What Windows program will convert MPEG2 video to MPEG4 retaining its playback aspect ratio and its video resolution?

What Windows program will convert mpeg2 (or ATI *.VCR) video to MPEG4
retaining its playback aspect ratio and its video resolution? Dr.Divx
and ATI MMC change a MPEG2 file playback aspect ratio to video
resolution aspect ratio or change video resolution when converting to
mpeg4. For example, Dr.Divx and ATI MMC change a 4x3 playback aspect
ratio of a 480X576 resolution video to a 480X576 playback aspect ratio.
What Windows program allows editing a MPEG2 (or ATI *.VCR) video
retaining its playback aspect ratio and its video resolution?

Dima