Category Audiovisual Resources

Codecs, Bandwidth, and Latency

In our Video Over IP post, we touched on the encoding and decoding process that makes it possible to send video signals over the network. Now let’s take a brief overview of the codecs — which are encoding and decoding protocols — that employ these processes.

Codecs that use about 10Mbps (megabits per second) are ideal for transporting networked AV since they won’t allow the signals to monopolize your network.  Conversely, a 10Gbps (gigabits per second) codec will use up all the available bandwidth on a 10-gigabit network link. On the plus side, the latency — the delay caused by the process of encoding and decoding a video signal — will be low for this bandwidth-heavy codec.

Mezzanine, Intra-frame, and Inter-frame

Mezzanine, intra-frame, and inter-frame codecs will look at the source signal in different ways before compressing it for transmission. You want to have the most bandwidth-efficient codecs handling your signals. Even though there will be a trade-off in latency, that trade-off can be acceptable.

  • Mezzanine: These include TICO and DSC compression codecs. Latency is very low, but they also use the most bandwidth.
  • Intra-frame: These are JPEG2000 and VC-2 codecs. More efficient than Mezzanine in terms of bandwidth, but unable to stream to laptops and mobile devices.
  • Inter-frame: H.264 and H.265. H.264 AVC is the most common codec in use today. H.265 HEVC is the next generation. Latency will be about 200ms in the best case, which is considered acceptable.

Crestron’s “State of Networked Video and Integrated System Design” offers an easy-to-understand overview of these codec types, and the areas you need to address to have an integrated system of video distribution and devices — including network management, control, and security.

Download Crestron’s paper “The State of Networked Video and Integrated System Design” >

Video Over IP — How It’s Done

In a previous post, you learned why video over IP makes sense. Now we’ll look at how to make it happen.

First, let’s define a couple of terms:

  • Encoding: When you encode data, you’re making it suitable for transmission over an Ethernet network. So an encoder distributes high-definition AV signals over an IP network. Video In can be HDMI, and Video Out is Ethernet. An example of an encoder is Crestron’s DM-TXRX-100-STR.
  • Decoding: As you’d expect, this means you’re making the signal suitable for an uncompressed HDMI transmission. So a decoder receives high-definition AV signals over an IP network. Video In is an Ethernet stream, and Video Out can be HDMI. An example of a decoder is the Crestron DM-RMC-100-STR.

In a point-to-point network, you can send a signal from a computer over your LAN to a display in another room. Both areas can have Crestron’s DM-TXRX-100-STR, and they don’t need a matrix switcher. You can also multicast from a single encoder that sends signals to each room that has a decoder and display.

You can also use those rooms as collaboration spaces, where you connect your computer so that your content appears on the display. The Crestron DGE-100 has the ability to receive the LAN stream, and also can take a local connection from a laptop. Watch this Crestron video to see how easy it is to create a network AV solution.

Here’s Where Financial Institutions Go for Reliable AV and Video Communications

A new video on AVI-SPL’s YouTube channel speaks to those working in finance, and their need for quality communication systems. It’s the latest in a series designed to let people know we understand the challenges of their industry and work hard to give them the systems and support they need to work smarter.

Watch the newest production below, and then check out our videos for sectors like healthcare, government, and education. If you’re feeling inspired to get in touch with us and make your planned project a reality, contact our team at 866-559-8197 or sales@avispl.com. You can always explore our success stories at www.avispl.com/case-stories.