`mp4san` has parts of a (de)muxer already, we'd just need to add an API and (de)serialization of `stts`, `stsz`, `stss`, and `ctts` boxes.
mp4sanhas parts of a (de)muxer already, we'd just need to add an API and (de)serialization ofstts,stsz,stss, andcttsboxes.