How can I convert flv files to avi, mov, or other video formats? For free and without downloading?

I use Nidesoft video converter, this converter can convert between almost all popular video and audio formats in high quality at fast speed, it is also easy to use, you may use it to convert flv files to those formats U use mac for download flv converting, right?I use FlashVideo Converter for Mac - program for converting any flash video (flv it's flash video) file to one of many popular video formats including .3gp, MPEG2, and MP4. Converted movies can be saved for custom editing, or recorded for use in DVD players, or on iPod, iPhones and other mobile devices.support formats .3gp, .MP4, .MOV, .MPEG2, .MPEG