NDI®/NDI®|HX/NDI®|HX2有什么区别？

Kiloview
03/20/2021

NDI®|HX是第一代基带转换器和PTZ摄像机所使用的NDI协议，它是一种混合协议。设计用于在传统的IP流（如RTSP/RTP）和易于集成的NDI世界之间建立桥梁。虽然设备固件发生了变化，但构建NDI|HX的大部分工作是在接收设备HX驱动程序中完成的。

NDI®|HX2是下一代高效的NDI协议，NDI|HX2是真正的原生NDI流，从源设备一直到目的地。这意味着它是一个比NDI|HX更“干净”的实现，并且可以提供更可靠、更低的延迟和更灵活的连接，它共享NDI的所有一般特性。NDI|HX2可以通过WiFi提供类似Full NDI的画面质量。NDI延迟在很大程度上取决于发送和接收设备中的编解码器实现，但理论上可以低到几帧。

NDI/NDI|HX/NDI|HX2对比：

Parameter	NDI®	NDI®\|HX	NDI®\|HX2
Transport	TCP/UDP/Multi-TCP	UDP (TCP)	TCP/UDP/Multi-TCP
Image Format	Size / Aspect Independent	Size / Aspect Independent	Size / Aspect Independent
Tally Feedback	Yes	Yes	Yes
Bidirectional Device Control	Yes	Yes	Yes
Integrated Alpha Channel	Yes	No	No
Compression	NDI® Codec	HX (H.264)	H.264/H.265
Connection	Socket, Unicast / Multicast and FEC	Unicast/MultiCast	Socket, Unicast / Multicast and FEC
HD (1080i) Data Rate	~ 100 Mbit/s	8-20 Mbit/s	1-50 Mbit/s
Essence Packing	Discrete Audio, Metadata and Video Frame packets, single connection	Delivered as Discrete Audio, Metadata and Video Frame packets, single connection	Discrete Audio, Metadata and Video Frame packets, single connection
Infrastructure	Gigabit / Load Balanced Multi NIC / 10GBit	Gigabit / Wireless	Gigabit / Wireless
Service Discovery	Bonjour (mDNS), NDI® Access (manual), Server (NDI®4)	automatic via HX Driver	Bonjour (mDNS), NDI® Access (manual), Server (NDI®4)
API	free license, SDK Libraries for Win(x86), Mac, Linux(x86 & ARM), iOS, FPGA reference	hardware encode, Decode with NDI® Libraries	Send with NDI® Embedded SDK, Receive with Free NDI® Libraries