He encontrado un Conversor Multiple "SUPER" que de momento parece muy muy interesante (no solo porque sea FREEWARE ). Estoy haciendo pruebas con el y ya os comentare resultados. De momento os dejo un pelin de info (aunque este en ingles, lo que pone lo entendeis seguro ).
"SUPER © Simplified Universal Player Encoder & Renderer.
A GUI to ffmpeg, MEncoder, mplayer, x264, mppenc,
ffmpeg2theora & the theora/vorbis RealProducer plugIn.
If you need a simple, yet very efficient tool to convert (encode) or play any Multimedia file,
without reading manuals or spending long hours training, then SUPER © is all you need.
It is a Multimedia Encoder and a Multimedia Player, easy-to-use with 1 simple click.
Supported input source file formats are:
– Video format: 3gp/3g2(Nokia,Siemens,Sony,Ericsson) asf, avi (DivX,H263,H263+,H264,XviD,MPEG4,MSmpeg4 etc..), dat,
fli, flc, flv (used in Flash), mkv, mpg (Mpeg I,Mpeg II), mov(H263,H263+,H264,MPEG4 etc..), mp4(H263,H263+,H264,MPEG4), ogg,
qt, rm, ram, rmvb, str (Play Station), swf (Flash), ts (HDTV), viv, vob, wmv
– Audio format: aac, ac3, amr, mmf, mp2, mp3, mp4, mpc, ogg, ra, wav, wma
– AviSynth Script Files: avs. Let you specify advanced encoding commands using AviSynth scripts!
Mas info en: http://www.erightsoft.net/home.html