Please find below the requirements to run In-stream video ads in your campaigns.
Preferable Video Format
Type: MPEG-4 video (video/mp4)
Video Codec: H.264
Audio Codec MPEG-4 AAC
Video File Size
Currently the uploaded video files are limited to 50MB.
Popular video players automatically resize the video so that it fits to their dimensions while keeping the ratio. Nevertheless, a ratio matching the player ratio (if known) is preferable.
At least viewable by all site viewers.
Minimum 15 seconds, no limitation on maximum duration but consider the file size limitation above.
Requirements using VAST creatives
VAST Creatives need to include the skip event, the skipOffset attribute on the linear element must be set to 00:00:05, example <Linear skipoffset="00:00:05">