We already know such solution as "Rarjpeg"[0]: "letter file" + "letterbox file"[1]
Supported "letter files" (which could make box files selfexecutable):
- archives (selfexecutable): .rar/.7z
- other (not selfexecutable): any other files
Actually, supported "letterbox files" are:
- audio: .wav/.mp3/.aac/.amr
- image: .jpg/.png/.gif/.webp
- other: .torrent , .html
So, there are nothing new in your solution.