SDI vs IP: The Technological Dilemma

The Future of Signal Transport in the Media and Entertainment Industry.
Notícias SDI vs IP: The Technological Dilemma

The Future of Signal Transport in the Media and Entertainment Industry

With the continuous evolution of workflows and technology in the Media and Entertainment (M&E) industry, crucial decisions must be made regarding the choice between baseband SDI systems and innovative IP-based solutions for signal transport.

M&E companies looking to renovate face the dilemma of whether to stick with reliable baseband SDI transport or migrate to IP technologies, which, with the adoption of the 4K UHD format and, in the future, 8K, makes the need for greater bandwidth and flexibility an attractive option for IP integration. However, this transition brings a series of challenges and considerations.

It is essential to acknowledge the various existing processes for signal transport in order to choose the one that will benefit each company the most. With this in mind, Ross decided to write a Whitepaper to examine the current hybrid reality, explain and analyze the strengths and weaknesses of each available technology on the market, discuss Use Cases, and share its experience on how it views the future of these technologies.

Ultrix Hyperconverged Signal Routing & Processing from Ross Video is an example of a product that supports a variety of signal transport options, meeting the hybrid transport needs of the modern Media and Entertainment production environment.

SDI: the foundation of traditional transmission

Since its introduction by the Society of Motion Picture and Television Engineers (SMPTE) in 1989, the Serial Digital Interface (SDI) has been the backbone of digital video and audio transmission. With successive updates—HD-SDI, 3G-SDI, and 12G-SDI, among many others—SDI continues to support high-quality workflows but may face challenges in terms of scalability and flexibility compared to IP solutions.

SMPTE ST 2110: the future of IP transport

To meet the growing need for an IP-based transport standard, SMPTE launched the ST 2110 series in 2017. This set of standards offers a robust infrastructure for media content transport over IP networks, separating video, audio, and metadata as distinct IP data streams. Therefore, the ST 2110 standards have become ideal for live productions, thanks to their ability to transmit high-bandwidth video with extremely low latency and the flexibility to distribute each type of signal to its destination without embedding or de-embedding needs. However, implementing this alternative can be expensive and complex.

Within the ST 2110 standard set, there are:

- SMPTE ST 2110-20: Defines the transport of uncompressed video over IP networks, ensuring lossless video quality with minimal latency.

- SMPTE ST 2110-22: Supports the transport of compressed video over IP networks, balancing quality and latency.

Approved in 2021 by the Video Services Forum (VSF), a set of technical recommendations emerged:

- TR-07: Recommends the transport of JPEG XS video, along with audio and metadata, in MPEG-2 TS containers over IP, used in wide-area networks (WANs).

- TR-08: Describes the transport of JPEG XS in SMPTE ST 2110-22, separating IP data for video, audio, and metadata, used in compressed on-prem applications over LAN networks.

Other Protocols

- Internet Protocol Media Experience (IPMX): Finalized by the Alliance for IP Media Solutions (AIMS) in January of this year, IPMX is aimed at AV-over-IP transport for media, entertainment, and Pro AV users. Based on TR-08 and ST 2110-22, it is an alternative to HDMI and DisplayPort, supporting compressed video applications over LAN.

- Network Device Interface (NDI): Developed by NewTek in September 2015, NDI supports compressed video over LAN with several revisions such as NDI-HB, NDI|HX/HX2, and NDI|HX3, each with specific competencies in quality and latency.

- Reliable Internet Stream Transport (RIST): An open-source protocol developed by the RIST Activity Group of the VSF, RIST enables the transmission of compressed video in unpredictable IP network environments. It is a secure and reliable format, designed for site-to-site and ground-to-cloud video contribution.

- Secure Reliable Transport (SRT): Created by Haivision in 2013 and later managed by the SRT Alliance, SRT enables compressed video transport over unpredictable IP networks, used in remote contributions for productions following the Remote Integrated (REMI) model, as well as in site-to-site and ground-to-cloud applications.

- WebRTC: First launched in 2011, this peer-to-peer transport protocol is used for compressed video in video conferencing and remote contributions, integrated into browsers such as Chrome, Firefox, and Safari, among others.

Advantages and Disadvantages

Each of these technologies has its own advantages and disadvantages:

- SDI: Simple, reliable, and inexpensive. It does not require an IP network infrastructure and is widely recognized within the supplier community, resulting in high interoperability. However, its strengths are balanced by some weaknesses.

- SMPTE ST 2110-20: High quality and low latency, but costly and complex to implement.

- SMPTE ST 2110-22: A balance between quality, bitrate, and low latency, as well as compatibility with TR-07. While less expensive than ST 2110-20, it remains complex to implement.

- TR-07 and TR-08: Good quality and low latency but with limited adoption.

- NDI: Easy to use and compatible with most networks.

- SRT and RIST: Secure and low latency, but SRT may trade latency for reliability, and RIST has lower adoption.

- WebRTC: Easy integration with software applications but limited to web browsers.

Amid multiple signal transport technologies, media and entertainment organizations will face difficult decisions in the future. Even organizations opting for a single technology will eventually have to integrate others, whether to enhance on-prem workflows with cloud solutions or for IP content streams.

Beyond the direct cost of acquiring IP transport hardware such as routers and switches, consideration must also be given to the cost of managing the new equipment, as well as hiring professionals for training.

For all these reasons, evaluating an organization's current and future workflow needs is crucial to selecting the technology that best suits its working method. It is essential to find a balance between technologies and to find reliable advisors, like Ross Video, which has over 50 years of experience and can provide appropriate and personalized guidance to any Media and Entertainment company.

Download the whitepaper from our partner Ross Video on "The ins & outs of Today’s Signal Transport": HERE.

 

July, 2024