You should try some online converter, follow me and see the top online converters
Zamzar
(1) simply enater a file you want to convert by pointing to its location on your local drive or address on the web(ex; youtube video),
(2) select output format(eg. PDF, doc, 3GP mobile, iPod, PSP…),
(3) enter email address where it should send converted file and
(4) convert it.
Special features:
◆supports all popular video, music, image and document formats. More details
◆provides browser bookmarklet(Firefox, IE) which lets you convert and save files from any webpage.
◆convert and save any video while you are watching it(supports Youtube, GoogleVideo, Myspace, Revver, PutFile, Break.com, Apple, Trailers, Dailymotion, Metacafe, iFilm, Grouper, Blip.tv)
◆file size can’t exceed 100 MB.
Media-Convert
Special features:
◆each converted file remains accessible for 6 more days, so if you want to share it with friends you can forward them a link to download page.
◆input file format auto-detection(no need to specify input format)
◆additional option to adjust conversion settings(like fps, bitrate, codec, audio rate, etc..)
◆download file directly to your mobile via WAP or GPRS.
◆file size can’t exceed 150 MB.
Mux
Special features:
◆for more demanding users there is a power mux which allows users set additional settings on output file(bitrate, fps, file length…etc).
◆there is also a mux mobile which lets you convert web-videos to mobile format(3GP, AMR) and instantly forward them to any mobile for free.
Vixy is a professional FLV file converter,it can only support converting Flash video or FLV files. The procedure is very easy, just input the url of the YouTube video or the FLV files, then choose output format, click "Start". it support output in AVI for Windows, MOV for Mac, MP4 for iPod/PSP, 3GP for Mobile, and MP3 only.
Special features:
◆It is using a compressed domain transcoder technology . It converts FLV to MPEG4 faster and less lossy than a typical transcoder.
◆When you submit a URL, it will download and convert to the video format, and then you can download the converted file.
◆FLV to MPEG4 Conveter engine is now OpenSource. You can download the source code via subversion:http://sourceforge.net/svn/?group_id=183657