Lv is light viewer.
If your OS is Windows, you need to install Git Windows. (If you don't have already.)
Download git from https://git-scm.com/download/win
Install it.
For other OS, I expect you have it.
Type git in terminal for check.
Download go from https://golang.org/dl/
Follow the installation steps. then,
$ go get github.com/coldmine/lv # will also automatically install lv to $GOPATH/bin
$ cd $GOPATH/src/github.com/coldmine/lv
$ lv sample/pngseq/*