There are set of file formats that Asset Bank doesn't attempt to compress when they are added to zip files for download.
This is because the file formats themselves are heavily compressed media formats and the amount of compression achieved when attempting to compress them into a zip file is greatly outweighed by the improvement in speed when the asset is just stored in the zip file.
By default the following file types are stored in zip files rather than compressed...
...all other files are compressed.
The set of files that are compressed can be changed by updating entries in the FileFormat table of the Asset Bank database.
To make a particular format compress when it is added to a zip run the following statement:
UPDATE FileFormat SET CompressedInZip=1 WHERE FileExtension='jpg';
Make sure to replace 'jpg' with the extension of whatever file you are adding to the set of files that are compressed. To change a file type so that it is stored rather than compressed just replace 'CompressedInZip=1' with 'CompressedInZip=0' in the above statement.
If you need further help with this process or have any further questions about zip compression in Asset Bank please contact Asset Bank Support.