Jperf is a GUI based utility using iperf commands in background.
Flazr is a Java implementation of protocols such as RTMP used for multimedia streaming. The Flazr project includes a streaming media server and related utilities.
A list of mostly all of the ffmpeg commands that can be used in daily use for conversion, creating images, editing videos . Read the post below for more details.
You will see this error probably because the filezilla erver needs to support opening files in shared mode & it has a setting for it.