Besides convert HD video to SD(Standard Definition) video, Aiseesoft HD Converter for Mac also owns the solution to HD video to HD video, convert SD video to HD video, or SD video to SD video conversion. Audio Converter or Audio Extractor are added in this Mac HD Converter.
Furthermore, the editing tools provides you the ability to optimize your output video/audio quality, like convert part of your HD video, crop, merge, and set video/audio settings, capture picture or something else.