Below is the preferable Video Ad 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.
Aspect Ratio 16:9
Resolution: No limitation.
Minimum Duration: 5 seconds
Max Duration: 30 seconds
Maximum amount of creatives/banners: 10

If you have further questions/clarifications, please hit us up via Live Chat or email us at support@adnium.com.