We can also use azure media service and create video portal with more powerful media features and Live streaming too.plus it's super easy

Can't we use Office 365's new product "Stream" to build a video portal?. This will allow you to upload the video and share that with your internal users.

SharePoint's built-in Asset Library app is pre-configured to help you manage rich media assets, such as image, audio, and video files.Asset Libraries feature:Thumbnail–centric viewsOverlay calloutsDigital asset content typesAutomatic metadata extraction for image filesFor more go to Official Link of MS: https://support.office.com/en-us/article/set-up-an-asset-library-to-store-image-audio-or-video-files-96532bf6-dc72-4f82-bf0a-21ef945c4d04

SharePoint list/library to store the metadata of video file with the urls to the video streams, Azure media services to store and convert videos to different formats to stream videos to different devices, Azure schedulers to update the stream URls to SharePoint list, A HTML 5 player to play the videos.