CaptionSync accepts a number of different media formats as input. All we really need from you is the audio track of your video, so if your video is very large you may just extract the audio program and submit that — the results you get back will work fine with your original video. Following is a list of acceptable formats for submitting media to CaptionSync:
| Extension | Description |
|---|---|
| .FLV | Flash video |
| .F4V | Flash MPEG4 video |
| .MOV | QuickTime video or audio |
| .MP4 | MPEG4 video or audio |
| .M4A | iTunes audio |
| .M4B | iTunes audiobook audio |
| .M4V | iTunes video |
| .MP3 | MPEG2 layer 3 compressed audio |
| .RA | Real Player audio |
| .RM | Real Player video |
| .WAV | PCM audio |
| .WMA | Window Media Player audio |
| .WMV | Window Media Player video |
| .ASF | Window Media ASF container video |