The importance of video compression

Until network bandwidth is increased dramatically and ubiquitously to carry large volumes of uncompressed video there will be a need for video compression. Selecting video compression requires a trade-off between quality, cost efficiency. The aim of compression is to maximise quality and efficiency while minimising cost. This is especially the case in live broadcast where even the largest capacity connections can buckle under the huge amounts of raw data requiring transport and storage.

Broadcasters seek the highest image quality with the most economical means of transport but there are other factors for consideration too. Live production, for example, requires very low latency and bit-rates in order to transmit video content in real time. Standardized protocols for connecting signals (or files), equipment and workflows together are vital for efficiency, interoperability and flexible delivery formats.

As more of the broadcast ecosystem moves to IP networks including unmanaged internet for contribution, production and distribution the battle to maintain ‘broadcast quality’ in the eyes of the consumer has never been more heated. It is essential to retain competitive advantage.

Video compression is the key. This is the process of converting digital video into a format that takes up less capacity when it is stored or transmitted. Video compression formats (in the form of an algorithm) do this by shrinking the total number of bits needed to represent a given image or video sequence.

Compressing the data can significantly reduce the bandwidth required making it possible for video to be easily transmitted across constrained or unmanaged networks in realtime while retaining quality of final product.

Video Compression Overview

There are several different codecs and methods of compression, but the basic concepts remain the same. Codecs will either deliver better image quality at the same compressed bitrate or a lower compressed bitrate for the same image quality.

Most codecs use “lossy” compression methods which means that when a video is compressed, some redundant spatial and temporal information is reduced. Lossy typically means compression ratios of 50:1 up to 100:1. In this case, the compression becomes visible but remains perfectly adequate for some applications.

Visually “Lossless” compression is sometimes used when the goal is to reduce file and stream sizes by only a slight amount in order to keep picture quality identical to the original source. Lossless typically achieves lower compression ratios of 10:1 to 20:1.

Here are the most commonly used by professional media for contribution, production, and professional media distribution.

JPEG XS

Part 22 of the SMPTE ST 2110 defines a standardized way for transporting JPEG XS compressed video over IP workflows. JPEG-XS is a visually lossless compression standard. It provides relatively low latency and low complexity, particularly in comparison to H.264 or H.265, and as such is likely to play a major role in Remi productions and live event streaming.

JPEG 2000

The JPEG 2000 video compression standard uses a technique based on wavelet technology. This enables images to be compressed in lossy, and visually or mathematically lossless modes. The intra-frame nature of JPEG2000 allows every frame to be encoded independently. In comparison, inter-frame encoding formats (such as MPEG-4) need to work with Groups of Pictures (GOP) that require a longer processing time. This makes JPEG 2000 video compression ideal for critical low latency contribution and remote production applications.

MPEG-4 / H.264

The MPEG-4 video compression (also known as H.264/AVC) was standardized in 2003 and remains the widely adopted codec for streaming. It builds on the concepts of earlier standards such as MPEG-2 and offered better compression efficiency and greater flexibility in compressing, transmitting and storing video. As the demand for higher video resolution continues, further efficiencies are required.

ST 2110

Modern production facilities use ST 2110 technology to connect equipment using standard IT COTS switches. In the facility, uncompressed is predominantly used. Connecting different facilities, stadiums, etc uncompressed stream consumes a large amount of BW why compression needs to be used. Networks and equipment supporting SMPTE Standard 2110 can carry uncompressed video over IP. ST 2110 supports different compression formats like ST 2110-22 for JPEG-XS but other compressions formats can be used to transport ST 2110 content such as JPEG 2000 using TR-01, MPEG-4 using 2022-2, and JPEG-XS using TR-07. Which compression technique is used depends on the cost and availability of bandwidth.

H.265

HEVC (High Efficiency Video Coding) or H.265 is the successor to MPEG-4. In most implementations it halves the compressed bitrate for the same image quality. HEVC also supports 8K resolution. A slower than expected adoption is attributed to an opaque licencing scheme.

Managing unmanaged networks

Network capacity today is not yet limitless and ubiquitous. This impacts the need to adapt and process content to fit different networks types and implies that different solutions will be used for different scenarios.

Compression schemes like JPEG 2000, JPEG XS, and emerging codecs like MPEG-I Part 3 H.266 (also known as Versatilie Video Coding/ VVC) can extend the network capacity to manage 4K UHD and 8K UHD streams over IP keeping latency ultra low and to a visually lossless quality.
Media networking needs to adapt to different scenarios like high/low latency, high/low bandwidth (equating to low/high cost), reliable/unreliable networks and whether the production is high-end (Tier 1) or at the lower end (Tier 3)

Unmanaged networks (Internet) with public cloud can transport and process with high quality with higher latency and low bandwidth which serves contribution and distribution markets well/. Provided you have the right media transport and compression system in place.

Some production environments can accept higher latency, shifting the transport to cloud based infrastructure, using ARQ transport over public Internet or unmanaged IP.
We believe it is beneficial if this can be done in one system with easy, uniform management.

Nimbra and Aperi support multiple video compression standards

Cloud solutions will be the standard building practice for IP production and distribution. This means that the transport solution will need to handle high-quality, low delay, multi-camera productions for high-end productions spanning sport, studio shows, and live events.

The solutions need to handle a large number of signals with less compression than today’s MPEG4/HEVC solutions. The solution needs to support a variety of video compression schemes for ultimate flexibility including uncompressed, JPEG XS, and JPEG2000 as well as MPEG4 and HEVC.

Net Insight incorporates advanced video encoding in the heart of both the Aperi and the Nimbra products. The encoding schemes used are JPEG2000, H.264/MPEG-4, JPEG XS, and H.265/HEVC.

The Nimbra and Aperi platforms also support uncompressed transport for HD 1080p and 4K UHD. Net Insight focuses on open standards such as ST2110 to ensure the widest and most robust interoperability. This also means that it is possible to combine uncompressed or light compression technologies with other compression formats in the same system to allow for more advanced and potentially more cost-efficient workflows. These workflows could interconnect production processing sites.

IP networking has revolutionized media contribution and distribution with the SMPTE standards at the core of new live workflows, distributed workflows, and cloud-based operations. Video compression will continue to advance to enable even greater flexibility, scalability, and accessibility allowing users to transport high-bandwidth 4K and 8K content over cost-effective COTS GigabitE networks.

Net Insight will be one step ahead of all the way.

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Video compression is the process of converting digital video into a format that takes up less capacity when it is stored or transmitted. Video compression formats (in the form of an algorithm) do this by shrinking the total number of bits needed to represent a given image or video sequence.

Until network bandwidth is increased dramatically and ubiquitously to carry large volumes of uncompressed video there will be a need for video compression. The aim of compression is to maximise quality and efficiency while minimising cost.