Is there a way to convert .thumbdata3 directly to .mp3 format?
Converting Android Thumbnail Database Format directly to MP3 Audio Files (.thumbdata3 to .mp3 conversion) is unfortunately not possible.
You can find such THUMBDATA3 database files on SD cards of Android devices. They neither contain documents, nor any other multimedia data, which is why you cannot simply extract, export or convert them to other formats, such as MP3.
In a word, direct thumbdata3 to mp3 conversion is not possible.
So don't expect any so-called thumbdata3 to mp3 converter or thumbdata3 to mp3 free online conversion tool available.
The database currently does not contain any thumbdata3 software converter.