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== Videos ==
== Videos ==
[[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.
[[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.
Each 0x40000-byte chunk in the Movie data stream is validated with a SHA256 hash table, where hash_index=offset>>18. Whether an error is thrown on mismatch is controlled by [[System_Settings|system-setting]] "capsrv!enable_album_movie_filehash_verification".
Note: the Album process itself uses libstagefright for video playback.
Note: the Album process itself uses libstagefright for video playback.
[[Category:Services]]
[[Category:Services]]