There are two ways to deal with videos in SharePoint 2013. There is a content type called video in SharePoint 2013.When you upload the video to this content type it will store as BLOB in the content database. You can store up to 1 GB videos in the content database. The Advantage of storing in the content database is security like other content type. But more video you store more will be the cost of storage as the blob using SQL server for storage.
The other way of storing videos is as a link to other physical locations. The security of the videos needs to be explicitly handled in this case.
When you store the videos in the SharePoint the blob cache need to be optimized for smooth streaming, Like Size the BLOB cache to a certain percentage of the total size of unique videos viewed in a week, this can be 60-80 % of total size of unique videos viewed. To optimize performance, do not place the BLOB cache on the same drive as the system drive, and ensure that the drive where BLOB is cached have enough space.
When the videos are stored in the external locations to the SharePoint like a web severer (IIS server) or a media streaming server the streaming is performed by the external location's source.
With a single WFE with 12 GB ram, 4 core processor and 8 core 16 GB DB server, it supports 400 concurrent video viewing in the acceptance level. As no of WFE increases it support a minimum 200 more additional smooth streaming. The no of smooth streaming is not linear but shows exponential increases by adding additional WFEs.
With a IIS Server same as the configuration of WFE 600 smooth concurrent streaming can be expected. By using media streaming services and media servers this can gain boosted. Bit Rate throttling is another extension to ISS to increases the bandwidth while streaming videos.
