To allow you to enjoy the videos that you have downloaded from YouTube on your walkman, you must need SWF FLV to MP3 Converterto convert them into audio format.
SWF FLV to MP3 Converter allows you to convert SWF and FLV files into MP3 or Wav format. It supports both batch process and individual conversion. For that, you only have to add your files to the interface and to right click to open the appropriate menu and then you can play back your file or delete it directly. In addition, this software can also merge MP3 files to get a single file.