Dtube properly accepts videos with following specs:
1.480p resolution
2.AAC audio format (in video)
3.mp4,h264,webm

You can also join the dTube and onelove dTube discord groups and they will be more than happy to help you

https://steemit.com/dtube/@melsa/dtube-s-discord
https://steemit.com/onelovedtube/@reseller/introducing-the-one-love-dtube-discord-community