From time to time, I have to deal with video file conversion and try to compress the file as much as possible. It’s because Media Library file size restrictions for WordPress web publishing platform. You can only upload to the Media Library up to 40MB in size (Correction 18/06/17: My new hosting server allows me to upload up to 128MB. It appears upload limit changes according to you hosting server set up). If that is MP4 video file (which is to be used sometimes for the Header Sliders section and others), you may have issues because it not such a big file for MP4 video format.
Of course, you can upload bigger video files to different folders created in the hosting server using FTP (File Transfer Protocol) software and link the file so that it will be shown on your web page. However, I understand the restrictions of WordPress for the file size upload because it will eat up the bandwidth of viewers.
I tried many video conversion and compression program, however, I found I could get the best MP4 video file conversion and compression result by uploading to YouTube without loosing much of the quality of the original video file.
YouTube accepts MOV, MPEG4, MP4, AVI, WMV, MPEGPS, FLV, 3GPP and WebM video file for uploading. More than enough for you to deal with conversions and copression by yourself. And you can get converted YouTube video files by your favorite YouTube video downloader program such as 4k Video Downloader.
You simply upload your video file to your account of YouTube as an unlisted video file and when YouTube processes the file, you can simply download the end result MP4 file you want by using 4K Video Downloader program. What I like about 4K Video Downloader is that automatically downloads the best quality YouTube videos and it’s free of charge. (Licensed version is also available for US$15 which enables you to download YouTube play list) Thanks for YouTube and 4K Video Downlaoder.