Use FREE & FREEWARE software
Oxelon Media Converter
Oxelon Media Converter can convert video or audio files into the following formats:
Video Formats: 3GP, 3G2, ASF, AVI, DV, DVD MPEG2, FFM, FLV, GIF, MOV, MP4, MPEG1, MPEG2 PS, MPEG2 TS, NUT, PSP, RAW YUV, RM, SVCD MPEG2, SWF, VCD MPEG1, VOB, YUV4MPEG, M1V, M2V, M4V.
Audio Formats: AC3, AAC, AIFF, AMR, AU, FLAC, MMF, MP2, MP3, OGG, VOC, WAV.
This software can use as right context menu. So user can right-click on the selected file(s), and choose "Oxelon - Convert to Video" or "Oxelon - Convert to Audio" and next select the format.
Download Link: http://www.oxelon.com/media_converter.html