Windows DVDx supported audio/video formats:

  DVDx 2 DVDx 4
  Standard Edition Ultra Edition Open Edition Smart Edition
File output format        
3G2 / 3GP     Yes Yes
AVI - DivX / Xvid Yes Yes Yes Yes
Audio AC33     Yes Yes
Audio AU     Yes Yes
Audio M4A     Yes* Yes*
Audio MP3     Yes Yes
Audio WAV     Yes Yes
FLV     Yes Yes
iPOD     Yes* Yes*
MKV - Matroska     Yes Yes
MOV - QuickTime     Yes* Yes*
MP4 - MPEG-4 movie     Yes Yes
MPEG - (x)VCD / (S)VCD / DVD Yes Yes Yes Yes
OGG     Yes* Yes*
PSP - Sony PlayStation Portable     Yes Yes
WebM     Yes* Yes*
Windows Media Video Yes Yes    
         
Video output format        
H.263     Yes Yes
H.264 / MPEG-4 AVC     Yes Yes
H.264 HD / MPEG-4 AVC HD     Yes Yes
MPEG -1 / VCD / xVCD Yes Yes Yes Yes
MPEG-2 / SVCD / DVD Yes Yes Yes Yes
MPEG-4     Yes Yes
MPEG-4 / Xivd / DivX Yes Yes Yes Yes
Theora     Yes* Yes*
VP8     Yes* Yes*
WMV Yes Yes    
         
Audio ouput format        
AC-3 Dolby Diggital     Yes Yes
AMR-NB     Yes* Yes*
Apple Lossless Audio Codec     Yes* Yes*
Free Lossless Audio Codec     Yes Yes
MP2 / MPEG-1 Layer II Yes Yes Yes Yes
MP3 / MPEG-1 Layer III Yes Yes Yes Yes
MP4 / MPEG-4 AAC     Yes Yes
PCM     Yes* Yes*
Vorbis     Yes* Yes*
WMA Yes Yes    
 
(*) file input (DVD must be converted first to AVI or MKV)