Future of the PDFium adapter in Readium (16 KB page sizes issue) #709
Description
As you probably know:
Starting November 1st, 2025, all new apps and app updates that use native C/C++ code targeting Android 15+ devices submitted to Google Play must support 16 KB page sizes. This is a crucial step towards ensuring your app delivers the best possible performance on the latest Android hardware.
https://android-developers.googleblog.com/2025/07/transition-to-16-kb-page-sizes-android-apps-games-android-studio.html
LCP is ready for 16 KB page sizes but we still use an old unmaintained dependency which is not compatible in the Readium toolkit: PDFium.
Unfortunately, core maintainers are not able to allocate time to maintain the PDF adapter for PDFium to handle 16 KB page sizes. If you are interested in preserving this support in the Readium toolkit, we encourage you to submit a PR to implement it.
Apparently, a few forks exist which support 16 KB page sizes:
- https://github.com/AhmerAfzal1/AhmerPdfium
- https://github.com/v-mas/PdfiumAndroid/
- UnsatisfiedLinkError with PDFium on Android 15 Emulator with 16 KB Page Size DImuthuUpe/AndroidPdfViewer#1191 (comment)
The tricky part is that, due to a conflict with liblcp, the Readium toolkit is stuck with the PdfiumAndroid 1.8.2 codebase, which may not be updated for 16 KB in these forks.
If this is important to you and you would like to contribute to this update, please come forward. Otherwise, we will remove support for PDFium in early October, to be prepared for the November deadline.