Which encoding are ridibooks epub?

[guiniol]

Hello,

I managed to get the epubs from ridibooks, but I can't open them, it's all garbled. I think it's because of the encoding. Do you open ridibooks epubs? If so, how?

Thanks,

[salkkji]

There's a Calibre plugin here for ridibooks, however after installing the plugin I still couldn't open ridibooks file. Further instruction please?

https://github.com/hkjinlee/calibre-ridibooks-plugin

[Cryental]

It's not because of the encoding. They locked with DRM system.