Here's the recommendation for video and audio codec, take a look at the link for additional format recommendations.
Audio codec: AAC-LC
•Channels: Stereo or Stereo + 5.1
•Sample rate 96khz or 48khz
Video codec: H.264
•Progressive scan (no interlacing)
•2 consecutive B frames
•Closed GOP. GOP of half the frame rate.
•Variable bitrate. No bitrate limit required, though we offer recommended bit rates below for reference
•Chroma subsampling: 4:2:0