This is a paid asset, but now you can download AVPro Live Camera Free.
Detail this asset from Unity Store: Original Link
AVPro Live Camera v2.9.1 (Latest version)
AVPro Live Camera delivers next-level camera support that surpasses the performance and device support of Unity’s WebCamTexture class.
Visit the web page for the demos and docs.
Features:
+ *NEW* Unity 2020 support
+ *NEW* XSplit-VCam support
+ Supported by Chroma Key Kit
+ High performance
+ Easy to use
+ Supports high-end cameras & formats
+ Supports Blackmagic DeckLink capture cards
+ Supports TV capture cards
+ Supports Unity 5.6 and above
+ 5 demos included
+ NGUI component included
+ No scripting required (for most usage)
Ideal for:
+ Interactive installations
+ Serious games
+ Kiosks
+ Video apps
Windows 32-bit and 64-bit only