Amazon Web Services (AWS) Elemental has a long and rich history when it comes to 4K / Ultra High Definition (UHD) encoding in both live and file-based video workflows. AWS Elemental Live—which processes video streams in near real time—supported the world’s first near-real-time 4K High Efficiency Video Coding (HEVC) transmission when it streamed the Osaka Marathon in 2013. Another first for the Elemental Live encoder was during the 2017 NAB show from the National Association of Broadcasters (NAB), when the National Aeronautics and Space Administration (NASA) collaborated with the AWS Elemental team to deliver the first-ever live 4K stream from space. The live stream was powered by AWS Elemental Live software running on the International Space Station 250 miles above the Earth.
AWS Elemental continues to enhance 4K support in the AWS Elemental Live encoder software and appliances. The latest L800 series of the Elemental Live encoder appliances unlocks new capabilities that reduce both the energy requirements and complexity of large 4K workflows. In this blog post, we present the latest 4K advancements plus a summary of 4K features in the Elemental Live encoder.
As a prerequisite, make sure to become familiar with AWS Elemental Live concepts and terminology.
Highlights of the AWS Elemental Live L800 series
The AWS Elemental Live encoder L800 series appliances are 1–rack unit (RU) chassis servers categorized into five major lines or subseries: L810, L820, L840, L850, and L880. A full list of available Elemental Live appliance models in the L800 family is available on the AWS Elemental Live resources page. The main difference between AWS Elemental Live appliance models resides in their processing capacity (CPU cores), in addition to network and serial digital interface (SDI) configuration. Only the L840, L850, and L880 lines have the required capacity to process live 4K content.
Compared to the previous generation of AWS Elemental Live encoder appliances, the L800 series is up to 10 inches shorter, depending on model, and offers both lower power consumption and heat dissipation. In our lab qualification testing, the L800 appliances achieved up to 42 percent power savings over the L730 series for the same 4K encoding settings. The L800 series also brought with it new 25 Gibabit Ethernet (GbE) network interfaces that let AWS Elemental Live support 4K workflows with Society of Motion Picture and Television Engineers (SMPTE) 2110 uncompressed SDI over internet protocol (IP) inputs and outputs.
4K processing capabilities of L800 series appliances
The L840 and L850 series provide similar 4K HEVC encoding performance and can each process one high-quality, high-bitrate 4K output up to 60 frames per second (fps)—or “4Kp60” for short. The maximum qualified 4Kp60 HEVC output bitrate is 80 megabits per second (Mbps), making these appliances suitable for 4K contribution and on-premises internet protocol TV (IPTV) applications.
On the other hand, the remarkable power of the flagship L880 series unlocks two new 4K HEVC capabilities that are unique to this series of AWS Elemental Live encoder appliances:
- Dual 4Kp60 encoding: a single L880 appliance can encode two 4Kp60 contribution inputs to high-quality, high-bitrate 4Kp60 HEVC outputs in 1-RU chassis. In other words, one L880 chassis can replace two chassis of L840, L850, or L730 series when processing 4Kp60 content.
- 4K HEVC adaptive bitrate (ABR) encoding: the L880 appliance can process a full 4K HEVC ABR stack in a 1-RU chassis, eliminating the need to encode the stack across multiple nodes as illustrated in figures 2 and 3, thus simplifying configurations because output locking is no longer required.
When it comes to ABR configurations, we understand that there are a multitude of combinations. In Table 1, we present an example of 4K HEVC ABR that we qualified and tested in our labs. If you need a custom 4K ABR stack, make sure to work with your AWS Elemental account team for qualification and density testing.
|Resolution||Bitrate (Mbps)||Frame rate (fps)|
|3840 x 2160||18||59.94|
|1920 x 1080||8||59.94|
|1280 x 720||3.5||59.94|
|960 x 540||1.4||59.94|
|640 x 360||1||59.94|
|480 x 270||0.54||29.97|
Table 1: Example of a 4Kp60 HEVC ABR stack qualified on the L880 series
4K inputs supported in AWS Elemental Live encoder
The AWS Elemental Live encoder supports a wide range of input and output protocols—a full list of which, including hardware requirements, can be found in the AWS Elemental Live User Guide. More specifically, at the time of writing this post, the following input types can be used to ingest 4K content:
- SMPTE 2110-20 uncompressed SDI over IP with SMPTE 2022-7 seamless protection
- JPEG XS (ISO/IEC 21122) with SMPTE 2022-7 seamless protection
- 12G SDI (late Q4 2021) and Quad HD-SDI
- Reliable transport stream (TS)—Secure Reliable Transport (SRT) / Zixi
- Real-Time Streaming Protocol (RTSP)
- MPEG-TS—User Datagram Protocol (UDP) and Real-time Transport Protocol (RTP)
- Multiple 4K file source formats, inclusion MP4, M2TS, MOV, and Material Exchange Format (MXF)
The AWS Elemental Live encoder supports flexible input configuration and protection (failover) options when you configure AWS Elemental Live events to process 4K content. These options include the following:
- The same AWS Elemental Live event can support multiple inputs, and multiple source types can be added to it. For instance, the first input can be Quad-SDI and the second can be MPEG-TS. Each event can support up to 30 inputs.
