ExifTool is a Perl library and command-line tool for reading and updating common meta data information in various file formats. Foremost it works on image files, EXIF, PNG, GPS, IPTC, XMP, JFIF/JPEG, GeoTIFF, ICC Profile, Photoshop IRB, FlashPix, AFCP, AIFF, DJVU, Postscript, GZIP, OpenDocument, PDF, SVG, OGG and ID3. It can also edit maker notes of digital (RAW) camera files from Canon, Casio, FLIR, FujiFilm, GE, HP, JVC/Victor, Kodak, Leaf, Minolta/Konica-Minolta, Nikon, Nintendo, Olympus/Epso
lsdvd is a terminal application which retrieves meta information about a DVD and displays it. It reveals the number and type of tracks, video or audio information, eventual subtitles, etc. It can print out plain text or XML, and even Perl or Ruby code for easy integration.
FileBot can automatically rename tv show / movie files, and download subtitles. It requires little work, as media files can just be drag'n'dropped in for operation. It's cross-platform and comes with a command-line version.