PS3 can natively play MP3/WMA, JPG/PNG/GIF/TIFF for the Audio and Pictures, for the video, per the PS3 online manual at http://manuals.playstation.net/document/en/ps3/current/video/filetypes.html (http://manuals.playstation.net/document/en/ps3/current/video/filetypes.html) you can play the following:
Memory Stick Video Format
- MPEG-4 SP (AAC LC)
- H.264/MPEG-4 AVC High Profile （AAC LC）
- MPEG-2 TS（H.264/MPEG-4 AVC, AAC LC）
MP4 file format
- H.264/MPEG-4 AVC High Profile (AAC LC)
MPEG-1 (MPEG Audio Layer 2)
MPEG-2 PS (MPEG2 Audio Layer 2, AAC LC, AC3(Dolby Digital), LPCM)
MPEG-2 TS（MPEG2 Audio Layer 2, AC3（Dolby Digital）, AAC LC）
MPEG-2 TS（H.264/MPEG-4 AVC, AAC LC）
AVI
- Motion JPEG (Linear PCM)
- Motion JPEG (μ-Law)
AVCHD （.m2ts / .mts）
DivX
WMV
- VC-1（WMA Standard V2）
The DLink NAS does not do any transcoding of videos not in the above types, and not all AVI and MP4 files are necessarily encoded as above. You will need to convert your ISO or VOB file to one of the above in order to play via your PS3 (see programs like WinFF, VLC, FFMpeg, Super for this ability, plenty of guides if you look up how to convert videos to PS3 format).
Good luck!