There are many different ways to convert FLV files to an MP3 format, and they vary depending on if the FLV file stored on a computer or a website. Converting an FLV file that is located on the web can usually be done via special websites that convert the files for you. An flv file that is located on a hard drive can usually be converted by using special conversion software that can change the FLV to an MP3.
FLV (flash video) files are multimedia containers that are used to stream video over the internet. These files are popular because of its small size and broad compatibility with most operating systems. Sites such as YouTube and Metacafe primarily use the FLV format to transmit video content. Even though it is a popular format, it has limitations. One of them being that most sites will not let you download the FLV file or convert FLV to MP3, or any other media format for that matter.
There are sites that convert FLV to mp3, and most of them are free and easy to use. Typically, the process involves little more than cutting and pasting a site URL into a text box and clicking on a "convert" button. The site will go from there, and will convert flash for windows media center, iTunes or any other media player that supports the MP3 format. Doing a simple search for "FLV to MP3" on most search engine will bring up a multitude of sites that offer this service. Some are free, but others are pay services.
If converting an FLV to MP3 from a computer's hard drive, it is usually necessary to download a program that can convert media formats. Many of these can convert flash video to MP3, as well as other formats including WMA and FLAC. Alternatively, you can use recording software to simply record the audio while playing the FLV file. Make sure that all other programs are muted however, so you don't get sounds from them in your recording.
While it is easy to record or convert FLV to MP3, it is not always legal. Making an audio file out of an FLV with copyrighted material is considered piracy or copyright infringement in many countries. The process of copying the file off of a website may also be in violation of the Digital Millennium Copyright Act in America as well. Before attempting to convert FLV to MP3 you should be sure that you have a legal right to the audio on the file.