Searching for "FMAB 1080p Audio Latino" leads you to the fruits of this labor: MKV files where Edward’s automail gleams in HD while Sergio Bonilla’s voice remains perfectly synchronized. This is where the "Fullmetal" part of the title becomes literal. Creating this hybrid file is an act of technical alchemy.
In the end, the anime is about the bond between two brothers. Appropriately, the file itself is a bond: the union of pristine, high-definition video (the body) and the beloved Latin American audio track (the soul).
Thus, the fan project was born. Dedicated preservationists took the high-quality 1080p Blu-ray rips (often from the Japanese or US releases) and extracted the pristine Latin American audio track from older DVD releases or TV broadcasts. They then painstakingly synced the audio frame-by-frame to the 1080p video.