FreeBSD Limitations

Non-Compressible Files

The following is a list of non-compressible files:

Non-Compressible Files
Archive
.7z	.bz2
.gz	.rar
.xz	.zip
Audio
.aac	.ac3
.aifc	.amr
.flac	.m4a
.mka	.mp2
.mp3	.mpa
.ogg	.ra
.rm	.snd
.ssm	.wma
Graphics
.gif	.jfif
.jpeg	.jpg
.png	.wim
.wmp	.wmz
Video
.3gp	.asf
.divx	.ivf
.m4v	.mkv
.mp2v	.mp4
.mpeg	.mpg
.mts	.qt
.rv	.smil
.vob	.webm
.wmd	.wmv
.avi	.m1v
.mov	.mpe
.mpv2	.rmvb
.swf	.wm