What is SDI? Features and Applications of Serial Digital Interface Technology

March 24, 2025

Whether you’re filming and editing a promotional video, setting up a security system for a commercial building, or planning to broadcast a live event, you need high-quality audio visual (AV) connections. So what is SDI, and what is it used for?

Serial digital interface (SDI) is a professional AV transmission standard that uses coaxial or fiber optic cables to deliver exceptional, uncompressed video and audio. SDI is used across a wide range of applications, including TV and film production, live broadcasting for virtual events, security and surveillance, and medical imaging.

Key Features of SDI

Uncompressed Video and Audio

SDI transmits high-quality audio and visual signals without any compression artifacts, preserving the minute details produced by the original signal.

Low Latency

Latency or “lag” refers to the time it takes from when a packet of data is sent to when it’s received. One of the reasons SDI is so popular in live broadcasting is its minimal latency.

High Bandwidth

While latency refers to the speed of data transmission, bandwidth refers to the amount of data that can be sent at one time. SDI connections support high data rates, which result in high-resolution video and a smoother user experience.

Point-To-Point Interface

Each SDI cable carries a signal directly from one device to another, creating an ultra-reliable connection.

Long-Distance Transmission

SDI connections can transmit video and audio signals over long distances using coaxial cables up to 300 meters with standard-definition SDI.

Embedded Audio

SDI doesn’t just ensure high-quality images and videos. These connections can also carry multiple channels of embedded audio, streaming high-quality audio and video in tandem.

Multiple Standards

Over time, a variety of different SDI standards have been developed to support different resolutions and frame rates, including SD-SDI (standard definition), HD-SDI (high definition), 3G-SDI, 6G-SDI, and more.

Built-In Error Correction

SDI has integrated error correction mechanisms to minimize disturbances caused by noise interference and enhance reliability and signal stability.

What is SDI Used For?

Broadcasting

SDI is the standard in both pre-recorded and live broadcasting. From news reporting, to sports, to dramatized television, SDI offers reliable transmission of video and audio signals in multi-camera productions.

Video Production

SDI is ideal for professional video production as it can distribute uncompressed footage over long distances. It’s also beneficial for video editing as signals can be sent back and forth between various types of equipment including switchers, cameras, and monitors.

Security and Surveillance

SDI is often used in high-end home and commercial security systems. Due to its ability to maintain signal quality when traveling far distances, surveillance footage can be transmitted to monitoring stations with little-to-no degradation.

Medical Imaging

High-quality imaging is essential in a wide variety of medical settings. For example, endoscopes are often used in screenings and surgical procedures to transmit detailed images into a screen, allowing medical professionals to see accurate, live video of what’s happening inside the patient's body.

Audio-Visual Integration

In addition to video, SDI can also transmit embedded audio signals over multiple channels. This allows the audio to maintain its quality and synchronize with the accompanying footage through a single cable.

Video Conferencing

SDI can be used for virtual meetings, allowing users to communicate between remote locations without significant latency or quality issues. This is particularly helpful in large-scale professional settings with multiple participants.

Live Streaming and Event Production

SDI can be effectively utilized in live streaming and event production for virtual and hybrid events. Its seamless application with multiple cameras, screens, and switchers affords exceptional flexibility during live events.

What is HD-SDI?

High Definition Serial Digital Interface (HD-SDI) is a version of SDI that can transmit high-definition (HD) video signals via coaxial or fiber-optic cables.

SDI vs HD-SDI – What is the Difference?

The key difference between SD-SDI and HD-SDI is that they support different resolutions, data rates, and applications. HD-SDI can support higher resolution video, but SD-SDI can transmit audio and video across further distances.

Here’s a breakdown of the differences between SDI and HD-SDI:

Feature Comparison Table
Feature SDI HD-SDI
Video quality Standard definition High definition
Maximum resolution 480i/576i (SD) 720p, 1080i, 1080p (HD)
Data rate 270 Mbps 1.485 Gbps
Maximum transmission distance 300m 100m

Choosing the Right Interface Technology for Your AV Needs

When choosing between various interface technologies, it’s important to consider your specific needs, the features that are most important, and relevant applications.

Here’s a brief overview of popular interface technologies that can be incorporated into AV systems:

  • SDI: Provides excellent integrated audio and video transmission and is ideal for broadcasting and live events
  • IP-based systems: Offers scalability and high-resolution support for large-scale productions
  • HDMI: Easy-to-set-up, and transmits high-quality video over shorter distances, making it ideal for home theater and small production setups
  • Wireless systems: Good for versatile productions and doesn’t require a physical cable, but it is susceptible to video degradation over long distances

Make Your Next Event a Success With Advanced AV Technology and Support

At Catalyst, we’re on a mission to transform what’s possible in AV event production. We work with organizations of all shapes and sizes, delivering high-quality AV equipment setups, event design services, and integrated support to help create truly memorable moments for attendees.

Contact us today to set up a free event consultation and learn more about our services.

March 24, 2025

Whether you’re filming and editing a promotional video, setting up a security system for a commercial building, or planning to broadcast a live event, you need high-quality audio visual (AV) connections. So what is SDI, and what is it used for?

