Tipard FLV Video Converter Suite combines a video converter and a ripper. The video converter allows you to convert your videos to quite a few different formats, including DivX, XviD, H.264, MPEG-4, MOV, M4V, FLV, SWF, 3GP, MPEG-1, MPEG-2, etc. It can open different formats as well. I tried an AVI file and an MKV file and both were opened just fine. The DVD ripper lets you convert your DVD movies into the same formats I listed above.
Both of the apps that make up this suite look identical. They have a different color scheme, but that seems to be the only real difference. Both have a video player for video playback and a very nice video editor that allows you to trim and crop videos and to adjust their brightness and contrast. There are conversion profiles for devices like iPods, iPhones, gaming consoles, mobile phones, etc.
In my testing, I converted an AVI file into an MKV file. The whole process took less than 2 minutes for a 1-minute file. That is what most converters take to convert this file. The resulting file looked good. The process was smooth enough.
All in all, these apps are not only for converting files to FLV or viceversa, lots of different formats are supported.