Dear maintainers,version 2.0.0 of smpeg does support compilation on top of SDL2. So I have filed an RFP for src:smpeg2 [1]. Unluckily, all recent updates since version 2.0.0 are only to be found in the Git repository. There hasn't been published any newer version than 2.0.0 so far.
Best regards, Thomas Uhle [1] https://bugs.debian.org/1039593
