Freeware XMediaRecode will do a nice job. The download site is German but the GUI (graphic user interface) is in English. It also lets you convert and edit video and audio.
• Input formats: Supports most formats, including Blu-ray,
3GP, 3G2, AAC, AC3, AIFF, AMR, APE, ASF, AVI, AviSynth,
AU, DVD, DTS, E-AC3, FLAC, FLV, H.261, H.263, H.264, M2TS,
M1V, M2V, M3U, M3U8, M4A, M4P, M4V, Matroska, MMF, MP2,
MP3, MP4, MP4V, MP3, MPEG-1, MPEG-2, MPEG-4, QuickTime,
Ogg, OGM, PVA, REC, RealMedia, RMVB, SVCD, SWF, THP, TS,
TRP, TP0, VCD, VOB, WebM, WMA, WMV, WPL.
• Output formats (Video): Asus V1, Asus V2, MPEG-4 Part 2,
MS MPEG4 V2, MS MPEG4 V3 DV Video, Flash Video, Flash
Screen Video, H.261, H.263, H.263+ H.264/MPEG-4 AVC (using
x264 = lossless), Huffyuv (lossless), M-JPEG, MPEG-1,
MPEG-2, Theora, VP8, WMV V7, WMV V8.
• Output formats (Audio): AAC, AC3, ADPCM Microsoft, ADPCM
Yamaha, A-LAW, AMR NB, AMR WB, MP2, MP3, Vorbis, WAV-PCM 16
little endian, WAV-PCM 16 little endian, WAV-PCM 24 Little-
Endian, WAV-PCM U8, WMA V7, WMA V8.
• Supported output device profiles: Acer, Apple, Asus, Archos,
BlackBerry, Cowon, Creative Labs, Dell, DVD Player (Stand-
alone), Epson, HTC, LG, Microsoft, Motorola, Nokia, O2,
Palm, Philips, iRiver, SanDisk, Samsung, Sony, Sony Ericsson,
T-Mobile, Toshiba, Vodafone.