What video codecs do you support as inputs?
That being said, we should handle most modern codecs you can throw our way. PDFs are going to fail (you'd be shocked at how often I've seen this). If you can, use h264 video and AAC audio as that's what our system is optimized for and will you give you the best performance.
We can support almost any valid h264 file :D
In an ideal world, you'd send 1080p high profile h264 encoded with a bitrate above 8Mbps (or CRF 18 for x264 nerds), with a max keyframe interval of around 5 seconds. Closed GOPs also makes processing more efficient.