Microsoft's ASF format is also based on the MPEG-4 compression technology (an earlier version of the format used in DivX), but the problem with this container format is that it is proprietary, and not too many ASF editing/conversion tools are freely available.
By converting ASF to AVI, one can access the wide range of AVI/DivX software tools, and luckily, converting between the two containers is extremely easy and will only take a few seconds. Another advantage of converting ASF files to AVI is that you will be able to easily skip to sections in the video (ie. keyframes) and in a few of my conversions, the file size actually decreased by about 20% without any loss in quality.
Below is an short instruction on how to do this :
Start by downloading and installing the following software :
VirtualDub 1.4c - a earlier (unofficial) version of VirtualDub that has ASF support
1. Installing the required software :
Please install both the MPEG-4 VKI codec and the VirtualDub software. Instructions on installing the MPEG-4 codec are on the download page.
2. VirtualDub conversion :
Once you have all the required software installed, you'll need to do the following in VirtualDub :
Load your ASF file into VirtualDUB.
From the "Video" menu, select "Direct Stream Copy".
From the "Audio" menu, select "Direct Stream Copy".
Save the AVI file - your have just converted your ASF file to a brand new AVI file - it should have only taken a few seconds for the "conversion", since all you really did was change the container from ASF to AVI.