As of now you can go to the PlayStation Store and download the free dedicated media player app, which now adds the ability to stream content via DLNA or play content via a USB dongle. Finally, yes finally we have DLNA functionality on the PS4. You will also be able to play music in the background while playing games.
The supported file formats and codecs are as followed:
Video
MKV
Visual: H.264/MPEG-4 AVC High Profile Level4.2
Audio: MP3, AAC LC, AC-3(Dolby Digital)
AVI
Visual: MPEG4 ASP, H.264/MPEG-4 AVC High Profile Level4.2
Audio: MP3, AAC LC, AC-3(Dolby Digital)
MP4
Visual: H.264/MPEG-4 AVC High Profile Level4.2
Audio: AAC LC, AC-3(Dolby Digital)
MPEG-2 TS
Visual: H.264/MPEG-4 AVC High Profile Level4.2, MPEG2 Visual
Audio: MP2(MPEG2 Audio Layer 2), AAC LC, AC-3(Dolby Digital)
AVCHD: (.m2ts, .mts)
Photo
JPEG (based on DCF 2.0/Exif 2.21)
BMP
PNG
Music
MP3
AAC (M4A)
The app supports a number of different file formats, including MKV, AVI, MP4, MPEG3, MP3, and AAC
Sony has been going two years without functions that your older generation PS3 can perform. Sony has stated in the past that the PS3 was more concentration on gaming before media, but support will be coming. Now, two years in, its finally here.