Are Media Overlays supported?

[garconvacher]

EpubTest 0320 test: media overlays doesn't work.

[HadrienGardeur]

This is a known issue.

Media overlays are properly parsed but we don't have support for them yet in the navigator and the test app.

[llemeurfr]

By the way, I'm always curious to know which are the real usages of EPUB media overlays. @garconvacher, what is your use case? or is it only that you've passed the EpubTest suite to check the progress on R2 swift?

[garconvacher]

Yes, I've noticed this issue while testing. I don't know the use of media overlays, but there could be an interesting use for language books for example. PLS Lexicon is not implemented in app reader :(

[ManfredMuchenberger]

about a use case:
We produce fulltext/fullaudio books with synchronization on word level between text and audio using media overlays.
So far there is no app for iOS or Android that can play these typ of books.
It would be great to have that working in the R2 apps similar to Readium for PCs.

[garconvacher]

@ManfredMuchenberger,
Lis-a reader works fine with media overlays (MO) in ePub on iOS (at least on <p> level) but not on Android.
Lea reader works fine on Android.

Outside Readium,
iBooks on iOS reads MO too but only with FXL.
Reasily on Android reads MO.

[ManfredMuchenberger]

@garconvacher
Thank you very much for the various hints and links. These are really some apps I didn't know about and I just tried them out:

Reasily in Android: plays MO but is completely out of synch and audio is stuttering

Lea Reader in Android: seems to be a nice app!, but crashed while loading big books, plays MO nicely in smaller book with word-synch, audio interruptions while app is sturning to next page/screen,

Lis-a reader: seems to be a nice app!, plays MO nicely with word-synch, continues audio at the end of screen but is not always turning text to next screen/page. If you turn page manually it falls out of synch.

iBooks: we knew about iBooks and its FXL limitation