- The AWS Elemental Live event can fail over between heterogeneous 4K sources, such as from SMPTE 2110-20 primary input to Quad-SDI backup input.
- The AWS Elemental Live encoder can up-convert high definition (HD) and standard definition (SD) sources to 4K, so lower-resolution sources can also be used as inputs for 4K encoding. For instance, you can configure an HD source as the backup input for a primary 4K source if no secondary 4K source is available.
- SMPTE 2022-7 seamless protection is supported for RTP / MPEG-TS and SMPTE 2110 inputs. (Note that SMPTE 2022-6 is not supported for 4K).
- The AWS Elemental Live encoder supports dual 4K source decoding—decoding two inputs, simultaneously facilitating seamless switching between them. This is also known as “hot backup.” Decoding a pair of 4K contribution sources consumes additional CPU cycles and uses larger network bandwidth. Thus, it is recommended that you perform channel density testing to qualify the appropriate AWS Elemental Live appliance model for your workflow.
4K outputs in AWS Elemental Live encoder
The AWS Elemental Live encoder can produce 4K HEVC content in multiple output formats, which facilitates the different workflows and use cases described in this section.
MPEG-TS (UDP and RTP)
MPEG-TS outputs are mainly used in on-premises 4K processing workflows for both single bitrate and ABR applications.
SMPTE 2110-20 uncompressed SDI over IP
The SMPTE 2110-20 output format is mostly used on premises in broadcast production deployments. Automation and control through the Networked Media Open Specifications (NMOS) protocol as well as 2022-7 protection are supported. For an in-depth look at SMPTE 2110, check out the three-part SMPTE ST 2110 blog series for AWS Elemental Live.
JPEG XS (SMPTE 2110-22)
The JPEG XS format can be used for a low-latency contribution of uncompressed 4K content to the cloud. A typical use case is using the Elemental Live encoder to encode a SMPTE 2110-20 uncompressed 4K source to JPEG XS for contribution by means of AWS Direct Connect (a cloud service that links your network directly to AWS) to AWS Elemental MediaConnect (a high-quality transport service for live video). The Elemental Live encoder supports 2:1 to 12:1 JPEG XS compression ratios and requires the use of SMPTE 2022-7 protection when sending video to MediaConnect. The blog post introducing JPEG XS provides details on this exciting new workflow.
The L880 series encoder can produce a full 4K ABR stack prepackaged into HTTP Live Streaming (HLS) format. A typical use case is when the AWS Elemental Live encoder is pushing 4K content to AWS Elemental MediaPackage, Amazon Simple Storage Service (Amazon S3), or third-party origins in the AWS Cloud or on premises. (MediaPackage is an AWS service that reliably prepares and protects your video for delivery over the internet, and Amazon S3 is an object storage service that offers industry-leading scalability, data availability, security, and performance.)
The 4K ABR stack can also be packaged by the L880 appliance into Dynamic Adaptive Streaming over HTTP (DASH)–ISO format and pushed to AWS Elemental MediaStore (an AWS storage service optimized for media), Amazon S3, or third-party origins. The AWS Elemental Live encoder DASH-ISO output supports chunked transfer encoding (CTE), which facilitates the implementation of low-latency live streaming workflows.
The Reliable-TS output supports Zixi and SRT protocols as well as a native integration with MediaConnect. Reliable-TS formats are suitable for live 4K content contribution over unreliable networks like public internet.
HDR 4K support
The AWS Elemental Live encoder supports processing 4K high-dynamic-range (HDR) content in multiple input and output formats. The three-part series about live and video-on-demand–to-Live HDR goes into more detail on this workflow. In addition, the Getting started with AWS Elemental Live and Dolby Vision blog post dives deeper on Dolby Vision workflow configuration.
Using the AWS Elemental Live encoder, you can also archive the 4K content to 4K-supported file formats like MP4 and M2TS.
In this blog post we introduced the new L800 series and provided an overview of the 4K/UHD processing capabilities of the AWS Elemental Live encoder. The L880 subseries allows the processing of either two 4Kp60 sources or a full 4Kp60 ABR stack in a 1-RU machine.
These advancements facilitate a reduction in the number of appliances and the overall footprint required to process 4K content on premises. The lower power consumption and heat dissipation translate to additional savings, including air-conditioning costs.
For any questions or additional details regarding the AWS Elemental Live encoder and 4K workflows, reach out to your AWS Elemental account team. If you have questions, feedback, or would like to get involved in discussions with other community members, visit the AWS developer Discussion Forums: Media Services.
This post is authored by Andy Chandler, an AWS Enterprise Account Engineer and Abbas Nemr, a Sr. Elemental Specialized Soutions Architect.