List of audio and video converters by category

Video converters

Video → AVI / MPG

MP4 → AVI / MPG
MKV → AVI / MPG
FLV → AVI / MPG
MOV, QT → AVI / MPG
3GP, 3G2 → AVI / MPG
WebM → AVI / MPG

Video → MP4

Video / Audio → MP4
AVI, DivX, Xvid → MP4
MKV → MP4

Flash Video Converters

Video → FLV, SWF
Flash Video → AVI / MPG

3GP Video Converters

Video → 3GP, 3G2
3GP, 3G2, 3GPP, 3GP2 → AVI / MPG

HTML5 Video Converters

Video → WebM
Video → OGV
Video → MP4

Audio converters

Audio & Video → MP3, AAC, WMA, Ogg, M4A, Opus, FLAC, AC3, E-AC3, MKA, WAV, WV

Universal audio converter & extractor

Audio → MP3 / WAV

M4A, M4B, M4R → MP3 / WAV
FLAC → MP3 / WAV
APE → MP3 / WAV
WMA → MP3 / WAV
LAME frontend

Video → MP3 / WAV

MP4, M4V → MP3 / WAV
FLV → MP3 / WAV
AVI, DivX, Xvid → MP3 / WAV
WebM, 3GP → MP3 / WAV
WMV, ASF → MP3 / WAV

CUE Sheet Splitters

FLAC CUE → MP3 / WAV
APE CUE → MP3 / WAV