checked now, and the document validates in Sigil, for what that's worth!
The value for “content” matches the image file’s “item id” as specified in the “manifest” section lower down in this file - in this case, “coverimage”.
The image's item in the manifest looks like this:
<item href="Images/cover.jpeg" id="coverimage" media-type="image/jpeg" />
When the page that contains the cover image is set as the first item in the spine, the cover appears in ADE. When I set it as the second or item in the spine, it no longer appears as the cover in ADE.
I borrowed an iPad to check this on, and ( I think!) the cover showed as the image whether or not the page was first in the spine, as long as it was identified in that meta-tag. But I no longer have that iPad so I dont have any way to test whether this is just an ADE thing, or whether I have, indeed, messed up somewhere.
I found this link http://epingsoft.com/blog/?p=30
Which says that
"Adobe(and all devices based on its SDK) will consider the first HTML page as coverpage and get it as cover automatically, while Apple and some other devices only recognize a defined cover picture(not a page).
So if there’s no cover page of a ePub book, ADE will use the screenshot of the first page as cover, while Apple will not."
Which I interpret as meaning that Apple devices look for that metatag, and ADE does not. What am I not understanding?
09-27-2012, 06:32 AM
There is NO specification in the ePub standard for cover (at least in 2.1), so whatever ADE does, it's not against the spec.
The <meta> tags are all out-of-spec (allowed, but without any particular meaning, whatever their "name" and "content"). Some software might interpret them some way, but others might ignore them, and they wouldn't be doing anything wrong.
That said, your <meta name="cover" content="coverimage" /> tag is recognized by many readers and programs, but I believe not by ADE.
Thanks Jellby, that makes sense. That's what I suspected but I was suddenly unsure.