Serial digital interface (SDI) is a professional AV transmission standard that uses coaxial or fiber optic cables to deliver exceptional, uncompressed video and audio. SDI is used across a wide range of applications, including TV and film production, live broadcasting for virtual events, security and surveillance, and medical imaging.

Key Features of SDI

Uncompressed Video and Audio

SDI transmits high-quality audio and visual signals without any compression artifacts, preserving the minute details produced by the original signal.

Low Latency

Latency or “lag” refers to the time it takes from when a packet of data is sent to when it’s received. One of the reasons SDI is so popular in live broadcasting is its minimal latency.

High Bandwidth

While latency refers to the speed of data transmission, bandwidth refers to the amount of data that can be sent at one time. SDI connections support high data rates, which result in high-resolution video and a smoother user experience.

Point-To-Point Interface

Each SDI cable carries a signal directly from one device to another, creating an ultra-reliable connection.

Long-Distance Transmission

SDI connections can transmit video and audio signals over long distances using coaxial cables up to 300 meters with standard-definition SDI.

Embedded Audio

SDI doesn’t just ensure high-quality images and videos. These connections can also carry multiple channels of embedded audio, streaming high-quality audio and video in tandem.

Multiple Standards

Over time, a variety of different SDI standards have been developed to support different resolutions and frame rates, including SD-SDI (standard definition), HD-SDI (high definition), 3G-SDI, 6G-SDI, and more.

Built-In Error Correction

SDI has integrated error correction mechanisms to minimize disturbances caused by noise interference and enhance reliability and signal stability.

What is SDI Used For?

Broadcasting

SDI is the standard in both pre-recorded and live broadcasting. From news reporting, to sports, to dramatized television, SDI offers reliable transmission of video and audio signals in multi-camera productions.

Video Production

SDI is ideal for professional video production as it can distribute uncompressed footage over long distances. It’s also beneficial for video editing as signals can be sent back and forth between various types of equipment including switchers, cameras, and monitors.

Security and Surveillance

SDI is often used in high-end home and commercial security systems. Due to its ability to maintain signal quality when traveling far distances, surveillance footage can be transmitted to monitoring stations with little-to-no degradation.

Medical Imaging

High-quality imaging is essential in a wide variety of medical settings. For example, endoscopes are often used in screenings and surgical procedures to transmit detailed images into a screen, allowing medical professionals to see accurate, live video of what’s happening inside the patient's body.

Audio-Visual Integration

In addition to video, SDI can also transmit embedded audio signals over multiple channels. This allows the audio to maintain its quality and synchronize with the accompanying footage through a single cable.

Video Conferencing

SDI can be used for virtual meetings, allowing users to communicate between remote locations without significant latency or quality issues. This is particularly helpful in large-scale professional settings with multiple participants.

Live Streaming and Event Production

SDI can be effectively utilized in live streaming and event production for virtual and hybrid events. Its seamless application with multiple cameras, screens, and switchers affords exceptional flexibility during live events.

What is HD-SDI?

High Definition Serial Digital Interface (HD-SDI) is a version of SDI that can transmit high-definition (HD) video signals via coaxial or fiber-optic cables.

SDI vs HD-SDI – What is the Difference?

The key difference between SD-SDI and HD-SDI is that they support different resolutions, data rates, and applications. HD-SDI can support higher resolution video, but SD-SDI can transmit audio and video across further distances.

Here’s a breakdown of the differences between SDI and HD-SDI:

Feature Comparison Table
Feature SDI HD-SDI
Video quality Standard definition High definition
Maximum resolution 480i/576i (SD) 720p, 1080i, 1080p (HD)
Data rate 270 Mbps 1.485 Gbps
Maximum transmission distance 300m 100m

Choosing the Right Interface Technology for Your AV Needs

When choosing between various interface technologies, it’s important to consider your specific needs, the features that are most important, and relevant applications.

Here’s a brief overview of popular interface technologies that can be incorporated into AV systems:

  • SDI: Provides excellent integrated audio and video transmission and is ideal for broadcasting and live events
  • IP-based systems: Offers scalability and high-resolution support for large-scale productions
  • HDMI: Easy-to-set-up, and transmits high-quality video over shorter distances, making it ideal for home theater and small production setups
  • Wireless systems: Good for versatile productions and doesn’t require a physical cable, but it is susceptible to video degradation over long distances

Make Your Next Event a Success With Advanced AV Technology and Support

At Catalyst, we’re on a mission to transform what’s possible in AV event production. We work with organizations of all shapes and sizes, delivering high-quality AV equipment setups, event design services, and integrated support to help create truly memorable moments for attendees.

Contact us today to set up a free event consultation and learn more about our services.

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Ensure Your Event Exceeds Expectations With Cutting-Edge AV Production

Are you planning a shareholder meeting, conference, product launch, trade show, or other type of major event? You need to make sure the production value matches the quality of your event’s content. Working with a reliable, proven leader in audio visual event production like Catalyst ensures your event runs smoothly, exceeds the expectations of your audience, and has the impact you want.

Get in touch today to schedule a free consultation, learn more about our services, and tell us about your event.