I am trying to convert some old ASF clips to mp4 using Handbrake so that I can import them into iMovie. The first ten clips worked fine but the latest batch of five come out pixelated although the sound is still OK. The ASF files play perfectly with VLC. Any ideas anyone?
However, you could look for any difference in the detail of the input formats by comparing a file that worked properly with one that didn't. Perhaps the poor quality is coming from interlaced files or something similar?
There is a file converter called MPEG Streamclip from http://www.squared5.com I don't know if it handles ASF files, but it is free so perhaps work a try.