What file types do you generate?

We try to generate MP4 files for videos and M4A for audio. If for a given input it's not possible you may get some Matroska (MKV) or Vorbis (OGG) files. Have a look here to find players for these file types. If you want a different file type (e.g. MP3, MP4, MOV) use a program like Handbrake to transcode your clip to the desired format.