Caractéristiques principales:

• 16.05mp Live MOS sensor
• Venus Engine image processor is quad-core cpu
• Max ISO 25,600
• 50% faster readout of sensor reduces rolling shutter
• Photos up to 60 minutes
• 12fps stills bursts
• Splash proof (and they even explain what that means – other camera companies don’t seem to want to explain their phrases)
• Real time HDMI out (4:2:2 / 8 bit (recorded to SD as 4:2:0) or 4:2:2 / 10 bit)

• ** Not sure if this REQUIRES the Professional 4K Video Interface Unit (Optional)

• Video:

• 4k 24p video (4k and QFHD)
• Different compressions and outputs (.mov/mp4/ALL-I or IPB)
• Vast number of options for frame rate and bitrate depending
• on compression selections
• Up to 94fps
• Cinelike Gamma (flatter profile similar to CineStyle on Canon I’m guessing)
• Zebras
• Focus Peaking – also available over wi-fi for smartphone! (also for stills)
• Headphone jack for monitoring
• Time Code – Rec or Free Run
• Color Bars
• Center Marker
• Synchro Scan (suppress flicker under fluorescent lights)
• No recording time limits (within limitations of format and camera sales area)

• wifi – stills and video control and viewing via smartphones and tablets
• Can embed GPS data via smartphone connection
• NFC (Near Field Communication)
• Connect with smartphone via QR code display on monitor
• Timelapse built in
• Stop Motion animation support
• Professional 4K Video Interface Unit (Optional)

• adds 2 XLR inputs
• audio monitoring
• volume controls
• professional workflow

• 4k video with simultaneous 8.8mp photo capture (not specified how you capture these).

http://blog.planet5d.com/2014/02/hot-new-panasonic-gh4-to-knock-socks-off-the-dslr-video-market/