SRT and NDI
Secure Reliable Transport (SRT) and Network Device Interface (NDI) stand for AV-over-IP solutions that enable high-quality video transmission with low latency, but still serve different applications.
SRT has an integrated two-way return channel that transmits essential performance information during streaming. This enables the protocol to detect and rectify problems. To use SRT, the encoder and decoder must be SRT-compatible. When using SRT, bandwidths of 2–8 Mbit/s are sufficient to stream in high quality.
Advantages of using SRT
- reliably delivers videos with low latency and high quality
- enables simple and cost-effective deployment of remote locations
- Easily overcomes firewalls between source and destination
- High security (up to 256-bit AES encryption)
NDI stands for a software standard with which videos can be transmitted and received in high quality and with low latency via a local area network (LAN). This means that several audio and video devices in the network can be accessed via a single LAN connection.
The main prerequisite for NDI streaming is that the sending (NDI-capable) and receiving device are in the same network. For example, the video image from an NDI-capable PTZ camera can be sent and received via a company-wide network. At the same time, the camera can be controlled via the network. Other devices may require additional setup.
NDI technology uses a special codec and a transport method to achieve virtually lossless image quality without latency. However, this means that NDI requires a very high network bandwidth. A single 1080p NDI stream at 30 fps requires a bandwidth of at least 125 Mbps.
Until recently, these high bandwidth requirements meant that NDI-based video workflows were only plausible over stable local networks. With the release of NDI 5, this limit has now been exceeded. By using the NDI bridge tool, two remote NDI networks can be connected to each other. Live audio and video can be contributed via a URL using the NDI remote tool.
Advantages of using NDI
- Almost lossless quality without latency
- All video sources are easily accessible from anywhere in the network
- offers cost-effective video production via LAN
Source: epihan.com
