Quality-Defined Variable Bitrate (QVBR) encoding is a rate control mode that launched in AWS Elemental MediaConvert and AWS Elemental MediaLive in 2018. QVBR is an enhanced version of variable bitrate (VBR) rate control that minimizes wasted bits and adjusts bitrate to maintain consistent video quality. QVBR is also available in the appliance and software products AWS Elemental Live and AWS Elemental Server.

QVBR is featured on the AWS Media and Entertainment resources page, which explains more about what the technology is, what challenges it addresses, how it improves video quality, and its overall advantages. The page also includes a short video that demonstrates how to enable and use QVBR with AWS Elemental Live. The demo features QVBR Viewer, a web tool that visualizes the bitrate savings with QVBR compared to more traditional rate control settings like constant bitrate (CBR).

Screenshot of QVBR Viewer tool

The QVBR Viewer tool, built by AWS Elemental’s James Au, has been made open source and is now available from our GitHub repo called aws-elemental-qvbr-tools. The tool includes players that allow you to view the same content encoded in different rate control modes side-by-side to compare them visually.

Two versions of the viewer are available: one for live video, and one for video-on-demand (VOD). The live viewer shows the segment bitrates of the various encodings updated dynamically on the page in real-time as content is processed, as well as the average bitrate savings over a 30-minute period. In addition, it features a statistics page that shows hourly bitrate averages over a week-long period. The VOD viewer displays the segment bitrates of the various encodings, as well as the average bitrate savings, over the entire file.

Try it for yourself today! Deploy either the Live or the VOD version of the QVBR Viewer in your AWS account using the AWS CloudFormation template and your own video content, then see how QVBR can help you save on your storage and delivery costs while generating consistent, high-quality video.

from AWS Media Blog