Cine like D with the usual recommended settings: ISO 200
ISO 1600 With standard profile:It's hard to tell on YouTube, but it looks normal to me. Just severely underexposed.
If you want to see in the dark you should get faster lenses, a Sony A7s or an infrared camera. It's been proved that properly exposed the GH4 can provide great results.
What lens are you using? In the video you acknowledge underexposing, so I'd think you'd expect the noise. Looks normal.
Looks pretty normal to me for a Panny m4/3 sensor, especially using cineD which has a gamma curve on it.
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