Though I think ShareX is still the best freeware for this (especially on compression with long videos). There's another: youtube-dl.
youtube-dl is a command line program. Simple. But requires ffmpeg or I got this error: "...download detected but ffmpeg or avconv could not be found...", which I downloaded and extracted to C:\. Then I need to set the Environmental Variables to the ffmpeg\bin folder (probably not that important with environmental path, because in the youtube-dl command line, it appears that I had to specify --ffmpeg-location PATH anyway)
Sample command: youtube-dl https://www.youtube.com/watch?v=oFEQK1BMnAQ --ffmpeg-location "C:\ffmpeg\bin"
youtube-dl is better than ShareX in a way that it can download a published video faster than ShareX because ShareX requires live capture.
So far, I can't find a way to download an ongoing live stream from the beginning (the very beginning of the stream), in spite of the many ways to speed download hours of youtube videos within minutes. Even though Youtube live streams allow user to slide the video backward in time to watch what's missed from the beginning of the ongoing stream.
I wish I know how this can be achieved.