How to convert .thumbdata33 files to .mp4 format.
Converting Android Thumbnail Database Format directly to MPEG-4 Videos (.thumbdata33 to .mp4 conversion) is not possible.
THUMBDATA33 files, found on SD cards of Android devices, neither contain documents, nor any other multimedia data, which is why it is not possible to extract, export or convert these files to any other format, including MP4.
In a word, direct thumbdata33 to mp4 conversion is not possible.
So don't expect any so-called thumbdata33 to mp4 converter or thumbdata33 to mp4 free online conversion tool available.
The database currently does not contain any thumbdata33 software converter.