[[4.0.0]] includes video playback etc support in Album via mp4. These include a JPEG thumbnail, which is used for video "validation". The EXIF is also much larger: the MakerNote is 0x498-bytes, with encrypted data starting at offset +0x8. This encryption uses AES-CTR with hardcoded key/ctr. MAC calculation works the same way as the [[3.0.0]]+ JPEG MAC calculation, except with a different movie_kek_source/movie_key_source.
Note: the Album process itself uses libstagefright for video playback.