| sbv | SubViewer Subtitle Format File |
| scc | Sonic Scenarist Closed Caption File |
| scke | SpyClock Encrypted Video |
| scm | ScreenCam Movie File |
| sdr2 | Seorim MICRO DVR Camera Video |
| sgv | Self-Guard Security Camera Video |
| siv | Silicon Imaging Video |
| skm | SKM Video |
| smk | Smacker Video |
| smov | Sealed Quicktime Movie |
| smp1 | Sealed MPEG-1 Video |
| smp4 | Sealed MPEG-4 Video |
| smpg | Sealed MPEG Movie |
| smv | SigmaTel Motion Video |
| splash | Splash Pro EX Video |
| srt | SubRip Subtitle Format |
| ssa | SubStation Alpha Subtitle |
| sst | Sonic Scenarist Subtitle |
| ssts | Stream SubText Script Subtitle |
| stj | STLabs Video Data |
| stl | EBU-STL Standard Subtitle File |
| str | Sony Playstation Video Stream |
| strg | E-Viewer Recorded Stream |
| sub | VobSub Subtitle |
| sub | MicroDVD Subtitle Format File |
| svi | Samsung Video File |
| svq3 | Sorenson Video v3 |
| tdt | AVCHD Thumbnail Data |
| theater | iMovie Theater Movie |
| thm | Panasonic HD Camcorder Thumbnail |
| tid | AVCHD Thumbnail Index |
| tivo | TiVo DVR Video |
| tix | DivX Ticket |
| tlv | Plotwatcher Time Lapse Video |
| tmi | TCM-3 Encoded Video File |