There are a number of file extensions that are already mostly compressed that are not yet listed in DEFAULT_DONT_COMPRESS in loadparm.c. These are probable candidates to add:
- webm (audiovisual media file formt)
- webp (image format)
- ogv (Ogg container format)
- squashfs (used for e.g. Debian live images)
I'm sure there are more, hopefully people can add those to this bug report?
I just added the extensions you mentioned.